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Nov 1986

Volume 4, Issue 6, pp. 2441-3173


First principles investigation of chemisorption of moderately heavy atoms on semiconductor surfaces—bromine on silicon

S. M. Mohapatra, N. Sahoo, K. C. Mishra, B. N. Dev, W. M. Gibson, and T. P. Das

J. Vac. Sci. Technol. A 4, 2441 (1986); http://dx.doi.org/10.1116/1.574088 (6 pages)

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Self‐consistent field Hartree–Fock cluster investigations have been carried out for bromine atoms chemisorbed on Si (111) surface using 5, 14, and 27 atom clusters. For the first two clusters, both all‐electron and pseudopotential procedures have been used and the total energy curves as a function of adatom position have been found to compare very well. The third cluster has been studied by the pseudopotential procedure alone. For the five‐atom cluster which corresponds to the SiH3Br molecule, the Si–Br bond distance and 79Br quadrupole coupling constant (e2qQ) are obtained as 2.20 Å and 355.4 MHz, respectively, in very good agreement with the experimental values from microwave measurements of 2.21 Å and 346 MHz. For the surface chemisorbed system, we have studied the location of the bromine atom, the local density of states (LDOS), the frequencies and amplitudes of the Si–Br vibrations and the 79Br quadrupole coupling constant. The calculated Si–Br bond distance of 2.23 Å agrees very well with two experimental values of (2.22±0.01) and (2.17±0.04) Å available in the literature. For the vibrational amplitude, satisfactory agreement is found with the available result for Br on germanium surface. It is hoped that experimental data will become available in the future to test our predictions for the other properties. In particular, it would be desirable to have UPS data to compare with the interesting trends found in the LDOS curves in going from fluorine to chlorine to bromine and quadrupole interaction data to verify the significant decrease in e2qQ in going from the molecule to the surface‐adsorbed system.
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68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
68.43.-h Chemisorption/physisorption: adsorbates on surfaces

Hydrogen isotope sorption and recovery by a nonevaporable getter combined with a chemical compressor material

F. Doni, C. Boffito, and B. Ferrario

J. Vac. Sci. Technol. A 4, 2447 (1986); http://dx.doi.org/10.1116/1.574089 (5 pages) | Cited 2 times

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Due to the spreading use of hydrogen isotopes in many advanced fields of physics such as nuclear fusion, there is an increasing interest in devices able to sorb, store, and release these gases safely and controllably. In some cases there is also the requirement to purify the gas during the same adsorption–desorption process. A way to obtain this is to use a nonevaporable getter, which is able to sorb H2 isotopes reversibly and permanently sorb active gases, combined with a chemical compressor material (usually U). The present investigation refers particularly to a combination of getter materials with chemical compressors based on La–Ni–Al and Zr–Fe–V alloys. The nonevaporable getter sorbs H2 isotopes in the temperature range of 20–400 °C, at low pressures, and in a second stage, on heating, releases these gases at higher pressures allowing sorption by the chemical compressor at room temperature. Subsequent heating (200–400 °C) of the compressor provides a hydrogen isotope source at a substantially constant pressure of around 1 atm. The characteristics of these compressor alloys in terms of isotope equilibrium pressure, physical–chemical properties, and their use at defined pressures and temperatures are discussed, together with anticipated practical operation modes.
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68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
28.52.-s Fusion reactors
68.43.-h Chemisorption/physisorption: adsorbates on surfaces

Surface processes leading to carbon contamination of photochemically deposited copper films

F. A. Houle, R. J. Wilson, and T. H. Baum

J. Vac. Sci. Technol. A 4, 2452 (1986); http://dx.doi.org/10.1116/1.574090 (7 pages) | Cited 8 times

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Copper films exhibiting periodic microstructure have been grown by photolytic decomposition of bis‐(1,1,1,5,5,5‐hexafluoropentanedionate) copper (II) [Cu(hfac)2] and its ethanolate using ultraviolet light. The composition of the films has been analyzed by Auger spectroscopy as a function of cell temperature, precursor, mode of illumination (pulsed or continuous), and light intensity at nearly constant wavelength. The results show that the concentration of the principal contaminant of the films, carbon, is a function of cw light intensity. Addition of ethanol in the form of Cu(hfac)2(ethanol) also has a profound effect on carbon incorporation. Although the elements O and F are a large component of the gas phase copper complex, they are essentially absent from the films under all conditions. These data, when combined with high‐resolution analysis of the periodic structures on the films, provide information on surface photochemical and thermal processes likely to be important during film growth. They also allow a general comparison to be made between homogeneous and heterogeneous decomposition of Cu(hfac)2.
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68.55.Nq Composition and phase identification
82.50.-m Photochemistry
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

An x‐ray photoelectron spectroscopy study of poly(methylmethacrylate) and poly(α‐methylstyrene) surfaces irradiated by excimer lasers

M. C. Burrell, Y. S. Liu, and H. S. Cole

J. Vac. Sci. Technol. A 4, 2459 (1986); http://dx.doi.org/10.1116/1.574091 (4 pages) | Cited 4 times

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X‐ray photoelectron spectroscopy (XPS) has been used to study the surface composition of poly(methylmethacrylate) (PMMA) and poly(α‐methylstyrene) (α‐MePS) following excimer laser irradiation at 193 nm. For fluence levels between 50 and 300 mJ/cm2, no surface compositional changes were observed after irradiation of PMMA. However, α‐MePS samples showed a decrease in aromatic character following irradiation, as indicated by the decrease in pi–pi∗ intensity in the C 1s region.
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68.35.Dv Composition, segregation; defects and impurities
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
81.65.-b Surface treatments

A correlation of Auger electron spectroscopy, x‐ray photoelectron spectroscopy, and Rutherford backscattering spectrometry measurements on sputter‐deposited titanium nitride thin films

Brad J. Burrow, Alan E. Morgan, and Russell C. Ellwanger

J. Vac. Sci. Technol. A 4, 2463 (1986); http://dx.doi.org/10.1116/1.574092 (7 pages) | Cited 26 times

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Auger and electron spectroscopy for chemical analysis (ESCA) data of TiNx were analyzed as a function of film composition as established by Rutherford backscattering spectrometry (RBS). The overlap of the N(KVV) and Ti(LMM) Auger transitions necessitated the assessment of two methods previously proposed for the derivative spectra. These results were compared with peak height and peak area measurements (after background subtraction) of the well‐separated N(1s) and Ti(2p) ESCA photoemissions. Neither the Auger nor the ESCA N/Ti intensity ratios scaled linearly with the N/Ti compositional ratios determined by RBS, especially for low nitrogen content. This behavior most likely results from ion‐bombardment‐induced losses of nitrogen in those phases with dissolved nitrogen rather than from an increased satellite emission in the Ti(2p) spectra from the near‐stoichiometric nitride. In terms of precision and analysis speed, the Auger peak‐to‐peak quantification methods are preferred over ESCA quantification. In the near‐stoichiometric phase (N/Ti≊1), RBS analysis shows higher sensitivity to nitrogen compositional changes than either ESCA or Auger.
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82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
68.55.Nq Composition and phase identification
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)

Surface analyses of the CdSe0.65Te0.35/aqueous polysulfide interface in relation to its photoelectrochemical properties

R. Tenne, C. Levy‐Clement, and G. Sawatzky

J. Vac. Sci. Technol. A 4, 2470 (1986); http://dx.doi.org/10.1116/1.574093 (7 pages) | Cited 1 time

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The photocorrosion of n‐Cd(Se,Te) electrodes, in potassium and cesium polysulfide solutions, is investigated by x‐ray photoelectron spectroscopy and Auger electron spectrometry. It is shown that Se and Te are exchanged with sulfur from the solution during photocorrosion, possibly via two separate mechanisms: (a) preferential bleaching of tellurium from the crystal matrix, and (b) uniform photocorrosion of the crystal as a whole. Photocurrent spectrum measurements which are presented suggest that a graded band gap is formed when tellurium is preferentially bleached out of the original Cd(Se,Te) crystal. It is shown that cesium is present on the electrode surface which may explain the negative shift of the flat band potential, i.e., increased open circuit voltage of the photoelectrochemical cell. This suggests that the cesium treatment could be used to increase the open circuit voltage of photovoltaic cells.
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81.65.-b Surface treatments
84.60.Jt Photoelectric conversion
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
82.47.-a Applied electrochemistry

The influence of substrate temperature on the optical losses of ZnS film

A. A. J. Al‐Douri

J. Vac. Sci. Technol. A 4, 2477 (1986); http://dx.doi.org/10.1116/1.574094 (5 pages) | Cited 1 time

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Loss measurements in waveguide thin films are shown to exhibit a sensitive optical probe of surface and volume losses and thus of film quality. The high accuracy and sensitivity of this device was exploited for assessing the role of substrate temperature on the optical performance of ZnS films. In general, film losses tend to increase with substrate temperature. However, broad optima in losses are observed at 200 and 250 °C. A correlation between film structure and scatter losses as measured by the integrating sphere method with results of losses obtained from waveguide mode technique is discussed. This correlation leads to more reliable interpretation of the influence of substrate temperature on the losses of ZnS film.
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75.20.Ck Nonmetals
42.79.Gn Optical waveguides and couplers
81.40.Tv Optical and dielectric properties related to treatment conditions
77.55.-g Dielectric thin films

Surface morphology of chemical vapor deposition grown Ge on Ge substrates

Herzl Aharoni

J. Vac. Sci. Technol. A 4, 2482 (1986); http://dx.doi.org/10.1116/1.573715 (10 pages) | Cited 3 times

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Geometrically defined Ge structures, projecting out from Ge surfaces deposited by a GeH4–He system on (100) Ge substrates, all oriented in the same direction and having a similar shape, are observed using scanning electron microscopy. They indicate the existence of an epitaxial layer–substrate relationship. Under the same growth conditions, but at short deposition periods, these projections are isolated, but as the growth time increases their lateral dimensions increase, the average distance between them decreases, and coalescence occurs. They are identified as local overgrowth, which yields a rough surface, and their origin is attributed to surface and deposition conditions. Morphometric measurements made by an image analyzer have shown the time dependence of these progressive changes.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.-a Thin film structure and morphology

The determination of amorphous layer thickness in ion implanted silicon using secondary ion mass spectrometry

Howard E. Smith, G. H. Morrison, and D. T. Hodul

J. Vac. Sci. Technol. A 4, 2492 (1986); http://dx.doi.org/10.1116/1.573716 (7 pages)

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Secondary ion mass spectrometry has been used to study boron‐doped Si[100] that was rendered amorphous by the implantation of 75As. Using oxygen bombardment and negative secondary ion detection, all secondary ion species show a shift in ion energy of greater than 2 eV upon sputtering through the amorphous layer and into the underlying crystalline silicon. After regrowth of the same specimens by rapid thermal annealing, the secondary ion energy shift occurs significantly deeper, at approximately the p–n junction. In both specimens, the energy shift was shown to be due to bombardment‐induced specimen charging. Thus, the thickness of the amorphous layer in the as‐implanted specimen can be determined by profiling with a narrow secondary ion energy window. Mechanisms for this effect are discussed.
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68.55.-a Thin film structure and morphology
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.80.Jh Ion radiation effects

Properties of a‐Si,Ge:H,F alloys prepared by rf glow discharge in an ultrahigh vacuum reactor

J. Kolodzey, S. Aljishi, R. Schwarz, D. Slobodin, and S. Wagner

J. Vac. Sci. Technol. A 4, 2499 (1986); http://dx.doi.org/10.1116/1.573717 (6 pages) | Cited 12 times

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a‐Si1−xGex@B:H,F alloys with the Ge concentration x ranging from 0 to 1 have been prepared by the rf glow discharge decomposition of SiF4, GeF4, and H2 gas mixtures. An ultrahigh vacuum deposition system has been designed and constructed for the preparation of these alloys. The stainless‐steel deposition chamber has Cu gasket‐sealed flanges, is turbomolecular pumped, and reaches a base pressure below 10−7 Torr (10−5 Pa). This deposition system incorporates a load lock which permits short pump‐down cycles and which may reduce impurity contamination of the films. The system is described in detail. Compositional, structural, optical, and electronic properties of alloy films made with this system are reported.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
75.20.Ck Nonmetals
73.61.Cw Elemental semiconductors
73.61.Ey III-V semiconductors
73.61.Ga II-VI semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors
68.55.Nq Composition and phase identification

Radio frequency‐plasma oxidation of fine‐grained Pb‐alloy films formed by codeposition at 90 K

Masato Wada

J. Vac. Sci. Technol. A 4, 2505 (1986); http://dx.doi.org/10.1116/1.573718 (5 pages)

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Oxidation characteristics of fine‐grained (30–50 nm) Pb‐alloy film formed by the codeposition of Pb, In, and Au onto a liquid‐nitrogen‐cooled substrate (∼90 K) were studied in comparison with conventional film of 200 nm grain size formed by the sequential deposition of Au, Pb, and In at room temperature. The oxidized films were examined by Auger electron spectroscopy as well as x‐ray photoelectron spectroscopy and ellipsometry, and the normal tunneling resistance of Josephson junctions fabricated using the above films as base electrodes was measured. The thermal oxides formed on the fine‐grained and conventional films are identical. Rf‐plasma oxidation with these thermal oxides also present results in oxides of identical structure and thickness. In the absence of the thermal oxides, rf‐plasma oxidation of the fine‐grained film leads to In‐rich oxides of smaller thickness compared to the conventional films. It seems reasonable to attribute these results to the difference in grain sizes, i.e., the smaller‐grained films offer the In more available paths to diffuse through the alloy film. When the thermal oxides are present, rf‐plasma oxidation rate is reduced such that the difference in the diffusion rate of In through the alloy film is not evident and identical oxide structure and thickness are obtained.
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81.05.Bx Metals, semimetals, and alloys
68.55.-a Thin film structure and morphology
85.25.-j Superconducting devices
74.50.+r Tunneling phenomena; Josephson effects

Self‐positioned thin Pb‐alloy base electrode Josephson junction

Kenichi Kuroda and Kenji Sato

J. Vac. Sci. Technol. A 4, 2510 (1986); http://dx.doi.org/10.1116/1.573719 (5 pages)

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A self‐positioned thin (SPOT) Pb‐alloy base electrode Josephson junction is developed. In this junction, a 50‐nm thick Pb‐alloy base electrode is restricted within the junction region on an Nb underlayer using a self‐alignment technique. The grain size reduction and the base electrode area restriction greatly improve thermal cycling stability, where the thermal cycling tests of 4000 proposed junctions (5×5 μm2) showed no failures after 4000 cycles. In addition, the elimination of insulator layer stress on the Pb‐alloy base electrode rectifies the problem of size effect on current density. The Nb underlayers also serve to isolate the Pb‐alloy base electrodes from the resistors.
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85.25.-j Superconducting devices
74.50.+r Tunneling phenomena; Josephson effects
74.78.-w Superconducting films and low-dimensional structures
68.55.-a Thin film structure and morphology

Aluminum alloy ultrahigh vacuum system for molecular beam epitaxy

M. Miyamoto, Y. Sumi, S. Komaki, K. Narushima, and H. Ishimaru

J. Vac. Sci. Technol. A 4, 2515 (1986); http://dx.doi.org/10.1116/1.573720 (5 pages) | Cited 1 time

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As a research project for aluminum alloy molecular beam epitaxy systems, a large aluminum alloy chamber with a special surface finish was constructed. Its outgassing rate and ultimate pressure were measured. The special surface finish was analyzed using Auger electron spectroscopy. The oxide layer on the aluminum alloy was about 40 Å thick. The outgassing rate before baking was measured as 10−11 Torr l/s cm2, and the rate after baking (150 °C, 24 h) was 3×10−13 Torr l/s cm2. This value is approximately one to two orders of magnitude lower than that of a stainless‐steel chamber, such as SUS 304. The ultimate pressure was 7×10−11 Torr when pumped with a turbomolecular pump and an ion pump. With addition of the newly developed titanium sublimation pump, the ultimate pressure was 6×10−12 Torr (6.5×10−12 mbar). This ultimate pressure is very low for a large aluminum alloy vacuum chamber. Ceramic coating of SiO2 using a spark discharge in a silicate solution on aluminum alloy was not corroded by gallium. This ceramic treatment was suitable for an ultrahigh vacuum.
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07.30.Hd Vacuum testing methods; leak detectors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics

Data analysis for particle balance studies on the axially symmetric divertor experiment

Y. G. Wang, W. P. Poschenrieder, and G. Venus

J. Vac. Sci. Technol. A 4, 2520 (1986); http://dx.doi.org/10.1116/1.573721 (6 pages) | Cited 1 time

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Throughput of H2 or D2 fueling gas during and after a plasma discharge is a strongly time‐dependent quantity. Various data, such as divertor pressure and integral fueling rate, are used in a computer routine to investigate the particle balance on the axially symmetric divertor experiment (ASDEX). It is seen that the dominant portion of the gas required to fuel the plasma is reversibly pumped by the walls. This is due to the dissociation of molecules and subsequent strong wall adsorption of the resulting atoms. The amount of gas lost to the wall increases with plasma density. After the discharge most of the gas is released depending somewhat on the preconditioning of the walls by previous discharges and the time interval in between discharges.
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52.40.Hf Plasma-material interactions; boundary layer effects
52.55.Fa Tokamaks, spherical tokamaks
52.25.Fi Transport properties
28.52.-s Fusion reactors

A three‐point‐pressure method for measuring the gas‐flow rate through a conducting pipe

Haruo Hirano and Nagamitsu Yoshimura

J. Vac. Sci. Technol. A 4, 2526 (1986); http://dx.doi.org/10.1116/1.573722 (5 pages) | Cited 1 time

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A new method for measuring the gas‐flow rate through an outgassing pipe has been introduced, in which the pressures at three different points in the pipe are measured to calculate the real gas‐flow rate. This method was applied to measuring the flow rate of nitrogen through a pipe. The gas‐flow rates calculated using three pressures were compared with those calculated using two pressures under the same condition. The method based on three pressures gave real rates which were higher than those based on two pressures, especially in lower pressure regions, thus indicating the presence of outgassing.
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47.60.-i Flow phenomena in quasi-one-dimensional systems
47.80.-v Instrumentation and measurement methods in fluid dynamics
07.30.Cy Vacuum pumps

The advantages of vertical turbomolecular vacuum pumps with an upper journal bearing

