Process for producing high purity silicon carbide powder for preparation of a silicon carbide single crystal and single crystal
US5863325A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1995 |
| Grant date | Jan 26, 1999 |
| Priority date | — |
| Expiry date | Sep 27, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/80
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for producing high purity silicon carbide uses a high purity tetraethoxysilane or the like as the silicon source and a novolak-type phenol resin or the like as the carbon source. The process comprises a step of forming silicon carbide in which silicon carbide powder is prepared by calcining a mixture of these sources in a non-oxidizing atmosphere, and a step of post-treating silicon carbide in which the silicon carbide powder thus obtained is treated by heating at a temperature of 2000.degree. to 2100.degree. C. for 5 to 20 minutes at least once while the silicon carbide powder is kept at a temperature of 1700.degree. or higher to lower than 2000.degree. C., to obtain silicon carbide powder having an average particle diameter of 10 to 500 .mu.m and a content of impurity elements of 0.5 ppm or less. The high purity silicon carbide powder is advantageously used as a material for producing an excellent silicon carbide single crystal having a decreased number of crystal defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.