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Showing papers on "Chemical vapor deposition published in 1977"


Journal ArticleDOI
TL;DR: In this article, the photoelectrochemical properties of polycrystalline metal oxide electrodes were investigated, including tunneling effects and the operation of Fe/sub 2/O/sub 3/ in a solar cell.
Abstract: An investigation was made of the photoelectrochemical properties of several polycrystalline metal oxide electrodes prepared by chemical vapor deposition, direct oxidation of the metal or heating of suitable metal salt solutions. Further data are given on the behavior of the previously discussed TiO/sub 2/ and Fe/sub 2/O/sub 3/ electrodes including tunneling effects and the operation of the Fe/sub 2/O/sub 3/ in a solar cell. Other n-type materials studied were V/sub 2/O/sub 5/, WO/sub 3/, and PbO. WO/sub 3/ and PbO showed good anodic photocurrents but only WO/sub 3/ appeared stable. Bi/sub 2/O/sub 3/ showed both n- and p-type photocurrents, but had a poor stability. CuO produced a good cathodic photocurrent (indicating p-type behavior) with a photoresponse at wavelengths of 700 nm and below. Two other oxides, Cr/sub 2/O/sub 3/ and CoO, exhibited small p-type photoeffects.

400 citations


Journal ArticleDOI
TL;DR: In this paper, fine-grained monoclinic HfO 2 films were characterized by using transmission electron microscopy, X-ray diffraction, electron microprobe analysis and measurements of dielectric and optical properties.

351 citations


Journal ArticleDOI
TL;DR: A review of deposition processes for forming dielectric passivation layers on silicon semiconductor devices, with emphasis on recent advances in this field, is presented in this paper, where the fundamental principles, deposition parameters, advantages, applicability, and limitations of the various types of chemical vapor deposition (CVD) processes are described and compared.
Abstract: A review is presented of deposition processes for forming dielectric passivation layers on silicon semiconductor devices, with emphasis on recent advances in this field. Materials of prime interest are thin‐film dielectrics used as secondary passivants deposited by several types of chemical vapor deposition (CVD) processes. The fundamental principles, deposition parameters, advantages, applicability, and limitations of the various types of CVD for dielectric passivation films are described and compared. The CVD processes discussed include low‐ and high‐temperature CVD at normal pressure, and the relatively new technologies about to emerge for large‐scale applications−low‐pressure CVD at low and high temperatures, and plasma‐enhanced CVD.

172 citations


Journal ArticleDOI
TL;DR: In this article, the growth characteristics with MBE were found to be entirely different from those obtained from similar experiments when LPE was used, indicating that this etch-and-fill technique using MBE as the growth process should be particularly useful in fabricating injection lasers, laser arrays, and integrated optics components which require planar definition.
Abstract: In this paper, studies of the molecular beam epitaxy (MBE) of GaAs‐Ga1−xAlxAs multilayer structures over preferentially etched channels on GaAs substrates are described. It is found that the growth characteristics with MBE are entirely different from those obtained from similar experiments when LPE is used. Results obtained indicate that this etch‐and‐fill technique using MBE as the growth process should be particularly useful in fabricating injection lasers, laser arrays, and integrated optics components which require planar definition.

138 citations


Journal ArticleDOI
TL;DR: In this paper, the electrical and optical properties of rf•sputtered Sn•doped In2O3 (ITO) films have been found to depend strongly on the O2 partial pressure during deposition.
Abstract: The electrical and optical properties of rf‐sputtered Sn‐doped In2O3 (ITO) films have been found to depend strongly on the O2 partial pressure during deposition. For the sputtering conditions used, films with both low electrical resistivity (ρ ∼ 3 × 10−4 Ω cm) and high visible transmission (∼ 90%) were obtained only over a narrow range of O2 pressures, from 3 × 10−5 to 4 × 10−5 Torr. Our results appear to explain the difficulties that have previously been encountered in obtaining high‐quality ITO films, and indicate that control of the O2 pressure during deposition is essential for reproducible preparation of such films.

