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Jan 2004

Volume 22, Issue 1, pp. 1-224

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Poly (ethylene terephthalate) decomposition process in oxygen plasma; emission spectroscopic and surface analysis for oxygen–plasma reaction

Hidetoshi Kumagai, Denbo Hiroki, Nobuyuki Fujii, and Takaomi Kobayashi

J. Vac. Sci. Technol. A 22, 1 (2004); http://dx.doi.org/10.1116/1.1624286 (7 pages) | Cited 11 times

Online Publication Date: 13 November 2003

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Emission spectroscopy was applied to observe the reaction process of poly (ethylene terephthalate) (PET) in an oxygen (O2) plasma generated by a microwave discharge. As the PET was exposed in the O2 plasma flow, light emitted from the PET surface was monitored. In the diagnosis measurement, several emission peaks assigned to the Hα atomic line at 652 nm, Hβ at 486 nm, OH (2Σ→2Π) transition near 244–343 nm and CO (b3 Σ→a3 Σ) near 283–370 nm were observed and measured at various discharge times. These results indicated that after the plasma etching, the PET sample was decomposed by the oxygen plasma reaction, and then, hydrogen abstraction and carbon oxidation processes. We also observed the time profile of oxygen atom, as the atom-emission intensity at 777 nm was monitored. As Hβ atomic and OH molecule lines appeared in the presence of PET, the O atom intensity was significantly reduced. In the surface analysis on Fourier transform infrared and x-ray photoelectron spectroscopy measurements, it was found that for the PET surface treated by O2 plasma containing excited atomic oxygen species, ester bands were broken and carbonization formed on the PET surface. © 2004 American Vacuum Society.
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81.65.Cf Surface cleaning, etching, patterning
52.77.Bn Etching and cleaning
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials

Remote plasma enhanced atomic layer deposition of TiN thin films using metalorganic precursor

Ju Youn Kim, Sangwon Seo, Do Youl Kim, Hyeongtag Jeon, and Yangdo Kim

J. Vac. Sci. Technol. A 22, 8 (2004); http://dx.doi.org/10.1116/1.1624285 (5 pages) | Cited 18 times

Online Publication Date: 13 November 2003

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TiN films were deposited by remote plasma enhanced atomic layer deposition (PEALD) method using tetrakis-dimethyl-amino-titanium precursor and hydrogen, hydrogen/nitrogen mixture, and nitrogen plasmas. Remote PEALD method showed a relatively wide temperature window compared to that of conventional ALD process due to the increased reactivity of reactant gas. TiN films showed significantly lower impurity contents than those of the films deposited by other methods such as plasma enhanced chemical vapor deposition, metalorganic chemical vapor deposition, and conventional ALD using the same precursor. TiN films deposited using N2 plasma showed better characteristics than the films deposited using H2 and H2/N2 mixture plasmas. TiN films deposited by remote PEALD at 250 °C showed the resistivity value as low as about 300 μΩ cm and exhibited excellent conformal step coverage on 0.25-μm-wide and 2.5-μm-deep contact hole structure. © 2004 American Vacuum Society.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
52.77.Dq Plasma-based ion implantation and deposition
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
85.40.Ls Metallization, contacts, interconnects; device isolation
68.55.-a Thin film structure and morphology
85.40.Sz Deposition technology
68.35.Fx Diffusion; interface formation
73.61.At Metal and metallic alloys

Amorphous fluorocarbon polymer (a-C:F) films obtained by plasma enhanced chemical vapor deposition from perfluoro-octane (C8F18) vapor I: Deposition, morphology, structural and chemical properties

Costel Biloiu, Ioana Arabela Biloiu, Yosuke Sakai, Yoshiyuki Suda, and Akitsugu Ohta

J. Vac. Sci. Technol. A 22, 13 (2004); http://dx.doi.org/10.1116/1.1624284 (7 pages) | Cited 17 times

Online Publication Date: 13 November 2003

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The method of obtaining amorphous fluorocarbon polymer (a-C:F) films by plasma enhanced chemical vapor deposition in a capacitively coupled, 13.56 MHz reactor, from a new monomer, namely perfluoro-octane (C8F18) vapor, is presented. For monomer pressure ranging from 0.2 to 1 Torr and input power density from 0.15 to 0.85 W/cm3, the maximum deposition rate reached 300 nm/min, while 10% monomer dilution with argon led to a deposition rate of 200 nm/min. The film surface and bulk morphologies, chemical and structural compositions were investigated using scanning electron microscopy, x-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. It was revealed that the films have a dense and compact structure. The fluorine to carbon ratio (F/C) of the films was between 1.57 and 1.75, and the degree of cross-linking was between 55% and 58%. The relative amount of perfluoroalkyl (CF2) groups in the films was 29%. The FTIR spectra showed absorption bands corresponding to the different vibrational modes of CF, CF2, and CF3 moieties. © 2004 American Vacuum Society.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
52.77.Dq Plasma-based ion implantation and deposition
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
68.55.-a Thin film structure and morphology

Influence of negative ion resputtering on ZnO:Al thin films

Loren W. Rieth and Paul H. Holloway

J. Vac. Sci. Technol. A 22, 20 (2004); http://dx.doi.org/10.1116/1.1626641 (10 pages) | Cited 11 times

Online Publication Date: 13 November 2003

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The influence of negative ion resputtering (NIR) by oxygen ions during sputter deposition of aluminum doped zinc oxide (ZnO:Al) thin films is investigated. A planar rf diode sputter deposition source with a ceramic ZnO:Al2O3 (98 wt %:2 wt %) target is used for deposition at 250, 500 and 1000 W. The resulting thin films are characterized by four point probe, Hall measurements, secondary ion mass spectrometry (SIMS), x-ray diffraction (XRD), and atomic force microscopy (AFM). The resistivity and carrier concentration show an order of magnitude variation between 2×10−2 and 1.5×10−3 Ω cm and 7.2×1019 and 5.4×1020 cm−3, respectively, with the position on the substrate and deposition power. The Hall mobility changes are small, from 4.7 to 11.5 cm2/V s. Data from SIMS show that the variations in electrical properties do not result from contamination by alkali metals or changes in the Al dopant concentration. Spectra from XRD have one predominant peak near 34.4° indicating that the film is wurtzite and strongly textured in the (002) basal direction. All peaks are lower in 2θ than literature values, which indicates an expanded lattice in the c direction. Grain size estimates based on AFM data suggest that changes in grain size are not large enough to cause the changes in electrical properties. Compensation of free carriers by interstitial oxygen ions due to implantation and Frenkel pair generation resulting from an energetic oxygen ion flux are consistent with the data, and are postulated to be the mechanisms by which NIR influences the electrical properties of ZnO. The flux of negative ions is estimated to be 1% of the total ion flux. The correlation between NIR and the influence of deposition parameters is discussed. © 2004 American Vacuum Society.
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68.55.-a Thin film structure and morphology
73.61.Ga II-VI semiconductors
81.15.Cd Deposition by sputtering

