Process for preparing a silicon carbide sintered body for use in semiconductor equipment

摘要

A process for the preparation of a silicon carbide sintered body of high purity which has a content of 1 ppm or less of each atom harmful to the manufacture of semiconductor equipment including the step of shaping a silicon carbide powder, calcining the shaped body in a non-oxidizing atmosphere to form a porous body, and subjecting the porous body to reaction sintering while being impregnated with molten metallic silicon. The starting silicon carbide powder also has a content of 1 ppm or less of each harmful atom and it has a free carbon content of not greater than 20% by weight and an average particle diameter of 0.5-20 mu m. Such silicon carbide powder can be prepared from a carbon- and silicon-containing starting mixture including at least one liquid hydrolyzable silicon compound and 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 harmful atoms by solidifying the starting mixture and heating it so as to react and form silicon carbide.