131 citations


Journal ArticleDOI
TL;DR: In this paper, single crystal semiconductors were coated with n-type TiO~ by a chemical vapor deposition technique, and the electron and hole transfer properties across the heterojunction so produced were investigated.
Abstract: Single crystal semiconductors (n-Si, p-Si, n-GaAs, p-GaAs, n-GaP, n-In.P, and n-CdS) were coated with n-type TiO~ by a chemical vapor deposition technique, and the electron and hole transfer properties across the heterojunction so produced were investigated. The quality of the deposited TiO~ film depended upon several factors including temperature and substrate material. When high quality crack-free TiO2 coats were obtained on n-type substrates, the substrate was stabilized with no dissolution during the photo-oxidation of water. However, the oxidation was due o~y to the photoexcitation of the TiO~, and any holes produced in the substrate were not transferred through the TiO~ to the solution. The use of p-type substrates coated with TiO2 as photocathodes was limited by band-bending requirements at the p-n heterojunction and the TiO~-solution interface.

130 citations


Journal ArticleDOI
TL;DR: In this paper, fine-grained nearly stoichiometric monoclinic ZrO2 films were characterized by transmission electron microscopy, X-ray diffraction and electron microprobe analysis and by measuring their dielectric and optical properties.

115 citations


Journal ArticleDOI
TL;DR: In this paper, the underpotential deposition of copper and silver ions on platinum electrodes has been studied using X-ray photoelectron spectroscopy (x.p.s.).

75 citations


Journal ArticleDOI
TL;DR: In this article, high efficiency GaAlAs/GaAs heterostructure solar cells have been grown by metalorganic chemical vapor deposition (MO−CVD) and simulated air-mass-zero (AM0) short-circuit current densities of 24.5 mA/cm2, opencircuit voltages of 0.99 V, fill factors and efficiencies of 12.8% have been measured on devices without AR coatings (uncorrected for contact area).
Abstract: High‐efficiency GaAlAs/GaAs heterostructure solar cells have been grown by metalorganic chemical vapor deposition (MO−CVD). Simulated air‐mass‐zero (AM0) short‐circuit current densities of 24.5 mA/cm2, open‐circuit voltages of 0.99 V, fill factors of 0.74, and efficiencies of 12.8% have been measured on devices without AR coatings (uncorrected for contact area). These cell structures employ a thin (∼520A) GaAlAs : Zn window and a GaAs : Zn/GaAs : Se p‐n junction grown entirely by the MO‐CVD process.

71 citations


Journal ArticleDOI
TL;DR: The growth, structural, and electrical characterization of vacuum-deposited n and p-type CuInTe2 thin films utilizing a high-evaporation-rate technique (≳100 A/s) is reported in this article.
Abstract: The growth, structural, and electrical characterization of vacuum‐deposited n‐ and p‐type CuInTe2 thin films utilizing a high‐evaporation‐rate technique (≳100 A/s) are reported. Complementary transmission electron microscopy (TEM) and Auger electron spectroscopy (AES) are used to investigate the films’ crystalline (grain size, orientation, structure) and compositional (elemental) properties. The effects of substrate temperature on these quantities are presented. A substrate temperature range (400

70 citations


Journal ArticleDOI
TL;DR: In this article, the authors used defocus contrast to reveal a large number of small voids in all of the thin gold films investigated, and the void density and total void volume were found to be highly sensitive to the substrate temperature and only moderately sensitive to residual gas pressure during the deposition.
Abstract: Thin gold films were vapor deposited onto KCl single crystals under a variety of substrate temperatures, residual gas pressures, and deposition rates. The films were subsequently examined by high‐resolution transmission‐electron microscopy. The use of the defocus contrast technique revealed a large number of small (10–50 A in size) voids in all of the films investigated. The void density and total void volume were found to be highly sensitive to the substrate temperature and only moderately sensitive to the residual gas pressure during the deposition. Typical values of the void density in films prepared at a residual gas pressure of 10−7 Torr (∠10−5 Pa) ranged from the order of 1010/cm2 at a substrate temperature of 280° C to that of 1011/cm2 at 55° C. Similar results were obtained for a residual gas pressure of 10−4 Torr (∠10−2 Pa).

Journal ArticleDOI
TL;DR: In this article, an analytical solution to the problems of heat and mass transfer in a tapered annulus based on constant transport properties and fully developed laminar flow is presented.
Abstract: Momentum, heat, and mass transfer processes were studied in a vertical cylinder reactor for the epitaxial growth of Si from SiCl/sub 4/ in H/sub 2/ by chemical vapor deposition. An analytical solution to the problems of heat and mass transfer in a tapered annulus based on constant transport properties and fully developed laminar flow is presented. The mean gas-phase temperature and deposition rate distribution of silicon are calculated within the reactor by using a developing temperature model. Results of experimental studies of silicon deposition from SiCl/sub 4/ in H/sub 2/ at 1200/sup 0/C in a vertical cylinder reactor are compared with the analytical results and with other models of diffusion-controlled chemical vapor deposition. This study provides an analytical method for calculating epitaxial deposition rate distributions in vertical cylinder reactors, and for designing reactors to improve the yield and uniformity of epitaxial growth. 7 figures, 2 tables.

