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Mar 2008

Volume 26, Issue 2, pp. L1-311

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Research on metastable electron traps in the modified SOI materials induced by Si ion implantation

Enxia Zhang, Zhishui Yu, Yanggen Cao, Hui Yang, Zhengxuan Zhang, and Xi Wang

J. Vac. Sci. Technol. A 26, L1 (2008); http://dx.doi.org/10.1116/1.2839858 (4 pages)

Online Publication Date: 28 February 2008

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Silicon-On-Insulator (SOI) materials were modified by Si ion implantation with different doses, as reported in this letter. The electrical performance was studied and the effect of a modification technique on the SOI materials was investigated. The characteristic, obtained by pseudo-metal-oxide-semiconductor (pseudo-MOS) method, showed that the drain ID current versus gate voltage VG(ID−VG) curves shifted along the axis of VG with the change of Si ion implantation doses. The results of electron paramagnetic resonance (EPR), x-ray photoelectron spectroscopy (XPS), and electronic test suggested that the parameters of implantation affect the electrical performance and that the metastable electron traps are introduced into the buried oxide layers of SOI materials.
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72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.61.Cw Elemental semiconductors
61.72.uf Ge and Si
61.80.Jh Ion radiation effects
76.30.-v Electron paramagnetic resonance and relaxation
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Crystallographic texture, morphology, optical, and microwave dielectric properties of dc magnetron sputtered nanostructured zirconia thin films

D. Pamu, K. Sudheendran, M. Ghanashyam Krishna, and K. C. James Raju

J. Vac. Sci. Technol. A 26, 185 (2008); http://dx.doi.org/10.1116/1.2827492 (8 pages) | Cited 1 time

Online Publication Date: 17 January 2008

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Nanocrystalline zirconia thin films have been deposited at ambient temperature by dc magnetron sputtering on glass and quartz substrates. The crystallite size as calculated from the x-ray diffraction patterns in the films varies between 10 and 25 nm and is dependent on oxygen percentage in the sputtering gas. Interestingly, the presence of monoclinic and cubic phase is observed for the films deposited on glass at 40%, 60%, and 80% of oxygen in the sputtering gas, while those deposited on quartz showed only the monoclinic phase. Refractive index decreased with increase in percentage of oxygen in the sputter gas. Significantly, even at 100% oxygen in the sputtering gas, films of thickness of the order of 500 nm have been grown starting from the metallic Zr target. The dielectric constants were measured using the extended cavity perturbation technique at X-band frequency (8–12 GHz). The dielectric constant and loss tangent showed a very small decrease with increase in frequency but exhibited a stronger dependence on processing parameters. The dielectric constants of the films at microwave frequencies ranged between 12.16 and 22.3.
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81.07.Bc Nanocrystalline materials
81.15.Cd Deposition by sputtering
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.55.-g Dielectric thin films
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

First principles calculation of Stillinger-Weber potential parameters for InN

C. Fulk, W. Walkosz, A. Chatterjee, S. Ogut, C. H. Grein, and P. W. Chung

J. Vac. Sci. Technol. A 26, 193 (2008); http://dx.doi.org/10.1116/1.2830635 (5 pages) | Cited 1 time

Online Publication Date: 17 January 2008

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The compliance coefficients and Stillinger-Weber interatomic potential parameters of wurtzite InN were determined by first principles methods. The structural parameters of InN were calculated within the local density approximation of Ceperley-Alder and the generalized gradient approximation of Perdew-Wang exchange-correlation functionals. It was found that the shallow 4d electrons were required as part of the valence shell to obtain accurate results due to the large difference in electronegativity between In and N. The calculated compliance parameters were in good agreement with previously reported theoretical values and in fair agreement with the scattered experimental values. The ab initio results were then fitted to Stillinger-Weber potential forms.
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71.20.Nr Semiconductor compounds
71.15.Nc Total energy and cohesive energy calculations
71.15.Mb Density functional theory, local density approximation, gradient and other corrections

Synthesis and characterization of Al2O3 and SiO2 films with fluoropolymer content using rf-plasma magnetron sputtering technique

