Showing papers on "Epitaxy published in 1970"
251 citations
TL;DR: In this paper, the dependence of the equilibrium configurations of a thin singlecrystalline epitaxial film, on the strength of substrate overgrowth and overgrowth overgrowth bonds and the interfacial misfit is calculated neglecting substrate deformations.
Abstract: The dependence of the equilibrium configurations of a thin single‐crystalline epitaxial film, on the strengths of substrate‐overgrowth and overgrowth‐overgrowth bonds and the interfacial misfit is calculated neglecting substrate deformations. Previous analyses of the system were based on a one‐dimensional model, allowing for misfit, i.e., differing lattice parameters, in one interfacial direction only. The results of these analyses show (i) that interfacial mismatch is accommodated by a parallel sequence of misfit dislocations, (ii) that the mismatch decreases when appropriate overall lateral strains are introduced, (iii) that in stable and metastable film configurations both dislocations and overall strains are present, and (iv) that there exist limiting misfits 2/πl0 and 1/l0, respectively, below which the stable and metastable states are pseudomorphic; the film is homogeneously strained to coherency, i.e., exact fit, with the substrate. The transition to the noncoherent state is critical, the change in...
113 citations
TL;DR: In this paper, the ternary phase diagram was calculated using Darken's quadratic formalism to describe the Ternary liquid and assuming the solid solution in equilibrium with the liquid to be regular.
Abstract: layers grown by liquid‐phase epitaxy were obtained in the range of , when grown on the (111 Ga) plane of GaAs. Attempts to grow alloys on the (110), (111 As), (100), and (112 As) planes resulted in polycrystalline layers. The alloy composition was determined by x‐ray fluorescence and the band gap by infrared transmission. The ternary‐phase diagram was calculated using Darken's quadratic formalism to describe the ternary liquid and assuming the solid solution in equilibrium with the liquid to be regular. It was found that the experimental results were in good agreement with the calculated phase diagrams. A number of liquidus isotherms were calculated in the temperature range of 700°–1200°C. Gallium arsenide isoconcentration curves are shown for 0.95, 0.90, 0.80, 0.50, and 0.30 mole fraction.
89 citations
TL;DR: In this paper, the diffusion equation was solved for the epitaxial crystallization of gallium arsenide from gallium solution, and the minimum temperature gradient allowed to avoid constitutional supercooling was calculated for the cases of a semi-infinite and a finite melt.
85 citations
TL;DR: In this paper, the authors showed that the c axis of the ZnO could be made to lie parallel to the (0112) oriented sapphire substrate, and the resistivities were generally from 1 to 10 cm but could be significantly increased by diffusion of lithium or sodium.
Abstract: Epitaxial layers of ZnO have been deposited by chemical vapor transport on single‐crystal sapphire substrates. The ZnO layers have been deposited up to thicknesses of 100μ. X‐ray analysis showed that the c axis of the ZnO could be made to lie parallel to the (0112)‐oriented sapphire substrate. Resistivities were generally from 1 to 10 Ω‐cm but could be significantly increased by diffusion of lithium or sodium.
78 citations
TL;DR: The electron mobility of indium phosphide was measured as 44,000 cm 2 /Vsec at 77°K as mentioned in this paper, which was higher than any previously reported value for indium.
52 citations
TL;DR: In this paper, the authors show that the strength of the interaction between the deposits and the substrate, especially its relative magnitude with respect to the surface energy, is the essential factor which determines the apparent characteristics of the epitaxial behavior.
49 citations
TL;DR: In this paper, a simple optical transmission and excitation technique is demonstrated for the measurement of extremely short excess carrier lifetimes in GaAs, where the middle layer of an epitaxial n+/n/n+ sample, in which excess carriers tend to be confined to the center of the structure, is selectively excited optically and serves essentially as a surface free sample that exhibits the recombination properties intrinsic to bulk material.