Journal ArticleDOI
TL;DR: In this paper, the first Ga(1−y)AlyAs active layers of 0.8≲y≲0.12 and emit in the wavelength range 8000 <λ <8300 A.
Abstract: Room‐temperature operation of Ga(1−x)AlxAs/Ga(1−y)AlyAs double‐heterostructure lasers grown by metalorganic chemical vapor deposition (MO‐CVD) has been achieved. These devices have Ga(1−y)AlyAs active layers of 0.8≲y≲0.12 and emit in the wavelength range 8000<λ<8300 A. Broad‐area Fabry‐Perot lasers with pulsed threshold current densities as low as ∼1.2 kA/cm2 have been fabricated. These lasers are produced from five‐layer epitaxial structures grown entirely by the MO‐CVD process and are the first such devices to be fabricated from materials grown by a vapor‐phase process.


Journal ArticleDOI
TL;DR: In this paper, thin films of a new iron oxide phase,, were prepared by chemical vapor deposition (CVD) from tris(trifluoroacetylacetonato) iron (III) at 300°C in the presence of oxygen onto a variety of substrates.
Abstract: Thin films of a new iron oxide phase, , were prepared by chemical vapor deposition (CVD) from tris(trifluoroacetylacetonato) iron (III) at 300°C in the presence of oxygen onto a variety of substrates. The films were characterized by x‐ray diffraction analysis, scanning electron microscopy, and Mossbauer spectroscopy. For the latter measurements the films were prepared from enriched . The ultraviolet, visible, and infrared spectra of the films were also recorded. The iron (III) oxide phase prepared was bcc having the bixbyite structure, Ia3 space group and the lattice constant . There are 16 formula molecules to the unit cell and the two iron atoms occupy two nonequivalent distorted octahedral lattice sites: (8b); 2(24d).


Journal ArticleDOI
TL;DR: In this article, single crystal films were obtained on (111) p-type silicon substrates at room temperature when the silicon ion current density, which was about 25% of the total incident silicon atoms, exceeded 80 µA/cm2.
Abstract: Silicon films were formed on single crystal silicon substrates by partially ionized vapor deposition. Single crystal films were obtained on (111) p-type silicon substrates at room temperature when the silicon ion current density, which was about 25% of the total incident silicon atoms, exceeded 80 µA/cm2. Anneal behaviors of epitaxial films grown at room temperature and 400°C at an ion current density of 100 µA/cm2 were investigated by He+ backscattering measurements and by measurement of change in resistivity.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the deposition mechanisms of boron trichloride and hydrogen vapors by using a stagnation flow technique and deduced the characteristics of gas flow from experimental deposition rates.
Abstract: The deposition mechanisms of boron from boron trichloride and hydrogen vapors are investigated by a stagnation flow technique. The characteristics of gas flow are first deduced from experimental deposition rates. Then, by use of the Stefan--Maxwell equations for diffusion, the interfacial conditions of deposition, equilibrium, or supersaturation are inferred from experimental rates of deposition in the stagnation zone. Three mechanisms of deposition are deduced, mass transfer--interfacial equilibrium, mass-transfer-surface kinetics, and surface kinetics. They occur as a function of three experimental parameters: temperature, mass flow rate, and inlet composition BCl/sub 3//H/sub 2/. A correlation for mass transfer in impinging jets is obtained. 15 figures, 1 table.

Journal ArticleDOI
TL;DR: In this paper, chemical vapor deposition of silicon on a graphite substrate coated with a 5μm-thick fluid tin layer provides a possibility for the production of large grained polycrystalline silicon layers.
Abstract: Chemical vapor deposition of silicon on a graphite substrate coated with a 5‐μm‐thick fluid tin layer provides a possibility for the production of large grained polycrystalline silicon layers. Using silane as a source material, crystallites can be produced with a mean grain size of about 20 μm, compared with 5 μm on a substrate without fluid layer. The grain size can be further enhanced by adding HCl as an etching agent to the gas phase. Mean crystallite sizes of 100 μm and larger can be obtained by the use of a fluid layer and a proper combination of SiH4 and HCl.

