The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 31, 1996
Filed:
Jan. 18, 1994
Shoichi Kojima, Tokyo, JP;
Kazuhiro Minagawa, Amagasaki, JP;
Haruyuki Kano, Ibaraki-ken, JP;
Tadaaki Miyazaki, Higashi-Yamato, JP;
Hiroaki Wada, Kawasaki, JP;
Sumitomo Metal Industries, Ltd., Tokyo, JP;
Abstract
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.