Abstract: A simple optical transmission and excitation technique is demonstrated for the measurement of extremely short excess carrier lifetimes in GaAs. The middle layer of an epitaxial n+/n/n+ sample, in which excess carriers tend to be confined to the center of the structure, is selectively excited optically and serves essentially as a surface‐free sample that exhibits the recombination properties intrinsic to bulk material. Excited from lower to higher level (77°K), this layer (Nd∼2−3×1015/cm3, μ=6340 cm2/V sec) varies continuously in carrier lifetime from τ≈10−9 sec (spontaneous recombination) to τ≈2×10−10 sec (stimulated recombination), as determined by the measured change in sample absorption caused by Burstein shift of the carrier quasi‐Fermi levels (carrier population). The carrier distribution and generation rate are shown to be quite uniform within the sample as a result of the inverse dependence of the absorption upon the carrier concentration.
49 citations
TL;DR: Au, Ag and Al films evaporation in ultrahigh vacuum on LiF and MgO surfaces, showing insignificant role of lattice misfit for epitaxy as mentioned in this paper.
Abstract: Au, Ag and Al films evaporation in ultrahigh vacuum on LiF and MgO surfaces, showing insignificant role of lattice misfit for epitaxy
49 citations
TL;DR: The mechanism of growth of GaP on a cleaved CaF2 (111) surface was studied in situ in a high-energy reflection electron diffraction system as discussed by the authors, where it was found that in the early stages of growth, GaP formed tetrahedral nuclei with {111} faces.
Abstract: The mechanism of growth of GaP on a cleaved CaF2 (111) surface was studied in situ in a high‐energy reflection electron diffraction system. It was found that in the early stages of growth, GaP forms tetrahedral nuclei with {111} faces. The three edges of the tetrahedron are parallel to the three 〈110〉 directions. These microcrystals coalesce and form a smooth film after a mean thickness of more than 300 monolayers of GaP is deposited on the surface. Temperatures for epitaxial growth of a single crystal without twinning as a function of the atom arrival rate were studied for GaP on a clean CaF2 surface and on a GaP‐covered CaF2 surface. It was found that growing GaP without twinning on a bare cleaved CaF2 surface requires a temperature ∼65°C higher than on a surface that is covered with GaP. The structural characteristics of the GaP film as a function of the substrate temperature are also discussed.
47 citations
TL;DR: In this paper, the partial pressure dependence of doping level in the epitaxial layers of silicon is measured over a wide range of dopant partial pressures at low doping levels, solid solutions of boron and arsenic obey dilute solution theory.
TL;DR: In this article, thin, smooth epitaxial layers of GaAs were generated in a matter of seconds by dipping a cooler substrate into a hotter solution, and, because the extent of growth is necessarily limited, reproducibility in layer thickness was achieved.
TL;DR: In this paper, it was proved that treatment at water vapour pressures near saturation is best suited for the epitaxy of (100)Au |(100)NaC1 |100]Au| [100]NaC 1 orientation were produced on the hydroxide surfaces at 330°c.
Abstract: Chloride, hydroxide and bicarbonate surfaces of rocksalt were produced by vacuum cleavage, water vapour treatment, and combined water vapour—CO2 treatment of NaC1 single crystals. Epitaxial films of the (100)Au |(100)NaC1 [100]Au| [100]NaC1 orientation were produced on the hydroxide surfaces at 330°c. Polycrystalline films were obtained on both the (bi)-carbonate and chloride surfaces. No effective lowering of the epitaxial temperature was observed in the case of the hydroxide surfaces. It was further proved that treatment at water vapour pressures near saturation is best suited for the epitaxy. Comparison of the different gold films led to the conclusion that air-cleaved rocksalt crystals present mainly hydroxide surfaces.
TL;DR: In this article, various devices have been fabricated using silicon films grown epitaxially on low aluminum-rich spinel substrates, including MOS capacitors, MOS transistors, and vertical junction diodes.