Effect of the substrate bias voltage on the physical characteristics of copper films deposited by microwave plasma-assisted sputtering technique

F. Thièry, Y. Pauleau, and L. Ortega

J. Vac. Sci. Technol. A 22, 30 (2004); http://dx.doi.org/10.1116/1.1626643 (6 pages) | Cited 7 times

Online Publication Date: 13 November 2003

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Pure copper films have been deposited by microwave plasma-assisted sputtering on (100)-oriented single crystal silicon substrates mounted on a water-cooled substrate holder either maintained at the floating potential or biased to various dc voltages ranging from 0 to −125 V. The argon pressure was fixed at 0.13 Pa and argon ions from the discharge produced in a distributed electron cyclotron resonance microwave plasma chamber were used for sputtering of a copper target biased to −600 V. The crystallographic structure and surface morphology of copper films were determined by x-ray diffraction techniques and atomic force microscopy, respectively. The magnitude of residual stresses developed in these films was calculated from the radius of curvature of Si substrates. The electrical resistivity of films was deduced from the thickness and sheet resistance of films determined by profilometry and four point probe measurements. The evolution of the deposition rate, surface roughness, microstructure, magnitude of residual stresses, and electrical resistivity of films was investigated as a function of the substrate bias voltage. The major characteristics of copper films were found to vary significantly as the negative substrate bias voltage increased from −40 to −125 V or with increasing argon ion energy. The resputtering process of a fraction of copper atoms by energetic incident argon ions was responsible for the modification of characteristics of films deposited on biased substrates. The quality of copper films in terms of surface morphology and electrical resistivity in particular was found to be excellent for incident argon ion energy values lower than 70 eV. © 2004 American Vacuum Society.
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81.15.Cd Deposition by sputtering
73.61.At Metal and metallic alloys
68.37.Ps Atomic force microscopy (AFM)

Simple method of gas flow ratio optimization in high rate deposition of SiO2 by electron cyclotron resonance plasma enhanced chemical vapor deposition

D. Daineka, P. Bulkin, G. Girard, and B. Drévillon

J. Vac. Sci. Technol. A 22, 36 (2004); http://dx.doi.org/10.1116/1.1626645 (3 pages) | Cited 2 times

Online Publication Date: 13 November 2003

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We propose a simple method to optimize silane-to-oxygen flow ratio in low pressure, high-density plasma enhanced chemical vapor deposition of SiO2 from silane/oxygen mixtures. It is well known that the increase of SiH4/O2 flow ratio R results in degradation of oxide quality. We have found that the critical flow ratio can be estimated from the analysis of the difference between gas pressures with and without plasma. The evolution of optical properties of the films shows that the critical value obtained from pressure measurements gives a good indication of the limits for the deposition of optical quality SiO2. © 2004 American Vacuum Society.
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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.)
52.77.Dq Plasma-based ion implantation and deposition

Performance of inductively coupled plasma assisted sputtering with internal coil for ferromagnetic CoCrTa film deposition

Kunio Okimura and Junya Oyanagi

J. Vac. Sci. Technol. A 22, 39 (2004); http://dx.doi.org/10.1116/1.1627770 (7 pages) | Cited 8 times

Online Publication Date: 13 November 2003

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The performance of inductively coupled plasma (ICP)-assisted sputtering with an internal coil was revealed for deposition of ferromagnetic Co-based alloy films. Three types of internal coil, a directly grounded bare coil, a capacitively coupled bare coil and an insulated coil, were investigated with regard to the crystalline structure of films and plasma characteristics. Highly c-axis textured hexagonal-close-packed (hcp) film growth was achieved in the bare coil system at a medium operating Ar pressure of 1.3 Pa. Pole figure measurements showed that the film grown on a low-temperature Si substrate contained small face-centered-cubic phase in the c-axis textured hcp crystal. Plasma diagnostics suggested that high plasma space potential beyond 80 V caused highly textured growth through the effect of ion bombardment with proper energies for crystallization. The superior capability of ICP-assisted sputtering with a capacitively coupled bare coil was revealed for textured growth in the thin layer on a substrate surface. A high deposition rate was achieved as a result of high electron density of the order of 1011 cm−3 in ICP-assisted sputtering with an insulated coil. However, the insulated coil system could not achieve textured growth. © 2004 American Vacuum Society.
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68.55.-a Thin film structure and morphology
75.50.Cc Other ferromagnetic metals and alloys
75.70.Ak Magnetic properties of monolayers and thin films
81.15.Cd Deposition by sputtering
52.77.Dq Plasma-based ion implantation and deposition

Orientation selective epitaxial growth of CeO2(100) and CeO2(110) layers on Si(100) substrates

Tomoyasu Inoue, Naomichi Sakamoto, Masayuki Ohashi, Shigenari Shida, Akihiro Horikawa, and Yoshiyuki Sampei

J. Vac. Sci. Technol. A 22, 46 (2004); http://dx.doi.org/10.1116/1.1626644 (3 pages) | Cited 4 times

Online Publication Date: 18 November 2003

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It is found that epitaxial CeO2 layers with (100) or (110) orientation can be selectively grown on Si(100) substrates by controlling substrate bias in reactive dc magnetron sputtering. Adopting a two step growth method; ultrathin metallic Ce layer deposition at room temperature followed by a silicidation process at 800 °C, and subsequent reactive sputtering in an Ar/O2 mixture environment, the CeO2(100) layer is grown on practical Si(100) surfaces prepared by the usual wet cleaning method. © 2004 American Vacuum Society.
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68.55.-a Thin film structure and morphology
81.15.Cd Deposition by sputtering
68.47.Gh Oxide surfaces
68.55.A- Nucleation and growth

Contrast differences between scanning ion and scanning electron microscope images

T. Suzuki, N. Endo, M. Shibata, S. Kamasaki, and T. Ichinokawa

J. Vac. Sci. Technol. A 22, 49 (2004); http://dx.doi.org/10.1116/1.1626646 (4 pages) | Cited 9 times

Online Publication Date: 18 November 2003

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The contrasts of scanning ion microscope images (Ga+ ion) at 30 keV are compared to those of scanning electron microscope images at 30 keV. Remarkable differences are observed in the surface sensitivity, crystal orientation, and atomic number effects of target material. The examples are shown by the secondary electron images and the origins of those differences are discussed on the basis of the different interactions of those particles with solid. © 2004 American Vacuum Society.
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68.37.-d Microscopy of surfaces, interfaces, and thin films
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Role of fluorocarbon film formation in the etching of silicon, silicon dioxide, silicon nitride, and amorphous hydrogenated silicon carbide

