Showing papers on "Silicon carbide published in 1971"
TL;DR: In this article, the strength of the absorption bands due to carbon (16·5 μm) and oxygen (9 μm), from the measurements, heats of solution of the two impurities of 53±6 and 38±4 kcal/mole have been deduced respectively.
180 citations
01 Jul 1971
TL;DR: In this paper, the fabrication of a silicon carbide (SiC) junction field effect transistor (J-FET) was shown to be feasible and a simplified building block amplifier was constructed and tested.
Abstract: : The fabrication of a silicon carbide (SiC) junction field effect transistor (J-FET) was shown practicable. Several amplifier designs were breadboarded with silicon devices to study the required parameters. A simplified building block amplifier was constructed and tested. (Author)
101 citations
TL;DR: The thermal decomposition of a gallium tribromide-ammonia complex in an ammonia, argon, or nitrogen atmosphere has been used for the deposition of gallium nitride films on silicon and hexagonal silicon carbide substrates in a gas flow system as discussed by the authors.
Abstract: The thermal decomposition of a gallium tribromide‐ammonia complex in an ammonia, argon, or nitrogen atmosphere has been used for the deposition of gallium nitride films on silicon and hexagonal silicon carbide substrates in a gas flow system. The substrate temperature and the nature of the ambient are the most important parameters of the deposition process. Adherent and transparent films of gallium nitride have been deposited at substrate temperatures up to about 600°C in an ammonia atmosphere and up to about 750°C in a nitrogen or argon ambient. At higher temperatures, the deposit became contaminated with gallium. The gallium nitride films deposited on {111} oriented silicon substrates at 600°–700°C were found to show a (110) fiber orientation. Epitaxial, single crystalline gallium nitride films have been grown successfully on the basal plane of hexagonal silicon carbide substrates at 520°–600°C. These films are of high resistivity indicating that the thermal decomposition of gallium nitride is negligible. Thus, the thermal decomposition of the gallium tribromide‐ammonia complex provides a new promising technique for the crystal growth of gallium nitride.
95 citations
TL;DR: In this article, single crystal epitaxial layers of gallium nitride have been grown on α-SiC and α-Al2O3 substrates in the temperature range 1000-1150 °C.
77 citations
Patent•
23 Dec 1971
TL;DR: In this paper, heat resistant and strengthened composite materials are obtained by mixing, and sintering in a non-oxidizing atmosphere, the combination of powders of aluminum nitride and/or silicon nitride, with powders or whiskers of silicon carbide, boron nitride or carbon.
Abstract: Heat resistant and strengthened composite materials are obtained by mixing, and sintering in a non-oxidizing atmosphere, the combination of powders of aluminum nitride and/or silicon nitride, with powders of an oxide of lanthanum, cerium, scandium, yttrium, and/or yttrium aluminum garnet, and with powders or whiskers of silicon carbide, boron nitride and/or carbon. The composite material so produced is characterized by high shock resistance and excellent mechanical strength.
75 citations
TL;DR: In this paper, it was shown that above 600 °C, a thermal annealing mechanism can cause continuous expansion, with the rate increasing with temperature up to at least 1200 °C with doses up to 5 × 1021 n/cm2.
72 citations
TL;DR: Epitaxial boron phosphides single crystals growth, using thermal decomposition and reduction for deposition on hexagonal silicon carbide substrates basal plane was described in this article.
Abstract: Epitaxial boron phosphides single crystals growth, using thermal decomposition and reduction for deposition on hexagonal silicon carbide substrates basal plane
59 citations
TL;DR: In this paper, a direct transformation from the ABAB to the ABCACB packing has been observed in silicon carbide single crystals, on annealing at 2400 °C in argon atmosphere.
55 citations
TL;DR: In this paper, needle-shaped single crystals of 2H (wurtzite type) SiC, grown by a vapour-liquid-solid mechanism, are transformed to the 3C (sphalerite) structure on annealing in argon at temperatures above 1400°C.
