Download or read book A Review of Candidate Techniques for the Growth of Beta Silicon Carbide Single Crystals written by Erh-Nan Chou and published by . This book was released on 1984 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Some Factors Affecting the Growth of Beta Silicon Carbide written by Charles Edward Ryan and published by . This book was released on 1966 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report discusses the growth of beta silicon carbide by the hydrogen reduction of methyl trichlorine onto carbon substrates at 1500C. It is shown that alpha inclusions present are the rare 2H (Wurtzite) modification of silicon carbide and that their presence resulted from a vapor-liquid-solid growth mechanism which was dominated by impurities in the substrate. By carefully cleaning the substrate and purifying the methyltrichlorosilane, the alpha inclusions were eliminated. The 2H alpha crystals were then deliberately grown by introducing selected impurities locally on the substrate. Beta crystals were also intentionally grown by the vapor-liquid-solid technique by introducing appropriate impurities. Growth of beta silicon carbide from the melt is also briefly discussed. (Author).
Download or read book Development of Manufacturing Methods for Growing Large Beta silicon Carbide Single Crystals written by Walter E. Nelson and published by . This book was released on 1966 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth of Single Crystal Beta Silicon Carbide written by and published by . This book was released on 1992 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beta-SiC is a promising, wide bandgap material for high power electronic devices capable of operation at high temperatures. Its high saturation velocity, high breakdown electric field, and high thermal conductivity point to superior performance for high frequency applications. The successful fabrication of Beta-SiC devices requires high quality films to be epitaxially grown on lattice-matched substrate materials. Single crystals of Beta-SiC offer the optimum substrate material for lattice matching. The major problem to be overcome in the growth of large single crystals of Beta-SiC is polytype alpha-SiC formation. Cubic Beta-SiC crystallizes only below 2000 deg C. Above this temperature, SiC undergoes a phase transformation from the Beta-to the alpha-phase. In Phase I, we investigated two crystal growth techniques: sublimation and gas-vapor transport. We were able to grow small 3C-SiC crystals by both methods.
Download or read book Method of Forming Single Crystals of Beta Silicon Carbide Using Liquid Lithium as a Solvent written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of growing single crystals of beta SiC from solution using molten lithium as a solvent for polycrystalline SiC feed material. Reasonable growth rates are accomplished at temperatures in the range of about 1330.degree. C. to about 1500.degree. C.
Download or read book Growth Processing and Characterization of Beta silicon Carbide Single Crystals written by Arne Rosengreen and published by . This book was released on 1969 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Equipment and growth procedures for growing beta-silicon carbide epitaxially on beta-silicon carbide substrates from methyltrichlorosilane in a carrier gas of hydrogen is described. Hall and resistivity measurements and electron spin resonance measurements are discussed. The results show that the quality of the epitaxially grown material is comparable with that of the best solution grown crystals. Processing steps such as oxidation, masking, and etching have been performed and simple electroluminescent diodes have been fabricated. (Author).
Download or read book The Growth of SiC Crystals from Vapor by the Bridgman Stockbarger Method written by Juris Smiltens and published by . This book was released on 1974 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the dissociation curve (P vs. T), an equation for the rate of raising the pressure P of the binary vapor for obtaining the required linear growth rate of the crystal of c centimeters per hour is derived. It is shown that the rate is nearly proportional to P. Modifications of the furnace since the last report (Mat. Res. Bull. 4, S85, 1969) are described. Justification for the use of helium as the inert ambient gas is given. Two techniques are used: (1) growing with constant temperature of the crucible point and (2) growing with constant pressure of the sublimation bottle. To date, only polycrystalline boules consisting of large grains have been obtained. It is believed, however, that with certain technological improvements the methods that are developed here will ultimately yield single crystal boules. As a by-product, small cubic crystals, about one mm in the largest dimension, with good quality faces (cube and octahedron) have been obtained.