T. E. F. M. Standaert, C. Hedlund, E. A. Joseph, G. S. Oehrlein, and T. J. Dalton

J. Vac. Sci. Technol. A 22, 53 (2004); http://dx.doi.org/10.1116/1.1626642 (8 pages) | Cited 79 times

Online Publication Date: 25 November 2003

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The etching of Si, SiO2, Si3N4, and SiCH in fluorocarbon plasmas is accompanied by the formation of a thin steady-state fluorocarbon film at the substrate surface. The thickness of this film and the substrate etch rate have often been related. In the present work, this film has been characterized for a wide range of processing conditions in a high-density plasma reactor. It was found that the thickness of this fluorocarbon film is not necessarily the main parameter controlling the substrate etch rate. When varying the self-bias voltage, for example, we found a weak correlation between the etch rate of the substrate and the fluorocarbon film thickness. Instead, for a wide range of processing conditions, it was found that ion-induced defluorination of the fluorocarbon film plays a major role in the etching process. We therefore suggest that the fluorocarbon film can be an important source of fluorine and is not necessarily an etch-inhibiting film. © 2004 American Vacuum Society.
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52.77.Bn Etching and cleaning
81.65.Cf Surface cleaning, etching, patterning

Temperature-resolved Fourier transform infrared study of condensation reactions and porogen decomposition in hybrid organosilicon-porogen films

Daniel D. Burkey and Karen K. Gleason

J. Vac. Sci. Technol. A 22, 61 (2004); http://dx.doi.org/10.1116/1.1627766 (10 pages) | Cited 16 times

Online Publication Date: 25 November 2003

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Composite organosilicon/porogen thin films were deposited via pulsed-plasma chemical vapor deposition. The organosilicon monomer was polymerized using water as the oxidant, allowing incorporation of silanol (Si–OH) moieties for subsequent condensation reactions and crosslinking for enhanced mechanical properties. The porogen monomer [methylmethacrylate (MMA)] was codeposited in the same step, and the degree of MMA incorporation was shown to scale with both the peak plasma power and porogen flow rate. Fourier transform infrared (FTIR) spectroscopy spectra of the composite material show features from both the organosilicon precursor and the porogen species, indicating that both materials are successfully incorporated into the thin film. The kinetics of both the condensation reaction and porogen removal were determined by a temperature/time-resolved FTIR method. The condensation reaction and crosslinking events occur between 100 and 425 °C. Porogen decomposition occurs simultaneously between approximately 325 and 400 °C, which is consistent with the decomposition of poly(methylmethacrylate). Using these data, the activation energy for the primary decomposition mode was found to be approximately 53.6 kJ/mol (12.8 kcal/mol). Both the index of refraction and the dielectric constant scale with the degree of porogen removal, suggesting the formation of free volume in the films. The lowest index of refraction and dielectric constant obtained was 1.404 and 2.3, respectively, for a 1 h anneal at 425 °C. Worst-case thickness loss for the films was approximately 36% of the as-deposit thickness. © 2004 American Vacuum Society.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
78.66.Qn Polymers; organic compounds
78.30.Jw Organic compounds, polymers
52.77.Dq Plasma-based ion implantation and deposition
81.07.Pr Organic-inorganic hybrid nanostructures
68.55.-a Thin film structure and morphology
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
77.22.Ch Permittivity (dielectric function)

Measurement of absolute radical densities in a plasma using modulated-beam line-of-sight threshold ionization mass spectrometry

Sumit Agarwal, Guido W. W. Quax, M. C. M. van de Sanden, Dimitrios Maroudas, and Eray S. Aydil

J. Vac. Sci. Technol. A 22, 71 (2004); http://dx.doi.org/10.1116/1.1627767 (11 pages) | Cited 30 times

Online Publication Date: 25 November 2003

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Using modulated beam line-of-sight threshold ionization mass spectrometry (LOS-TIMS) we measured absolute O, O2, and Ar densities, and the average neutral-gas temperature in an O2/Ar electrical discharge as a function of pressure in the plasma chamber and the mole fraction of Ar in O2; the pressure and mole fraction range was 25–200 mTorr and 0–0.90, respectively. Although LOS-TIMS is a versatile tool for measuring absolute radical densities, it requires careful vacuum design and calibration to account for various sources of error such as the contribution to the quadrupole mass spectrometer (QMS) ion current from the background gases, the ion mass-to-charge ratio dependent sensitivity of the various QMS components, and space-charge limitations in the QMS ionizer. In addition, collisions within the molecular beam extracted from the discharge must be taken into account particularly for higher plasma chamber pressures (>75 mTorr). In our measurements, these effects are carefully considered and the consequences of ignoring them are discussed. The O atom density increases with pressure and O2 mole fraction in the feed gas and is in the range of 2.1×1018–2.6×1019 m−3. At low pressures, our measurements show that the O2 translational temperature is higher than that for Ar. © 2004 American Vacuum Society.
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52.70.Nc Particle measurements
52.25.-b Plasma properties

Correlation between density and oxidation temperature for pyrolytic-gas passivated ultrathin silicon oxide films

Hiroshi Yamada

J. Vac. Sci. Technol. A 22, 82 (2004); http://dx.doi.org/10.1116/1.1627768 (6 pages) | Cited 9 times

Online Publication Date: 25 November 2003

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Pyrolytic-gas passivation (PGP) with a small amount nitrogen gas enhances the breakdown reliability of silicon oxide gate films. To clarify the reliability retention of the PGP-grown films oxidized at low temperature, densities (ρox’s) of the 3.5–6.5-nm-thick PGP-grown films on Si(100) oxidized at 700–900 °C were investigated. Since ρox’s correlate well with the reliability and are useful as an index of the intrinsic structural characteristics of the films. Moreover, changes in ρox and nitrogen content corresponding to oxidation temperature are similar to those in breakdown reliability and interface state density (Dit), respectively. In addition, ρox’s of the 700 °C-grown PGP films do not deteriorate as much when compared with those of the films grown by normal ultradry oxidation at 800 °C and their Dit’s are less than about 6×1010/eV cm2. This suggests that PGP probably improves the reliability by generating the higher-ρox microscopic structure with few Si dangling bonds and effective passivation. © 2004 American Vacuum Society.
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81.65.Mq Oxidation
81.65.Rv Passivation
77.55.-g Dielectric thin films
68.55.-a Thin film structure and morphology
77.22.Jp Dielectric breakdown and space-charge effects
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.