Leonid Livshits and Scott Richter

J. Vac. Sci. Technol. A 4, 2531 (1986); http://dx.doi.org/10.1116/1.573723 (2 pages)

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Abstract Unavailable
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07.30.Cy Vacuum pumps

An extended core‐hole Hamiltonian for a combined study of electron stimulated desorption and photoemission

J. M. López Sancho, J. Rubio, M. P. López Sancho, and M. C. Refolio

J. Vac. Sci. Technol. A 4, 2533 (1986); http://dx.doi.org/10.1116/1.573724 (4 pages)

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Recent developments (two‐hole states) in electron stimulated desorption (ESD) from adsorption systems involving d bands are incorporated into an extended valence‐hole model Hamiltonian which includes explicitly a short‐range Coulomb interaction between adsorbate and substrate. This allows a combined study of photoemission and ESD from the same model. A novel relaxation effect of the metal surface (different from surface plasmon screening) may have a strong effect on the intra‐adsorbate relaxation due to the valence hole and, therefore, on adsorbate–substrate charge transfer processes.
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68.43.-h Chemisorption/physisorption: adsorbates on surfaces
79.60.Jv Interfaces; heterostructures; nanostructures
73.20.-r Electron states at surfaces and interfaces

TiN high temperature diffusion barrier for copper‐gasketed stainless‐steel flanges

E. L. Garwin, E. W. Hoyt, and A. R. Nyaiesh

J. Vac. Sci. Technol. A 4, 2537 (1986); http://dx.doi.org/10.1116/1.573725 (2 pages)

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Klystrons manufactured at the Stanford Linear Accelerator Center are typically baked at temperatures of 550 °C for times as long as 200 h. During these long bakeouts the copper‐gasketed type 304 stainless steel flange joints (seven in all) diffusion bond so intimately that the flanges can be separated only with a jacking fixture, and copper is left on the sealing surfaces. Removal of this copper necessitates the use of abrasive materials, which can result in contamination of the klystron body and compromise its reuse. We report on the use of 50 and 150 Å TiN thin films as a diffusion barrier between the Cu gasket and the stainless‐steel flange.
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68.35.Fx Diffusion; interface formation
66.30.-h Diffusion in solids
68.60.Wm Other nonelectronic physical properties

Erratum: Summary Abstract: Aluminum deposition on low‐temperature GaAs [J. Vac. Sci. Technol. A 4, 882 (1986)]

M. K. Kelly, Nacira Tache, E. Colavita, G. Margaritondo, and A. Kahn

J. Vac. Sci. Technol. A 4, 2539 (1986); http://dx.doi.org/10.1116/1.573726 (1 page)

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Abstract Unavailable
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.-a Thin film structure and morphology
73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions
99.10.Cd Errata

Evaluation of sputter ion plated CoCrAlY and NiCrAlTi coatings for gas turbines

D. S. Rickerby and M. I. Wood

J. Vac. Sci. Technol. A 4, 2557 (1986); http://dx.doi.org/10.1116/1.573727 (8 pages)

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This paper highlights the potential of a simple dc sputtering process to deposit the complex MCrAlY overlay compositions onto the hot end components of gas turbines. Particular advantages of sputter ion plating technology include good control of coating composition, no need to rotate the components to be coated, and deposition in a clean environment. The effect of peening on coating microstructure and the subsequent oxidation behavior of the coating has been examined for a range of MCrAlY compositions. Peening serves to eliminate leader defects from the surface layers by compaction of the coating and also affects the oxide‐growth mechanisms. The surface roughness of the sputter ion plating coatings, both as deposited and after glass bead peening, increases with that of the substrate and compares favorably with published values for electron beam evaporated coatings. For coatings tested between 1020 °C and room temperature in a heat treated and peened condition, fatigue cracks occurred after 100–150 cycles, while for peened and heat treated coatings, the time to crack initiation was extended to 800 cycles. Results from engine endurance trials are also summarized.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.05.Bx Metals, semimetals, and alloys
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure

Titanium distribution in multilayer oxide scales on oxidized INCOLOY 800H

H. B. Grübmeier, A. Naoumidis, and H. A. Schulze

J. Vac. Sci. Technol. A 4, 2565 (1986); http://dx.doi.org/10.1116/1.573728 (6 pages) | Cited 2 times

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Different samples of INCOLOY 800H were exposed up to 950 °C and 10 000 h to a gas atmosphere simulating exposure to steam reforming methane process gas. The results indicated the predominant role of titanium in the formation of the main reaction products. The influence of titanium could be described by the following modifications of the primary oxide phases: (1) changing the lattice parameters of Cr2O3 by small amounts of Ti, (2) formation of solid solution of the spinels MnCr2O4 and Mn2TiO4, and (3) existence of an additional Ti containing phase of ilmenite type. Furthermore, it was observed that (1) manganese was practically insoluble in the Cr2O3 and (2) after long annealing time manganese was lost.
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81.05.Bx Metals, semimetals, and alloys
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.40.Gh Other heat and thermomechanical treatments

Structure and 700 °C hot corrosion behavior of chromium modified platinum–aluminide coatings

M. Dust, P. Deb, D. H. Boone, and S. Shankar

J. Vac. Sci. Technol. A 4, 2571 (1986); http://dx.doi.org/10.1116/1.573729 (6 pages) | Cited 2 times

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It is well known that the addition of chromium to coatings on nickel‐base superalloys improves the hot corrosion resistance of the coating. Recognizing this advantage, the low‐temperature (700 °C) hot corrosion (LTHC) testing of chromium modified platinum aluminides was initiated in order to determine whether combined additions of Cr and Pt were even more beneficial. The substrates chosen were IN100 and IN738, two commercially used nickel‐base superalloys. It was found that the structure of the chromium modified platinum–aluminide coating was dependent on the sequence of modifying element addition. The optimum coating for LTHC resistance was obtained by the Cr–Pt–Al deposition sequence which resulted in a coating with a continuous PtAl2 layer on the surface backed up with a fairly high level of Cr and Pt.
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81.05.Bx Metals, semimetals, and alloys

The oxidation behavior of some FeCrAlY, FeCrAl, and yttrium ion‐implanted FeCrAl alloys compared and contrasted

J. G. Smeggil and A. J. Shuskus

J. Vac. Sci. Technol. A 4, 2577 (1986); http://dx.doi.org/10.1116/1.573730 (6 pages) | Cited 5 times

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The 1050 °C oxidation behavior of an iron–25 wt. % chromium–4 wt. % aluminum alloy modified by yttrium additions was studied. Yttrium was added to this alloy in the form of (1) a metallic addition; (2) an ion implant; and (3) as yttrium sulfide. In agreement with other investigators, metallic yttrium additions effected thin, essentially flat adherent scales. As compared with the base line alloy without any yttrium, implantation did improve the resistance of the scale to cracking. However, highly convoluted scales resulted with the yttrium implants. When yttrium was added as the sulfide, scales were produced similar to those found when no yttrium was added to the alloy. For the base line alloy without yttrium additions, aluminum oxide protrusions (or pegs) developed at the base of the alumina scales. Despite this, the scales were clearly cracked and poorly adherent. In the yttrium‐containing alloy, indigenous sulfur was present in the form of precipitates associated with yttrium.
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81.05.Bx Metals, semimetals, and alloys

High‐temperature behavior of different coatings in high‐performance gas turbines and in laboratory tests

L. Peichl and G. Johner

J. Vac. Sci. Technol. A 4, 2583 (1986); http://dx.doi.org/10.1116/1.573731 (10 pages) | Cited 1 time

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Turbine blades of advanced engines are often subject to a surface attack caused by oxidation or hot corrosion. Typical features of the different modes of high‐temperature surface attack are presented using results of failure analysis of turbine parts and of laboratory experiments. At very high temperatures, interactions take place between the coatings, which are indispensable in this temperature range, and the base metal. Some examples are described that have been gained from cyclic oxidation tests with a nickel‐base single‐crystal alloy and different types of coatings. The development of a broad diffusion zone and the depletion of β phase of the coatings indicate that interdiffusion plays an important role in determining the coating life. In a particular temperature range platelike phases precipitate in the matrix close to the coating. Kirkendall porosity, which frequently occurs at the coating substrate interface at very high temperatures, can markedly reduce the adhesive strength. The behavior of coated parts under mechanical loading is influenced by the coating–substrate combination. Some examples are shown describing creep and thermal fatigue properties of coated components.
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81.05.Bx Metals, semimetals, and alloys
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
81.40.Lm Deformation, plasticity, and creep

The development of electrodeposits for high‐temperature oxidation/corrosion resistance

F. J. Honey, E. C. Kedward, and V. Wride

J. Vac. Sci. Technol. A 4, 2593 (1986); http://dx.doi.org/10.1116/1.573732 (5 pages) | Cited 3 times

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Electrodeposited composite coatings (ECC’s) are well established as an economical means of combating wear. By use of a plating barrel of novel design, far greater control of the ECC composition is possible. ECC’s have been produced which, after heat treatment, give alloy coatings of the MCrAlY overlay type (M=Co and/or Ni) suitable for high‐temperature corrosion or oxidation resistance. Other coatings containing internal oxides have also been produced. The coating composition, structure, and properties are dependent on the plating parameters, solution chemistry, powder composition, heat treatment, and coating substrate interactions. Furthermore, the coating composition and its reproducibility are governed by the parameters operative within the barrel in which components are coated. Selected coatings have been tested by isothermal oxidation in cyclic oxidation and on a hot corrosion burner rig and have given superior results compared to similar coatings produced by alternative techniques. Turbine blades are being successfully plated in batch quantities with low reject rates and good reproducibility. Finally, a brief comparison of alternative coating techniques is made from both technical and commercial viewpoints with regard to the coating of gas turbine components.
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81.05.Bx Metals, semimetals, and alloys
81.10.Fq Growth from melts; zone melting and refining

Stabilized zirconia–alumina thin films

C. M. Gilmore, C. Quinn, E. F. Skelton, C. R. Gossett, and S. B. Qadri

J. Vac. Sci. Technol. A 4, 2598 (1986); http://dx.doi.org/10.1116/1.573733 (3 pages) | Cited 2 times

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Thin films of zirconia–alumina of 1 to 2 μm in thickness have been produced by reactive magnetron sputtering. Mixtures from pure Al2O3 to pure ZrO2 were produced. The crystal structures of annealed specimens were determined with x‐ray diffraction and the results indicate that the tetragonal phase of zirconia was stabilized at room temperature with alumina. Chemical analysis of the deposited films was determined with Rutherford backscattering and proton scattering.
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68.60.Dv Thermal stability; thermal effects
68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
81.15.Cd Deposition by sputtering

A study of yttrium‐modified aluminide coatings on IN 738 alloy

David C. Tu, C. C. Lin, S. J. Liao, and J. C. Chou

J. Vac. Sci. Technol. A 4, 2601 (1986); http://dx.doi.org/10.1116/1.573734 (8 pages) | Cited 1 time

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The beneficial effect of yttrium in high temperature protective coatings applied by EB–PVD and vacuum plasma spray against oxidation and hot corrosion has been recognized in many studies. In this study, the feasibility of adding yttrium into aluminide coatings has been successfully demonstrated by the conventional pack cementation process. It was found that yttrium oxide was the only practical inert filler material among the oxides investigated. Yttrium can be added into the aluminide coating either prior to or after the pack aluminizing process. Specimens prepared by the different pack cementation sequences were evaluated at 1000 °C for cyclic oxidation resistance up to 250 cycles. The yttriumized IN 738 and the yttriumized/aluminized IN 738 specimens showed very poor resistance compared to either the uncoated or the straight aluminized IN 738 specimens. Gross internal oxidation was found in the yttriumized/aluminized coating. On the other hand, the aluminized/yttriumized IN 738 showed marginal improvement over the straight aluminized IN 738. The aluminized/yttriumized coating had an yttrium rich outer oxide scale and an aluminum oxide inner scale, while the straight aluminized coating had a chromium rich outer oxide scale and an aluminum oxide inner scale.
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81.05.Bx Metals, semimetals, and alloys
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.20.-n Methods of materials synthesis and materials processing

Thin‐film temperature sensors for gas turbine engines: Problems and prospects

R. C. Budhani, S. Prakash, and R. F. Bunshah

J. Vac. Sci. Technol. A 4, 2609 (1986); http://dx.doi.org/10.1116/1.573735 (9 pages) | Cited 3 times

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The increasing trend towards high‐temperature, fuel efficient jet engines has led to the development of complex cooling schemes for the turbine blades. The measurement of temperature of the blade during operation, which is accomplished in conventional blade design by embedding wire thermocouples in the blade wall, causes serious structural and aerodynamic problems in the case of cooled turbines. In order to meet the requirement of temperature measurement in cooled turbines, it is desirable to develop surface‐mounted thin‐film thermocouples or a resistance thermometer. In the current state of the art of thin‐film thermocouples, the sensing element consists of 2‐μm‐thick Pt and Pt 10% Rh thin‐film elements deposited on the insulating surface of the blades and vanes. The insulator is developed by thermal oxidation of a MCrAlY coating which is deposited on the blade and vane surface in the current state of turbine technology. The understanding of the structural and thermoelectric stability of the sensor elements and of the insulating layer of Al2O3 in the hostile environment of a gas turbine requires an in‐depth study of the metallurgical reactions occurring at the thin‐film Al2O3 and Al2O3–MCrAlY interfaces and of the corrosive reactions on the surface of the metal film. The work presented in this review addresses the problems associated with obtaining highly adherent and insulating Al2O3 on the MCrAlY surfaces, adhesion of the sensor elements, thermoelectric stability of the sensors on contamination, and finally the development of a corrosion protection coating. The desired quality Al2O3 has been grown on NiCoCrAlY‐coated nickel‐based superalloy substrates by a combination of oxidation treatments. The interface‐modified Pt and Pt/Rh films are deposited on the oxide by a dc magnetron sputtering technique. The corrosion protection requirements involve deposition of Si–O–N and Si3N4 graded structures on the sensors by the plasma‐assisted chemical vapor deposition process. Details of the electrical and metallurgical characteristics of the device at each stage of the coating/film growth have been analyzed by a number of surface sensitive and bulk analytical techniques.
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07.20.Dt Thermometers
81.05.Bx Metals, semimetals, and alloys
68.60.Bs Mechanical and acoustical properties

Thin film thermocouples for internal combustion engines

Kenneth G. Kreider

J. Vac. Sci. Technol. A 4, 2618 (1986); http://dx.doi.org/10.1116/1.573736 (6 pages) | Cited 6 times

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The feasibility of fabricating thin film thermocouples on internal combustion engine hardware was investigated. The goal was to find a procedure that would be useful for the measurement of the surface metal temperature of valves, valve seats, combustion chamber surfaces, cylinder walls, and piston heads during engine operation. The approach pursued was to coat the engine hardware material with an aluminum‐containing, oxidation‐resistant ferrous alloy (FeCrAlY) which forms a thermal oxide layer with good electrical resistance. This thermal oxide was coated with a thin layer of reactively sputtered aluminum oxide and sputtered thin film type S thermocouple legs of platinum and platinum plus rhodium. This project was used to investigate the materials problems related to obtaining good adhesion in the metal/metal–oxide/oxide/metal laminate and the electrical insulating properties of the oxide. Thermal oxidation, reactive sputtering of Al2O3, and platinum alloy sputtering were investigated using optical microscopy, x‐ray photoemission spectroscopy (XPS), laminar adhesion testing, and the evaluation of high temperature electrical properties. A successful method for fabricating thin film thermocouples on internal combustion engine materials was developed. Adherent, electrically insulating aluminum oxide with a type S thermocouple was produced on a 10 cm long stainless steel bar. The fabrication techniques and results of tests run on that bar as well as on numerous small test coupons are presented.
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07.20.Dt Thermometers
89.40.-a Transportation

Coatings for performance retention

R. V. Hillery

J. Vac. Sci. Technol. A 4, 2624 (1986); http://dx.doi.org/10.1116/1.573693 (5 pages)

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Performance and performance retention are becoming increasingly important in today’s gas turbine engines. The military aircraft engine operator wants the flexibility and flight envelope that increased performance will give, and the commercial user—aircraft, utility generation, or pumper—demands the long term fuel economy that improved performance retention will provide. Materials advances have provided the intrinsic strength and temperature increases to push the capability of today’s engines, and coatings have been an integral part of that advancement. Specifically, in the performance retention area, coatings and seal systems have become increasingly important in both compressor and turbine components. It is the intent of this overview paper to present a brief review of the coating systems presently in use and in development and to consider areas in which the technology might be heading.
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89.40.-a Transportation
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.-a Thin film structure and morphology

A new chromium carbide‐based tribological coating for use to 900 °C with particular reference to the Stirling engine

Harold E. Sliney

J. Vac. Sci. Technol. A 4, 2629 (1986); http://dx.doi.org/10.1116/1.573694 (4 pages)

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A new chromium carbide‐based coating (PS 200) is described. This coating is shown to have good friction and wear properties over a wide temperature range. A nickel alloy‐bonded chromium carbide coating was used as a baseline material for comparison with experimental formulated coatings. Coatings were plasma sprayed onto metal disks, then diamond ground to a thickness of 0.025 cm. Friction and wear were determined using a pin on disk tribometer at temperatures from 25 to 900 °C in hydrogen, helium, and air. Pin materials included several metallic alloys and silicon carbide. It was found that appropriate additions of metallic silver and of barium fluoride/calcium fluoride eutectic to the baseline carbide composition significantly reduced friction coefficients while preserving, and in some cases, even enhancing wear resistance. The results of this study demonstrate that PS 200 is a promising coating composition to consider for high‐temperature aerospace and advanced heat engine applications. The excellent results in hydrogen make this coating of particular interest for use in the Stirling engine.
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62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear

Properties of Co+Cr2O3: A wear protective dispersion coating for use at high temperatures