Mohammad Islam and Osman T. Inal

J. Vac. Sci. Technol. A 26, 198 (2008); http://dx.doi.org/10.1116/1.2831503 (7 pages)

Online Publication Date: 17 January 2008

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Pure and molecularly mixed inorganic films for protection against atomic oxygen in lower earth orbit were prepared using radio-frequency (rf) plasma magnetron sputtering technique. Alumina (Al2O3) and silica (SiO2) films with average grain size in the range of 30–80 nm and fully dense or dense columnar structure were synthesized under different conditions of pressure and power. Simultaneous oxide sputtering and plasma polymerization (PP) of hexafluoropropylene (HFP) led to the formation of molecularly mixed films with fluoropolymer content. The degree of plasma polymerization was strongly influenced by total chamber pressure and the argon to HFP molar ratio (nAr/nM). An order of magnitude increase in pressure due to argon during codeposition changed the plasma-polymerization mechanism from radical-chain- to radical-radical-type processes. Subsequently, a shift from linear CH2 group based chain polymerization to highly disordered fluoropolymer content with branching and cross-linking was observed. Fourier transform infrared spectroscopy studies revealed chemical interaction between depositing SiO2 and PP-HFP through appearance of absorption bands characteristic of SiF stretching and expansion of SiO2 network. The relative amount and composition of plasma-polymerized fluoropolymer in such films can be controlled by changing argon to HFP flow ratio, total chamber pressure, and applied power. These films offer great potential for use as protective coatings in aerospace applications.
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81.15.Cd Deposition by sputtering
68.55.aj Insulators
68.55.J- Morphology of films
78.66.Nk Insulators
78.30.Hv Other nonmetallic inorganics
82.35.-x Polymers: properties; reactions; polymerization

Etching characteristics and mechanism of Ge2Sb2Te5 thin films in inductively coupled Cl2/Ar plasma

Nam-Ki Min, Alexander Efremov, Yun-Ho Kim, Mansu Kim, Hyung-Ho Park, Hyun Woo Lee, and Kwang-Ho Kwon

J. Vac. Sci. Technol. A 26, 205 (2008); http://dx.doi.org/10.1116/1.2831502 (7 pages) | Cited 1 time

Online Publication Date: 18 January 2008

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This work reports the investigations of both etch characteristics and mechanisms for the Ge2Sb2Te5 (GST) thin films in the Cl2/Ar inductively coupled plasma. The GST etch rates and etch selectivities over SiO2 were measured as functions of the Cl2/Ar mixing ratio (43%–86% Ar), gas pressure (4–10 mTorr), and source power (400–700 W). Langmuir probe diagnostics and zero-dimensional (global) plasma modeling provided the information on plasma parameters and behaviors of plasma active species. From the model-based analysis of surface kinetics, it was found that with variations of the Cl2/Ar mixing ratio and gas pressure, the GST etch rate follows the changes of Cl atom density and flux but contradicts with those for positive ions. The GST etch mechanism in the Cl2-containing plasmas represents a combination of spontaneous and ion-assisted chemical reactions with no limitation by ion-surface interaction kinetics such as physical sputtering of the main material or the ion-stimulated desorption of low volatile reaction products.
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81.65.Cf Surface cleaning, etching, patterning
52.70.Ds Electric and magnetic measurements
52.77.Bn Etching and cleaning
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Dimerization of titanyl phthalocyanine in thin films prepared by surface polymerization by ion-assisted deposition

Adam M. Zachary, Martin Drabik, Yongsoo Choi, Igor L. Bolotin, Hynek Biederman, and Luke Hanley

J. Vac. Sci. Technol. A 26, 212 (2008); http://dx.doi.org/10.1116/1.2835091 (7 pages) | Cited 1 time

Online Publication Date: 18 January 2008

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Surface polymerization by ion-assisted deposition (SPIAD), the simultaneous dosing of hyperthermal ions while depositing an organic oligomer, was used to deposit titanyl phthalocyanine (TiOPc) thin films with 50 and 100 eV acetylene ions. The properties of the SPIAD TiOPc thin films are compared with films of the evaporated TiOPc monomer via examination of the electronic structure, ultraviolet-visible absorbance, and composition. Mass spectrometry, x-ray photoelectron spectroscopy, and other methods were used to determine the film composition, chemical bonding, and to examine the electronic structure. These results showed the formation of TiOPc dimers bound face to face. However, the overall phthalocyanine ring structure otherwise remained intact, except for small amounts of atmospheric oxidation at ion-induced radical sites.
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68.55.jd Thickness
68.55.Nq Composition and phase identification
81.15.Jj Ion and electron beam-assisted deposition; ion plating
78.40.Me Organic compounds and polymers
79.60.Fr Polymers; organic compounds
71.20.Rv Polymers and organic compounds
78.66.Qn Polymers; organic compounds