Plasma etching of high dielectric constant materials on silicon in halogen chemistries

Lin Sha and Jane P. Chang

J. Vac. Sci. Technol. A 22, 88 (2004); http://dx.doi.org/10.1116/1.1627771 (8 pages) | Cited 44 times

Online Publication Date: 25 November 2003

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Plasma etching of ZrO2 and HfO2 was studied in BCl3/Cl2 plasmas, as functions of the ion energy, chamber pressure, microwave power, and gas compositions. MClx is found to be the major etching product in Cl2 plasmas while MBxCly is the major etching product in BCl3 plasmas. The etching selectivity to Si is increased at lower ion energies and higher electron temperatures. Increasing microwave powers and reducing chamber pressures in BCl3/Cl2 plasmas increased the Cl and BCl2+ densities in the gas phase and consequently increased the metal oxide etch rate. A phenomenological model that takes into account the Cl density, BCl2+ density, and metal oxygen bond strength is proposed to describe the etch rate of ZrO2 and HfO2 in pure BCl3 plasmas as functions of the ion energy, microwave power, and chamber pressure. More accurate Cl flux measurement is needed to improve the model predictions. © 2004 American Vacuum Society.
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81.65.Cf Surface cleaning, etching, patterning
52.77.Bn Etching and cleaning
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.22.Ch Permittivity (dielectric function)
77.55.-g Dielectric thin films

Plasma diagnostic study of silicon nitride film growth in a remote Ar–H2–N2–SiH4 plasma: Role of N and SiHn radicals

W. M. M. Kessels, F. J. H. van Assche, J. Hong, D. C. Schram, and M. C. M. van de Sanden

J. Vac. Sci. Technol. A 22, 96 (2004); http://dx.doi.org/10.1116/1.1631294 (11 pages) | Cited 11 times

Online Publication Date: 25 November 2003

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A remote expanding thermal plasma operated on an Ar–H2–N2–SiH4 mixture has been studied by several plasma diagnostics to obtain insight into the plasma processes and the hydrogenated amorphous silicon nitride (a-SiNx:H) growth mechanism from the N2–SiH4 reactant mixture. From Langmuir probe measurements, ion mass spectrometry, and threshold ionization mass spectrometry, it is revealed that the Ar–H2–N2 operated plasma source leads mainly to N and H radicals in the downstream region. The H radicals react with the SiH4 admixed downstream creating a high SiH3 density as revealed by cavity ringdown spectroscopy. By cavity ringdown measurements, it is also shown that Si and SiH have a much lower density in the downstream plasma and that these radicals are of minor importance for the a-SiNx:H growth process. The ground-state N radicals from the plasma source do not react with the SiH4 injected downstream leading to a high N density under the a-SiNx:H deposition conditions as revealed by threshold ionization mass spectrometry. From these results, it is concluded that N and SiH3 radicals dominate the a-SiNx:H growth process and the earlier proposed growth mechanism of a-SiNx:H from the N2–SiH4 mixture [D. L. Smith et al., J. Vac. Sci. Technol. B 8, 551 (1990)] can be refined: During deposition, an a-Si:H-like surface layer is created by the SiH3 radicals and at the same time this a-Si:H-like surface layer is nitridated by the N radicals leading to a-SiNx:H formation. This growth mechanism is further supported by the correlation between the SiH3 and N plasma density and the incorporation flux of Si and N atoms into the a-SiNx:H films as deposited under various conditions. © 2004 American Vacuum Society.
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52.77.Dq Plasma-based ion implantation and deposition
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.A- Nucleation and growth
52.70.Nc Particle measurements

Effect of temperature on the growth of ultrathin films of p-sexiphenyl on KCl(001)

E. J. Kintzel, D.-M. Smilgies, J. G. Skofronick, S. A. Safron, and D. H. Van Winkle

J. Vac. Sci. Technol. A 22, 107 (2004); http://dx.doi.org/10.1116/1.1631471 (4 pages) | Cited 10 times

Online Publication Date: 3 December 2003

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Ultrathin films of p-sexiphenyl, formed by vapor-deposition onto KCl(001) substrates, have been investigated by x-ray diffraction (XRD) and atomic force microscopy (AFM). Analysis of the XRD data shows that the temperature of the alkali halide substrate during deposition affects the orientations of the molecules within the adsorbed films. AFM images contribute independent evidence consistent with the XRD results. The results are reproducible and suggest that ultrathin films of p-6P molecules can be grown with desired molecular orientations by carefully selecting the appropriate substrate temperature during deposition. © 2004 American Vacuum Society.
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68.55.-a Thin film structure and morphology
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.05.Hd Other semiconductors
68.37.Ps Atomic force microscopy (AFM)

Influence of substrate misorientation on vibrational properties of In1−x−yGaxAlyAs grown on InP

S. Tripathy, Thwin-Htoo, and S. J. Chua

J. Vac. Sci. Technol. A 22, 111 (2004); http://dx.doi.org/10.1116/1.1633567 (6 pages) | Cited 2 times

Online Publication Date: 24 December 2003

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Using micro-Raman scattering, we have investigated the vibrational properties of nominal In1−x−yGaxAlyAs (x=0.13, y=0.34) layers that were grown lattice matched to InP (100) substrates by molecular-beam epitaxy. In order to control and optimize crystalline quality of these layers, the quaternary alloy films were also grown on (100) substrates oriented 1°, 2°, 3°, and 5° toward the [math10] direction. Atomic force microscopy has been employed to investigate the surface topography. The micro-Raman technique has been applied to evaluate the quality of these epitaxial films. Optical phonons show three-mode behavior in these quaternary alloys and the dominant bands observed in the spectra are of three binaries, namely, the GaAs-, InAs-, and AlAs-like optical phonons. The narrowest Raman linewidth and much weaker forbidden modes observed in the layer grown on InP(100) oriented 2° toward the [math10] direction, suggest the best crystalline quality among the quaternary alloys grown on misoriented substrates. © 2004 American Vacuum Society.
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63.20.D- Phonon states and bands, normal modes, and phonon dispersion
68.60.-p Physical properties of thin films, nonelectronic
68.47.Fg Semiconductor surfaces
78.30.Fs III-V and II-VI semiconductors
78.66.Fd III-V semiconductors
81.05.Ea III-V semiconductors
68.55.-a Thin film structure and morphology
68.37.Ps Atomic force microscopy (AFM)
68.35.B- Structure of clean surfaces (and surface reconstruction)