Download or read book Growth and Characterization of Beta silicon Carbide Single Crystals written by Frank A. Halden and published by . This book was released on 1965 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Changes in crystal size and morphology were obtained by modifying the process for growing crystals of betasilicon carbide from solution in carbon-saturated melts. Well developed laths and plates were grown under conditions favoring dendritic growth mechanisms (low thermal gradient with moderate stirring). Polyhedral crystals grew under high thermal gradient conditions when high velocity stirring was employed. Three-dimensionaltype growth was also produced from a 73 wt percent ironsilicon alloy under conditions that normally produce lath-type growth. Uncorrected electron mobilities of 700 to 1000 sq cm/v-sec were measured at room temperature, and a few preliminary Hall measurements were made over the temperature range from 77 to 300 K. (Author).
Download or read book Growth and Characterization of Large High Purity Beta Silicon Carbide Single Crystals written by William R. Harding and published by . This book was released on 1970 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report summarizes the development program in the growth of large high purity beta silicon carbide crystals. Conditions for stable beta growth were partially established. Beta silicon carbide can be grown in the region of 2000-2200C and 28-42 microns pressure. Within this region, large beta crystals will grow by sublimation. Lang topographs of crystals were compared with etched surface structures and petrographic examination. Correlation among the results of these techniques was shown to exist. This analysis indicated the presence of large stacking faults within the structure as well as polytype intergrowths. Resistivity and Hall measurements were made with indications of highly compensated material. (Author).
Download or read book Investigation of the Growth of Single Crystal Silicon Carbide by the Travelling Solvent and Other Methods written by B. N. Das and published by . This book was released on 1967 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Travelling Heater Method (THM) crystal growth of SiC from a graphite crucible in Cr-Si-C was investigated. Porous, coarse crystalline, cylindrical SiC rods were obtained. Preliminary results strongly suggest that the growth of solid SiC rods by THM will be experimentally feasible, if axial and radial heat flow and temperature gradient are properly monitored. Beta-SiC whiskers were grown by a VLS mechanism. An attempt is being made to analyze the composition of the growth matrix material by X-ray and electron diffraction so that SiC whiskers, or large SiC crystals, could reproducibly be grown from this solvent. The recently developed laser reflectogram technique was applied to the study of the SiC surface crystallography for various SiC crystal preparations and surface treatments. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Method of Forming Single Crystals of Beta Silicon Carbide written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of growing single crystals of beta SiC from solution using molten lithium as a solvent for polycrystalline SiC feed material. Reasonable growth rates are accomplished at temperatures in the range of about 1330/sup 0/C or about 1500/sup 0/C.
Download or read book A Unique High temperature High pressure Crystal Growth System for Silicon Carbide written by J. R. Littler and published by . This book was released on 1973 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high-pressure, high-temperature furnace system is described for crystal growth experiments using crucibles up to 13 cm in diameter and 26 cm high. The vertical temperature gradient is electronically controlled during growth such that the ends of the crucible can be maintained at temperatures above or below the crucible center. Temperatures up to 2800C can be maintained at pressures up to 50 atmospheres. A vacuum capability up to .000001 torr at 1800C has been incorporated into the system. Single crystals of alpha silicon carbide grown in this system at 2600C are described to illustrate its use. (Author).
Download or read book The Influence of Annealing on Thin Films of Beta SiC written by Irvin Berman and published by . This book was released on 1972 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin films of beta silicon carbide were prepared on alpha silicon carbide substrates by the chemical vapor deposition (CVD) technique involving the hydrogen reduction of silane and propane. The films were prepared under a variety of conditions and subsequently subjected to thermal annealing cycles between 1600 degrees C and 2000 degrees C. It is shown that the single crystallinity of the beta films improved with continued annealing. The beta polytype was found to be stable over the entire range of temperatures studied.
Download or read book Growth of Silicon Carbide Single Crystals written by F. A. Halden and published by . This book was released on 1961 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Near Thermal Equilibrium Growth of 4H 6H and 15R silicon Carbide Single Crystals written by Norbert Schulze and published by . This book was released on 2001 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Manufacturing Methods for Growing Large B silicon Carbide Single Crystals written by Stanford Research Institute and published by . This book was released on 1967 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