54 citations
TL;DR: In this article, the second harmonic coefficients, refractive indices, and optical transmission of hexagonal SiC have been measured at room temperature and the observed Miller δ coefficients are in poor agreement with the values calculated from Levine's bond charge model.
Abstract: Optical second harmonic coefficients, refractive indices, and optical transmission of hexagonal SiC have been measured at room temperature. The nonlinear coefficients measured relative to quartz for a 1.064‐μm fundamental are d15SiC=(25± 3)d11α −SiO2, d31SiC=(27± 3)d11α −SiO2, and d33SiC=(45± 5)d11α −SiO2. The observed Miller δ coefficients are in poor agreement with the values calculated from Levine's bond‐charge model. Type‐II phase matching should be achievable with SiC for fundamental wavelengths greater than 2.0 μm.
54 citations
Patent•
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09 Sep 1971
TL;DR: In this article, a method of brazing together bodies composed either of dense self-bonded silicon carbide containing free silicon or dense carbon using a brazening material consisting of an alloy of silicon with one or more metals, in particular germanium, iron, gold, nickel, palladium, platinum, chromium, titanium, which alloy contains at least 5 atomic per cent of silicon, has a melting temperature not higher than 1400 DEG C, has thermal expansion characteristics matching those of the bodies to be brazed together, and in the molten state is
Abstract: A method of brazing together bodies composed either of dense self-bonded silicon carbide containing free silicon or dense carbon using a brazing material consisting of an alloy of silicon with one or more metals, in particular germanium, iron, gold, nickel, palladium, platinum, chromium, titanium, which alloy contains at least 5 atomic per cent of silicon, has a melting temperature not higher than 1400 DEG C, has thermal expansion characteristics matching those of the bodies to be brazed together, and in the molten state is capable of wetting the surfaces of the bodies. The method is especially suitable for bracing silicon carbide caps to silicon carbide nuclear fuel element containers.
TL;DR: Krishna et al. as mentioned in this paper showed that single crystal needles of alpha (2H-wurtzite) silicon carbide have been grown under controlled conditions by the hydrogen reduction of purified methyltrichlorosilane onto silicon carbides coated graphite susceptors.
TL;DR: Mechanical property data for silicon nitride/silicon carbide fibre composite materials is presented and it is shown that high work of fracture can be obtained in the carbon/silica system.
Abstract: THE brittleness of ceramic materials, compared with metals, limits their use in engineering, in spite of such attractive properties as high temperature strength and oxidation resistance. Possible solutions to the brittleness problem therefore continue to be of interest. One approach advocated1 for silicon nitride has been that of fibre reinforcement, practical feasibility of which has been demonstrated2. In the carbon/silica system Crivelli-Visconti3 and Cooper have shown that high work of fracture can be obtained : we present here mechanical property data for silicon nitride/silicon carbide fibre composite materials. The potential of silicon nitride ceramics as engineering materials has been described elsewhere4.
TL;DR: In this paper, a high density of planar defects, often forming closed figures on {111} planes, was observed in chemically-vapor-deposited β-SiC. The defects were identified as extrinsic stacking faults by electron diffraction contrast analysis.
Abstract: A high density of planar defects, often forming closed figures on {111} planes, was observed in chemically-vapor-deposited β-SiC. The defects were identified as extrinsic stacking faults by electron diffraction contrast analysis.
Patent•
10 Feb 1971TL;DR: In this paper, a method for controlling the grow-out of SILICON CARBIDE CRYSTALS by carrying out the growth in the presence of an ELEMENT of Group III-B of the PERIODIC system of the LANTHANUM is presented.