Luminescence enhancement of plasma-etched InAsP/InGaAsP quantum wells

Meng Cao, Yanfeng Lao, Huizhen Wu, Cheng Liu, Zhengsheng Xie, Chunfang Cao, and Huizhen Wu

J. Vac. Sci. Technol. A 26, 219 (2008); http://dx.doi.org/10.1116/1.2831497 (5 pages)

Online Publication Date: 22 January 2008

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Luminescence enhancement effects are observed in the plasma-etched InAs0.45P0.55/In0.68Ga0.32As0.45P0.55 quantum wells (QWs). Characterizations of photoluminescence, atomic force microscopy, and secondary-ion mass spectroscopy reveal that surface roughening due to ion bombardment onto surface and microstructure changes resulted from Ar+ ions tunneling into the material in the plasma etching process account for the PL enhancement phenomenon. The combination of plasma etching and selective lift-off of the InP cap layer of the InAs0.45P0.55/In0.68Ga0.32As0.45P0.55 QW structures allows us to separate the two enhancement factors, which indicates the Ar+ ions tunneling into the crystal is the dominant factor that enhances the luminescence emission of InAs0.45P0.55/In0.68Ga0.32As0.45P0.55 quantum wells.
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78.67.De Quantum wells
78.55.Cr III-V semiconductors
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
52.77.Bn Etching and cleaning
81.65.Cf Surface cleaning, etching, patterning
68.35.bg Semiconductors

Effect of growth temperature on the characteristics of ZnO films grown on Si(111) substrates by metal-organic chemical vapor deposition

Junjie Zhu, Ran Yao, Haiyan Song, Zhuxi Fu, A. Yu. Kuznetsov, and In-Hwan Lee

J. Vac. Sci. Technol. A 26, 224 (2008); http://dx.doi.org/10.1116/1.2835090 (4 pages)

Online Publication Date: 23 January 2008

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ZnO films have been grown on Si(111) substrates by metal-organic chemical vapor deposition using diethylzinc and CO2 as precursors. The effects of growth temperature on growth rate, structure, and optical properties of the ZnO films were investigated in a temperature range between 450 and 700 °C. As growth temperature increased, the growth mode changed from kinetics-limited to mass-transfer-limited, and finally, to desorption-limited mode. Using the Arrhenius equation, the activation energy for the kinetics-limited growth mode was estimated to be 105 meV. The crystalline quality was also strongly dependent on growth temperature. With increasing growth temperature, the width of x-ray diffraction peaks decreases and the photoluminescence intensity enhances. Using CO2 as the oxygen source, we found that the optimal growth temperature was near 600 °C.
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81.05.Dz II-VI semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.ag Semiconductors
78.66.Hf II-VI semiconductors
78.55.Et II-VI semiconductors

Rarefied gas flow through short tubes into vacuum

S. Varoutis, D. Valougeorgis, O. Sazhin, and F. Sharipov

J. Vac. Sci. Technol. A 26, 228 (2008); http://dx.doi.org/10.1116/1.2830639 (11 pages) | Cited 7 times

Online Publication Date: 24 January 2008

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A rarefied gas flow into vacuum through a tube of finite length is investigated over the whole range of gas rarefaction by the direct simulation Monte Carlo method. The nonequilibrium effects at the inlet and outlet of the tube have been considered by including in the computational domain large volumes of the upstream and downstream reservoirs. Results for the dimensionless flow rate and for the flow field are presented for a wide range of the gas rarefaction and for various values of the length to radius ratio in the range from 0 to 10. The influence of the gas-surface interaction model, as well as the effect of the intermolecular potential model on the gas flow, is examined. A good agreement has been obtained between the present numerical results and the corresponding experimental ones available in the literature.
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47.45.-n Rarefied gas dynamics
47.11.-j Computational methods in fluid dynamics