M. Thoma

J. Vac. Sci. Technol. A 4, 2633 (1986); http://dx.doi.org/10.1116/1.573695 (5 pages)

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Co+Cr2O3 is a composite coating of a cobalt matrix with 25 vol % Cr2O3 embedded in it. The mechanical properties of this coating are discussed. The main attribute is the excellent wear resistance of the coating, especially in the temperature range 300–700 °C, owing to the formation of a protective Co3O4 glaze layer. Reciprocating wear was reduced by plating both parts of a pairing, but plating only one part of the pairing reduced the wear of the uncoated part to a similar extent, irrespective of the alloy used. In the temperature range 300–700 °C the wear of both the Co+Cr2O3 coating and the uncoated alloy was reduced to a minimum by the formation of the glaze layer on the Co+Cr2O3 coating. The glaze prevented metal to metal contact and changed the wear mechanism. In the temperature range of optimum wear protection there was also a beneficial effect on the fatigue properties. The high‐cycle fatigue of Co+Cr2O3‐coated Waspaloy was not influenced either when heat treated previously or by use at these temperatures. Low‐cycle fatigue loss of Waspaloy was decreased by a 600 °C preheat treatment. Fretting fatigue of Ti–6Al–4V was increased when coated with Co+Cr2O3 and used at 350 °C.
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62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear
62.20.M- Structural failure of materials
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure

Characterization of coating processes and coatings for steam turbine blades

J. Qureshi, A. Levy, and B. Wang

J. Vac. Sci. Technol. A 4, 2638 (1986); http://dx.doi.org/10.1116/1.573696 (10 pages)

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The exfoliated scale from boiler tubing results in hard particles that erode steam turbine components, particularly stationary and rotating blading. To select an erosion resistant protective coating for steam turbine blades, six promising coating processes comprising ten different coatings were selected for evaluation by erosion testing, metallography, and mechanical tests of coated blade materials. This paper describes the results of the erosion tests and metallographical studies and discusses how erosion resistance is related to coating morphology.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.05.Bx Metals, semimetals, and alloys
68.55.-a Thin film structure and morphology
89.30.-g Fossil fuels and nuclear power

Calculations and experimental study of the thermally affected layer caused by friction

L. Rozeanu and D. Pnueli

J. Vac. Sci. Technol. A 4, 2648 (1986); http://dx.doi.org/10.1116/1.573697 (4 pages)

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The concept of a thermally affected layer (TAL) is introduced and used to analyze the temperature field which develops in a coating layer. The analysis is done for both one‐pass surface interaction and for cyclic‐pass interactions. It is shown that for coating materials with low thermal diffusivities the coating thickness must not exceed the TAL thickness. Conditions which thin coatings can withstand may become disastrous for thicker coatings. The results are substantiated by experimental example of a coating of a barrel of a rifle.
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68.60.Bs Mechanical and acoustical properties
81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness

Dip process thermal barrier coatings for gas turbines

Ibrahim M. Allam and David J. Rowcliffe

J. Vac. Sci. Technol. A 4, 2652 (1986); http://dx.doi.org/10.1116/1.573698 (4 pages)

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A new concept to apply zirconia‐based thermal barrier coatings on cobalt base alloys has been developed. Contrary to plasma spraying or electron beam vaporization, the new process produces a dense and highly adherent zirconia coating that resists thermal cycling and penetration by corrosive molten salts. The new method is based on thermally growing a ZrO2‐based layer from a Zr‐rich alloy, predeposited on a Y‐rich substrate by hot dipping. The coating consists of an outer ZrO2/Y2O3 layer and an inner oxide–metal composite layer next to the substrate surface. The outer oxide layer acts as a thermal barrier, while the inner layer acts as a graded seal that improves the adhesion of the coating to the substrate. Thermal cycling experiments showed that the coating has a good resistance to spallation between room temperature and 1100 °C.
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81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
81.65.-b Surface treatments
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties

Ionization assisted physical vapor deposition of zirconia thermal barrier coatings

K. S. Fancey and A. Matthews

J. Vac. Sci. Technol. A 4, 2656 (1986); http://dx.doi.org/10.1116/1.573699 (5 pages) | Cited 4 times

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Yttria stabilized zirconia has been deposited by electron beam physical vapor deposition under a range of process conditions. The influence of rf plasma assistance, pressure, surface finish, and source to substrate distance on structure, phase, uniformity, and adhesion has been studied. Coatings were found to be predominantly cubic; their texture could be modified by plasma assistance. Also plasma assistance was found to improve adhesion, permit control of coating structure and densification, and provide the possibility to increase pressures, to improve coating thickness uniformity without loss of structure control. Excellent adhesion was obtained even on polished substrates at low temperatures (<400 °C), which when coupled with the fact that the coating tends to replicate the original surface finish, suggests that good aerodynamic efficiencies and performance should be achieved with thermal barrier coatings produced by this method.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.55.-a Thin film structure and morphology
68.60.Dv Thermal stability; thermal effects
68.35.Gy Mechanical properties; surface strains

Material selection for hard coatings

H. Holleck

J. Vac. Sci. Technol. A 4, 2661 (1986); http://dx.doi.org/10.1116/1.573700 (9 pages) | Cited 104 times

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Multicomponent refractory material systems can provide opportunities for specific materials for wear resistant coatings. The multitude of potential hard coating materials can be subdivided into three groups according to variations in chemical bonding character of the compounds. Many fundamental relations between the position of coating material components in the Periodic Table of the elements and the properties can be used to optimize these material selections. However, restrictions exist because of increasing hardness and strength which primarily decrease toughness and adherence. Multicomponent boride, carbide, nitride, and oxide systems are discussed in view of their potential as coating materials. Additional options for materials selection and optimization arise from the possibility of adjusting specific microstructures in the layers, especially in multilayer and multiphase coatings.
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68.60.Bs Mechanical and acoustical properties
62.20.Qp Friction, tribology, and hardness

The color of TiN and HfN: Aging effects

A. J. Perry

J. Vac. Sci. Technol. A 4, 2670 (1986); http://dx.doi.org/10.1116/1.573701 (4 pages) | Cited 4 times

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The color of TiN films made by plasma enhanced physical vapor deposition (PVD) methods is found to age during storage; this can be accentuated by tempering. A contraction towards the equilibrium value of the pre‐expanded lattice is thought to be responsible for the changes. This is in general accord with a previously presented model. Similar effects are found in HfN films. When studying highly reflecting films the effect of changing measuring geometry from the so‐called d/8 to the d/0 configuration significantly affects the color data.
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81.40.Tv Optical and dielectric properties related to treatment conditions
75.20.Ck Nonmetals

The reflectance and color of titanium nitride

A. J. Perry, M. Georgson, and C. G. Ribbing

J. Vac. Sci. Technol. A 4, 2674 (1986); http://dx.doi.org/10.1116/1.573702 (4 pages) | Cited 3 times

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It is shown that lattice expansion at constant composition can affect the location and slope of the reflectance curve of TiN films in a complex way comparable to the effect of substoichiometry or carbon substitution. Lattice expansion first shifts the reflectance shoulder to lower photon energies, causing the color (chroma) to lighten, and then to higher energies leading to a red cast. Tempering reduces the extremes but leaves a range of color where films made at lower deposition rates are more intensely yellow. The effects are discussed in terms of a simple ionic model and considering lattice defects.
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75.20.Ck Nonmetals
68.55.Nq Composition and phase identification
81.40.Tv Optical and dielectric properties related to treatment conditions
68.55.-a Thin film structure and morphology

Summary Abstract: Hard composite coatings of TiN with C or BN

J. Machet, C. Lory, C. Weissmantel, D. Roth, and E. Siegel

J. Vac. Sci. Technol. A 4, 2678 (1986); http://dx.doi.org/10.1116/1.573703 (2 pages)

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Abstract Unavailable
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62.20.Qp Friction, tribology, and hardness
81.05.Bx Metals, semimetals, and alloys
68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains

Summary Abstract: The use of intermediate layers to improve the adherence of diamondlike carbon films on ZnS and ZnSe

Michael J. Mirtich, Dan Nir, Diane Swec, and Bruce Banks

J. Vac. Sci. Technol. A 4, 2680 (1986); http://dx.doi.org/10.1116/1.573704 (2 pages) | Cited 2 times

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Abstract Unavailable
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62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains

A transmission electron microscopy study on Ti–N films deposited by ion plating

L. S. Wen, X. Jiang, and C. Y. Si

J. Vac. Sci. Technol. A 4, 2682 (1986); http://dx.doi.org/10.1116/1.573705 (4 pages) | Cited 1 time

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The microstructure and interface structure of Ti–N coating deposited by hollow cathode discharge ion plating were investigated with transmission electron microscopy and other methods of microanalysis. A layered structure of the coating was observed, consisting of substrate–FeTi–Ti–Ti2N–TiN. The transition layers FeTi and Ti2N were identified with microbeam electron diffraction. It was also shown that there was a microcrystalline region at the substrate surface. Preferential orientation has been observed and correlated with deposition parameters. The orientation relationships between different layers have been determined. The formation mechanism of transition layers was discussed.
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68.55.-a Thin film structure and morphology
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

Turning performance of reactively ion plated Ti–N coatings

J. M. Molarius, A. S. Korhonen, H. Kankaanpää, and M. S. Sulonen

J. Vac. Sci. Technol. A 4, 2686 (1986); http://dx.doi.org/10.1116/1.573706 (5 pages) | Cited 1 time

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Ti–N coatings containing from 29 to 53 at. % nitrogen were deposited on high‐speed steel inserts by triode ion plating. The cutting performance of the inserts was compared in a standard turning test and distinct differences were observed between the individual coatings. No direct relation between the thickness and cutting performance was found although some of the thinnest coatings wore out more rapidly and in general scatter was increased due to thickness variations. The cutting performance of the coatings was found to improve with increasing nitrogen content towards stoichiometric TiN. The results indicate that by properly selecting the deposition parameters, coatings having good cutting performance can be prepared in a wide range of compositions extending from about 40 to 50 at. % nitrogen.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.55.Nq Composition and phase identification

Electrochemically measured porosity of magnetron sputtered TiN films deposited at various substrate orientations

H. Freller and H. P. Lorenz

J. Vac. Sci. Technol. A 4, 2691 (1986); http://dx.doi.org/10.1116/1.573707 (4 pages) | Cited 1 time

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TiN layers were deposited by magnetron sputtering on polished stainless steel substrates, the position of which was changed in steps from parallel to perpendicular relative to the target surface. Substrate target distance was varied between 25 and 50 mm. Bias current density and substrate temperature at the beginning of deposition were also varied. The porosity of the films deposited under these circumstances was measured by an electrochemical method. The double layer capacity electrolyte/TiN film is a measure of the porosity and the true surface area of the deposited film. Dense films were deposited in all substrate positions when the starting temperature was around 300 °C and the bias current densities were above 2 mA/cm2. With bias current densities below 1 mA/cm2 or no bias and a position of the coated plane perpendicular to the target surface, the true surface of the film is enlarged to 500 times that of the geometrical area of the substrate used. The structural changes responsible for the increase in the porosity are shown in scanning electron microscope (SEM) micrographs.
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68.55.-a Thin film structure and morphology

On structure and properties of sputtered Ti and Al based hard compound films

O. Knotek, M. Böhmer, and T. Leyendecker

J. Vac. Sci. Technol. A 4, 2695 (1986); http://dx.doi.org/10.1116/1.573708 (6 pages) | Cited 35 times

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After investigating basic correlations between process and film characteristics in previous works new multicomponent hard coatings, on the basis of Ti–Al and Ti–Zr, have been deposited by magnetron sputtering. These ternary and quaternary nitrides are crystallizing in a face centered cubic TiN lattice with reduced or enlarged lattice parameters depending on the amount and the radius of foreign atoms. Improved wear behavior compared to chemical vapor deposition (CVD) TiN coatings has been stated with (Ti,Al)N, (Ti,Zr)N, and (Ti,Al,V)N coatings. According to these results the development of the coating material itself will be of major interest in the future.
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68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains

Morphology and properties of sputtered (Ti,Al)N layers on high speed steel substrates as a function of deposition temperature and sputtering atmosphere

Hermann A. Jehn, Siegfried Hofmann, Vera‐Ellen Rückborn, and Wolf‐Dieter Münz

J. Vac. Sci. Technol. A 4, 2701 (1986); http://dx.doi.org/10.1116/1.573709 (5 pages) | Cited 16 times

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(Ti,Al)N layers were prepared by reactive dc and radio‐frequency (rf) magnetron sputtering onto polished flat high speed steel (HSS) surfaces. The rectangular samples were mounted on a special sample holder providing a temperature gradient in the range of 500 °C to room temperature along the length of the sample. The (Ti,Al)N layers were deposited at various N2 and Ar pressures. The target was a Ti–50 at. % Al alloy. The film morphology and composition was observed by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES), respectively, and correlated to mechanical properties like hardness and critical load (scratch test). The results are discussed with the respect of the sputtering conditions.
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68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
68.60.Bs Mechanical and acoustical properties
81.15.Cd Deposition by sputtering

Summary Abstract: Chemical vapor deposition of titanium oxides

Eva Fredriksson and Jan Otto Carlsson

J. Vac. Sci. Technol. A 4, 2706 (1986); http://dx.doi.org/10.1116/1.573710 (1 page)

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Abstract Unavailable
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Composition, structure, and wear resistance of TiAlOC coatings deposited by chemical vapor deposition

Alfred S. Gates

J. Vac. Sci. Technol. A 4, 2707 (1986); http://dx.doi.org/10.1116/1.573711 (6 pages)

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The deposition of TiwAlxOyCz (TiAlOC) coatings onto cemented tungsten carbide cutting tool inserts by chemical vapor deposition is reported. The TiAlOC coatings are shown to exist in three phase regions: a single‐phase TiAlOC solid solution, a mixture of TiAlOC solid solution and α‐Al2O3, and a mixture of TiC and α‐Al2O3. The wear resistance of coatings from each phase region versus standard commercial coatings is reported.
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68.55.Nq Composition and phase identification
68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

The role of interface development during chemical vapor deposition in the performance of TiC‐coated cemented carbide cutting tools

D. G. Bhat, T. Cho, and P. F. Woerner

J. Vac. Sci. Technol. A 4, 2713 (1986); http://dx.doi.org/10.1116/1.573712 (4 pages) | Cited 1 time

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The effect of interaction between the furnace atmosphere and the surface of cemented carbide substrate on the properties and performance of TiC coated cutting tools is described. It is shown that a highly decarburizing atmosphere during chemical vapor deposition (CVD) results in the formation of M12C eta phase and tungsten, and considerable diffusion of cobalt into the TiC film. This type of coating is shown to have a poor spalling resistance. On the other hand, a nondecarburizing atmosphere is shown to prevent the formation of tungsten, and diffusion of cobalt into the coating. Also, both M6C and M12C eta phases are found to exist under these conditions. The relative increase in the amount of M6C as compared to M12C is shown to improve the spalling resistance of TiC coating.
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68.35.Fx Diffusion; interface formation
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.40.Pq Friction, lubrication, and wear
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Titanium aluminum nitride films: A new alternative to TiN coatings

Wolf‐Dieter Münz

J. Vac. Sci. Technol. A 4, 2717 (1986); http://dx.doi.org/10.1116/1.573713 (9 pages) | Cited 71 times

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TiAl films have been produced in various compositions by using the sputter ion plating process. Films sputtered reactively from a target with the composition of TiAl 50:50 at. % have been deposited with a composition of 27.5 at. % Ti, 28.9 at. % Al, and 43.6 at. % N. The crystal structure found was that of sodium chloride with a lattice parameter of 4.20 Å; the microhardness such films was found to be HV 2100–2300. The incorporation of Al into the nitride films improves the oxidation resistance as well as the cutting performances of TiAlN coated drills. TiN films start to oxidize at a temperature level of 550 °C, whereas TiAl coatings react with hot air at a temperature of 800 °C severely. TiAlN coated drills have been tested with two different steels and performed better by a factor >2 compared with TiN coated drills.
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81.15.Cd Deposition by sputtering
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.05.Bx Metals, semimetals, and alloys
68.55.-a Thin film structure and morphology

Deposition of TiN and Ti(O,C,N) hard coatings by a plasma assisted chemical vapor deposition process

P. Mayr and H.‐R. Stock

J. Vac. Sci. Technol. A 4, 2726 (1986); http://dx.doi.org/10.1116/1.573714 (5 pages) | Cited 7 times

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Using conventional plasma nitriding equipment with a dc power supply, TiN coatings have been deposited from TiCl4, H2, N2, and Ar onto tool steel substrates at temperatures about 500 °C. Coatings of the type Ti(O,C,N) have also been deposited using an organic titanium compound instead of TiCl4. The advantage of this compound is the absence of any chlorine products in the deposited layers.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Problems encountered with the introduction of ion plating to large‐scale coating of tools

J. Vogel and E. Bergmann

J. Vac. Sci. Technol. A 4, 2731 (1986); http://dx.doi.org/10.1116/1.573671 (9 pages) | Cited 2 times

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Performance improvements to cutting tools through the use of ion plated coatings are discussed as they relate to the quality of tools used, the specific geometry, and the material type of tool to be coated, as well as variations inherent in the coating process. Current state of the art for mass producing coated tools and the difficulties in quality assurance of tools having different geometries and end purposes is reviewed. Numerous examples are given showing the important aspects of tool condition on tool performance, such as surface roughness, presence of burrs, oxide layers, internal segregation, and heat treatment residues. Extensive data on coated tool life, types of failure, and performance as well as the range of tool material types presently considered suitable for coating are given.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.40.Pq Friction, lubrication, and wear
68.35.Gy Mechanical properties; surface strains
68.35.Fx Diffusion; interface formation

Advances in the electrospark deposition coating process

Roger N. Johnson and G. L. Sheldon

J. Vac. Sci. Technol. A 4, 2740 (1986); http://dx.doi.org/10.1116/1.573672 (7 pages)

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Electrospark deposition (ESD) is a pulsed‐arc microwelding process using short‐duration, high‐current electrical pulses to deposit an electrode material on a metallic substrate. It is one of the few methods available by which a fused, metallurgically bonded coating can be applied with such a low total heat input that the bulk substrate material remains at or near ambient temperatures. The short duration of the electrical pulse allows an extremely rapid solidification of the deposited material and results in an exceptionally fine‐grained, homogeneous coating that approaches (and with some materials, actually is) an amorphous structure. This structure is believed to contribute to the good tribological and corrosion performance observed for hardsurfacing materials used in the demanding environments of high temperatures, liquid metals, and neutron irradiation. A brief historical review of the process is provided, followed by descriptions of the present state of the art and of the performance and applications of electrospark deposition coating in liquid–metal‐cooled nuclear reactors.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
28.50.-k Fission reactor types
81.05.Bx Metals, semimetals, and alloys
81.40.Pq Friction, lubrication, and wear