Abstract: Various devices have been fabricated using silicon films grown epitaxially on low aluminum-rich spinel substrates. The insulating substrate provides complete isolation of the semiconductor devices and eliminates the parasitic capacitances of the back-biased p−n junctions. The low aluminum-rich spinel offers the advantages of better thermal stability and easier surface preparation for silicon epitaxy over both the conventional high aluminum-rich (MgO:3Al2O3) and the stoichiometric (MgO:Al2O3) materials. MOS capacitors, MOS transistors, and vertical junction diodes were constructed and studied using films with mobilities equal to or near the bulk values. Information on MOS capacitance vs. bias behavior, transistor characteristics, diode junction properties, and minority carrier lifetime was obtained. The silicon-spinel composites were also characterized by physical methods, and the nature of the defect structures was examined.
TL;DR: In this article, the epitaxial relation was nominally Ag(111) ∥ Ni(111), Ag[110] ∥Ni[110], and no evidence was found for either alloying or pseudomorphism.
TL;DR: Epitaxial beta SiC film formation on SiC by reactive evaporation or sputtering at low temperature was studied in this article, where it was shown that SiC films can be formed on SiCs with either reactive or non-reactive sputtering.
Abstract: Epitaxial beta SiC film formation on SiC by reactive evaporation or sputtering at low temperature
TL;DR: In this article, the role of the substrate surface in the epitaxy of vacuum-deposited f.c. metal films on alkali halide substrates is discussed.
Abstract: A model is presented which explains semi-quantitatively the role of the substrate surface in the epitaxy of vacuum-deposited f.c.c. metal films on alkali halide substrates. The concept of critical accommodation centres is introduced. With the aid of the model the relative nucleation densities as well as the orientations of the nuclei in the initial stages of film growth are predicted for common substrate overgrowth combinations under a variety of growth conditions. The predictions seem to be in general agreement with experimental results.
TL;DR: In this paper, a solid-state travelling-wave amplifier was fabricated in 1 µm n type epitaxial GaAs on a semi-insulating substrate, with a net gain around 5, 7.5, 9 and 11.5 GHz.
Abstract: A solid-state travelling-wave amplifier has been fabricated in 1 µm n type epitaxial GaAs on a semi-insulating substrate. It shows a net gain around 5, 7.5, 9 and 11.5 GHz, with a maximum value of 13 dB at 11.5 GHz. Other features include c.w. operation, 20-30 dB isolation, and voltage-controlled phase shifting with constant gain.
TL;DR: In this paper, an open tube flow method was used for the growth of zinc sulphide on silicon (111) substrates, in which hydrogen was used as the reactive transport agent.
Abstract: Epitaxial growth of zinc sulphide on silicon (111) substrates has been achieved by an open tube flow method in which hydrogen was used as the reactive transport agent. Epitaxy occurred for flow rates between 40 and 300 cc/min, and for substrate temperatures from 450 to 600°C, giving growth rates between 200 and 1300 A/h, The crystal structure of the overgrowths was examined by electron and X-ray diffraction and was without exception single crystal. Both hexagonal and twinned cubic reflections were observed in the diffraction patterns from films grown from pure zinc sulphide powder, but films grown from photoluminescent material were entirely hexagonal.
TL;DR: In this article, single crystal layers of CdS have been grown on the three low index planes of GaAs and the growth rate decreased in the order (1 IIB), (110), (111 A), (100) substrate orientation and the orientations of S-face, (10 1 ¯ 3), (0001) Cd-face and (30 3 ¯ 4), respectively.
TL;DR: Zn deposition on Zn single crystals in KOH solution, examining time and potential effects on deposit morphology was discussed in this article, where the authors examined the potential effects of the deposition on the morphology of the Zn deposits.
Abstract: Zn deposition on Zn single crystals in KOH solution, examining time and potential effects on deposit morphology
TL;DR: In this article, the effect of direct transitions in indirect alloys has been observed, and is consistent with previous estimates of the composition corresponding to the crossover from direct gap to indirect gap alloys.
Abstract: Photoluminescence excitation spectroscopy of (InGaP) has been used to analyse alloy inhomogeneities and variations in impurity concentration which arise owing to growth by liquid phase epitaxy. The method has experimental advantages over absorption techniques for rapid assessment of III-V semiconductors. The effect of direct transitions in indirect alloys has been observed, and is consistent with previous estimates of the composition corresponding to the crossover from direct gap to indirect gap alloys
TL;DR: In this paper, the temperature dependence of the mobility, Hall coefficient, and resistivity of PbTe-rich epitaxial films between 77 and 300 K were studied.