Journal ArticleDOI
K. J. Bachmann1, Ernest Buehler1, Barry Miller1, J. H. McFee1, F.A. Thiel1 
TL;DR: In this paper, the growth of bulk single crystals and of epitaxial single crystalline layers of p-type InP was reviewed and the electrical properties obtained for various dopants (Cd, Zn, Mg, Mn, Be) in bulk crystals and in epitaxially p-InP layers prepared via liquid phase epitaxy, chemical vapor deposition and molecular beam epitaxy are discussed and a comparison is made of the photoluminescence properties of acceptor impurities in bulk InP and MBE epilayers.

Journal ArticleDOI
TL;DR: In this article, the crystallization process of chemically vapor deposited (CVD) amorphous Si films was studied by using a differential scanning calorimeter, and a sharp exothermic peak due to polycrystalline transition was obtained in the 665-700°C range.
Abstract: The crystallization process of chemically vapor deposited (CVD) amorphous Si films was studied by using a differential scanning calorimeter. A sharp exothermic peak due to amorphous–polycrystalline transition was obtained in the 665–700 °C range. The crystallization temperature was determined to be 665 °C. Transmission‐electron diffraction and transmission‐electron microscopic examinations revealed that, when amorphous Si film is heated at a slightly higher temperature than the crystallization temperature, the Si dendrite grains nucleate, and grow in size with heating time.

Journal ArticleDOI
TL;DR: Techniques for forming dielectric layers for fabricating semiconductor components are reviewed in this article, including low pressure techniques: evaporation, sputtering, plasma deposition, and low pressure CVD, and a number of miscellaneous techniques: roller coating, offset printing, centrifugation-sedimentation, and transfer.
Abstract: Techniques for forming dielectric layers for fabricating semiconductor components are reviewed, including (1) low‐pressure techniques: evaporation, sputtering, plasma deposition, and low‐pressure CVD, (2) techniques operating at one atmosphere total pressure: thermal oxidation, chemical vapor deposition, anodization, electrophoresis, spin on, spray on, silk screening, and (3) a number of miscellaneous techniques: roller coating, offset printing, centrifugation–sedimentation, and transfer. The advantages and limitations of the methods are presented and typical applications are given. Novel applications of the technology to other‐than‐silicon semiconductor devices are outlined, and future trends in the technology are indicated.

Journal ArticleDOI
TL;DR: The influence of various process parameters on the deposition of TiC is discussed in this article, where it is shown that the deposition rate is almost independent of the total pressure, proportional to the concentration of CH4 and inversely proportional to HCl, assuming that the HCl is formed by decomposition of TiCl4 into lower chlorides in a homogeneous reaction.

Patent
23 Dec 1977
TL;DR: A process for producing semiconductor grade silicon is described in this paper, where metallurgical grade silicon, silicon dioxide, and silicon tetrafluoride are chemically combined at an elevated temperature to form silicon difluorside gas.
Abstract: A process for producing semiconductor grade silicon. Metallurgical grade silicon, silicon dioxide, and silicon tetrafluoride are chemically combined at an elevated temperature to form silicon difluoride gas. The silicon difluoride gas is then polymerized, preferably in a two-step process. An initial small quantity of silicon difluoride polymers is formed at a first temperature. This initial polymerization removes most of the impurities that were present in the original metallurgical grade silicon and which were transported by the silicon difluoride gas. The bulk of the remaining silicon difluoride gas is then polymerized at a second, lower temperature. These polymers are substantially free from all impurities. The pure silicon difluoride polymers are then thermally decomposed at temperatures below 400° C. to form binary silicon fluoride homologues. The homologues can be distilled for even higher purity, or can be used or stored as formed. The binary silicon fluoride homologues produce pure silicon and silicon tetrafluoride when heated to a temperature between 400° C. and 950° C. The disproportionation of the homologues can be accomplished by chemical vapor deposition techniques onto heated substrates of silicon, metal, or quartz. This disproportionation will result in amorphous, polycrystalline, or monocrystalline silicon depending on the temperatures employed and on the substrate used for deposition.

