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Showing papers on "Thin film published in 1972"


Journal ArticleDOI
S.R. Herd1, P. Chaudhari1, M.H. Brodsky1
TL;DR: In this paper, the crystallization and compound formation temperature of vacuum deposited amorphous Si (and Ge) while in contact with various crystalline metals as a thin film sandwich are investigated by electron microscopy and electron diffraction.
Abstract: The crystallization and compound formation temperature of vacuum deposited amorphous Si (and Ge) while in contact with various crystalline metals as a thin film sandwich are investigated by electron microscopy and electron diffraction. The results show that in simple eutectic systems the Si crystallizes at 0.72 (and Ge at approximately 0.65) of the eutectic temperature expressed in degrees Kelvin. Compounds are formed generally by the more rapid diffusion of Si into the metal.

284 citations


Journal ArticleDOI
G. Dittmer1
TL;DR: In this article, the electrical conductivity of discontinuous thin metal films is assumed to be by a substrate-assisted tunnelling, and it is shown that electrons are emitted from small islands in the cathode region where the main voltage drop occurs.

244 citations


Journal ArticleDOI
TL;DR: An investigation of new films made by an rf discharge polymerization process of organic chemical monomers, focused on films prepared from vinyltrimethylsilane and hexamethyldisilbxane, which exhibit very low loss for light-wave propagation and the possibility of controlling the refractive index of the films.
Abstract: The continued development of integrated optics is heavily dependent upon the availability of materials that are suitable for the construction of thin-film optical circuitry and devices We report here an investigation of new films made by an rf discharge polymerization process of organic chemical monomers We concentrate our discussion on films prepared from vinyltrimethylsilane and hexamethyldisiloxane These films are smooth, tough, pinhole-free, transparent from 04 μm to 075 μm, and exhibit very low loss (<004 dB/cm) for light-wave propagation More importantly, experiments demonstrate the possibility of controlling the refractive index of the films either by the mixing of the two monomers before deposition or by chemical treatment after the film is deposited The use of the prism–film coupler for studying the refractive index of each material is discussed in detail

171 citations


Journal ArticleDOI
TL;DR: The GaN and InN thin films were grown on sapphire, silicon, and metallic substrates using rf sputtering at temperatures of 25 −750°C and presputtering vacuum of 10−8 Torr.
Abstract: GaN and InN thin films were grown on sapphire, silicon, and metallic substrates using rf sputtering at temperatures of 25–750°C and presputtering vacuum of 10−8 Torr. The GaN films were high in resistivity (> 108 Ω cm), but the InN layers were highly conducting with an electron concentration of 7×1018 cm−3. The refractive index for GaN ranged from 2.1 to 2.4 at long wavelengths and was dispersive below 8000 A; the index for InN is higher, 2.9. The absorption coefficient was measured from wavelengths of 2 μ to 2000 A.

169 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used backscattering of MeV He ions to investigate the composition and growth kinetics of metal silicides formed from thin films of Pd, Ti, Cr, and Mo evaporated onto Si.
Abstract: Backscattering of MeV He ions has been used to investigate the composition and growth kinetics of metal silicides formed from thin films of Pd, Ti, Cr, and Mo evaporated onto Si. In each system studied, one silicide phase predominated (Pd2Si, TiSi2, CrSi2, and MoSi2). The thickness of the phase increased with (time)0.5 for Pd2Si and TiSi2, and linearly in time for CrSi2 and MoSi2. It was found that these two time dependencies correlate directly with the reaction sensitivity to a thin oxide interface (<100 A) and to the extent of the silicide formation in the neighborhood of a typical device contact region.

160 citations


Journal ArticleDOI
TL;DR: In this article, the thin oxide films of TiO2, ZrO2 and HfO2 have been deposited on single crystals of (111) silicon, by chemical vapor deposition (CVD) of the respective organometallic compounds.

128 citations


Journal ArticleDOI
Reinhard Ulrich1, H. P. Weber1
TL;DR: Low optical loss, in combination with the hotographic sensitivity of the KPR, offers the possibility of fabricating integrated optical circuits directly in the photoresist films.
Abstract: Light-guiding thin films of various materials have been deposited on glass substrates from liquid solutions by slow evaporation of the solvent. The attenuation of the guided light wave in some of these films is as low as that in the best films prepared by other methods. Film deposition from solution is done at or near room temperature. Therefore, this technique allows us to dope the thin films with organic molecules, e.g., laser dyes. The preparation and light-guiding properties of the doped and undoped films are described. The materials studied were epoxy, lead-silica, polyurethane, and Kodak photoresist KPR. Films of the first and second material have shown losses as low as 0.3 dB/cm at wavelengths of 0.633 microm and 1.064 microm, respectively. Films of polyurethane have been prepared with rhodamine 6G doping. When pumped with a pulsed nitrogen laser, the doped films showed optical gains of up to 100 dB/cm. The KPR films have an attenuation of ~1 dB/cm at 1.064 microm. This low optical loss, in combination with the hotographic sensitivity of the KPR, offers the possibility of fabricating integrated optical circuits directly in the photoresist films.

