Russell E Kremer

US Patent:

49990829, Mar 12, 1991

Filed:

Sep 14, 1989

Appl. No.:

7/406987

Inventors:

Russell E. Kremer - Woodland Park CO
David M. Francomano - Colorado Springs CO

Assignee:

Akzo America Inc. - New York NY

International Classification:

C30B 1104

US Classification:

156605

Abstract:

This disclosure relates to a process for producing monocrystalline Group II-IV or Group III-V compounds from the polycrystalline form of said Group II-IV or Group III-V compound, said process comprising coating the interior surface of a crucible with a powdered solid having a melting point higher than the polycrystalline form of the compound, placing an amount of polycrystalline compound into the coated crucible, heating the crucible to produce a melt while maintaining the powder in solid form and cooling the crucible to produce a solid compound. The preferred powdered solid is pyrolitic boron nitride. The process may be used to produce, inter alia, semi-insulating gallium arsenide having a neutral EL2 concentration greater than or equal to about 0. 85. times. 10. sup. 16 cm. sup. -3 and a dislocation density between about 500 cm. sup. -2 and 7,800 cm. sup. -2.