Abstract: METHOD FOR CONTROLLING THE GROWTH OF SILICON CARBIDE CRYSTALS BY CARRYING OUT THE GROWTH IN THE PRESENCE OF AN ELEMENT OF GROUP III-B OF THE PERIODIC SYSTEM OF THE ELEMENTS, ESPECIALLY, LANTHANUM. THE WURTIZITE MODIFICATIONS CAN BE PRODUCED, WHICH WILL BE USEFUL IN SEMICONDUCTOR DEVICES. IN ADDITION, VERY LONG THIN WHISHERS CAN BE PRODUCED USEFUL FOR REINFORCING OTHER MATERIALS.
Patent•
19 Apr 1971
TL;DR: Hard, dense composite ceramic bodies of titanium diboride, boron carbide, silicon carbide and silicon, having a wide variety of utilities, are produced by forming a mixture of the three materials into a desired shape to obtain a coherent green body which is siliconized by heating it in contact with silicon to a temperature above the melting point of silicon as discussed by the authors.
Abstract: Hard, dense composite ceramic bodies of titanium diboride, boron carbide, silicon carbide and silicon, having a wide variety of utilities, are produced by forming a mixture of titanium diboride, boron carbide and a temporary binder into a desired shape to obtain a coherent green body which is siliconized by heating it in contact with silicon to a temperature above the melting point of silicon, whereupon the molten silicon infiltrates the body and reacts with some of the boron carbide therein to produce silicon carbide in situ.
TL;DR: In this article, a review of the operating characteristics of light emitting diodes (LEDs) and radiation effects in these devices are reviewed and criteria are developed for radiation insensitivity of LED's.
Abstract: Following a brief discussion of the operating characteristics of light emitting diodes (LED's), radiation effects in these devices are reviewed. Recent results on neutron damage effects in SiC LED's are also presented. Based on this review, criteria are developed for radiation insensitivity of LED's.
TL;DR: In this article, the equilibrium partial pressures of various vapor species in the system silicon-carbon-hydrogen were computed for conditions under which epitaxial deposition has been achieved, and it was found that in the temperature range 1300°-1700°C the tendency to form solid silicon carbide decreases with increasing temperature and with increasing silicon to carbon atom ratio.
Abstract: The equilibrium partial pressures of various vapor species in the system silicon‐carbon‐hydrogen were computed for conditions under which epitaxial deposition has been achieved. It was found that in the temperature range 1300°–1700°C the tendency to form solid silicon carbide decreases with increasing temperature and with increasing silicon to carbon atom ratio. The limiting conditions under which single crystalline deposits of could be experimentally obtained were those within which was computed to be the only thermodynamically stable solid phase. At 1650° single‐phase silicon carbide condenses at ratios ranging from 0.2 to 0.89. The computed results were in good agreement with experiments.
TL;DR: In this article, the 6H-polytype of silicon carbide has been studied by means of transmission electron microscopy and diffraction, and the displacement vector was deduced from contrast and extinction criteria to be of the type 16 〈2201〉.
Patent•
27 Dec 1971
TL;DR: In this paper, a graphite-alumina-silicon carbide base refractory has been proposed which provides good erosion resistance, spalling resistance and durable for oxidizing attack at elevated temperature.
Abstract: This invention provides a graphite-alumina-silicon carbide base refractory having good erosion resistance, spalling resistance and durable for oxidizing attack at elevated temperature. This refractory contains more than 85 wt. percent of main components of graphite (including combined carbon), alumina and silicon carbide (the weight ratio of graphite:alumina:silicon carbide being 10-38:60-80:2-18), and these three main components are combined with each other by a carbon bond which contains glassy material (2-6 wt. percent) and forms the network structure.
TL;DR: In this article, thin films of silicon have been deposited epitaxially by chemical vapor deposition using tetramethyl silane, Si(CH 3 ) 4, (TMS) as the transporting agent.
TL;DR: In this paper, an empirical equation has been constructed for the enthalpy and heat capacity of silicon carbide in the temperature range 273.15 to 2900 K, and a table of entropy, heat capacity, entropy, and Gibbs energy function for temperatures from 0 to 1000 K is also presented.