The role of hard coatings in carbide milling tools

G. J. Wolfe, C. J. Petrosky, and D. T. Quinto

J. Vac. Sci. Technol. A 4, 2747 (1986); http://dx.doi.org/10.1116/1.573673 (8 pages) | Cited 5 times

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The role of hard coatings in prolonging the life of cemented carbide tools is now well‐documented for continuous turning applications. In contrast, relatively few studies have elucidated the effect of such coatings in milling, where both mechanical and thermal cyclic loading impose special requirements on the tool cutting edge. This investigation describes the wear mechanisms observed in coated carbide milling tools which have been the object of recent commercial tool development. Coated carbide tools (by CVD and PVD) of varying cutting edge geometry, substrate, and coating composition were subjected to fly‐cutter milling tests under a nominal range of cutting conditions. Examination of the used cutting edges under optical and electron microscopy showed both thermal‐fatigue‐induced vertical cracks, perpendicular to the cutting edge, as well as lateral cracks parallel to the edge which result from mechanical cyclic stresses. The wear patterns and the sequential progression of these cracks were characterized on the used tools. It is noted that the coatings tend to inhibit crack propagation rather than reduce crack initiation and serve to delay the onset of typical failure mechanisms found in uncoated tools. The fracture toughness of the cutting edge is more critical in milling than in turning applications. A discussion is given on matching the requirements of edge geometry, material properties of the substrate, and the hard coating to optimize the performance of the coated carbide milling insert.
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62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear
68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains

TiN‐coated high‐speed steel cutting tools

H. Randhawa

J. Vac. Sci. Technol. A 4, 2755 (1986); http://dx.doi.org/10.1116/1.573674 (4 pages) | Cited 3 times

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TiN‐coated cutting tools have gained a wide acceptance in the marketplace over the last few years. This has largely been due to the increased productivity, short machining times, and increased tool life benefits obtained using coated cutting tools. However, the successful coating of tools imposes requirements both in terms of coating processes and/or tool design and substrate materials. This prerequisite of optimizing tool designs, metallurgy, and surface finish to obtain optimum tool benefits when coated can only be achieved by close cooperation between manufacturing operations. This presentation addresses the issues of coatings, tool design, metallurgy, and surface finish quality to yield superior coated cutting tools.
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62.20.Qp Friction, tribology, and hardness
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics

Spalling resistance of physical vapor deposited and chemical vapor deposited TiN coated carbide indexable inserts in a short duration milling test

D. J. Rich and P. F. Woerner

J. Vac. Sci. Technol. A 4, 2759 (1986); http://dx.doi.org/10.1116/1.573675 (4 pages) | Cited 3 times

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Test results are reported from a short duration milling test which is designed to compare the relative resistance to spalling of coated carbide inserts. Carbide inserts coated with TiN by four different commercial physical vapor deposition processes showed consistently lower resistance to spalling than identical inserts coated by a chemical vapor deposition process. This difference in resistance to spalling increased as the coating thickness increased from 2 to 5 μ.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Comparison of wear characteristics and properties of TiN‐coated gear cutting hobs

E. Niemi, A. S. Korhonen, E. Harju, and V. Kauppinen

J. Vac. Sci. Technol. A 4, 2763 (1986); http://dx.doi.org/10.1116/1.573676 (5 pages) | Cited 2 times

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Two types of TiN‐coated gear cutting hobs were compared in the hobbing of case hardening steel under production conditions. The coating reduced the wear of the hobs significantly, even though 25% and 50% increased cutting speeds as compared to the uncoated hobs were used. The performance of the two types of TiN coatings denoted by A and B differed markedly. The coating B lasted generally from 1.5 to 2 times longer than A. Mechanical testing of hardness and adhesion by a scratch test gave, however, slightly better values for coating A. Nuclear resonance broadening analysis showed coating A to be essentially stoichiometric TiN, while B showed a gradually increasing nitrogen content towards the surface. Scanning electron micrographs revealed columnar microstructure with coating A while B was almost featureless. The columnar microstructure of coating A is suggested as an explanation for the poor performance of coating A as compared to coating B.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains

Some observations of gear‐cutting operations with TiN‐coated hobs and shaper cutters

Predrag Stosic

J. Vac. Sci. Technol. A 4, 2768 (1986); http://dx.doi.org/10.1116/1.573677 (2 pages)

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As a big manufacturer of tractor gear boxes, IMT was specifically interested in improving productivity with TiN‐coated hobs and gear‐shaper cutters, due to the potential benefits which TiN coatings offer on HSS gear‐cutting tools. For this reason, a number of comparative tests were recently carried out with both uncoated and TiN‐coated hobs and shaper cutters. The studies and tests included microscopic examinations of testing tools at the end of each shift as well as before each resharpening of hobs and shaper cutters and recorded the number of gears produced, resharpening depth, and number of resharpenings. At the same time, the main types of tooth wear, such as cutting‐edge dullness and cratering were observed and adequately examined. Test results definitely proved that an effective contribution to maximum productivity could be expected by exploitation of those characteristics of TiN coatings which permit higher cutting speeds and feeds and therefore reduce machining time.
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62.20.Qp Friction, tribology, and hardness

Microstructural and microchemical characterization of hard coatings

J.‐E. Sundgren, A. Rockett, J. E. Greene, and U. Helmersson

J. Vac. Sci. Technol. A 4, 2770 (1986); http://dx.doi.org/10.1116/1.573678 (14 pages) | Cited 7 times

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There is presently a rapidly expanding interest in the use of hard wear‐resistant coatings, especially transition metal nitrides and carbides which are among the hardest and most chemically inert compounds known. The complex bonding structure in these materials—a mixture of covalent, metallic, and ionic components—gives rise to a unique set of properties which has resulted in a wide range of applications. Nevertheless, there is still no detailed understanding of the relationship between film deposition parameters and the resulting microchemistry, microstructure, and hence physical properties, of the coating. This is primarily because the coatings are, in most cases, poorly characterized. In this paper, microchemical and microstructural analysis techniques appropriate for the study of hard coatings are critically reviewed and compared. The relative advantages and disadvantages of each technique are discussed together with possible problems in data interpretation which can arise due to measurement artifacts.
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68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
82.80.-d Chemical analysis and related physical methods of analysis
62.20.Qp Friction, tribology, and hardness

Low temperature oxidation behavior of reactively sputtered TiN by x‐ray photoelectron spectroscopy and contact resistance measurements

C. Ernsberger, J. Nickerson, T. Smith, A. E. Miller, and D. Banks

J. Vac. Sci. Technol. A 4, 2784 (1986); http://dx.doi.org/10.1116/1.573679 (5 pages) | Cited 23 times

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Electronic and electrical contact applications of TiN require a detailed understanding of the surface chemistry behavior in a variety of operating environments. For electromechanical contacts, contact resistance is the figure of merit and is a strong function of the structure and chemistry of the surface region. Thin (on the order of a few monolayers) insulating or semiconducting overlayers on a metallic conductor can raise contact resistance several orders of magnitude. In this study low temperature (22–100 °C) oxidation kinetics of reactively sputtered Ti and TiNx coatings of varying composition exposed at three humidity levels have been examined by x‐ray photoelectron spectroscopy (XPS) depth profiling, angle resolved XPS, and contact resistance measurements. Equilibrium overlayer conductivities can be up to nine orders of magnitude greater for TiN1.0 than Ti metal.
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81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.65.-b Surface treatments
73.40.Cg Contact resistance, contact potential
73.61.Ng Insulators
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Characterization of nitride coatings by Auger electron spectroscopy and x‐ray photoelectron spectroscopy

S. Hofmann

J. Vac. Sci. Technol. A 4, 2789 (1986); http://dx.doi.org/10.1116/1.573680 (8 pages) | Cited 27 times

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The dependence of technically important properties of wear resistant nitride coatings on chemical composition requires advanced methods of compositional analysis to establish optimized fabrication processes. High spatial resolution and chemical bonding specificity are provided by such techniques as Auger electron spectroscopy (AES) in the form of scanning Auger microscopy (SAM) and x‐ray photoelectron spectroscopy (XPS). A survey is given for the study of reactively sputter deposited Ti–N, Hf–N, and Ti–Al–N coatings on high‐speed steel substrates using point, line, and in‐depth distribution analysis by SAM in conjunction with sputter profiling. Capabilities and limitations of quantitative AES to determine the influence of processing parameters on coating composition are presented. XPS gives additional information on chemical bonding and on quantification. This is particularly important in cases of peak overlapping in Auger spectra (e.g., TiN).
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68.55.Nq Composition and phase identification
68.60.Bs Mechanical and acoustical properties
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
68.35.B- Structure of clean surfaces (and surface reconstruction)

Studies of interfacial composition of TiN films formed by plasma‐assisted chemical vapor deposition using an in situ scratching device

M. R. Hilton, A. M. Middlebrook, G. Rodrigues, M. Salmeron, and G. A. Somorjai

J. Vac. Sci. Technol. A 4, 2797 (1986); http://dx.doi.org/10.1116/1.573681 (4 pages)

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The interfacial composition of plasma‐assisted chemical vapor deposited TiN films on M2 tool steel is reported. An in situ scratcher with a scratch adhesion test type diamond stylus was used to create scratches in ultrahigh vacuum (UHV). Auger electron spectroscopy analysis of the adhesive mode failures revealed a sharp chlorine concentration gradient at the exposed surface representing the prior interface. The scratch removal technique data is compared to sputter depth profile data. Scanning electron microscopy and energy dispersive spectroscopy investigation of the scratches following the UHV work is also presented and discussed.
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68.35.Dv Composition, segregation; defects and impurities
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
62.20.Qp Friction, tribology, and hardness
68.60.Bs Mechanical and acoustical properties

States of residual stress both in films and in their substrates

A. J. Perry and L. Chollet

J. Vac. Sci. Technol. A 4, 2801 (1986); http://dx.doi.org/10.1116/1.573682 (8 pages) | Cited 7 times

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The study confirms that the sin2 ψ method can be used to determine the stress both in films and in their substrates. The application‐oriented model system chosen is Ti(CN) deposited onto high‐speed steel (HSS) and stainless steel by ion plating with a film deposited on HSS by chemical vapor deposition (CVD) as reference. The films are fine grained, hard, and strongly textured. The stress in the CVD film of 920 MPa compressive could be attributed to differential thermal contraction effects; in ion plated films it was over 4000 MPa. The stress in the steels was low and not measurably affected by the ion plating process. Problems in measurement and interpretation associated with texture, fluorescence, and penetration depth are illustrated and discussed.
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68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties

Internal stress and adherence of titanium nitride coatings

D. S. Rickerby

J. Vac. Sci. Technol. A 4, 2809 (1986); http://dx.doi.org/10.1116/1.573683 (6 pages) | Cited 7 times

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Titanium nitride coatings were deposited on various substrates by sputter ion plating and the state of stress was determined by the sin2 ψ method. The lattice distortions that occur in the nitride coatings have been resolved in terms of a macrostrain and microstrain, as determined from the breadth of the x‐ray reflections, and the origins of each are discussed. The internal stress present in a coating is shown to consist of two components, one thermal in origin and the other structural, and that its sign and magnitude varies with substrate material and bias potential. During cooling from deposition temperature partial relaxation of this internal stress (macrostrain) occurs via two mechanisms, plastic deformation of the substrate and yield of the film. The internal stress was completely relaxed on dissolution of the substrate, accompanied by a decrease in the lattice parameter of the film. By comparing the results from substrates biased and unbiased during deposition, and measurements made on adherent and free‐standing coatings, the microstrain measurements have been separated into two parts, one due to distortions at the grain boundaries and one due to defects in the crystallites. A model is proposed that accounts for all the experimental observations; this also provides an explanation for the distortions from cubic symmetry reported in titanium and hafnium nitride films.
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68.60.Bs Mechanical and acoustical properties
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
81.40.Pq Friction, lubrication, and wear

Acoustic emission during chromium electrodeposition

M. E. Todaro, G. P. Capsimalis, and E. S. Chen

J. Vac. Sci. Technol. A 4, 2815 (1986); http://dx.doi.org/10.1116/1.573684 (4 pages)

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The authors used acoustic emission to study crack formation during the electrodeposition of chromium over a range of temperatures and current densities which characterize the transition from high contraction (HC) to low contraction (LC) chromium. Several characteristics of the acoustic emissions were examined, including the amplitude distribution, signal energy, emission rate, count rate, and frequency spectrum. The acoustic emission technique detected the onset of cracking and yielded useful information regarding the number of cracks. Such information acquired during the actual deposition process can be an invaluable aid in determining the quality of the deposit and in developing improved chromium coatings. Experimental data were acquired and analyzed using commercial acoustic emission instrumentation, including standard piezoelectric transducers. The deposition bath was a standard aqueous solution of 250 g/l chromic acid and 2.5 g/l sulfuric acid. The solution temperature and deposition current density were varied to obtain deposits of differing crack content. The substrate was electropolished carbon steel.
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62.20.M- Structural failure of materials
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
62.65.+k Acoustical properties of solids

Very hard W–C coatings on stainless steel by rf reactive magnetron sputtering

P. K. Srivastava, V. D. Vankar, and K. L. Chopra

J. Vac. Sci. Technol. A 4, 2819 (1986); http://dx.doi.org/10.1116/1.573685 (8 pages) | Cited 5 times

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Tungsten carbide films having a single‐phase B1 fcc structure have been deposited by rf reactive magnetron sputtering on stainless‐steel substrates held at 500 °C. These films show a very high microhardness (∼3200 kgf/mm2) as compared to the bulk value (∼1800 kgf/mm2) and have very good adhesion (2.25×107g/cm2). The friction and wear of these films have been investigated by a pin and disk machine. A friction coefficient of 0.13 has been obtained. The wear resistance of coated stainless steel is reduced by a factor of 20. Further improvement in adhesion and reduction in both friction coefficient and wear rate is observed when an interlayer of Ti, Ta, W, Mo, and Si is introduced in between the stainless‐steel surface and W–C coatings. The relationship between the mechanical properties and the structure of the coatings and interlayers is discussed.
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68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.55.-a Thin film structure and morphology

On the morphology of thermochemically produced Fe2B/Fe interfaces

A. J. Ninham and I. M. Hutchings

J. Vac. Sci. Technol. A 4, 2827 (1986); http://dx.doi.org/10.1116/1.573686 (5 pages)

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A number of steels have been thermochemically boronized, and the morphology and composition of the boride layers have been examined. Theories to explain the morphology of the boride/substrate interface and based upon preferential diffusion of boron along the crystal ‘‘c’’ axis, or upon stress fields at the boride/substrate interface are discussed. These theories are shown to be unable to explain the morphology of the interface that is formed when high carbon steels are boronized. A new mechanism of boride growth is described which can account for the boride/substrate interface morphology in all cases. This involves the presence of impurities, which in plain carbon and low alloy steels controls the interface morphology by locally reducing the boride growth rate. The proposed mechanism is confirmed by the results of microanalysis, and has important consequences for the selection and specification of steels for boronizing.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
68.35.Fx Diffusion; interface formation
68.35.Dv Composition, segregation; defects and impurities

Chemical vapor deposition and physical vapor deposition coatings: Properties, tribological behavior, and applications

K.‐H. Habig

J. Vac. Sci. Technol. A 4, 2832 (1986); http://dx.doi.org/10.1116/1.573687 (12 pages) | Cited 3 times

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The main differences between chemical vapor deposition (CVD) and physical vapor deposition (PVD) processes are discussed in relation to a number of properties which are important for the functional behavior of coatings: chemical composition, phase composition, microstructure, thickness, hardness, texture, internal stresses, morphology, and roughness; each of which is discussed. Results of friction and wear tests which were performed under different conditions are reported, which reveal important aspects of the tribological behavior of different coatings. Examples of the application of CVD and PVD coatings are presented which show the possibilities for decreasing friction and wear of tools and machine elements.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.65.-b Surface treatments
81.40.Pq Friction, lubrication, and wear
68.55.-a Thin film structure and morphology

Friction and wear reduction in tool steel by ion beam enhanced TiN deposition

Hillary Solnick‐Legg, K. O. Legg, J. G. Rinker, and G. B. Freeman

J. Vac. Sci. Technol. A 4, 2844 (1986); http://dx.doi.org/10.1116/1.573688 (6 pages) | Cited 2 times

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A wear‐resistant surface has been produced on M2 and M43 tool steel by an ion‐assisted coating technique in which a TiN based film is ion beam mixed into the surface. Electron spectroscopy for chemical analysis shows the film to be a combination of TiN and TiO2, grading into the substrate. Friction and wear are greatly reduced and material pickup is virtually eliminated. Even when the coating has been worn away the friction and wear rate remain below those of the untreated steel, because of the presence of an ion‐implanted substrate. The results are discussed with reference to changes in the wear mechanisms.
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81.40.Pq Friction, lubrication, and wear
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.05.Bx Metals, semimetals, and alloys
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Tribological properties of MoNx coatings in contact with copper

J. Valli, U. Mäkelä, and H. T. G. Hentzell

J. Vac. Sci. Technol. A 4, 2850 (1986); http://dx.doi.org/10.1116/1.573689 (5 pages) | Cited 5 times

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In metal forming processes, coatings can be used to prevent adhesion between the tool and the workpiece in order to increase the lifetime of the tool. A new promising coating material for copper forming tools is MoNx, which has low galling tendency in an unlubricated contact with copper. MoNx coatings were deposited in a magnetron sputtering system. Tribological tests were carried out in a pin‐on‐disk tribometer. Also the adhesion and structure of the coatings were characterized. The lowest coefficient of friction and the lowest wear rate against copper was measured when the nitrogen concentration in the coating was 15 at. %–18 at. % and the Vickers microhardness about 2000 HV at a load of 10 g.
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62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
68.60.Bs Mechanical and acoustical properties

Summary Abstract: A physical vapor deposition technique for plating gun tubes

J. R. White

J. Vac. Sci. Technol. A 4, 2855 (1986); http://dx.doi.org/10.1116/1.573690 (2 pages)

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Abstract Unavailable
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81.15.Jj Ion and electron beam-assisted deposition; ion plating

Improving the wear resistance by forming hard metal matrix–ceramic composite surface layers