119 citations


Journal ArticleDOI
TL;DR: In this article, surface chemical analysis by Auger electron spectroscopy (AES) is carried out simultaneously with inert gas sputtering to obtain composition profiles normal to the solid-vacuum interface Chemical profiles are presented for as-evaporated and air-heated nichrome thin film resistors.
Abstract: An apparatus is described in which surface chemical analysis by Auger electron spectroscopy (AES) is carried out simultaneously with inert gas sputtering to obtain composition profiles normal to the solid–vacuum interface Chemical profiles are presented for as-evaporated and air-heated nichrome thin film resistors

116 citations


Journal ArticleDOI
TL;DR: In this article, it was shown theoretically and experimentally that stresses in a thin film on a quartz resonator surface can set up sufficient static mechanical bias in the resonator to cause measurable shifts in the frequency through finite strain effects.
Abstract: It is shown theoretically and experimentally that stresses in a thin film on a quartz resonator surface can set up sufficient static mechanical bias in the resonator to cause measurable shifts in the resonant frequency through finite strain effects. In particular, it is found that if a 5‐MHz AT‐cut fundamental mode and a 6.19‐MHz BT‐cut fundamental mode are subjected to the same combination of thin‐film stress and mass/cm2 changes on their surfaces, the sum of the observed frequency shifts is proportional to the mass/cm2 change alone, and the difference of the frequency shifts is proportional to the integral through the film thickness of the change in the thin‐film stress alone. This ``double‐resonator'' technique is demonstrated with implantation studies of 220‐keV 84Kr implants into Si films deposited on the flat electrodes of planoconvex 5‐MHz AT‐cut and 6.19‐MHz BT‐cut resonators. The double‐resonator technique stress results were verified quantitatively by implanting ions into a Si film on one surface of a quartz cantilever beam and monitoring the movement of the free end of the cantilever beam by the changes in capacitance between the free end and a fixed electrode. The sensitivity of the double‐resonator technique is 125 dyn/cm and 6 × 1014 amu/cm2 for a 0.1‐Hz frequency shift. The technique is suited best to thin‐film stress studies with small mass changes.

116 citations


Journal ArticleDOI
TL;DR: In this paper, annealing in air caused crystallization, with anatase formed beginning at 350°C and rutile at 700°C, while the density and index of refraction increased with increasing anneal temperature, while etch susceptibility in and decreased.
Abstract: Thin film was produced at 150°C by chemical vapor deposition using hydrolysis of tetraisopropyl titanate. Films were amorphous as grown, but annealing in air caused crystallization, with anatase formed beginning at 350°C and rutile at 700°C. Density and index of refraction increased substantially with increasing anneal temperature, while etch susceptibility in and decreased. Comparison with literature data showed two groups of processes. One group yields films having properties that gradually approach those of rutile with increasing process temperature. The other group gives rutile directly at moderate temperatures. Deposition of amorphous film, followed by etching and annealing is suggested as a means for pattern definition.

112 citations


Journal ArticleDOI
TL;DR: In this paper, the relationship between the electronic properties of mobility and resistivity, and electron scattering from film defects in slowly deposited cadmium sulphide polycrystalline thin films is investigated.
Abstract: The relationship between the electronic properties of mobility and resistivity, and electron scattering from film defects in slowly deposited cadmium sulphide polycrystalline thin films is investigated. The correlation of these properties is accomplished in a direction parallel to the substrate (``in‐plane'') where the defects of interest are grain boundaries and surfaces. The Petritz (grain boundary) theory is incorporated with surface‐scattering theory to formulate a simple model which predicts the effect of these defects on the electron mobility. Typical values for the grain‐boundary potential and surface‐scattering length are 0.07 eV and 1100 A at a substrate temperature of 180°C for these glass‐deposited films. The mobility is found to depend strongly on grain size, which was a function of substrate temperature. Hall data are presented as a function of evaporation rate, substrate temperature, film thickness, and film temperature. Finally, the grain‐boundary potential is found to depend on the fabrication parameters, especially the deposition rate.