Study of a micro chamber quadrupole mass spectrometer

Jinchan Wang, Xiaobing Zhang, Fuming Mao, Mei Xiao, Yunkang Cui, Daniel den Engelsen, and Wei Lei

J. Vac. Sci. Technol. A 26, 239 (2008); http://dx.doi.org/10.1116/1.2827512 (5 pages)

Online Publication Date: 29 January 2008

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The design of a micro chamber quadrupole mass spectrometer (MCQMS) having a small total volume of only 20 cm3, including Faraday cup ion detector and ion source, is described. This MCQMS can resist a vacuum baking temperature of 400–500 °C. The quadrupole elements with a hyperbolic surface are made of a ceramic material and coated with a thin metal layer. The quadrupole mass filter has a field radius of 3 mm and a length of 100 mm. Prototypes of this new MCQMS can detect a minimum partial pressure of 10−8 Pa, have a peak width of ΔM = 1 at 10% peak height from mass number 1 to 60, and show an excellent long-term stability. The new MCQMS is intended to be used in residual gas analyses of electron devices during a mutual pumping and baking process.
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07.75.+h Mass spectrometers

Atomic layer deposition of tin oxide films using tetrakis(dimethylamino) tin

Jeffrey W. Elam, David A. Baker, Alexander J. Hryn, Alex B. F. Martinson, Michael J. Pellin, and Joseph T. Hupp

J. Vac. Sci. Technol. A 26, 244 (2008); http://dx.doi.org/10.1116/1.2835087 (9 pages) | Cited 2 times

Online Publication Date: 29 January 2008

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The authors present a new method for preparing thin films of SnO2 by atomic layer deposition (ALD) using alternating exposures to tetrakis(dimethylamino) tin and hydrogen peroxide. This method avoids problems of corrosion and agglomeration associated with the halogenated compound, SnCl4. Tin oxide films were successfully deposited on a variety of substrates using deposition temperatures of 50–300 °C at an average growth rate of 1.2 Å/cycle. They use in situ quartz crystal microbalance and quadrupole mass spectrometry measurements to explore the mechanism for SnO2 ALD. Scanning electron microscopy of SnO2 films deposited on Si(100) show that the SnO2 films are smooth, conformal, and nearly featureless, while atomic force microscopy yields a surface roughness of only 0.84 nm for a film with a thickness of 92 nm. X-ray diffraction reveals that the SnO2 films are amorphous. Films deposited on glass yielded a resistivity of ∼ 0.3 Ω cm and an optical transmission of 94% for a film thickness of 140 nm. X-ray photoelectron spectroscopy measurements were consistent with residual dimethylamine ligands remaining in the film at deposition temperatures below 150 °C. This method allows, for the first time, low temperature (50 °C) growth of SnO2 films by ALD. Additionally, they show that this process is suitable for conformally coating high aspect ratio anodic alumina membranes.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.aj Insulators
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Ps Atomic force microscopy (AFM)
79.60.Dp Adsorbed layers and thin films

Low temperature plasma etching for Si3N4 waveguide applications

D. Celo, R. Vandusen, T. Smy, J. Albert, N. G. Tarr, and P. D. Waldron

J. Vac. Sci. Technol. A 26, 253 (2008); http://dx.doi.org/10.1116/1.2836424 (6 pages)

Online Publication Date: 30 January 2008

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Highly selective and anisotropic low temperature electron cyclotron resonance plasma etching process for silicon nitride optical rib waveguide devices compatible with integrated circuit technology is presented. Etching at low temperatures (−30 °C) with SF6/O2 chemistry in combination with a silicon dioxide hard mask achieved good anisotropy with the vertical sidewalls.
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52.77.Bn Etching and cleaning
42.79.Gn Optical waveguides and couplers

Optical properties and electrical properties of heavily Al-doped ZnSe layers

D. C. Oh, T. Takai, I. H. Im, S. H. Park, T. Hanada, T. Yao, J. S. Song, J. H. Chang, H. Makino, C. S. Han, and K. H. Koo