Khershed P. Cooper

J. Vac. Sci. Technol. A 4, 2857 (1986); http://dx.doi.org/10.1116/1.573691 (5 pages) | Cited 2 times

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Using an oscillating high energy laser beam, wide melt pools were formed on the surface of Inconel 625 alloy samples. Metal carbide particles, such as WC and TiC, were injected into the melt to form hard metal matrix–ceramic composite layers upon solidification. The injected layers were uniformly distributed in the carbide phase but exhibited variations in microstructure and microhardness. These variations were a result of carbide dissolution which depended upon the type of carbide and the thermal conditions within the melt pool. The wear behavior of the injected surface was characterized by coefficient of friction (μk) measurements. In contact with a hard 52100 steel ball, the μk values of the treated surface varied from 0.33 to 0.44 after a series of cycles. This compared with a value of 0.7 for the untreated surface. Observed wear modes included matrix abrasion and wear debris deposition, the extent and nature of which depended upon the matrix microhardness and the wear mechanism. The effects of carbide type and size on friction wear behavior of Inconel 625 are also discussed. Results show that Inconel 625 injected with 45–75 μm WC performs best under sliding friction conditions.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
81.05.Bx Metals, semimetals, and alloys

The effect of crystallization on the wear resistance of electroless deposited Ni–P amorphous coatings

Luo Shoufu, Ma Erming, and Li Pengxing

J. Vac. Sci. Technol. A 4, 2862 (1986); http://dx.doi.org/10.1116/1.573692 (5 pages)

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The changes in structure as well as the hardness and wear resistance of two electroless deposited Ni–P amorphous coatings (with phosphorus content 5.11 and 11.44 wt. %, respectively) after various heat treatments were studied by transmission electron microscopy, scanning electron microscopy (SEM), differential thermal analysis, and x‐ray diffraction. The results show that the hardness and wear resistance go through maximum values with increasing annealing temperature, but the peak of the wear resistance appears at a higher annealing temperature than that of the hardness for 11.44 wt. % P coating. At a given temperature, similar results were obtained with increasing annealing time. It was revealed by structural analysis that the increase of hardness is due to the formation of the Ni3P phase within the crystallized coatings during heat treatment. The lowering of hardness after the peak value is due to the decrease in lattice defects and the coarsening of grains as a result of recrystallization of the coatings. Different morphologies of the wear tracks were observed in the SEM for the amorphous and crystallized coatings. It is suggested that the wear of Ni–P coatings is influenced not only by its hardness, but also is closely related to the toughness of the coating and the adhesion between the substrate and the coating.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
68.55.-a Thin film structure and morphology
81.40.Gh Other heat and thermomechanical treatments

Tribological properties of metal/carbon coatings

E. Bergmann and J. Vogel

J. Vac. Sci. Technol. A 4, 2867 (1986); http://dx.doi.org/10.1116/1.573649 (3 pages)

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Dimigen and Hübsch discovered that carbon‐rich metal/carbon coatings that are deposited with a process combining reactive magnetron sputtering with plasma activated chemical vapor deposition show promising tribological properties. We investigated some of these for metal/carbon compounds of chromium, tungsten, and titanium of different stoichiometry. Friction coefficients against high‐carbon low‐alloy steel were measured in a three pin‐on‐disk configuration. Three‐body wear resistance was evaluated using a modification of the three pin‐on‐disk equipment, where a polishing powder suspension was fed continuously into the tribocontact. The results showed a strong dependence of the tribological properties on composition. The variation in the three‐body wear resistance of tungsten carbon compounds agreed with Rabinowicz’s model for the dependence on Vickers hardness.
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62.20.Qp Friction, tribology, and hardness
68.60.Bs Mechanical and acoustical properties
68.55.Nq Composition and phase identification
81.40.Pq Friction, lubrication, and wear

Predicted wear resistances of binary carbide coatings

Bruce M. Kramer

J. Vac. Sci. Technol. A 4, 2870 (1986); http://dx.doi.org/10.1116/1.573650 (4 pages) | Cited 4 times

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A mechanistic model of the tool wear process has been presented [B. M. Kramer and P. K. Judd, J. Vac. Sci. Technol. A 3, 2439 (1985)] that includes the effects of both the abrasion of the tool material by inclusions within the workpiece and the chemical dissolution of the tool material into the matrix of the workpiece. Machining tests have been run on steel with titanium carbide coated tooling and the resulting test data have been employed to produce a rough calibration of the proposed model. This model has been used to predict the wear resistances of the other group IV B carbides and of the (Ti,Hf)C system in the machining of steel.
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62.20.Qp Friction, tribology, and hardness

Reactively sputtered nitrides and carbides of titanium, zirconium, and hafnium

William D. Sproul

J. Vac. Sci. Technol. A 4, 2874 (1986); http://dx.doi.org/10.1116/1.573651 (5 pages) | Cited 14 times

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TiN, TiC, ZrN, ZrC, HfN, and HfC coatings were reactively sputtered at high rates of 2300 –5800 Å/min onto T‐15 high speed steel cutting tool inserts. Nitrogen was controlled through closed loop peak feedback control for the preparation of the nitride coatings, but either peak feedback control or flow control could be used for the carbide coatings. Methane was the reactive gas for TiC and ZrC, but it led to macrovoids in HfC. Acetylene produced dense HfC coatings. All of these coatings are much harder than the values for the bulk materials. Hafnium nitride was the hardest nitride with a Vickers microhardness (50 g) of 4690 kg/mm2, whereas ZrC was the hardest carbide with a hardness of 4840 kg/mm2. Except for TiC, all of the coatings have a lattice parameter that is greater than the bulk value. The coatings have the NaCl structure with a (111) preferred orientation. All of the coatings have an excellent adhesion to the T‐15 substrates, but a ZrN/Zr carbonitride interface was necessary with ZrC to obtain good adhesion. The ZrC and HfC coatings show an adhesion aging effect in which the adhesion increases with time. Vickers microhardness tests (50 g) show that ZrN and HfN have excellent hot hardness up through 800 °C, but at 1000 °C the hardness of HfN (440 kg/mm2) is much less than the hardness of ZrN (760 kg/mm2).
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62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
81.15.Cd Deposition by sputtering
61.66.Fn Inorganic compounds

Characterization of hard nitride and carbide titanium and zirconium coatings on high‐speed steel cutting tool inserts

G. Fenske, N. Kaufherr, C. Albertson, G. Mapalo, R. Nielsen, and M. Kaminsky

J. Vac. Sci. Technol. A 4, 2879 (1986); http://dx.doi.org/10.1116/1.573652 (6 pages) | Cited 2 times

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Hard nitride and carbide coatings of titanium and zirconium deposited by reactive evaporation and reactive sputtering techniques were characterized by electron microscopy and Auger spectroscopy to determine the effect of coating process on coating composition and microstructure. Analysis of the chemical composition by Auger spectroscopy revealed the coatings were of high purity with slight differences in stoichiometry depending on the coating technique. Both techniques produced coatings with a columnar microstructure. However, the reactive sputtering technique produced coarser (shorter and wider) columnar grains than the reactive evaporation technique. Furthermore, selected area diffraction analysis of reactively sputtered ZrN coatings showed a two‐phased zone (hcp Zr and fcc ZrN) near the substrate/coating interface, while TiC coatings deposited by reactive sputtering and evaporation only showed a single‐phase region of fcc TiC.
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68.55.Nq Composition and phase identification
68.55.-a Thin film structure and morphology
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Ion implantation of Ti and C in 440C steel for enhanced resistance to lubricated sliding wear

F. M. Kustas, M. S. Misra, and W. T. Tack

J. Vac. Sci. Technol. A 4, 2885 (1986); http://dx.doi.org/10.1116/1.573653 (7 pages)

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Sequential implantations of titanium (Ti) and carbon (C) into bearing steels have resulted in reduced coefficients of friction and improved wear resistance. These results, however, are highly dependent on the substrate material, test technique, and implantation parameters. Tribological property improvements have been reported for unimplanted and Ti and C implanted steel mating surfaces under dry sliding conditions, which may not be representative of anticipated bearing applications where both mating surfaces will be processed. Consequently, load‐friction‐wear (LFW) cylinders and rings fabricated from 440C steel were ion implanted with Ti and C to simulate anticipated bearing applications. Subsequent LFW tests showed a reduction in the steady‐state coefficient of friction of about 14%. More significant improvements were found in the reduction of sliding wear damage, i.e., smaller wear scar areas and elimination of stick–slip sliding wear behavior. Surface analysis was performed to correlate the Ti and C ion concentration–depth profiles with the observed tribological improvements. Comparisons with other published research concerning Ti and C implantation of bearing steels for improved tribological properties are also presented.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
61.72.up Other materials

Structure property relationships of carbonaceous films grown under ion enhancement

C. Weissmantel, E. Ackermann, K. Bewilogua, G. Hecht, H. Kupfer, and B. Rau

J. Vac. Sci. Technol. A 4, 2892 (1986); http://dx.doi.org/10.1116/1.573654 (8 pages) | Cited 3 times

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Based on our own results and in comparison with data published by other groups the structure property relationships of carbon and carbon/metal films prepared by sputtering and deposition of partially ionized species are discussed. Films grown by ion beam sputtering are dark brownish and amorphous with a small fraction of microcrystals. However, a transition to transparent and insulating layers can be effected by ion bombardment. C/Me coatings, where Me stands for Ti or Sn, were obtained by magnetron sputtering of composite targets. The films proved to be amorphous up to metal concentrations of more than 10 at. %, but metal and carbide crystals grow upon annealing. Measurements of the hardness, the electrical conductivity, and the contact behavior in dependence on the composition provided interesting information. For carbon films prepared by deposition of partially ionized benzene species it has been found that the properties depend characteristically on the ion energy; typical ‘‘diamondlike’’ i‐C films are obtained by applying a bias voltage from 1–3 keV. The thermal stability of the amorphous coatings is discussed in conjunction with their electrical conductivity. Summarizing extensive structure investigations, a structure model based on tetrahedrally interlinked carbon rings is proposed. Composites of the type i‐C/Me (Me: Al, Ti, Cr), which were prepared by simultaneous metal evaporation, exhibit a wide range of structure property relations.
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68.55.-a Thin film structure and morphology
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
81.40.Rs Electrical and magnetic properties related to treatment conditions
81.15.Cd Deposition by sputtering

Summary Abstract: The characterization and microanalysis of films with Auger and x‐ray photoelectron spectroscopies

J. T. Grant

J. Vac. Sci. Technol. A 4, 2900 (1986); http://dx.doi.org/10.1116/1.573655 (2 pages)

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68.35.Dv Composition, segregation; defects and impurities
68.55.Nq Composition and phase identification

Summary Abstract: Characterization of thin films by analytical electron microscopy

Thomas J. Headley

J. Vac. Sci. Technol. A 4, 2902 (1986); http://dx.doi.org/10.1116/1.573656 (3 pages)

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68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)

Summary Abstract: Effects of superalloy and coating structures on hot corrosion

G. William Goward

J. Vac. Sci. Technol. A 4, 2905 (1986); http://dx.doi.org/10.1116/1.573657 (2 pages) | Cited 1 time

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81.05.Bx Metals, semimetals, and alloys

Thermal stability of heat‐reflective films consisting of oxide–Ag–oxide deposited by dc magnetron sputtering

E. Kusano, J. Kawaguchi, and K. Enjouji

J. Vac. Sci. Technol. A 4, 2907 (1986); http://dx.doi.org/10.1116/1.573658 (4 pages) | Cited 8 times

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Transparent heat‐reflective films consisting of ITO–Ag–ITO or ZnO–Ag–ZnO were deposited onto soda‐lime glass by dc magnetron sputtering. In particular, the oxide layers were deposited from an electrically conductive oxide target. The transmittance in the visible range of the ITO–Ag–ITO film was more than 80% and the reflectance at 10 μm was nearly 95%. After the heat treatment at 650 °C, the transmittance of the films increased to nearly 85% and the reflectance at 10 μm was the same value of 95% as it was before the heat treatment. Moreover, the sheet resistance decreased to less than 4 Ω/cm2 by the heat treatment. Further, there were no visual changes or damage to the film up to 650 °C. The results showed that the ITO–Ag–ITO film was durable for the glass bending process. The ZnO–Ag–ZnO film also had high transmittance in the visible range and high reflectance in the infrared range, i.e., the transmittance in the visible range was more than 80% and the reflectance at 10 μm was 95%. However, these properties are much deteriorated by the heat treatment as compared with those of the ITO–Ag–ITO film.
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68.60.Dv Thermal stability; thermal effects
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
73.61.-r Electrical properties of specific thin films
81.40.Tv Optical and dielectric properties related to treatment conditions

A study of defects in sputtered TiN coatings by electrochemical polarization

A. Telama, T. Mäntylä, and P. Kettunen

J. Vac. Sci. Technol. A 4, 2911 (1986); http://dx.doi.org/10.1116/1.573659 (4 pages)

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Reactively rf‐sputtered TiN coatings were studied by taking electrochemical polarization measurements in an aerated 0.01N HCl aqueous solution. The substrate materials were Fe‐based alloy INCOLOY 800 and Ni‐based ODS alloy MA 6000. The effects of sputtering process parameters, such as deposition time, power, nitrogen partial pressure, bias voltage, and substrate temperature were studied. The electrochemical polarization of the thin coatings was compared with the polarization of the uncoated substrates. The observed polarization behavior of TiN coatings was correlated to structural details studied by scanning electron microscopy. The results of these tests are presented and discussed. TiN coatings produced by optimized parameters proved to be completely dense. The changes in process parameters gave clear indication in electrochemical polarization behavior. Some structural defects, such as nodules, were clearly indicated in the electrochemical measurement. The polarization measurements offer a sensitive method for discovering the existence of open porosity and other open structural defects, which are difficult to localize using other methods, and for determining the microstructural quality of the sputtered TiN coatings.
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68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Cd Deposition by sputtering
82.45.-h Electrochemistry and electrophoresis
68.55.-a Thin film structure and morphology

Transmission electron microscopy characterization of the microstructure of a CoCrAlY electron beam physical vapor deposition coating on IN738

J. R. Caola, G. H. Meier, and F. S. Pettit

J. Vac. Sci. Technol. A 4, 2915 (1986); http://dx.doi.org/10.1116/1.573660 (7 pages)

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The microstructures of commercially prepared electron beam physical vapor deposition CoCrAlY coatings on drop cast IN738LC substrates were studied using a technique developed for preparing cross‐sectional transmission electron microscope (TEM) specimens of exceptional mechanical stability. The microstructure was found to vary as a function of processing condition, starting as a fine dispersion of the α, β, and ϵ phases, after coating, distinguishable only with the aid of a TEM. This structure coarsened when exposed to the high temperature of the diffusion bonding heat treatment. In addition, flaws existing in the coating (leaders) were successfully sealed by glass bead peening and were observed to shrink with time when subjected to high temperature. Fine yttrium‐rich precipitates were observed in the coating which were difficult to identify due to their small size. Selected area diffraction revealed that one such precipitate was Y2O3. Additional analytical techniques included optical and scanning electron microscopy, x‐ray energy dispersive spectroscopy, and x‐ray diffraction.
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68.55.-a Thin film structure and morphology
81.05.Bx Metals, semimetals, and alloys

Summary Abstract: Structural consequences of ion assisted deposition

H. K. Pulker, M. Lardon, R. Buhl, and E. Moll

J. Vac. Sci. Technol. A 4, 2922 (1986); http://dx.doi.org/10.1116/1.573661 (3 pages) | Cited 4 times

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Abstract Unavailable
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68.55.-a Thin film structure and morphology
81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.60.Bs Mechanical and acoustical properties
61.80.Jh Ion radiation effects

Grain growth phenomena in films: A Monte Carlo approach

D. J. Srolovitz

J. Vac. Sci. Technol. A 4, 2925 (1986); http://dx.doi.org/10.1116/1.573662 (7 pages) | Cited 23 times

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A statistical model of microstructural evolution is developed for the evolution of grain structure during deposition. In cases where the atomic mobility on the surface greatly exceeds that in the bulk of the film, the bulk microstructure may be viewed as static while all of the evolution is controlled by the free surface. This leads naturally to a two‐dimensional model of microstructural evolution. Since the surface is advancing at a constant rate during deposition there is a linear relationship between time in the two‐dimensional model and depth in the film. A Monte Carlo computer simulation technique is described which models the evolution of microstructure in this way. Various driving forces are included. Simulated microstructures in the plane of the film and in the plane perpendicular to the free surface are shown.
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68.55.-a Thin film structure and morphology
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
68.35.Dv Composition, segregation; defects and impurities
68.35.B- Structure of clean surfaces (and surface reconstruction)

Adhesion and structure of rf‐sputtered magnesium oxide coatings on various metal substrates

P. Vuoristo, T. Mäntylä, and P. Kettunen

J. Vac. Sci. Technol. A 4, 2932 (1986); http://dx.doi.org/10.1116/1.573663 (6 pages) | Cited 1 time

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Magnesium oxide was rf‐sputtered on various metallic substrates to study the structure and adhesion of the coatings. The MgO coatings had a strong tendency to form a highly oriented and columnar structure with the growth orientation perpendicular to the planes (200). However, by decreasing the sputtering pressure and using a moderate temperature, less oriented coatings of denser structure could be obtained. The MgO coatings were found to be fully stoichiometric and free of argon even when deposited at low temperatures. Interaction between the growing MgO and the copper substrate was observed. This was manifested by diffusion of copper into the coating during sputtering and the formation of pores at the interface. The interaction was clearly a consequence of the open structure of the coating and could be minimized by controlling the sputtering parameters, e.g., pressure and temperature, or by using an intermediate layer to prevent the diffusion of copper. The rf‐sputtered MgO coatings showed excellent adhesion to most of the substrate materials during thermal cycling between 600 °C and room temperature in air or argon. This behavior was found to be due mostly to the high coefficient of thermal expansion of MgO, which is close to that of the substrates. Diffusion of copper through MgO and subsequent oxide scale formation was observed when coatings on oxygen‐free high‐conductivity Cu and Cu alloy were cycled in air. The dense coating structure as deposited, or the use of an intermediate layer, prevented the oxide scale formation.
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81.40.Pq Friction, lubrication, and wear
68.35.Fx Diffusion; interface formation
62.20.Qp Friction, tribology, and hardness
68.55.-a Thin film structure and morphology

