Process for preparing silicon carbide powder for use in semiconductor

Abstract

A process for the preparation of a beta-silicon carbide powder of high purity which is suitable for use in the manufacture of semiconductor equipment and which has a content of 1 ppm or less of each atom harmful to the manufacture of semiconductor devices. The process comprises preparing a carbon- and silicon-containing starting mixture comprising (a) at least one siliceous material selected from liquid silicon compounds and solid siliceous substances derived from a hydrolyzable silicon compound, and (b) at least one carbonaceous material selected from polymerizable or cross-linkable organic compounds prepared in the presence of a catalyst which is substantially free from atoms harmful to the manufacture of semiconductor devices. The starting mixture comprises at least one liquid substance used as component (a) or (b). The starting mixture is then solidified by heating and/or by use of a catalyst or a curing agent. The resulting solid body is optionally heat treated in a non-oxidizing atmosphere at a temperature in the range of from 500.degree. C. to 1300.degree. C. for a period sufficient to remove volatiles. The cured and optionally heat-treated body is calcined in a non-oxidizing atmosphere under conditions sufficient to give beta-silicon carbide powder.