Microstructure of α-alumina thin films deposited at low temperatures on chromia template layers

Jon M. Andersson, Zs. Czigány, P. Jin, and U. Helmersson

J. Vac. Sci. Technol. A 22, 117 (2004); http://dx.doi.org/10.1116/1.1636157 (5 pages) | Cited 27 times

Online Publication Date: 24 December 2003

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Radio frequency sputtering has been used to deposit α-alumina (α-Al2O3) thin films at substrate temperatures of 280–560 °C. The films are shown to be single phased and hard. Nanoindentation gives values of 306±31 and 27±3 GPa for elastic modulus and hardness, respectively, for a substrate temperature of 280 °C. Growth of the α phase was achieved by in situ predeposition of a chromia template layer. Chromia crystallizes in the same hexagonal structure as α-alumina, with a lattice mismatch of 4.1% in the a- and 4.6% in the c-parameter, and is shown to nucleate readily on the amorphous substrates (silicon with a natural oxide layer). This results in local epitaxy of α-alumina on the chromia layer, as is shown by transmission electron microscopy. The alumina grains are columnar with grain widths increasing from 22±7 to 41±9 nm, as the temperature increases from 280 to 560 °C. This is consistent with a surface diffusion dominated growth mode and suggests that α-alumina deposition at low temperatures is possible once initial grain nucleation has occurred. Results are also presented demonstrating chromia/α-alumina growth on a technological substrate (Haynes230 Ni-based super alloy, Haynes International, Inc.). © 2004 American Vacuum Society.
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68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains
81.65.-b Surface treatments
81.15.Cd Deposition by sputtering
68.35.Fx Diffusion; interface formation
81.40.Pq Friction, lubrication, and wear
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.20.D- Elasticity
62.20.Qp Friction, tribology, and hardness
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure

Evolution of surface roughness during metal silicides phase transformation

C. H. Pang, P. Hing, F. F. Zhao, A. See, Y. F. Chong, and P. S. Lee

J. Vac. Sci. Technol. A 22, 122 (2004); http://dx.doi.org/10.1116/1.1636158 (7 pages) | Cited 1 time

Online Publication Date: 24 December 2003

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This study monitors systematically the evolution of surface roughness during metal (Ti, Co, and Ni) silicides phase transformation and coupling to other physical parameters. During metal/silicon reaction film surface roughness evolves due to the effect of nucleation and growth of metal silicides and is sensitive to different processing conditions. In general, surface roughness increases as new phases are formed and decreases during grain growth. The difference in roughness between processes indicates whether a process is more inferior for new phase formation. The correlation of surface roughness towards sheet resistance, film thickness, and phase transformation are found to be independent of film thickness in C49-to-C54 TiSi2 polymorphic transformation but not for Co and Ni silicides. Any abnormalities from the trend indicate that the film is experiencing a physical degradation. © 2004 American Vacuum Society.
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68.35.Rh Phase transitions and critical phenomena
68.35.Ct Interface structure and roughness
68.55.A- Nucleation and growth
64.70.K- Solid-solid transitions
81.30.Hd Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder

ZnO film deposition on Al film and effects of deposition temperature on ZnO film growth characteristics

Giwan Yoon, Munhyuk Yim, Donghyun Kim, Mai Linh, and Dongkyu Chai

J. Vac. Sci. Technol. A 22, 129 (2004); http://dx.doi.org/10.1116/1.1627769 (6 pages) | Cited 4 times

Online Publication Date: 8 January 2004

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The effects of the deposition temperature on the growth characteristics of the ZnO films were studied for film bulk acoustic wave resonator (FBAR) device applications. All films were deposited using a radio frequency magnetron sputtering technique. It was found that the growth characteristics of ZnO films have a strong dependence on the deposition temperature from 25 to 350 °C. ZnO films deposited below 200 °C exhibited reasonably good columnar grain structures with highly preferred c-axis orientation while those above 200 °C showed very poor columnar grain structures with mixed-axis orientation. This study seems very useful for future FBAR device applications. © 2004 American Vacuum Society.
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81.15.Cd Deposition by sputtering
68.55.-a Thin film structure and morphology
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
43.58.Kr Spectrum and frequency analyzers and filters; acoustical and electrical oscillographs; photoacoustic spectrometers; acoustical delay lines and resonators

Magnetic domain structures in ultrathin FexNi(1−x) films on Cu(111): Dependence on film thickness and stoichiometry

Y. Sato, T. F. Johnson, S. Chiang, J. A. Giacomo, X. D. Zhu, D. P. Land, F. Nolting, and A. Scholl

J. Vac. Sci. Technol. A 22, 135 (2004); http://dx.doi.org/10.1116/1.1631295 (5 pages) | Cited 3 times

Online Publication Date: 8 January 2004

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The magnetic domain structures in thin FexNi(1−x) alloy films grown on Cu(111) have been investigated by the photoemission electron microscope (PEEM). By tuning the photon energy to respective x-ray absorption edges, element-specific information can be obtained with PEEM. We have observed clear ferromagnetic domains on samples with an iron concentration of x⩽0.6 and x=1.0. The PEEM images indicate that Fe and Ni form a good alloy on Cu(111), with the same domain structures and the magnetization in each domain aligned for both elements. The domain sizes and shapes exhibit dependence on thickness, stoichiometry x, and substrate quality. © 2004 American Vacuum Society.
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75.70.Kw Domain structure (including magnetic bubbles and vortices)
75.50.Bb Fe and its alloys
68.55.-a Thin film structure and morphology
68.37.Xy Scanning Auger microscopy, photoelectron microscopy
61.66.Bi Elemental solids
61.66.Dk Alloys
75.60.Ch Domain walls and domain structure
68.55.Nq Composition and phase identification

Effects of substrates and heat treatment on growing behavior and luminescent characteristics of ZnGa2O4:Mn thin film

Sung Mook Chung and Young Jin Kim

J. Vac. Sci. Technol. A 22, 140 (2004); http://dx.doi.org/10.1116/1.1631472 (6 pages) | Cited 2 times

Online Publication Date: 8 January 2004

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ZnGa2O4:Mn phosphor thin films were deposited on ZnO:Ga/glass, ZnO:Al/glass, ZnO/ITO/glass, and ITO/glass by rf magnetron sputtering. Effects of substrates and heat treatment on the structural and luminescent properties were investigated. The surface morphology, growing behavior, and luminescent properties of thin films depend on the crystallinity of the substrates. Thin film phosphors were heat-treated in a N2+vacuum, vacuum (∼10−3 Torr), and air atmosphere, respectively. The annealing conditions did not affect the surface morphology and crystallinity of the films. However, the Ga/Zn atomic ratios and luminescent characteristics were dependent on these conditions. © 2004 American Vacuum Society.
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78.60.Hk Cathodoluminescence, ionoluminescence
78.55.Hx Other solid inorganic materials
61.72.Cc Kinetics of defect formation and annealing
42.79.Kr Display devices, liquid-crystal devices
78.66.Nk Insulators
81.15.Cd Deposition by sputtering
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.55.A- Nucleation and growth