Stresses developed during oxidation of iron thin films

P. B. Abel and R. W. Hoffman

J. Vac. Sci. Technol. A 4, 2938 (1986); http://dx.doi.org/10.1116/1.573664 (5 pages) | Cited 1 time

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The forces developed by oxidizing thin iron films were measured using the cantilever beam technique, previously used to measure film deposition stress. Iron was evaporated onto a preoxidized stainless‐steel substrate before admission of 7.8×10−2 Pa oxygen to the high vacuum chamber at temperatures from 250 to 310 °C. The measured traction rapidly became large and tensile. A dual quartz crystal microbalance (DQCM) was used to measure oxygen mass uptake versus time curves, which resemble bulk iron oxidation curves from the literature. The plot of tensile traction versus oxygen mass uptake was roughly linear and of similar slope for all experimental temperatures. Auger electron spectroscopy with ion sputtering, Rutherford backscattering spectroscopy, and transmission electron microscopy were used to characterize the oxidized and unoxidized iron films. A sputter ion gun was constructed with the capability of simultaneously sputtering both the DQCM and cantilever beam substrates. The tensile traction loss versus oxide mass loss graph indicated the large tensile force existed in the oxide. The plot of average tensile stress versus oxide thickness gave an approximately constant value for each sample on the order of 100 MPa in the oxide.
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81.05.Bx Metals, semimetals, and alloys
68.60.Bs Mechanical and acoustical properties

Effect of film composition and microstructure on microindentation response in amorphous alloy coatings

R. J. Bourcier, G. C. Nelson, A. K. Hays, and A. D. Romig

J. Vac. Sci. Technol. A 4, 2943 (1986); http://dx.doi.org/10.1116/1.573665 (6 pages)

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Amorphous alloy coatings were deposited onto Ni substrates by decomposing metal carbonyls [Ni(CO)4 and Fe(CO)5] and metalloid hydrides (PH3 and B2H6) by chemical vapor deposition in an rf plasma. The chemical composition of these films was determined using Auger electron spectroscopy and the hybridization (i.e., bonding character) of the metalloids (phosphorus, boron, and carbon) has been evaluated by using Auger line‐shape analysis. The amorphous/crystalline nature of these alloys was evaluated using x‐ray and electron diffraction techniques. The microindentation load‐depth response of these films was measured with an ultralow‐load hardness tester capable of testing at loads less than 10 g and at penetration depths less than 1 μm. The results of these measurements are discussed in the light of theories which attempt to relate mechanical properties of amorphous alloys to the bonding character of the outer electrons of the component elements.
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68.55.Nq Composition and phase identification
68.55.-a Thin film structure and morphology
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.60.Bs Mechanical and acoustical properties

Variations in the microstructure of nickel‐based alloy coatings with the metalloids boron and silicon as a function of deposition parameters in a dual beam ion system

J. K. G. Panitz

J. Vac. Sci. Technol. A 4, 2949 (1986); http://dx.doi.org/10.1116/1.573666 (5 pages)

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We have deposited coatings using a dual beam ion source system with two different targets as sputtering sources; (i) a predominantly amorphous Ni63.5Cr12.3Fe3.5Si7.9B12.8 foil and (ii) a crystalline Ni55.3Cr16.9Si7.2B21.6 slab from a casting. Amorphous coatings were produced by the foil for all conditions studied. The coatings that were deposited from the slab target that were less than 400 nm in thickness which were deposited at rates from 8–50 nm/min appeared to be amorphous. The thicker (>400 nm) coatings and the extremely low deposition rate (2 nm/min) coatings produced by the slab comprised both partially polycrystalline and amorphous material. All of the coatings studied exhibited inferior wear and erosion resistance properties compared to iron‐based amorphous metal coatings containing Ti, C, or N, which have been studied by other groups. However, the corrosion resistance to 4 N HCl is good, ranging from less than 0.01 to 0.22 mm/yr as a function of deposition rate, concurrent ion bombardment conditions, and coating thickness.
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68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
81.05.Bx Metals, semimetals, and alloys
81.15.Cd Deposition by sputtering

Summary Abstract: Energy dependence of the stress in diamondlike carbon films

Dan Nir

J. Vac. Sci. Technol. A 4, 2954 (1986); http://dx.doi.org/10.1116/1.573667 (2 pages) | Cited 2 times

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Abstract Unavailable
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68.60.Bs Mechanical and acoustical properties
81.15.Cd Deposition by sputtering

Ultralow load hardness testing of coatings in a scanning electron microscope

H. Bangert and A. Wagendristel

J. Vac. Sci. Technol. A 4, 2956 (1986); http://dx.doi.org/10.1116/1.573668 (3 pages)

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Extremely low load indentation hardness testing is one of the few methods of obtaining quantitative information on the mechanical behavior of surfaces and layers. An instrument for testing is described and its capability demonstrated with selected examples. Some peculiarities associated with the evaluation of hardness data of, e.g., a soft layer on a hard substrate or a hard layer on a soft substrate, are discussed.
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68.35.Gy Mechanical properties; surface strains
68.60.Bs Mechanical and acoustical properties
81.40.Pq Friction, lubrication, and wear
07.10.-h Mechanical instruments and equipment

Summary Abstract: Microstructure and the optical properties of solids

B. O. Seraphin

J. Vac. Sci. Technol. A 4, 2959 (1986); http://dx.doi.org/10.1116/1.573669 (1 page)

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68.55.-a Thin film structure and morphology
75.20.Ck Nonmetals
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
68.35.Gy Mechanical properties; surface strains

Summary Abstract: Nondestructive determination of the microstructure of materials by visible‐near ultraviolet spectroellipsometry and spectrophotometry

D. E. Aspnes

J. Vac. Sci. Technol. A 4, 2960 (1986); http://dx.doi.org/10.1116/1.573670 (2 pages)

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68.35.B- Structure of clean surfaces (and surface reconstruction)
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
81.70.-q Methods of materials testing and analysis

Raman determination of molecular structure and physical properties of dielectric coatings

Gregory J. Exarhos

J. Vac. Sci. Technol. A 4, 2962 (1986); http://dx.doi.org/10.1116/1.573609 (7 pages) | Cited 6 times

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Single and multilayer coatings exhibit optical properties controlled by localized chemical bonding and inherent microstructure that result from a particular deposition technique. The application of Raman spectroscopy to characterize such materials is attractive in that it is one of the few available methods that directly probes the chemical bond. Furthermore, optical properties of the coating can advantageously be used to enhance the sensitivity of the Raman probe through interference and resonance phenomena as well as guided wave enhancement techniques. Polycrystallite grain size and extent of grain orientation can also be determined from the spectra. In addition, inherent compressional stress in coatings, manifested in vibrational line shifts, may be quantified; conversely, knowledge of the vibrational frequency dependence on applied pressure will allow an estimate of the coating elastic properties. The capability for real‐time in situ analysis represents a major strength of the Raman technique. Examples will be discussed detailing real‐time microstructural changes in oxidic coatings subjected to temperature fluctuations or high‐energy pulsed laser irradiation.
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77.55.-g Dielectric thin films
78.30.-j Infrared and Raman spectra
68.55.-a Thin film structure and morphology
75.20.Ck Nonmetals

Modifying structure and properties of optical films by coevaporation

A. Feldman, E. N. Farabaugh, W. K. Haller, D. M. Sanders, and R. A. Stempniak

J. Vac. Sci. Technol. A 4, 2969 (1986); http://dx.doi.org/10.1116/1.573610 (6 pages) | Cited 20 times

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Coevaporated e‐beam films show modification of structure and properties that depend on composition. In pure zirconia films, x‐ray diffraction indicates two crystal phases present and scanning electron microscopy (SEM) shows a columnar structure. The pore fractions in these films can exceed 25%. The admixture of small amounts of silica (<20% by volume) results in films having a single crystalline phase. At volume fractions of silica >20%, the films show an amorphous structure lacking columnar growth. Measurements of refractive index and thickness as a function of composition indicate an initial decrease in porosity with increasing silica content. A simple model gives the porosity of the films as a function of composition. In addition, the mixed films show greater index stability, decreased surface roughness, and decreased optical scatter.
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68.55.-a Thin film structure and morphology
68.35.Gy Mechanical properties; surface strains
75.20.Ck Nonmetals
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Effect of nucleation layers on the growth and magnetic properties of CoCr and CoCr‐X films

J. K. Howard

J. Vac. Sci. Technol. A 4, 2975 (1986); http://dx.doi.org/10.1116/1.573611 (13 pages) | Cited 2 times

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The initial growth region in CoCr thin films is discussed with regard to its effect on the magnetic and microstructural properties of perpendicular recording media. Various nucleation films have been evaluated by interposing the nucleation layer between the substrate and the CoCr film. In some instances, the nucleation layer significantly improved the c‐axis texture and perpendicular anisotropy of the CoCr film. The results are reviewed and trends are evaluated to clarify the physical mechanism by which the phase and texture of polycrystalline CoCr films can be modified by sublayer nucleation films. Ternary CoCr‐X films have also been considered for perpendicular recording media applications. Experiments have shown that initial growth layers of randomly oriented grains can degrade the magnetic and structural properties of the ternary CoCr‐X alloys by the same mechanism. This paper describes a detailed evaluation of various nucleation layers for CoCr(W) and CoCr(Ta) magnetic films. Amorphous (microcrystalline) nucleation layers and polycrystalline films as thin as 300 Å were used as seed layers for the controlled growth of magnetic films such as (Co80Cr20)90W10 and (Co82Cr18)90Ta10. The ternary alloy films were deposited as thin as 1000 Å and exhibited excellent c‐axis texture with no evidence of an initial growth region. The excellent magnetic properties of the CoCr(Ta) and CoCr(W) thin films were attributed to various properties of the nucleation layer, i.e., oriented nuclei, microcrystallinity, and low misfit between the nucleation layer and the magnetic film.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.-a Thin film structure and morphology
75.70.-i Magnetic properties of thin films, surfaces, and interfaces
75.50.Cc Other ferromagnetic metals and alloys

Nanosecond pulsed laser‐induced segregation of Te in TeOx films

W. Y. Lee, H. Coufal, C. R. Davis, V. Jipson, G. Lim, W. Parrish, F. Sequeda, and R. E. Davis

J. Vac. Sci. Technol. A 4, 2988 (1986); http://dx.doi.org/10.1116/1.573612 (5 pages) | Cited 2 times

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Thin films of TeOx deposited by coevaporation of Te and TeO2 or by reactive sputtering of Te in the presence of Ar and O2 are amorphous as‐deposited and are spatially homogeneous mixtures of Te and TeO2. Irradiation of these films by a nanosecond laser pulse leads to a substantial change in the optical properties (e.g., increase in the reflectivity) of the films. Electron spectroscopy for chemical analysis depth profiling, Rutherford backscattering, and x‐ray diffraction techniques were used to analyze these films before and after laser irradiation. The results obtained indicated that the segregation of Te from TeO2 matrix is responsible for most of the observed optical property changes. The segregation of Te results in the formation of a nearly pure Te layer in the hottest region of the film without changing the overall film composition. A model based on melting of Te and TeO2 composites, followed by segregation and crystallization of Te is proposed to describe the nanosecond pulsed‐laser irradiation of TeOx thin films. The possible effects of Te segregation on the optical recording characteristics of TeOx based media are also discussed.
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81.40.Tv Optical and dielectric properties related to treatment conditions
66.30.-h Diffusion in solids
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)

Friction‐reducing coatings by dual fast atom beam technique

Hiroki Kuwano and Kazutoshi Nagai

J. Vac. Sci. Technol. A 4, 2993 (1986); http://dx.doi.org/10.1116/1.573613 (4 pages) | Cited 3 times

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Friction‐reducing coatings were formed by the dual fast atom beam technique. The coatings were double‐layer films consisting of hard underlayers (B, TiB2, B4C, and BN) with an added upperlayer of MoS2 solid lubricant. The double‐layer solid lubricants had 50% lower friction coefficients than lubricant films alone, less than 0.01 and had high durability. The hard films obtained by the accelerated fast atom bombardment of their growth surface had either a single or polycrystalline structure, while those without bombardment had an amorphous structure. Feasibility of the double‐layer solid lubricants was demonstrated by fabrication (<40 g cm) double‐layer solid lubricant ball bearings which were tested up to 106 cycles and demonstrated a low (<40 g cm) motive torque under a 3‐kg load.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
81.40.Pq Friction, lubrication, and wear

Wear and friction measurements of ion beam induced Fe–Ti surface alloys on AISI 304 stainless steel

J.‐P. Hirvonen, M. Nastasi, J. R. Phillips, and J. W. Mayer

J. Vac. Sci. Technol. A 4, 2997 (1986); http://dx.doi.org/10.1116/1.573614 (5 pages) | Cited 2 times

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The wear and friction of ion beam mixed Fe–Ti alloys on AISI 304 stainless steel were measured under dry sliding conditions over the composition range 0%–100% Ti. Samples with linearly varying composition in the lateral direction were used together with a reciprocal pin‐on‐plate motion and hardened Cr‐steel pin. A reduction of the friction coefficient of better than 50% was observed in the low friction area around the equal atomic composition as compared to the pure stainless‐steel substrate. In all cases the friction coefficient had the maximum value at the Ti‐rich end. Increasing the load from 16.8 to 50.3 g slightly decreased the concentration range of the low friction region. Debris particle production during wear of the pure stainless‐steel surface was also remarkably reduced on ion beam mixed samples. Studies of the wear tracks using scanning electron microscopy and profilometer indicate significant changes in the sliding mechanism.
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62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear
68.35.Gy Mechanical properties; surface strains
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Friction, wear, and corrosion control in rolling bearings through coatings and surface modification: A review

R. E. Maurer

J. Vac. Sci. Technol. A 4, 3002 (1986); http://dx.doi.org/10.1116/1.573615 (5 pages) | Cited 1 time

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There is an increasing demand for extended operation of rolling bearings in applications involving extreme temperatures, severe lubrication constraints, and/or chemically aggressive environments. The combinations of bearing material property requirements for specific applications, and the diversity of the application environments, dictate needs that are unfulfilled by conventional bearing steels. Coatings and surface modification treatments provide access to an expanded range of required surface characteristics, while preserving the bulk material properties of performance‐proven bearing steels. Improvements in corrosion, wear, and friction control are being pursued. A review of recent and in‐progress investigations concerning the application of hard coatings and ion implantation to rolling contact surfaces is presented.
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62.20.Qp Friction, tribology, and hardness
81.05.Bx Metals, semimetals, and alloys
61.72.up Other materials
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

A review of adhesion test methods for thin hard coatings

J. Valli

J. Vac. Sci. Technol. A 4, 3007 (1986); http://dx.doi.org/10.1116/1.573616 (8 pages) | Cited 14 times

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Adhesion to the substrate is the most important property of a coating. Previously unattainable adhesion levels can be achieved by modern physical vapor deposition and chemical vapor deposition techniques. There is an urgent need to develop standard techniques of adhesion evaluation, to ensure user confidence and promote the widespread use of coating methods. An adhesion test for hard tribological coatings should be easy and quick to carry out and the results should be easy to interpret. The test should be practicable for real tools and machine parts. Special sample preparation should not be required. There are at least nine different basic techniques for adhesion assessment: pressure sensitive tape test, acceleration (body force) testing, electromagnetic stressing, shock wave testing, tensile and shear testing, laser techniques, acoustic imaging, indentation tests, and scratch testing. These methods are discussed in this paper in the light of the requirements mentioned above. In the author’s view only laser techniques, acoustic imaging, and the scratch test are practical for evaluating the adhesion of hard coatings on tools and machine parts. Of these, the scratch test has the widest commercial use at the moment, although there still exist some phenomena which are not well understood. For example, variations in the friction between the indenter and the coating can affect the test result. However, the effect of different parameters, such as substrate hardness and coating thickness, are well understood, at least empirically.
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81.70.-q Methods of materials testing and analysis
68.35.Gy Mechanical properties; surface strains
68.60.Bs Mechanical and acoustical properties
62.20.Qp Friction, tribology, and hardness

A microtribometer for measurement of friction and adhesion of coatings

S. Baba, A. Kikuchi, and A. Kinbara

J. Vac. Sci. Technol. A 4, 3015 (1986); http://dx.doi.org/10.1116/1.573617 (4 pages) | Cited 3 times

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A new apparatus is described which enables the tribological properties of a surface to be measured. A modified cartridge of the record player is driven to swing sinusoidally in parallel to the surface at a frequency of 30 Hz with an amplitude of 8–200 μm. The stylus load is applied from 0 to 1 N. As the stylus is pressed to the surface, a voltage signal which reflects the frictional properties of the surface is generated in the cartridge. The analysis of the signal with the increase of the load yields the coefficient of friction. When the load is high enough, the surface or the coating on the substrate is broken and the signal of both the fracture and the resultant roughness is picked up. The coefficient of friction for an MgO coated glass substrate was 0.26. The adhesion forces of Ag, Al, MgO, and TiN films on glass substrates were 0.7, 1.2, 1.7, and 3.3 GPa in shear stress, respectively.
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62.20.Qp Friction, tribology, and hardness
68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains
07.10.-h Mechanical instruments and equipment

Groove adhesion test for electrodeposited chromium

S. K. Pan and E. S. Chen

J. Vac. Sci. Technol. A 4, 3019 (1986); http://dx.doi.org/10.1116/1.573618 (4 pages)

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A quantitative test has been devised to evaluate the adhesion of electrodeposited chromium on steel substrates. The test involves the cutting of parallel grooves across a plated surface using a small metal shaper equipped with a carbide tool. The grooves are cut at a depth just below the interface and shearing stresses are generated which can produce failure of the coating. In general, varying amounts of residual chromium are left on the surface of the lands depending on the relative cohesive and adhesive bond strengths of the electrodeposited chromium. Energy dispersive x‐ray analysis is used to map the distribution of residual chromium and obtain an intensity count. The ratio of count intensity normalized against a reference of 100% chromium coverage provides a quantitative measurement of adhesion. The groove adhesion test was found to be equally applicable for the evaluation of both hard chromium and soft chromium deposits.
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62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)

Summary Abstract: Oxygen enhanced adhesion of platinum films deposited on thermally grown alumina surfaces