J. Vac. Sci. Technol. A 26, 259 (2008); http://dx.doi.org/10.1116/1.2836404 (6 pages)

Online Publication Date: 4 February 2008

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We have investigated optical properties and electrical properties of electrically degraded ZnSe layers by heavy Al doping, where their electron concentrations lie in the range of 7×1017–6×1018 cm−3. Low-temperature photoluminescence exhibits two dominant radiative trap centers of 1.97 eV (RD1) and 2.25 eV (RD2), which are ascribed to VZn-related complex defects. Deep-level-transient spectroscopy shows two electron-trap centers at 0.16 eV (ND1) and 0.80 eV (ND2) below the conduction-band minimum. On the other hand, it is found that RD2 is dominant in relatively lightly doped ZnSe:Al layers below 7×1018 cm−3 and RD1 is dominant in more heavily doped layers near 1×1019 cm−3, while ND1 and ND2 are independent of Al doping concentration and their trap densities are estimated be below 3×1016 cm−3. This indicates that RD1 and RD2 cause the carrier compensation in heavily doped ZnSe:Al layers. Their electron transport mechanism can be explained by ionized-impurity scattering mechanism.
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78.55.Hx Other solid inorganic materials
73.61.Le Other inorganic semiconductors
78.66.Li Other semiconductors

Graded refractive-index SiOx infrared filters prepared by reactive magnetron sputtering

Qiuming Song, Feng Huang, Ming Li, Bin Xie, Haiqian Wang, Yousong Jiang, and Yizhou Song

J. Vac. Sci. Technol. A 26, 265 (2008); http://dx.doi.org/10.1116/1.2837836 (5 pages)

Online Publication Date: 6 February 2008

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Dense, uniform SiOx (0 ⩽ x ⩽ 2) films were deposited by reactive magnetron sputtering. By controlling the oxygen flow rate and/or sputtering power during deposition, the refractive index of SiOx films can be continuously tuned from 1.44 to 3.69 at λ = 1550 nm. The authors fabricated an 11-layer bandpass filter of SiOx/SiO2 with high refractive-index contrast (nH/nL = 1.91 at λ = 1550 nm) and a 35-layer SiOx optical filter with a graded refractive-index profile. The measured reflectance and transmittance spectra correlate well with the designed spectra. This work demonstrates that SiOx material can be used to make infrared optical filters with graded refractive index and high refractive-index contrast.
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42.79.Ci Filters, zone plates, and polarizers
42.79.Ry Gradient-index (GRIN) devices

High sensitivity attenuated total reflection Fourier transform infrared spectroscopy study of ultrathin ZrO2 films: A study of phase change

S. Sayan, D. Chandler-Horowitz, N. V. Nguyen, and J. R. Ehrstein

J. Vac. Sci. Technol. A 26, 270 (2008); http://dx.doi.org/10.1116/1.2830642 (4 pages)

Online Publication Date: 12 February 2008

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Attenuated total reflection fourier transform infrared spectroscopy (FTIR ATR) was performed on ultrathin ZrO2 films as thin as ≈ 3.0 nm deposited on silicon. An observed vibrational mode near 710 cm−1 undergoes a very pronounced absorption line shape change, corresponding to a structural phase change, as a function of film thickness and thermal processing. This absorption, attributed to the Eu(LO2) and A2u(LO) modes of tetragonal ZrO2, marks the first experimental measurement and verification of vibrational modes for tetragonal ZrO2 in this spectral range. The FTIR-ATR method shows promise as an extremely sensitive and nondestructive tool for high-κ dielectric film characterization.
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77.55.-g Dielectric thin films
78.30.Hv Other nonmetallic inorganics
64.70.K- Solid-solid transitions

Molecular dynamics simulations of GaAs sputtering under low-energy argon ion bombardment