Abstract: Epitaxial films of Pb1−x Snx Te have been grown on cleaved and polished NaCl and KCl single crystal substrates for x in the range 0.05≤x≤0.76. Laue patterns show that films grown on CaF2 substrate, unlike those on rocksalt, were polycrystalline thus indicating that thermal mismatch between film and substrate is less detrimental than the absence of effective substrate strain-relief mechanisms. The temperature dependence of the mobility, Hall coefficient, and resistivity of the alloy films between 77 and 300 K were studied. These studies show that the films have electrical and transport properties similar to those found in bulk Pb1−x Snx Te alloys and in PbTe and SnTe, Low temperature isothermal annealing techniques were employed to reduce carrier concentrations in the PbTe-rich films to the low 1017/cm3 range. Results show that such carrier density reductions may be accompanied by reduced carrier mobilities which we attribute to thermal cycling effects.
TL;DR: In this article, the epitaxy of zinc sulphide films on silicon has been studied by means of X-ray and electron diffraction and by scanning electron microscopy, and it has been shown that planar defects will predominate in such a sphalerite structure material; this is similar to the results of Pashley and Stowell on face centred cubic metals.
Abstract: The epitaxy of zinc sulphide films on silicon has been studied by means of X-ray and electron diffraction and by scanning electron microscopy. Results have shown that due to the nature of the stacking of atoms, planar defects will predominate in such a sphalerite structure material; this is similar to the results of Pashley and Stowell on face centred cubic metals. Such defects have been shown to be more prevalent on (111) and (110) orientations, compared with the (100) orientation which gave the best epitaxial single crystal films. These results agree with other work from this laboratory on the epitaxy of zinc selenide on germanium and silicon.
TL;DR: In this article, thin films of Ag and Au were deposited on vacuum-cleaved alkali halides in ultrahigh vacuum with and without controlled-chlorine exposures, and the film structure and orientation was studied by conventional electron diffraction and electron microscopy.
Abstract: Thin films of Ag and Au were deposited on vacuum‐cleaved alkali halides in ultrahigh vacuum with and without controlled‐chlorine exposures. Chlorine exposures were made (1) prior to deposition, (2) continuously during deposition, or (3) with various delay times after the start of deposition. The film structure and orientation was studied by conventional electron diffraction and electron microscopy. Results show that chlorine induces nearly perfect epitaxy of Ag and Au on NaCl and enhances epitaxy of Ag and Au on KCl and Kbr under deposition conditions that otherwise would produce polycrystalline films. For example, epitaxy of Au on NaCl is obtained at room temperature in a partial pressure of ∼5×10−7 Torr Cl2. Possible mechanisms responsible for the influence of Cl2 on the orientation of Ag and Au are discussed.
Patent•
06 Oct 1970TL;DR: In this article, the method for making a single crystal silicon contact for integrated circuits is described, which is formed by coherent growth on a surface of monocrystalline silicon for protecting and contacting said surface.
Abstract: The method for making a single crystal silicon contact for integrated circuits is described. The epitaxial contact is selfpatterning and is formed by coherent growth on a surface of monocrystalline silicon for protecting and contacting said surface.
TL;DR: In this article, epitaxial Indium Arsenide films have been deposited on (111), (110) and (100) semi-insulating gallium arsenide by vacuum evaporation, using the three temperature method.
Abstract: Epitaxial Indium Arsenide films have been deposited on (111), (110) and (100) semi-insulating gallium arsenide by vacuum evaporation, using the “three temperature” method. The films have been examined by Laue back reflection and reflection electron diffraction. The electrical properties have been evaluated by Hall effect and conductivity measurements. Room temperature Hall mobilities of 23,000 cm2/V-sec and carrier concentrations of 2 × 1016 cm−3 have been achieved. The effect of film thickness on the mobility has been examined, indicating a rapid decrease in mobility with film thickness below a few microns.