R. C. Budhani, S. Prakash, H. J. Doerr, and R. F. Bunshah

J. Vac. Sci. Technol. A 4, 3023 (1986); http://dx.doi.org/10.1116/1.573619 (2 pages)

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Abstract Unavailable
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68.35.Gy Mechanical properties; surface strains
81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Summary Abstract: The requirements for developing corrosion resistant coatings

F. S. Pettit

J. Vac. Sci. Technol. A 4, 3025 (1986); http://dx.doi.org/10.1116/1.573620 (2 pages)

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81.05.Bx Metals, semimetals, and alloys
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
66.30.Ny Chemical interdiffusion; diffusion barriers

Summary Abstract: Tribochemistry in metals and ceramics

T. E. Fischer, M. D. Sexton, and H. Tomizawa

J. Vac. Sci. Technol. A 4, 3027 (1986); http://dx.doi.org/10.1116/1.573621 (3 pages)

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82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
62.20.Qp Friction, tribology, and hardness

Summary Abstract: Comparison of protective coatings for infrared transmitting windows

Diane M. Swec, Michael J. Mirtich, Dan Nir, and Bruce A. Banks

J. Vac. Sci. Technol. A 4, 3030 (1986); http://dx.doi.org/10.1116/1.573622 (2 pages)

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Abstract Unavailable
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81.65.-b Surface treatments
42.79.Wc Optical coatings
68.60.Bs Mechanical and acoustical properties
75.20.Ck Nonmetals

Morphology and erosive wear of Fe–Cr coatings for gun bores deposited by physical vapor deposition

V. Schlett, H. Stuke, and H. Weiss

J. Vac. Sci. Technol. A 4, 3032 (1986); http://dx.doi.org/10.1116/1.573623 (6 pages)

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Bores of high‐performance guns are often protected by electrodeposited Cr coatings. As those coatings show severe microcracking during service, a study was conducted to assess the performance of binary Fe–Cr coatings deposited by physical vapor deposition. Samples mountable as the outlet nozzle of a vented vessel were coated with alloys ranging from very low to 100% Cr by evaporating Fe and Cr from two separate crucibles. The coatings were characterized with respect to morphology and mechanical properties and then subjected to a number of propellant gas pulses using two different propellants of 2449 and 3046 K flame temperatures, respectively. The wear rates were measured after each round. The results revealed a rather complex interrelationship between wear rate and composition/morphology of the coatings with the thermochemical properties of the propellant as an additional factor. Interestingly, alloys with only 20%–40% Cr showed erosion rates as low as pure Cr, but with a much reduced tendency to microcracking. The comparatively low Cr content improved the mechanical properties of the coating without impairing the protective quality of the oxides formed. The findings obtained are discussed in the light of Auger electron spectroscopy depth profiles of the gas/coating reaction layers.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Coatings in magnetic fusion devices

M. F. Smith and J. B. Whitley

J. Vac. Sci. Technol. A 4, 3038 (1986); http://dx.doi.org/10.1116/1.573624 (8 pages) | Cited 1 time

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Coated surfaces have been exposed to plasmas in several magnetic confinement fusion devices, including Alcator‐C, DIVA, Doublet‐III, ISX‐B, JET, JFT‐2, JIPP T‐II, JT‐60, PDX, TEXTOR, TFTR, and ZT‐40. Chemical vapor deposited coatings of titanium carbide (TiC) have been most extensively tested and have had mixed results. Preliminary experiments with in situ deposition of thin carbon films inside tokamaks have also been performed, and the results look promising. This review paper summarizes the operational history of coatings in present generation fusion devices and discusses some of the coating successes and failures that have been observed. Some areas of coating research that are potentially interesting for future fusion devices are also briefly discussed.
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52.40.Hf Plasma-material interactions; boundary layer effects
52.55.-s Magnetic confinement and equilibrium
28.52.-s Fusion reactors

Structure and thermal resistance of chemically vapor deposited molybdenum on graphite

Y. Isobe, S. Yamanaka, P. Son, and M. Miyake

J. Vac. Sci. Technol. A 4, 3046 (1986); http://dx.doi.org/10.1116/1.573625 (4 pages)

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Molybdenum was chemically vapor deposited on graphite by a carbonyl method using molybdenum hexacarbonyl, Mo(CO)6, as a feed material. The deposition was carried out at the substrate temperature of 600 °C and at various deposition rates. The coatings prepared were columnar in structure, and the columnar grain size and the surface roughness of the coatings increased with decreasing deposition rate. The Vickers microhardness increased with increasing deposition rate. X‐ray analysis showed that the coatings had preferred orientation. To examine the thermal resistance of the coatings, thermal cycling tests were performed between a fixed minimum temperature of 500 °C and a maximum temperature of up to 1200 °C with heating and cooling rates at 10 °C/s. The results of the tests showed that the maximum temperature played an important role in causing thermal failures to the coatings, such as intergranular microcracking and recrystallization. The coating with large grain size and low carbon content prepared at low deposition rate, and the coating with greater thickness had good durability against thermal cycling.
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68.55.-a Thin film structure and morphology
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.35.Gy Mechanical properties; surface strains
68.60.Dv Thermal stability; thermal effects

Modifications of thin coatings by heat treatment: Behavior of redeposited material on the first wall of fusion devices during plasma wall interaction

J. Linke, H. Bolt, K. Koizlik, H. Nickel, E. Wallura, and J. B. Whitley

J. Vac. Sci. Technol. A 4, 3050 (1986); http://dx.doi.org/10.1116/1.573626 (5 pages)

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In magnetic confinement experiments the first wall and especially its high heat flux components (e.g., limiter, armor tiles) are subjected to plasma wall interaction which will cause physical and chemical erosion. The eroded wall material can enter the plasma where it contributes to plasma radiation losses especially when materials with medium or high atomic numbers (Z) are used. To avoid or reduce these objectionable processes, the application of thin low‐Z coatings for the first wall has been discussed and is occasionally already in use. A considerable disadvantage of thin films is their morphological instability under thermal loading. The stability of thin metallic coatings on different substrates was investigated in laboratory experiments under fusion‐relevant heat loading conditions and also under realistic conditions in magnetic confinement experiments.
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52.40.Hf Plasma-material interactions; boundary layer effects
52.55.Fa Tokamaks, spherical tokamaks
81.40.Gh Other heat and thermomechanical treatments
68.55.-a Thin film structure and morphology

Co60 radiation control using thin film coatings

T. V. Rao, B. Oral, G. T. Stauf, R. W. Vook, and W. Meyer

J. Vac. Sci. Technol. A 4, 3055 (1986); http://dx.doi.org/10.1116/1.573627 (4 pages)

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Boiling water nuclear reactors (BWR’s) undergo radioactive (mainly Co60) film buildup on the inner walls of their out‐of‐core stainless steel cooling water pipes. Great efforts are currently being made to passivate these stainless steel surfaces so as to reduce the rate of radiation buildup. They include (1) surface pretreatments such as electropolishing and steam oxidation, (2) techniques to reduce Co60 deposition into the natural oxide film, and (3) thin film protective coatings. In the present work, the effects of various metallic thin film coatings on radiation buildup in a simulated BWR test loop are reported. These coatings were prepared by vacuum evaporation and electroless deposition methods. The substrates consisted of 0.32 cm diam 316 NG stainless steel rods, which, for vacuum evaporation, were rotated during deposition to ensure uniform film growth. Most of the materials deposited were metallic, and both increases and decreases in radioactive buildup were obtained. In the best case a reduction of over 90% was obtained. Electron microscope analyses showed that the radioactive films grew by an island growth mechanism in which crystallographic faceting was common. These highly promising results may soon contribute to reducing the Co60 radiation buildup problem.
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81.05.Bx Metals, semimetals, and alloys
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties
28.41.-i Fission reactors
28.50.Hw Power and production reactors

The microstructure of sputter‐deposited coatings

John A. Thornton

J. Vac. Sci. Technol. A 4, 3059 (1986); http://dx.doi.org/10.1116/1.573628 (7 pages) | Cited 134 times

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Microstructure is a critical consideration when polycrystalline or amorphous thin films are used for applications such as microcircuit metallization layers and diffusion barriers. The trend in device fabrication toward lower processing temperatures means that such coatings must often be deposited at substrate temperatures T that are low relative to the coating material melting point Tm. The structure of vapor deposited coatings grown under these conditions consists typically of a columnar growth structure, defined by voided open boundaries, which is superimposed on a microstructure which may be polycrystalline (defined by metallurgical grain boundaries) or amorphous. The voided growth structure is clearly undesirable for most applications. Its occurrence is a fundamental consequence of atomic shadowing acting in concert with the low adatom mobilities that characterize low T/Tm deposition, and its formation can be enhanced by the surface irregularities which are common to microcircuit fabrication. This paper reviews some of the recent developments in understanding the fundamental aspects of the relationship between the deposition conditions and the microstructure of sputter‐deposited thin films, with particular emphasis on the origin of the growth structure and its suppression through energetic particle bombardment.
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68.55.-a Thin film structure and morphology
81.15.Cd Deposition by sputtering
85.40.Bh Computer-aided design of microcircuits; layout and modeling

Diffusion mechanisms and structural effects in grain boundaries

N. L. Peterson

J. Vac. Sci. Technol. A 4, 3066 (1986); http://dx.doi.org/10.1116/1.573629 (5 pages)

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A critical review is given of models and mechanisms for grain‐boundary diffusion in metals. A ‘‘pipe’’ mechanism of diffusion based on the well‐established dislocation model seems most appropriate for small‐angle boundaries. Open channels, which have atomic configurations somewhat like dislocation cores, probably play a major role in large‐angle grain‐boundary diffusion. Dissociated dislocations and stacking faults are not efficient paths for grain‐boundary diffusion. The diffusion and computer modeling experiments are consistent with a vacancy mechanism of diffusion by a rather well‐localized vacancy. The effective width of a boundary for grain‐boundary diffusion is about two atomic planes. By controlling the type of grain boundary in a solid, grain‐boundary diffusion can be reduced by a factor of 10 or more from that observed for a random grain‐boundary structure.
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66.30.J- Diffusion of impurities
68.35.Fx Diffusion; interface formation
61.72.Mm Grain and twin boundaries
68.35.B- Structure of clean surfaces (and surface reconstruction)

Atomic transport in amorphous alloys: An introduction

Robert W. Cahn

J. Vac. Sci. Technol. A 4, 3071 (1986); http://dx.doi.org/10.1116/1.573630 (7 pages) | Cited 6 times

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The measurement of the diffusivities of metallic and metalloid species in amorphous alloys has necessitated the development of techniques capable of a resolution of a few nanometers over a total penetration depth of less than a micron. Various profiling techniques employing ion beams and the ultrasensitive multilayer technique are outlined. Generalities concerning the diffusion of different solutes in the same amorphous alloy or family of alloys, and the diffusion of the same solute in different amorphous alloys are presented, and the effect of solute concentration discussed. The role of amorphous alloys as diffusion barriers in microelectronic circuitry is outlined with emphasis on recent results. The influence of the nature of the substrate and metallic overlayer receives special attention. Barrier layers effective up to 700 °C have recently been made.
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66.30.J- Diffusion of impurities
85.40.Bh Computer-aided design of microcircuits; layout and modeling
68.35.Fx Diffusion; interface formation

Thermal stability and nitrogen redistribution in the 〈Si〉/Ti/W–N/Al metallization scheme

F. C. T. So, E. Kolawa, H. P. Kattelus, X.‐A. Zhao, M‐A. Nicolet, and C.‐D. Lien

J. Vac. Sci. Technol. A 4, 3078 (1986); http://dx.doi.org/10.1116/1.573631 (4 pages) | Cited 2 times

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Backscattering spectrometry, Auger electron spectroscopy, and x‐ray diffraction have been used to monitor the thin‐film reactions and nitrogen redistribution in the 〈Si〉/Ti/W–N/Al metallization system. It is found that nitrogen in the W–N layer redistributes into Ti after annealing at temperatures above 500 °C. As a consequence of this redistribution of nitrogen, a significant amount of interdiffusion between Al and the underlayers is observed after annealing at 550 °C. This result contrasts markedly with that for the 〈Si〉/W–N/Al system, where no interdiffusion can be detected after the same thermal treatment. We attribute this redistribution of nitrogen to the stronger affinity of Ti for nitrogen than W. If the Ti layer is replaced by a sputtered TiSi2.3 film, no redistribution of nitrogen or reactions can be detected after annealing at 550 °C for 30 min.
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68.35.Fx Diffusion; interface formation
66.30.Ny Chemical interdiffusion; diffusion barriers
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
68.60.Dv Thermal stability; thermal effects

The effects of deposition variables on the electrical properties of silicon nitride films by chemical vapor deposition

Kyoung‐Soo Yi, Heung‐Lak Park, and John S. Chun

J. Vac. Sci. Technol. A 4, 3082 (1986); http://dx.doi.org/10.1116/1.573632 (3 pages)

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Amorphous silicon nitride thin films have been deposited by chemical vapor deposition (CVD) techniques using SiCl4, NH3, H2 gaseous mixtures onto silicon single crystals. The effects of deposition temperature and the flow rates of reactants on the deposition rate have been studied. The characteristics of nitride interface charge have been studied by fabricating metal–nitride–oxide–silicon (MNOS) structure. The experimental results show that the rate of deposition reaction is controlled by surface reactions. The apparent activation energy of silicon nitride deposition reaction is about 29.4 kcal/mol. The nitride charge density was obtained by measuring the flatband voltage of C–V plots. The positive initial nitride charge density in MNOS structure decreases with increasing the deposition temperature or the flow rate of ammonia. The negative electric field was applied to the gate of MNOS structure, and it was found that the trapped positive charge density in silicon nitride film decreases with increasing NH3/SiCl4 ratio of flow rate, and is hardly influenced by the deposition temperature.
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73.61.Ng Insulators
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.40.Rs Electrical and magnetic properties related to treatment conditions

Contact and metallization problems in GaAs integrated circuits

N. Braslau

J. Vac. Sci. Technol. A 4, 3085 (1986); http://dx.doi.org/10.1116/1.573633 (6 pages) | Cited 5 times

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Despite the rapid maturing of GaAs as an integrated circuit technology, both for digital and analog applications, the rather empirical nature of our contact metallurgy betrays a lack of basic scientific understanding of the metal–semiconductor interface and its electrical properties. Schottky barrier heights to GaAs are considered to be fixed and determined by Fermi level pinning due to surface states. On the scale of the control of barrier height required for integrated circuits (tens of millivolts), this is not the case. We have no accepted model which allows us to predict barrier heights on ideal barriers, much less ones on processed real surfaces. Where film stress is present, such as with refractory silicides used for self‐aligned gate metal gate field‐effect transistors, run‐to‐run variations may amount to hundreds of millivolts. Schottky barrier heights of metal–AlGaAs barriers, used with modulation‐doped field‐effect transistors, are now known, but not to the desired accuracy. Ohmic contacts are required to both n‐ and p‐type material over a large doping range, including contact to the two‐dimensional gas in modulation‐doped devices. The widely used alloyed contact does not appear to be extendable to lower contact resistance, better area uniformity, or processing temperature sensitivity. Some novel alternatives will be discussed, and their potential accessed. The need for minimal contact resistance to p‐doped bases of heterojunction bipolar transistors has focused attention recently on contacts to p‐GaAs. There is a distinct trend toward the use of refractory metal contacts due to the elevated temperatures to which they are subjected during processing which cause severe degradation to the presently used gold‐based metallurgy.
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85.40.Xx Hybrid microelectronics; thick films
73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions

Investigation of reactively sputtered tungsten nitride as high temperature stable Schottky contacts to GaAs

A. E. Geissberger, R. A. Sadler, F. A. Leyenaar, and M. L. Balzan

J. Vac. Sci. Technol. A 4, 3091 (1986); http://dx.doi.org/10.1116/1.573634 (4 pages) | Cited 9 times

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Tungsten nitride (WNx) was deposited onto 2‐in.‐GaAs substrates by reactively sputtering a tungsten target in a N2/Ar plasma. The films were deposited at a power density of 5.4 W/cm2 and total pressure of 1.33 Pa (10 mTorr). The partial pressure of N in Ar was varied from 0 to 0.5. Auger analysis of the WNx films indicated the nitrogen content varied between 0 and 20 at. %. The films were also found to contain between 0.5 and 2 at. % of oxygen. Resistivity measurements of the as‐deposited films indicate a linear relationship between film resistivity and atomic percent of nitrogen in the film. Stress measurements were erratic and showed no correlation with atomic percent of N in the film. The average interfacial stress was 2.4 GPa, with a standard deviation of 0.9 GPa. Schottky contacts were patterned on ion‐implanted 2‐in.‐GaAs wafers by reactive ion etching (RIE) the WNx film in a CF4/O2 plasma. The diodes were then capped with chemical vapor deposited (CVD) SiO2 and annealed at temperatures up to 850 °C. The temperature stability of WNx films is maximized at 4 at. % of nitrogen, and the postanneal (810 °C for 20 min) ideality factor (n) and barrier height (ϕB) for WN0.04 films are excellent: n=1.18, σn=0.008, ϕB=0.727 eV, and σϕB=0.005 eV. State‐of‐the‐art self‐aligned gate field‐effect transistors (FET’s) were fabricated using WN0.04 as the gate metallization.
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81.15.Cd Deposition by sputtering
73.61.Ng Insulators
68.35.Gy Mechanical properties; surface strains
73.30.+y Surface double layers, Schottky barriers, and work functions

Structure and electrical resistivity of low pressure chemical vapor deposited silicon

Hyung Sup Yoon, Chul Soon Park, and Sin‐Chong Park

J. Vac. Sci. Technol. A 4, 3095 (1986); http://dx.doi.org/10.1116/1.573635 (6 pages) | Cited 4 times

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Amorphous and polycrystalline silicon films were formed onto thermally oxidized silicon by low pressure chemical vapor deposition (LPCVD), and implanted with phosphorus or boron, and then annealed in N2 ambient. The structure and electrical resistivity of P‐ or B‐implanted LPCVD silicon have been investigated as a function of deposition temperature and annealing condition. The orientation preference of the polysilicon is described with the texture coefficient, and the mean crystallite size is calculated by weighing the texture coefficient. Common to the P‐ and B‐implanted cases, amorphous silicon (deposited at 560 °C) gets crystallites larger than the polycrystalline silicon (deposited at 625 °C) after thermal annealing. The resistivity of the P‐ and B‐implanted polycrystalline silicon varies significantly with process history. Mean crystallite size of the polysilicon is chosen for a normalizing parameter, and it is proved to specify the accumulating effect of LPCVD temperature and annealing condition on the polysilicon resistivity. An anomalous resistivity change of 80 keV‐B‐implanted polysilicon by thermal annealing is observed and believed to be owing to the boron loss into the buried oxide. The markedly improved conductivity of the polysilicon which was deposited in the amorphous state and crystallized subsequently is proven to be due to enhanced grain growth.
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68.55.-a Thin film structure and morphology
73.61.Cw Elemental semiconductors
73.61.Ey III-V semiconductors
73.61.Ga II-VI semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors
81.40.Rs Electrical and magnetic properties related to treatment conditions
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Effects of oxygen on the growth of vapor‐deposited aluminium films