Emilie Despiau-Pujo, Pascal Chabert, and David B. Graves

J. Vac. Sci. Technol. A 26, 274 (2008); http://dx.doi.org/10.1116/1.2836408 (7 pages) | Cited 3 times

Online Publication Date: 12 February 2008

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Results from molecular dynamics (MD) simulations of low-energy (50–200 eV) Ar+ ion bombardment on (110) GaAs surfaces are reported. A new analytical bond-order potential, originally developed for molecular beam epitaxy studies, is used and tested in the context of etching to investigate the nature and effects of physical sputtering on GaAs compounds. It is found that a thermal desorption model, which accounts for long time scale phenomena between MD simulated impacts, is necessary to achieve steady state sputtering. An initial rapid etch of both atomic species is observed up to 4×1016 ions/cm2 fluence with preferential sputtering of Ga atoms. At high fluences, simulations show the formation of an As-rich layer on the top surface, a subsurface enrichment of Ga, and a return to stoichiometry deeper in the solid. More than 97% of sputtered or desorbed species appear to be Ga or As atoms; sputtering of GaAs molecules is negligible. All these observations are in agreement with published experimental results. Finally, a significant fraction of the atoms leave the surface with more than 10% of the incident ion energy, which could alter passivation layers on sidewalls during etching.
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81.65.Cf Surface cleaning, etching, patterning
81.65.Rv Passivation
68.43.Mn Adsorption kinetics
61.66.Bi Elemental solids
61.66.Dk Alloys
52.77.Bn Etching and cleaning

Specific mechanism for strain relaxation dependent on crystallization route of LiNbO3 films on Al2O3(0001)

Housei Akazawa and Masaru Shimada

J. Vac. Sci. Technol. A 26, 281 (2008); http://dx.doi.org/10.1116/1.2841486 (7 pages) | Cited 2 times

Online Publication Date: 19 February 2008

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Distinct channels for relaxing strain were identified in epitaxial LiNbO3 thin films depending on whether the film was crystallized during or after sputter-deposition on an Al2O3(0001) substrate. When LiNbO3 continuously crystallizes during deposition, pseudomorphic growth continues with a build up of strain as the thickness increases. The primary process for relieving strain is achieved by dividing the crystal into small mosaic grains. Crystallization by postannealing amorphous films, in contrast, produces nearly dislocation-free, relaxed crystals with a wider domain of 100–200 nm. Introducing lattice disorder at antiphase positions that correspond to matching between 12 lattice units of LiNbO3 and 13 lattice units of Al2O3 in the a-direction limits the chemical interaction with the Al2O3 lattice within a short range and efficiently accommodates misfit strain. This results in atomic-scale grapho-epitaxy sustaining disordered lattice regions at the interface.
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68.55.A- Nucleation and growth
64.70.K- Solid-solid transitions
81.15.Cd Deposition by sputtering
81.40.Gh Other heat and thermomechanical treatments

Deposition of nanoscale multilayer CrN/NbN physical vapor deposition coatings by high power impulse magnetron sputtering

Y. P. Purandare, A. P. Ehiasarian, and P. Eh. Hovsepian

J. Vac. Sci. Technol. A 26, 288 (2008); http://dx.doi.org/10.1116/1.2839855 (9 pages) | Cited 3 times

Online Publication Date: 20 February 2008

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Nanoscale multilayer CrN/NbN physical vapor deposition (PVD) coatings are gaining reputation for their high corrosion and wear resistance. However, the CrN/NbN films deposited by ABS™ (arc bond sputtering) technology have some limitations such as macrodroplets, porosity, and less dense structures. The novel HIPIMS (high power impulse magnetron sputtering) technique produces macroparticle-free, highly ionized metal plasma, which brings advantages in both surface pretreatment and coating deposition stages of the PVD process. In this study, nanoscale multilayer CrN/NbN PVD coatings were pretreated and deposited with HIPIMS technology and compared with those deposited by HIPIMS-UBM (unbalanced magnetron) and by the ABS™ technique. In all cases Cr+ etching was utilized to enhance adhesion by low energy ion implantation. The coatings were deposited at 400 °C with substrate biased (Ub) at −75 V. During coating deposition, HIPIMS produced significantly high activation of nitrogen compared to the UBM as observed with mass spectroscopy. HIPIMS-deposited coatings revealed a bilayer period of 4.1 nm (total thickness: 2.9 μm) and hardness of 3025 HK0.025. TEM results revealed droplet free, denser microstructure with (200) preferred orientation for the HIPIMS coating owing to the increased ionization as compared to the more porous structure with random orientation observed in UBM coating. The dry sliding wear coefficient (Kc) of the coating was 1.8×10−15 m3 N−1 m−1, whereas the steady state coefficient of friction was 0.32. Potentiodynamic polarization tests revealed higher Ecorr values, higher pitting resistance (around potentials +400 to +600 mV), and lower corrosion current densities for HIPIMS deposited coatings as compared to the coatings deposited by ABS or HIPIMS-UBM. The corrosion behavior of the coatings qualitatively improved with the progressive use of HIPIMS from pretreatment stage to the coating deposition step.
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81.07.Bc Nanocrystalline materials
81.16.-c Methods of micro- and nanofabrication and processing
81.15.Cd Deposition by sputtering
81.05.Rm Porous materials; granular materials
68.65.Ac Multilayers
68.60.Bs Mechanical and acoustical properties