Crystallographic structure and composition of vanadium nitride films deposited by direct sputtering of a compound target

M. Y. Liao, Y. Gotoh, H. Tsuji, and J. Ishikawa

J. Vac. Sci. Technol. A 22, 146 (2004); http://dx.doi.org/10.1116/1.1631473 (5 pages) | Cited 6 times

Online Publication Date: 8 January 2004

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Vanadium nitride thin films (VN) were sputter-deposited on silicon substrates in an argon gas atmosphere with a VN compound target. Nearly stiochiometric cubic VN films with different crystallographic orientations were achieved at ambient substrate temperature. The crystallographic structure of the film could be controlled through adjusting working argon pressure. Films with preferred (100) and (111) orientations were obtained at pressures of 0.5 and 2.0 Pa, respectively, regardless of the sputtering power; while amorphous film may form at a middle pressure of 1.0 Pa. Composition of the resultant films was analyzed by Rutherford backscattering spectroscopy. It was revealed that nitrogen deficiency was responsible for the amorphous state. The electronic states related to nitrogen vacancy were disclosed by valence band spectrum. The film compositional variation was discussed in the text. © 2004 American Vacuum Society.
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68.55.Nq Composition and phase identification
68.55.-a Thin film structure and morphology
81.15.Cd Deposition by sputtering
82.80.Yc Rutherford backscattering (RBS), and other methods of chemical analysis
71.55.Ht Other nonmetals
61.66.Bi Elemental solids
61.66.Dk Alloys
68.49.Sf Ion scattering from surfaces (charge transfer, sputtering, SIMS)
61.43.Er Other amorphous solids

Growth of chemical vapor deposition aluminum titanate films at different CO2/H2 and aluminum butoxide inputs

Dong-Hau Kuo and Cheng-Nan Shueh

J. Vac. Sci. Technol. A 22, 151 (2004); http://dx.doi.org/10.1116/1.1632918 (7 pages) | Cited 2 times

Online Publication Date: 8 January 2004

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Amorphous aluminum titanate films are prepared on silicon substrates by low-pressure chemical vapor deposition (CVD) using a mixture of aluminum tri-sec-butoxide (ATSB), titanium tetrachloride (TiCl4), CO2, and H2 as the reactants (the ATSB/TiCl4/CO2/H2 system). The effects of the CO2/H2 and ATSB inputs and substrate temperature on the growth, microstructure, and composition of the CVD Al2O3–TiO2 films are discussed. The films have an increased growth rate and an increased Ti content at lower temperatures. The adsorption-controlled reaction is identified, which is attributed to the gas/solid reaction to weaken the film/substrate interface. The growth rates are also higher at higher H2 and ATSB flows. The film thickness is 0.47–1.13 μm for the CO2/H2-varying system and of 0.34–1.37 μm for the ATSB-varying system at deposition temperatures of 350–500 °C. The proposed reactions are presented to explain the film growth. The determined adsorption energy can explain the effect of temperature on composition. © 2004 American Vacuum Society.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
68.43.Mn Adsorption kinetics

Surface chemical changes of aluminum during NF3-based plasma processing used for in situ chamber cleaning

Xi Li, Xuefeng Hua, Li Ling, Gottlieb S. Oehrlein, E. Karwacki, and Bing Ji

J. Vac. Sci. Technol. A 22, 158 (2004); http://dx.doi.org/10.1116/1.1633566 (7 pages) | Cited 5 times

Online Publication Date: 8 January 2004

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During plasma-based in situ chamber cleaning of deposited dielectric films using NF3, a transformation of aluminum chamber parts into AlFx can take place. We studied the roles of fluorine atoms and ion bombardment in this process by employing NF3 discharges mixed with He, Ne, or Ar interacting with or without ion bombardment with sputter-deposited Al films on silicon. Aluminum oxide erosion rates and surface chemistry changes, and information on the species that evolve from the surfaces during the process, were obtained by real-time ellipsometry and mass spectrometry, respectively. Characterization of processed Al surfaces was also performed using x-ray photoelectron spectroscopy. We find that Al oxide is rapidly removed/transformed in NF3 discharges and also for C2F6/O2 rf powered discharges. We observe a complex interactive role of fluorine atoms and ion bombardment that leads to the formation of thick fluorinated Al reaction layers during exposure of Al to NF3-containing rf plasmas. For NF3-rich rf discharges, the Al fluoride layer thickness continues to grow as a function of time, without saturation. The Al fluoride layer formation can be prevented if NF3/noble gas mixtures containing a high noble gas proportion are employed instead. An increasingly thicker Al fluoride layer is produced with a greater proportion of NF3 in He/NF3, Ne/NF3, and Ar/NF3. © 2004 American Vacuum Society.
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81.65.Cf Surface cleaning, etching, patterning
52.77.Bn Etching and cleaning
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
52.80.Pi High-frequency and RF discharges
68.47.De Metallic surfaces
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)

Atomic transport and stability during annealing of HfO2 and HfAlO with an ultrathin layer of SiO2 on Si(001)

Hyo Sik Chang, Hyunsang Hwang, Mann-ho Cho, Hyun Kyung Kim, and Dae Won Moon

J. Vac. Sci. Technol. A 22, 165 (2004); http://dx.doi.org/10.1116/1.1633568 (5 pages) | Cited 11 times

Online Publication Date: 8 January 2004

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A medium-energy ion scattering spectroscopy study has been carried out on HfO2/SiO2/Si and HfAlO/SiO2/Si stacks with 5-nm-thick dielectric layers prepared by atomic layer chemical vapor deposition at 300 °C. We observed that there are negligible interface strain and surface silicon for the as-deposited sample. After annealing in nitrogen, the crystallization of HfO2 started to occur between 500 °C and 600 °C. As the annealing temperature increased, a silicate layer is formed at the top of the HfO2 film. However, the HfAlO film with about 25% Al did not exhibit surface silicon and crystallization. Adding Al2O3 to HfO2 can suppress the existence of surface Si but can build up compressive strain at the oxide/Si interface layer. After annealing, excess Si that is prone to move may displace Al in order to relax the interface strain. On the other hand, HfAlO film exhibits much stronger resistance to oxygen diffusion than HfO2 and tends toward densification during N2 annealing. © 2004 American Vacuum Society.
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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.)
68.49.Sf Ion scattering from surfaces (charge transfer, sputtering, SIMS)
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Characteristics and anticoagulation behavior of polyethylene terephthalate modified by C2H2 plasma immersion ion implantation-deposition