Journal ArticleDOI
TL;DR: In this paper, it is shown that the Tb3+ ion acts as a probe for the electron distribution in thin ZnS thin films, and that the electron energy distribution is shifted to higher energies by increasing the voltage across the structure.
Abstract: It is experimentally demonstrated in a new and direct manner that electroluminescence in thin films of ZnS: Tb3+ is excited by the direct impact of hot electrons on the Tb3+ ions. The scheme consists of monitoring as a function of applied voltage across the structure studied‐a ZnS: Tb3+, Ta2O5 sandwich‐the ratio of fluorescence intensities I(5D3)/I(5D4) originating from the 5D3 and 5D4 levels of Tb3+ at 3.25 and 2.54 eV, respectively. As the electron energy distribution is shifted to higher energies by increasing the voltage across the structure, I(5D3)/I(5D4) grows. The Tb3+ ion thus acts as a probe for the electron distribution in these films. By comparing the results obtained to simple theory, it is concluded that in considering low‐energy losses of the electrons in the active layer, inelastic scattering by low‐lying 7F levels of Tb3+ can not be the sole energy‐loss mechanism at the Tb concentration of interest. The optical phonons of ZnS must also be taken into account.

30 Sep 1972
TL;DR: In this paper, annealing in air caused crystallization, with anatase formed beginning at 350 C and rutile at 700 C, while density and index of refraction increased substantially with increasing anneal temperature while etch susceptibility in HF and H2SO4 decreased.
Abstract: Thin film TiO2 was produced at 150 C by chemical vapor deposition using hydrolysis of tetraisopropyl titanate. Films were amorphous as grown, but annealing in air caused crystallization, with anatase formed beginning at 350 C and rutile at 700 C. Density and index of refraction increased substantially with increasing anneal temperature, while etch susceptibility in HF and H2SO4 decreased. Comparison with literature data showed two groups of processes. One group yields films having properties that gradually approach those of rutile with increasing process temperature. The other group gives rutile directly at moderate temperatures. Deposition of amorphous film followed by etching and annealing is suggested as a means for pattern definition.

Journal ArticleDOI
Y. J. von der Meulen1
TL;DR: In this article, the rate of formation of very thin films thermally grown on [111] and [100] oriented silicon wafers was studied using ellipsometry to measure oxide thickness.
Abstract: The rate of formation of very thin films thermally grown on [111] and [100] oriented silicon wafers was studied using ellipsometry to measure oxide thickness. Film thicknesses from 10–300Aa were obtained by varying oxidation time, oxidation temperature (700°–1000°C), and oxygen concentration in O2‐N2 mixtures at 1 atm total pressure. The applicability of ellipsometry for such a study is discussed. Reproducibility of oxide films grown to thicknesses of 20–30Aa was approx. ±1.0Aa. Under otherwise equal conditions the oxide thickness grown differs for [100] and [111] oriented wafers. The pressure and temperature dependence of the linear rate constant, klin, show that the growth reaction is more complicated than was suggested earlier. In particular, a different pressure dependence for the two substrate orientations used indicates that several oxygen species participate in the rate determining steps.

Journal ArticleDOI
TL;DR: In this paper, the authors studied the nucleation rate and the rate of crystal growth in a-Ge films, paying particular attention to the effects of residual gases, and the activation energies for the relevant processes were obtained.
Abstract: The authors studied the nucleation rate and the rate of crystal growth in a-Ge films, paying particular attention to the effects of residual gases. Activation energies for the relevant processes were obtained.


Journal ArticleDOI
TL;DR: In this article, the decomposition of tetra-ethoxy silane in a radio frequency (1 MHz) glow discharge was studied as a function of time, total pressure, nature of background gas, partial pressure, substrate temperature, subtrate position.

Journal ArticleDOI
TL;DR: In this paper, the evaluation of atom fluxes to stable clusters of differing sizes is analyzed for the problem of nucleation and growth of thin films on a substrate. And the physical reasons for the discrepancy, recently noted by Zinsmeister (1971), between current approaches to thin film nucleation theory are discussed.
Abstract: The evaluation of atom fluxes to stable clusters of differing sizes is analysed for the problem of nucleation and growth of thin films on a substrate. The physical reasons for the discrepancy, recently noted by Zinsmeister (1971), between current approaches to thin film nucleation theory are discussed.

Journal ArticleDOI
R.C. Henderson1, Rohe F. Helm1
TL;DR: In this article, a SiH 4 pyrolysis at moderate temperatures (823 −983 °C) and low pressure (0.15 −0.02 torr) was used to demonstrate that the absence of detectable impurities was the necessary surface condition to obtain such material.

