The Growth Of Sic Crystals From Vapor By The Bridgman Stockbarger Method

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.

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.

Silicon Carbide — 1968 presents the proceedings of the International Conference on Silicon Carbide held in University Park, Pennsylvania on October 20-23, 1968. The book covers papers about the perspectives on silicon carbide; several problems in the development of silicon carbide semiconductors, such as the control of crystal structure and analysis. The thermal properties of beta-silicon carbide from 20 to 2000 degrees and the influence of impurities on the growth of silicon carbide crystals in chemical reactions and by recrystallization are also discussed. The book then presents papers about silicon carbide single crystal growth using the Norton process; the principles of solution and traveling solvent growth of silicon carbide; the growth of silicon carbide from cobalt-silicon solutions; and the growth of silicon carbide from vapor by the Bridgman-Stockbarger method. Papers about the growth of crystals and epitaxial layers of beta silicon carbide; the heteroepitaxy of beta-silicon carbide employing liquid metals; some aspects of disorder in silicon carbide; and the dependence of physical properties on polytype structure are also considered. The book describes topics about the optical properties of polytypes of silicon carbide as well as the phase stability of silicon carbide against nitrogen. Other papers about the physical and electronic properties of silicon carbide are also discussed in the book. People involved in semiconductor industries will find the book helpful.

This volume concludes the coverage of silicon carbide, SiC, begun in "Silicon" Supplement Volume B 2, 1984, subtitled "Silicon Carbide - Part I". Part I described the physical properties of SiC, SiC diodes, molecular species in the SiC-C gas phase, and amorphous silicon-carbon alloys. The current Part II ("Silicon" Supplement Volume B 3,1986) covers in its initial chapter the Si-C phase diagram and in the final chapters the higher order systems of Si and C with additional elements through boron, arranged according to the Gmelin system. In between some 95% of the volume focusses on SiC, beginning with its natural occurrence, preparation and formation, and purification, continuing with its chemical analysis, manufacture of special ized forms, electrochemistry, and chemical reactions, and concluding with descriptions of its myriad applications. The final applications section covering electronic devices also describes similar applications of the amorphous Si-C alloys. The successive chapters in this volume are often closely interrelated, since it is often necessary to synthesize SiC directly in a form in which it will be applied. SiC cannot be melted and cast, nor rolled nor drawn, nor is it easily electroplated or sintered or purified. Silicon carbide first became known to man when E. G. Acheson in 1891 used an electric current to heat a mixture of clay and carbon to extremely high temperatures.