J. Wang, C. J. Pan, S. C. H. Kwok, P. Yang, J. Y. Chen, G. J. Wan, N. Huang, and P. K. Chu

J. Vac. Sci. Technol. A 22, 170 (2004); http://dx.doi.org/10.1116/1.1633569 (6 pages) | Cited 4 times

Online Publication Date: 8 January 2004

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Acetylene (C2H2) plasma immersion ion implantation-deposition (PIII-D) is conducted on polyethylene terephthalate (PET) to improve its blood compatibility. The structural and physicochemical properties of the modified surface are characterized by, Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), and static contact angle measurement. Atomic force microscopy discloses that the average roughness (Ra) of film surface decreases from 58.9 nm to 11.4 nm after C2H2 PIII-D treats PET. Attenuated total reflection Fourier transform infrared spectroscopy shows that the specfic adsorption peaks for PET decrease after ion implantation and deposition. Raman spectroscopy indicates that a thin amorphous polymerlike carbon (PLC) film is formed in the PET. The effects of the surface modification on the chemical bonding of C, H, and O are examined by XPS and the results show that the ratio of sp3 C�C to sp2 C�C is 0.25. After C2H2 PIII-D, the polar component γp of surface energy increases from 2.4 mN/m to 12.3 mN/m and γp/γd increases from 0.06 to 0.35. The wettability of the modified surfaces is improved. Scanning electron microscopy and optical microscopy reveal that the amounts of adhered, aggregated and morphologically changed platelets are reduced by the deposition of an amorphous polymer-like carbon film. The thrombin time, prothrombin time, and activated partial thromboplastin time of the modified PET are longer than those of the untreated PET. Our result thus shows that the amorphous PLC film deposited on the PET surface by C2H2 PIII-D improves platelet adhesion and activation. © 2004 American Vacuum Society.
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87.85.J- Biomaterials
52.77.Dq Plasma-based ion implantation and deposition
61.41.+e Polymers, elastomers, and plastics
82.80.Gk Analytical methods involving vibrational spectroscopy
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
68.43.Jk Diffusion of adsorbates, kinetics of coarsening and aggregation
82.35.Gh Polymers on surfaces; adhesion
68.35.Md Surface thermodynamics, surface energies

Chemical states and band offsets of NH3-treated Si oxynitride films studied by high-resolution photoelectron spectroscopy

M. Oshima, S. Toyoda, J. Okabayashi, H. Kumigashira, K. Ono, M. Niwa, K. Usuda, and N. Hirashita

J. Vac. Sci. Technol. A 22, 176 (2004); http://dx.doi.org/10.1116/1.1635389 (5 pages) | Cited 3 times

Online Publication Date: 8 January 2004

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Ultrathin SiON films formed by thermal nitridation of SiO2 films with NH3 gas are analyzed by high-resolution angle-resolved photoelectron spectroscopy to investigate the interfacial chemistry, the chemical state in-depth distribution of nitrogen atoms, and the band offsets. Although nitrogen atoms are mostly homogeneously distributed in the NH3-treated SiON films, the [Si–Si3−xOx]3N or [Si–N3−xOx]3N component exists closer to the surface than the [Si–Si3−xNx]3N or Si3N4 component. The valence-band offsets of HN3-treated SiON films are determined by a substrate subtraction method to be 4.4 eV. This is the same as for SiO2 film. Valence-band offsets for NO-treated SiON film are measured to be 4.4 eV for SiO2/Si and 3.3 eV for SiON/Si. Furthermore, O 1s loss spectra reveal that SiON films consist mainly of a SiO2 region with a band gap of 8.9 eV, and a smaller region of probably Si3N4 with a band gap of about 5.3 eV. © 2004 American Vacuum Society.
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79.60.Jv Interfaces; heterostructures; nanostructures
79.60.Dp Adsorbed layers and thin films
73.20.At Surface states, band structure, electron density of states

Extremely low-outgassing material: 0.2% beryllium copper alloy

Fumio Watanabe

J. Vac. Sci. Technol. A 22, 181 (2004); http://dx.doi.org/10.1116/1.1635390 (11 pages) | Cited 7 times

Online Publication Date: 8 January 2004

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Exploration for low-outgassing materials for use in ultrahigh vacuum and extreme high-vacuum systems is one of the most important topics of a vacuum researcher. We have found that a copper alloy containing 0.2% beryllium (0.2% BeCu) can attain an extremely low hydrogen outgassing rate of 10−14 Pa (H2) m/s order. Almost the entire surface of 0.2% BeCu is dominated by a BeO layer, after a 400 °C×72 h prebakeout treatment in an ultrahigh vacuum. This layer functions as a barrier to the processes of oxidization and permeation of hydrogen. In addition, this layer resists carbon contamination. Temperature-programmed desorption spectra show only a single peak for water at 150 °C and small quantities of any other desorption gases. Therefore, an in situ bakeout process in which the temperature simply ramps up to 150 °C and immediately ramps back down is enough for degassing; it does not require an ordinary sustained-temperature bakeout. Using an outgassing sample consisting of 0.2% BeCu disks housed in a 0.2% BeCu nipple chamber, a lowest outgassing rate of the 5.6×10−14 Pa (H2) m/s was measured by the pressure-rise method after pump cutoff. The pressure-rise versus time curve was completely nonlinear. It rises over time to a constant slope of 1/2 in a log–log plot, due to hydrogen diffusion from the bulk, but this requires over a week at room temperature. The hydrogen outgassing from the 0.2% BeCu bulk is completely dominated by a diffusion-limited mechanism. This article will describe why we obtain such low-outgassing rates with 0.2% BeCu. It is based on the observed surface changes with prebakeout treatment seen by x-ray photoelectron spectroscopy, and the improvement of hydrogen outgassing measurements by the pressure-rise method. A comparison is made to ordinary stainless steel. In addition, the concept of an outgassing reduction method will be discussed from a review of the published ultralow-outgassing data and reduction methods. © 2004 American Vacuum Society.
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07.30.Bx Degasification, residual gas
68.47.De Metallic surfaces
68.35.Dv Composition, segregation; defects and impurities
68.43.Vx Thermal desorption
79.60.Bm Clean metal, semiconductor, and insulator surfaces
81.40.Gh Other heat and thermomechanical treatments
81.05.Bx Metals, semimetals, and alloys