Characterization of zirconium nitride films sputter deposited with an extensive range of nitrogen flow rates

N. Farkas, G. Zhang, R. D. Ramsier, E. A. Evans, and J. A. Dagata

J. Vac. Sci. Technol. A 26, 297 (2008); http://dx.doi.org/10.1116/1.2839856 (5 pages) | Cited 2 times

Online Publication Date: 20 February 2008

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ZrNx films are deposited by rf magnetron sputtering using a wide range of nitrogen flow rates to control film properties. Scanned probe microscope (SPM) oxidation is presented as a complimentary characterization tool to x-ray diffraction, colorimetric, and four point probe analyses. The SPM oxidation behavior of the ZrNx films is related to their structural, optical, and electrical properties. Whereas stoichiometric ZrN films have applications as protective and/or decorative coatings, ZrNx films sputtered with higher nitrogen flow rates have potential applications in devices where arrays of high aspect ratio nanostructures would be useful.
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81.15.Cd Deposition by sputtering
68.55.aj Insulators
68.55.-a Thin film structure and morphology
78.66.Nk Insulators
73.61.Ng Insulators
81.65.Mq Oxidation

Oxidation and diffusion processes during annealing of AlCrVN hard coatings

R. Franz, J. Neidhardt, C. Mitterer, B. Schaffer, H. Hutter, R. Kaindl, B. Sartory, R. Tessadri, M. Lechthaler, and P. Polcik

J. Vac. Sci. Technol. A 26, 302 (2008); http://dx.doi.org/10.1116/1.2841508 (7 pages)

Online Publication Date: 26 February 2008

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V-alloyed AlCrN hard coatings were deposited by reactive arc evaporation in an industrial-sized deposition system and subsequently annealed in ambient air at temperatures ranging from 550 to 700 °C in order to study the formation mechanisms of the desired lubricious oxides. The oxidized samples were investigated by means of secondary ion mass spectrometry depth profiling, x-ray diffraction, Raman spectroscopy, and analytical transmission electron microscopy. Vanadium diffusion in the oxidized part of the coating leads to the formation of a V-rich top layer containing AlVO4 and the desired lubricious oxide V2O5 followed by a V-depleted inner oxide layer consisting of a mixed or nanocrystalline (Al,Cr,V)2O3 on top of the intact AlCrVN coating.
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81.65.Mq Oxidation
66.30.Fq Self-diffusion in metals, semimetals, and alloys
68.60.Bs Mechanical and acoustical properties
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
78.30.Er Solid metals and alloys
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)

Coating techniques of metal chambers for remote catalytic chemical vapor deposition applications

Hironobu Umemoto, Shota Setoguchi, Hitoshi Uemura, and Hideki Matsumura

J. Vac. Sci. Technol. A 26, 309 (2008); http://dx.doi.org/10.1116/1.2844313 (3 pages)

Online Publication Date: 26 February 2008

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To obtain information for remote catalytic chemical vapor deposition, the authors constructed a two-chamber system in which the decomposition and deposition areas were separated. H2 molecules were decomposed on a heated tungsten filament in the first area and the H atoms produced were carried to the second area, where the absolute H-atom densities were measured by a vacuum-ultraviolet laser absorption technique. The gas pressure in the decomposition area was maintained ten times higher than that in the deposition area by mounting a diffusion barrier to prevent the possible back-diffusion of the material gases. The inner walls of the decomposition area as well as the diffusion barrier were coated with SiO2 or polytetrafluoroethene to minimize the recombination of H atoms. The H-atom density could be increased by one order of magnitude by such coatings, and it is shown that H-atom densities in the order of 1012 cm−3 can be achieved in the deposition area in the present system.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.65.-b Surface treatments
81.30.-t Phase diagrams and microstructures developed by solidification and solid-solid phase transformations
66.30.Ny Chemical interdiffusion; diffusion barriers
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