Journal ArticleDOI
A. Gangulee1, François M. d'Heurle1
TL;DR: Second phase Al 2 Cu particles were found to have a considerable effect in retarding secondary growth as discussed by the authors, presumably by rearrangement of misfit dislocations, only when Cu was introduced as a layer sandwiched between two equal Al layers.

Journal ArticleDOI
TL;DR: In this article, the authors used photoresist and ion-milling techniques to produce high-resolution gratings in durable materials which can provide feedback in low-gain laser media.
Abstract: Distributed feedback of a thin‐film optical guided mode has been produced by a periodic perturbation of the guide height. Using photoresist and ion‐milling techniques, gratings with a period of ∼0.2 μ and a peak‐to‐peak height of ∼0.1 μ have been formed on fused silica substrates. A film of polyurethane doped with Rhodamine 6G pumped by an N2 laser formed the gain medium. Data presented on the oscillation threshold of several lasers are in agreement with calculated feedback parameters. This technique is capable of producing high‐resolution gratings in durable materials which can provide feedback in low‐gain laser media.

Journal ArticleDOI
TL;DR: In this paper, heavy ion sputtering is a powerful method for the production of thin films of refractories, and both supported and self-supported films have been made, and the purity of the targets depends mainly on the purity in the starting material.


Patent
29 Dec 1972
TL;DR: In this article, a dielectric layer is formed by depositing the mixture on a first aluminum electrode by an electron beam deposition method, and a protective layer which has the same composition as the dielectrics may be deposited on the second electrode.
Abstract: A thin-film capacitor comprising a substrate plate, a dielectric layer, a first electrically conductive layer interposed between the substrate plate and one surface of the dielectric layer, and a second electrically conductive layer provided on the other surface of the dielectric layer. The dielectric layer is made of a mixture of a such as Al2O3, Y2O5, TiO2, SiO2, Ta2O5, BaTiO2, HfO or NbO and a divalent metal oxide such as an oxide of Be, Mg, Ca, Sr, Ba or Ra. The dielectric layer is formed by depositing the mixture on a first aluminum electrode by an electron beam deposition method. In order to further improve the properties of the thin-film capacitor, the surface of the aluminum electrode may be oxidized and the dielectric may be annealed in an atmosphere of nitrogen. Furthermore, a protective layer which has the same composition as the dielectric may be deposited on the second electrode.

Journal ArticleDOI
TL;DR: The role of diffusion in limiting the reliability of substrate bonding for bimetallic Cr-Au thin films was investigated using work function, Auger electron spectroscopy, and LEED measurements to characterize the structure and chemical composition of these films as mentioned in this paper.
Abstract: The role of diffusion in limiting the reliability of substrate bonding for bimetallic Cr–Au thin films was investigated using work function, Auger electron spectroscopy, and LEED measurements to characterize the structure and chemical composition of these films. The diffusion rates for Cr into Au films are measured by means of a new technique utilizing the change in electronic work function as a measure of the surface concentration change. It was found that the diffusion coefficient (D) depended on the deposition rate of the Au film, with a twofold increase in deposition rate giving rise to an order of magnitude increase in D. The presence of sulfur as an impurity in the Cr also had a significant effect on D. Comparison of these results with values of D obtained on Cr–Au films by other workers give similar activation energies, but much lower values of D0 (temperature independent part of D) were obtained in this work. The effect on the lifetimes of devices using thin bimetallic films is discussed in terms ...

Journal ArticleDOI
TL;DR: In this paper, the effects on spectrally resolved response caused by variations in applied electrical field, wavelength sweep rate, and optical belaching are reported, and the experiments were made on metal-oxide-semiconductor capacitors.

Journal ArticleDOI
S. Mader1, S. R. Herd1
TL;DR: In this article, the formation of second phase particles in Al+3% Cu alloy films was examined in order to find differences of the precipitation in thin films from that occurring in bulk alloys.

Journal ArticleDOI
TL;DR: In this paper, a thin pyrolytic BN has been formed by chemical vapor deposition and optical absorption measurements of the films indicate that the absorption edge is 5.83 eV.

Journal ArticleDOI
TL;DR: In this article, the authors studied the resistivity properties of bcc-tantalum films obtained from various bell jar systems in Bell Telephone Laboratories and found that the presence of the material causes an increasing positive α value at low temperatures.

Journal ArticleDOI
TL;DR: In this article, the structure of the intermediate state in superconducting lead films has been investigated as a function of magnetic field and film thickness, and the periodicity length of intermediate state structure was in reasonable agreement with the non-branching model of Landau.