TL;DR: In this paper, the authors discuss the potential of Silicon carbide (SiC) as a semiconductor for specific applications: they are operable up to 500oC, they have enhanced radiation resistance, and certain particular characteristics (e.g., band gap) lead to specific device applications.
Abstract: Publisher Summary Silicon carbide (SiC) is perhaps the oldest semiconductor Although in the last fifty years considerable use has been made of its abrasive properties, only in the past fifteen years has its potentialities as a semiconductor been exploited The chapter discusses that Sic devices have distinct properties that lead to specific applications: they are operable up to 500oC, they have enhanced radiation resistance, and certain particular characteristics (example, band gap) lead to specific device applications Applications in these areas determine the final utilization of Sic devices The future development of Sic devices probably depends more on engineering perseverence than on semiconductor physics breakthrough The sophisticated active devices and integrated circuits now being prepared from silicon will be prepared from Sic when suitable crystals are available and the fabrication techniques are refined
TL;DR: In this paper, three mathematical models for use in calculating the stresses and displacements in two-, three-, and four-layer pyrolytic carbon and silicon carbide coatings on microspheres of (Th,U)C2 or O2...
Abstract: Three mathematical models for use in calculating the stresses and displacements in two-, three-, and four-layer pyrolytic carbon and silicon carbide coatings on microspheres of (Th,U)C2 or (Th,U)O2...
Patent•
10 Mar 1971TL;DR: Glassy carbon monofilament containing additional sulfur in combined form, has '''''high-temperature creep'''' properties useful in the deposition of boron, borone carbide, silicon carbide and pyrolytic graphite thereupon'' as mentioned in this paper.
Abstract: Glassy-carbon monofilament containing additional sulfur in combined form, has ''''high-temperature creep'''' properties useful in the deposition of boron, boron carbide, silicon carbide, and pyrolytic graphite thereupon
Patent•
23 Nov 1971TL;DR: In this paper, an ELECTRICAL INSILATING COATING for a LIGHTNING ARRESTER VALVE BLOCK including a major amount of SILICON CARBIDE PARTICLES is described.
Abstract: AN ELECTRICAL INSILATING COATING FOR A LIGHTNING ARRESTER VALVE BLOCK INCLUDING A MAJOR AMOUNT OF SILICON CARBIDE PARTICLES WHICH HAVE BULK RESISTIVITY SUBSTANTIALLY HIGHER THAN THE RESISTIVITY OF THE ELECTRICALLY CONDUCTIVE PORTION OF THE VALVE BLOCK THE COATING IS PREPARED BY ADMIXING THE SILICON CARBIDE PARTICLES, PREFERABLY GREEN SILICON CARBIDE, WITH CERAMIC FORMING MATERIALS AND SUFFICIENT WATER TO FORM A MIXTURE WHICH CAN BE APPLIED AS A COATING TO THE DEVICE IN A CONVENIENT MANNER AFTER THE RESISTANCE DEVICE HAS BEEN COATED WITH THIS MIXTURE, IT IS FIRED AT AN ELEVATED TEMPERATURE TO MATURE THE CERAMIC-FORMING INGREDIENTS AND THEREBY FORM A HARD, HIGHLY-ADHERENT COATING
Patent•
17 Dec 1971
TL;DR: In this paper, a high-temperature, low-oxygen contact is made to a cylindrical body by forming a very thin layer of carbon-bide over the surface of the body and then forming a METALLIC LAYER over the layer.
Abstract: A HIGH TEMPERATURE LOW OHMIC ELECTRICAL CONTACT IS MADE TO A SILICON BODY BY FORMING A VERY THIN LAYER OF SILICON CARBIDE OVER THE SILICON BODY AND THEN FORMING A METALLIC LAYER, SUCH AS A REFRACTORY METAL, OVER THE SILICON CARBIDE TO FORM A HIGH QUALITY LOW OHMIC CONTACT TO THE SURFACE OF THE SILICON BODY.