M. J. Verkerk and G. J. van der Kolk

J. Vac. Sci. Technol. A 4, 3101 (1986); http://dx.doi.org/10.1116/1.573636 (5 pages) | Cited 2 times

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Aluminium films were grown by evaporation at different oxygen partial pressures. The oxygen partial pressure has a marked effect on the growth, the morphology, and the physical properties of the aluminium films. At low oxygen pressures homogeneous, faceted layer was grown. At oxygen partial pressures of about 1×10−5 Pa an inhomogeneous layer was obtained, which consists of rather large hillock‐like grains and small grains. The latter are covered by an oxide layer, on which secondary nuclei are found. At high oxygen partial pressures a fine‐grained, smooth surface is obtained. From a comparison with the results of a previous study it was concluded that oxygen and water affect the growth of aluminium films, by different mechanisms.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.-a Thin film structure and morphology
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties

Effects of deposition methods on the temperature‐dependent resistivity of tungsten films

L. Krusin‐Elbaum, K. Ahn, J. H. Souk, C. Y. Ting, and L. A. Nesbit

J. Vac. Sci. Technol. A 4, 3106 (1986); http://dx.doi.org/10.1116/1.573637 (5 pages) | Cited 11 times

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The resistivity of tungsten films prepared by magnetron sputtering, electron gun evaporation, and chemical vapor deposition was measured in the 4.2–297 K temperature range. The resistivity ρ in all films decreases linearly with temperature down to 60 K, indicating that scattering by lattice phonons is responsible for most of the resistivity at higher temperatures. Residual resistivity decreases with increasing grain size as determined from transmission electron microscopy (TEM). Residual resistivity ratio (RRR) values are in the 2–7 range and this includes the epitaxially grown film investigated for comparison. Annealing, in general, increases RRR and in the case of epifilm, a value of 20.5 is obtained after 1000 °C anneal. The temperature coefficient of resistivity is found to decrease with increasing ρ297 K, reflecting a growing contribution from defects and impurities. The effect of impurities is interpreted in terms of the grain boundary scattering model with reflection coefficient R, varying with deposition technique and thus with the amount of impurities incorporated in the films. Evaporated films have R less than 0.4, suggestive of low impurity content. In these films, defects observed in TEM play a major role. Cracks, precipitates, and dislocation loops contribute more significantly to ρ4.2 K than to ρ297 K. The contribution of defects can be reduced by raising substrate temperature ( ρ297 K =6.39 μΩ cm) or by anneal at 1000 °C.
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81.40.Rs Electrical and magnetic properties related to treatment conditions
73.61.At Metal and metallic alloys
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Properties of reactively sputtered tungsten films in nitrogen and oxygen

K. Y. Ahn, S. B. Brodsky, C. Y. Ting, and J. Kim

J. Vac. Sci. Technol. A 4, 3111 (1986); http://dx.doi.org/10.1116/1.573638 (6 pages) | Cited 2 times

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Tungsten films reactively sputtered in nitrogen or oxygen were characterized by measurements of electrical resistivity and microstructure. The deposition rate of W–N films is slightly reduced with increasing nitrogen partial pressure accompanied by an increase in electrical resistivity. For example, the nominal resistivity of pure tungsten films increases from 11 to 16 μΩ cm as the nitrogen partial pressure increases to 17%. Transmission electron microscopy shows that films are polycrystalline tungsten with bcc structure and typical grain size range of 200 to 300 nm. Upon annealing at high temperature above 700 °C, the effects of nitrogen are gradually diminishing. For example, the high values of resistivity are annealed out and approach that of pure tungsten film after annealing at 1000 °C for 30 min. Annealing does not change the film thickness nor the grain size, although films prepared in nitrogen partial pressure of greater than 7% show precipitates with typical size of 20 nm. The effects of oxygen partial pressure are much more pronounced. The electrical resistivity increases very sharply above 4% oxygen partial pressure. At 12.5%, the resistivity exceeds 400 μΩ cm. Transmission electron microscopy shows bcc tungsten structure in films deposited with oxygen partial pressure up to 6%, and amorphous structure for 12.5%. The average grain size decreases from 100 to 50 nm as the oxygen partial pressure increases from 2% to 6%. Upon annealing two significant changes occur: (1) the amorphous tungsten (for 12.5% oxygen) transforms to polycrystalline structure and (2) all samples show precipitation of WO2 phase. The grain size of these films is not affected by annealing, although a large drop in resistivity is obtained.
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73.61.At Metal and metallic alloys
68.55.-a Thin film structure and morphology
81.15.Cd Deposition by sputtering
81.40.Rs Electrical and magnetic properties related to treatment conditions

Metastable phase formation in reactively sputtered WxSiy films

J. S. Lin, R. C. Budhani, G. Pollock, C. V. Deshpandey, and R. F. Bunshah

J. Vac. Sci. Technol. A 4, 3117 (1986); http://dx.doi.org/10.1116/1.573639 (4 pages)

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Thin films of WxSiy ( y/x=0 to 2.7) have been deposited on (100) Si and thermally grown SiO2 by reactive sputtering of tungsten in silane diluted argon plasma. The as‐deposited films with y/x<0.37 have a metastable hexagonal structure, which on annealing at 400 °C transforms to stable bcc phase. The films with y/x≥0.37 are amorphous in the as‐deposited state. Annealing of the films above 600 °C in nitrogen ambients leads to in‐matrix and interfacial transformations. The extent of these transformations, as monitored by x‐ray diffraction, is decided by the thermodynamic stability of W–Si compounds and the availability of silicon at the film–substrate interface. The extent of bulk and interfacial reactions on isothermal annealing of the films up to 1000 °C has been studied.
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81.15.Cd Deposition by sputtering
68.60.Dv Thermal stability; thermal effects
68.55.Nq Composition and phase identification
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Hydrogen induced changes in the metallurgical interactions at PtSi–Si interfaces

T. T. Bardin, J. G. Pronko, R. C. Budhani, and R. F. Bunshah

J. Vac. Sci. Technol. A 4, 3121 (1986); http://dx.doi.org/10.1116/1.573640 (6 pages)

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This paper addresses the role of hydrogen in the kinetics of interfacial reactions between PtxSi1−x (x=0.67, 0.5) thin films, prepared by reactive sputtering of Pt in a silane plasma, and Si substrates and consequent changes in the electrical characteristics of PtSi/Si Schottky diodes. The effects of the deposition temperature and the alloy composition on the degree of the interfacial reactions have been examined with Rutherford backscattering and x‐ray diffraction techniques. The absolute hydrogen concentration in the films, as measured using ion beam forward scattering, decreases with increasing temperature of deposition and also with increasing Pt concentration. An important effect of hydrogen incorporation in the films with x<0.5 is a reduction in the kinetics of PtSi formation at the film–substrate interface. The diode parameters, (ϕb and η), for all the compositions of the films, improve with increasing deposition temperature until 400 °C; above 400 °C however, the barrier height decreases and the I–V characteristics deviate from ideality. The deterioration of the diode parameters has been found to be due to a significant degree of Pt diffusion into the bulk Si at the higher temperatures of deposition.
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82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
73.30.+y Surface double layers, Schottky barriers, and work functions
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics
68.55.Nq Composition and phase identification

Multilevel interconnections for wafer scale integration

J. F. McDonald, A. J. Steckl, C. A. Neugebauer, R. O. Carlson, and A. S. Bergendahl

J. Vac. Sci. Technol. A 4, 3127 (1986); http://dx.doi.org/10.1116/1.573641 (12 pages) | Cited 1 time

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Multilevel interconnections (MLIC) are the key to successful wafer scale integration (WSI). In this paper, we present a review of various approaches used in the implementation in MLIC to both monolithic WSI and wafer scale hybrid packaging. Electrical interconnections using both thin (micron dimensions) and thick (tens of microns dimensions) dielectric and metal films are discussed from a performance standpoint. The advantages of the thick film approach for realizing transmission line performance is indicated. Techniques for implementing thick electrical interconnections such as plate‐up, via etching and lift‐off, are described. This treatment includes silicon‐die‐on‐wafer, silicon‐die‐on‐ceramic, and GaAs‐on‐silicon wafer hybrids. Fabrication approaches which have been explored by several research groups are compared. Some projections concerning yield of the wafer interconnections are calculated. Finally, a brief examination of some potential approaches to three‐dimensional stacking of wafers is made, including two‐sided population of wafers.
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85.40.-e Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology
81.65.-b Surface treatments
85.40.Bh Computer-aided design of microcircuits; layout and modeling

Reaction of thin metal films with crystalline and amorphous Al2O3

X.‐A. Zhao, E. Kolawa, and M‐A. Nicolet

J. Vac. Sci. Technol. A 4, 3139 (1986); http://dx.doi.org/10.1116/1.573642 (3 pages) | Cited 5 times

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We have investigated the thermal reaction between thin transition metal films and sapphire, alumina or amorphous Al2O3 using backscattering spectrometry and x‐ray diffraction. Thin films of Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Pt were deposited on the substrates by rf sputtering in an Ar gas ambient. The samples were subsequently annealed in vacuum at 800–900 °C for 20 min to 4 h duration. We found that only films of Y, Ti, and Hf react, regardless of the type of substrate, by forming aluminides near the substrate and oxides on the surface. The other metal films do not react with the Al2O3 substrates. Our results agree with thermodynamic consideration based on the heats of reactions between metals and Al2O3.
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82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
68.35.Fx Diffusion; interface formation
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
82.60.Cx Enthalpies of combustion, reaction, and formation

Al‐doped Ni–Cr for temperature coefficient of resistance control in hybrid thin‐film resistors

M. A. Bayne

J. Vac. Sci. Technol. A 4, 3142 (1986); http://dx.doi.org/10.1116/1.573643 (4 pages) | Cited 1 time

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The temperature coefficient of resistance (TCR) was tailored by doping standard 60/40 nickel–chromium resistor film to reduce the TCR from ∼100 ppm/°C to ∼0 ppm/°C. For constant sheet resistance films, TCR was a function of both substrate surface roughness and dopant concentration. TCR may be kept near zero for a wide variety of hybrid substrate materials with varied surface finishes by changing dopant concentration in the sputtering target. By controlling alloy composition to 0.1 wt. %, using powder metallurgy techniques, TCR was controlled to ±5 ppm/°C for a constant sheet resistance and invariant substrate surface finish. Because rough substrates required thicker films to obtain the same sheet resistance, the factors which controlled TCR were slightly modified. The effect was an increase in TCR for the same resistance value. Doped resistors on aluminum oxide were slightly less stable in the high temperature storage test than undoped resistors. However, because their TCR was so much lower, the change in resistance during operation of a real circuit was less than one‐fourth the change in undoped resistors used on the same circuit.
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73.61.At Metal and metallic alloys
85.40.-e Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology
84.32.Ff Conductors, resistors (including thermistors, varistors, and photoresistors)
81.40.Rs Electrical and magnetic properties related to treatment conditions

Mechanisms of Al film growth by ultraviolet laser photolysis of trimethylaluminum

T. Motooka, S. Gorbatkin, D. Lubben, Djula Eres, and J. E. Greene

J. Vac. Sci. Technol. A 4, 3146 (1986); http://dx.doi.org/10.1116/1.573644 (7 pages) | Cited 5 times

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Mechanisms for the UV photolytic deposition of Al by KrF irradiation of trimethylaluminum (TMA) in ultrahigh vacuum have been investigated. Based upon optical emission spectra combined with molecular orbital calculations, a model for the UV photolysis of dimerized TMA, Al2(CH3)6, was developed in which Al and CH3 were produced through cascade one‐photon absorption processes in Al2(CH3)6 and Al(CH3)n (n=1,2,3). In addition, time‐resolved fluorescence measurements showed that CH was also generated in the gas phase by a photolytic side reaction involving photofragments of TMA. Film growth kinetics were analyzed using the UV photolysis model and the results of deposition experiments carried out as a function of TMA pressure P and the distance between the irradiated gas region and the substrate. The experimental configuration was designed to suppress surface irradiation and photoinduced reactions in adsorbed TMA. The mean free path of the precursor species for Al film growth was found to range from 97 to 25 μm for P=0.1–0.5 Torr consistent with the precursors being Al atoms. Auger electron spectroscopy analyses, before and after air exposure, of films deposited at Ts≲200 °C showed that they were pure porous Al with occluded hydrocarbon species. There was no indication of Al–C bonding. Combining these results with the UV photolysis model, we conclude that Al atoms, and not Al(CH3)n radicals, are the primary precursors for Al film growth and that deposition occurs simply by the diffusion of gas‐phase photogenerated Al atoms to the surface.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.50.-m Photochemistry

X‐ray diffraction characterization of multilayer semiconductor structures

Thad Vreeland and Bruce M. Paine

J. Vac. Sci. Technol. A 4, 3153 (1986); http://dx.doi.org/10.1116/1.573645 (7 pages) | Cited 7 times

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The analysis of double‐crystal x‐ray rocking curves of single‐crystal layered structures can give valuable information on layer strains, displacement of atoms from normal lattice sites (which reduces the structure factor), crystallographic misorientations, and crystal defects. Both strains and misorientations cause shifts in the Bragg angle. These two effects are readily separated using two or more rocking curves with appropriate hkl reflections. The thickness of a layer and its structure factor affect the integrated intensity of a shifted Bragg peak while the width of the peak is affected by the thickness of the layer and its defect content. Calculation of the x‐ray rocking curve of a crystal with strain, structure factor, and damage (displaced atoms) is done using the kinematical or single‐scattering theory for thin layers or the dynamical theory for thick strongly diffracting layers. The problem of uniqueness of the rocking curve calculated for a given structure is discussed. Application of the rocking curve technique to the characterization of multilayer semiconductor structures is presented. The applications include Si homoepitaxy and heteroepitaxy, metal silicide on Si, GaAs implanted with 0.3–15 MeV ions, quaternary compound laser structures, AlGaAs/GaAs and HgCdTe/CdTe superlattices, and strains in polycrystalline or noncrystalline films on a thin single crystal.
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68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Silicon films on amorphous substrates: Influence of boundaries and barriers

W. Scharff and C. Weissmantel

J. Vac. Sci. Technol. A 4, 3160 (1986); http://dx.doi.org/10.1116/1.573646 (5 pages)

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Silicon on insulator (SOI) structures were produced by recrystallization of polycrystalline silicon deposited on thermally grown SiO2 using either a single‐flash lamp pulse or light strip scanning. In the latter case of lateral zone melting, encapsulating coatings of Si3N4/SiO2 were found to be necessary to obtain closed films. Examinations by electron microscopy revealed the formation of subgrain boundaries that can be entrained under light‐absorbing strips of Si or MoSi2. In conclusion of basic considerations concerning the stability of the system during recrystallization, a major influence of the wetting behavior at the interface between the encapsulating layer and the molten silicon was deduced, and a rough interface and/or the addition of some monolayers of carbon was found to be favorable. Measurements performed with SOI test circuits confirmed the device‐worthy quality of the films, for which first applications in optoelectronic memories have been realized.
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68.55.-a Thin film structure and morphology
81.40.Rs Electrical and magnetic properties related to treatment conditions
68.08.Bc Wetting
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)

Confined ion beam cylinder sputtering: A new approach

D. J. Sharp

J. Vac. Sci. Technol. A 4, 3165 (1986); http://dx.doi.org/10.1116/1.573647 (4 pages)

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A new high rate sputter deposition technique is reported which employs axial projection of an ion beam into a negatively biased target cylinder. The resulting acute incident bombardment angle which occurs on the inner cylinder wall results in a high sputter yield as compared to other cathode sputter configurations. Calculations showed that near‐optimal argon ion incidence bombardment angles can be obtained with this technique. The resulting sputtered metal flux had a directional character and was projected radially inward from the cylinder walls and ‘‘downstream.’’ Rapid coating rates were observed on substrates placed at the approximate ‘‘focus’’ of deposition. Variations in the cylinder bias, the substrate bias, and the substrate–incident ion energy control were shown to modify the morphology of coatings during deposition. TEM showed that near‐amorphous or fine grain beryllium films were deposited as a function of substrate–incident argon ion flux (approximately 100 and 30 nm crystallites at 1000 eV at 0.2 and 0.5 mA/cm2, respectively) on single crystal NaCl substrates. Ion bombardment during sputter deposition provides a large number of nucleating sites causing numerous small crystallites during condensation of the metal.
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81.15.Cd Deposition by sputtering
81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.55.-a Thin film structure and morphology
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Growth, composition, and surface structure of Hg(1−x)CdxTe plasma oxides

W. H. Makky, A. Siddiqui, and C. H. Tang

J. Vac. Sci. Technol. A 4, 3169 (1986); http://dx.doi.org/10.1116/1.573648 (5 pages)

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Mercury cadmium telluride molecular beam epitaxially (MBE) grown layers were plasma oxidized at the rate of 8–10 Å/min. The thickness of the grown oxide inversely depended on the mercury content in the compound. The oxide composition was studied using x‐ray photoelectron spectroscopy surface analysis and Auger electron spectroscopy depth profiling. The plasma oxide consisted of a mixture of Cd and Te oxides. Oxygen incorporation in the oxide layer was greatly enhanced after etching and reoxidation. This is attributed to the large depletion of Hg in the reoxidized sample. Preliminary scanning electron microscopy surface microstructure studies showed very smooth surface for both the MBE layer and the plasma oxide. The oxide–HgCdTe interface appeared to be smooth as well.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.Nq Composition and phase identification
68.55.-a Thin film structure and morphology
81.65.-b Surface treatments
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