Determination of titanium temperature and density in a magnetron vapor sputtering device assisted by two microwave coaxial excitation systems

O. Leroy, L. de Poucques, C. Boisse-Laporte, M. Ganciu, L. Teulé-Gay, and M. Touzeau

J. Vac. Sci. Technol. A 22, 192 (2004); http://dx.doi.org/10.1116/1.1635391 (9 pages) | Cited 16 times

Online Publication Date: 8 January 2004

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We present an optical absorption diagnostic technique devoted to the simultaneous determination of titanium density and temperature during sputtering of Ti. These measurements were performed in a type of ionized physical vapor deposition reactor, consisting of a magnetron sputtering device assisted by two microwave systems for the ionization of the sputtered vapor of the magnetron. Our goal is to optimize the ionization in this reactor in order to improve the deposition process (film quality, recovery of the layers, etc.) compared to standard magnetron sputtering systems. In order to determine both titanium neutral and ion densities, we have used a titanium hollow cathode vapor lamp powered with pulsed power supply. Measurements were carried out at different positions in the reactor at different pressures (1–15 Pa). We have studied the effect of magnetron current from 100 mA to 2 A and of microwave power from 100 W to 1 kW. At lower pressures, we have shown that the titanium is not thermalized close to the magnetron, whereas it is thermalized at 10 Pa at all positions. The neutral titanium density is typically between 1010 and 3×1011 cm−3, and the ion density is ∼109 cm−3. The effect of microwave power is the decrease of neutral titanium density and the increase of its temperature. At a position located 1 cm after the crossing of the microwave plasma area, we showed that the illumination of the microwave plasma increases the degree of ionization of Ti from 2% to 10%. © 2004 American Vacuum Society.
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52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.25.-b Plasma properties
52.77.Dq Plasma-based ion implantation and deposition
52.80.Pi High-frequency and RF discharges
81.15.Cd Deposition by sputtering
68.55.A- Nucleation and growth
81.15.Jj Ion and electron beam-assisted deposition; ion plating

Mechanisms of SiO2 film deposition from tetramethylcyclotetrasiloxane, dimethyldimethoxysilane, and trimethylsilane plasmas

Jianming Zhang, Dattatray S. Wavhal, and Ellen R. Fisher

J. Vac. Sci. Technol. A 22, 201 (2004); http://dx.doi.org/10.1116/1.1635392 (13 pages) | Cited 15 times

Online Publication Date: 8 January 2004

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The deposition of SiO2 films from alkoxysilane/O2 and alkoxysilane/N2O plasmas has been investigated using 1, 3, 5, 7-tetramethylcyclotetrasiloxane, dimethyldimethoxysilane, and trimethylsilane as Si precursors. Films were analyzed using Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, spectroscopic ellipsometry, and scanning electron microscopy. Film deposition rates and hydrocarbon incorporation in the SiO2 films decrease with addition of O2 or N2O. High-quality SiO2 films are deposited at high oxidant concentrations with all three precursors. The effects of applied rf plasma power, substrate temperature, and substrate position in the reactor on film quality and deposition rate were also examined. Negative apparent activation energies for film deposition have been observed, suggesting a deposition process dominated by surface adsorption/desorption reactions. Gas phase species in these plasmas were studied with optical emission spectroscopy and mass spectrometry and are correlated with film deposition. For films deposited from low oxidant-containing plasmas, post deposition treatment with an O2 plasma serves to remove hydrocarbon contamination. © 2004 American Vacuum Society.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
77.55.-g Dielectric thin films
52.77.Dq Plasma-based ion implantation and deposition
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
68.55.A- Nucleation and growth
78.30.Hv Other nonmetallic inorganics
79.60.Bm Clean metal, semiconductor, and insulator surfaces
78.66.Nk Insulators
68.43.Mn Adsorption kinetics
52.70.Kz Optical (ultraviolet, visible, infrared) measurements

Growth and stress evolution of hafnium nitride films sputtered from a compound target

M. Y. Liao, Y. Gotoh, H. Tsuji, and J. Ishikawa

J. Vac. Sci. Technol. A 22, 214 (2004); http://dx.doi.org/10.1116/1.1636159 (7 pages) | Cited 8 times

Online Publication Date: 8 January 2004

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Hafnium nitride films were deposited on silicon substrates by direct sputtering a compound target in an Ar atmosphere using a radio-frequency magnetron sputtering system. X-ray diffraction, x-ray photoemission spectrum, and Rutherford backscattering spectrometry revealed the successful formation of cubic stoichiometric HfN films in a wide deposition condition range. The residual stress in stoichiometric HfN films is compressive, and depends strongly on Ar pressure and sputtering power. Unlike element metal deposition, a transition point of Ar pressure at which residual stress experiences from compressive to tensile state has not been found in stoichiometic HfN films. Although an increase in Ar pressure could lower the stress value, nitrogen enrichment was found at 2.0 Pa and much oxygen was incorporated in the film deposited at 3.0 Pa and above, which can lead to a dramatic increase in film resistivity. Shallow recoil implantation of HfN species receiving energy from fast Ar species reflected at the target surface is suggested responsible for the evolution of the stress. A possible explanation was also given for the stoichiometric composition. © 2004 American Vacuum Society.
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68.55.A- Nucleation and growth
81.15.Cd Deposition by sputtering
68.60.Bs Mechanical and acoustical properties
61.66.Bi Elemental solids
61.66.Dk Alloys
68.55.-a Thin film structure and morphology
79.60.Dp Adsorbed layers and thin films
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
68.49.Sf Ion scattering from surfaces (charge transfer, sputtering, SIMS)
82.80.Yc Rutherford backscattering (RBS), and other methods of chemical analysis
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Ion doses for low-energy ion-assist applications

H. R. Kaufman and J. M. E. Harper

J. Vac. Sci. Technol. A 22, 221 (2004); http://dx.doi.org/10.1116/1.1633565 (4 pages) | Cited 8 times

Online Publication Date: 8 January 2004

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We present simple, convenient procedures for calculating ion doses for ion-assist applications such as cleaning and property modification. For many of these applications, gridless ion sources of the end-Hall type are particularly well-suited to the generation of high ion-beam currents at ion energies low enough to minimize damage. © 2004 American Vacuum Society.
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07.77.Ka Charged-particle beam sources and detectors
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.65.Cf Surface cleaning, etching, patterning
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
29.25.Ni Ion sources: positive and negative
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