Journal ArticleDOI
TL;DR: In this article, low-temperature (400-540 °C) crystallization of amorphous and polycrystalline Si films was studied using SEM, TEM, electron diffraction, electron channeling, and MeV 4He + backscattering.
Abstract: Low-temperature (400–540 °C) crystallization of amorphous and polycrystalline Si films deposited on SiO2 and covered with an evaporated Al layer has been studied using SEM, TEM, electron diffraction, electron channeling, and MeV 4He + backscattering. Silicon deposited by evaporation and chemical vapor deposition (CVD) at 640 °C (both amorphous) was found to crystallize into islands of polycrystalline aggregates. Silicon deposited by CVD at 900 °C (polycrystalline with ~2000-A grains) produced relatively large (~10 µm) single-crystal islands. In both cases island size increased with annealing time, and the rate of crystallization increased with temperature. Crystallization rates were observed to be the same for both sources of amorphous Si, while 900 °C CVD Si was noticeably slower, consistent with the postulate that the driving force for the reaction is the free-energy difference between initial and final states. The crystallization rate for 900 °C CVD Si decreased when the Al layer thickness was reduced to a value less than the initial Si grain size. The inclusion of a native oxide layer between the deposited Si and Al layers greatly retarded the crystallization process.

01 Apr 1977
TL;DR: A study of experimental data on Cr-oxide-p-Si solar cells has led to a metal evaporation procedure which gives 0.50 V oc oc.
Abstract: A study of experimental data on Cr-oxide-p-Si solar cells has led to a metal evaporation procedure which gives 0.50 V oc oc . A high n-value and fixed charge in the oxide are not necessary to obtain a high V oc .

Journal ArticleDOI
TL;DR: In this paper, a simple linear rate expression was used to calculate an activation energy of the chemical kinetic mechanism for the chemical vapor deposition (CVD) of from,, and was experimentally determined as a function of CVD variables.
Abstract: Deposition rates and efficiencies for the chemical vapor deposition (CVD) of from , , and were experimentally determined as a function of CVD variables. These results, coupled with previously determined thermodynamic equilibrium compositions and deposit morphologies, were used to develop models for the deposition process. At high temperatures the principal rate‐limiting mechanism is the diffusion of gaseous species through a gas boundary layer above the deposition surface. However, low or high fractions in the reactant gas cause a chemical kinetic mechanism to become rate limiting. At lower deposition temperatures equilibrium no longer appears to exist at the substrate surface and a chemical kinetic rate‐limiting mechanism becomes important. A simple linear rate expression was used to calculate an activation energy of for the chemical kinetic mechanism.

Journal ArticleDOI
TL;DR: In this paper, the influence of mole ratios Ga/(Ga+In) and P/(As+P) in the input gas stream on the alloy composition of epitaxial layers has been investigated.
Abstract: Epitaxial layers of Ga1-yInyAs1-xPx alloys have been grown on GaAs substrates using an AsH3-PH3-Ga-In-HCl-H2 chemical vapor deposition system. The influence of mole ratios Ga/(Ga+In) and P/(As+P) in the input gas stream on the alloy composition of epitaxial layers has been investigated. As for the group V elements, the deposition probabilities of As and P species in gas phase are approximately equal for small y, but As deposition appears to become dominant for large y. As for group III elements, Ga is always incorporated more preferentially than In. The lattice constant of the quaternary alloys is ascertained to obey Vegard's law and the composition dependence of the bandgap, obtained from photoluminescence measurements, is compared with an interpolation formula, derived by use of the bowing parameters of ternary alloys.

Journal ArticleDOI
TL;DR: In this article, the importance of H2S admixture for the etching and cleaning of the surface of the InP surface was demonstrated, and a solar cell with an open-circuit voltage of 0.78 V, fill factor 0.75, and power conversion efficiency of 13.5% for AM2 conditions was presented.
Abstract: CdS/InP heterojunctions are grown by chemical vapor deposition of CdS on InP in an open‐tube H2S/H2 flow system. The importance of H2S admixture for the etching and cleaning of the InP surface is demonstrated. The solar cell has an open‐circuit voltage of 0.78 V, fill factor of 0.75, and a power conversion efficiency of 13.5% for AM2 conditions.

Patent
16 Mar 1977
TL;DR: In this paper, the authors describe how dies and crucibles, which come in contact with a silicon melt during the formation of single crystalline shaped silicon particles, e.g. thin sheets or ribbons, are coated with silicon oxynitride deposited by chemical vapor deposition techniques.
Abstract: Mechanical components such as dies and crucibles, which come in contact with a silicon melt during the formation of single crystalline shaped silicon particles, e.g. thin sheets or ribbons, are coated with silicon oxynitride deposited by chemical vapor deposition techniques.