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:
Apr. 15, 2003
Filed:
Mar. 10, 2000
Atsushi Ikari, Chiba, JP;
Masami Hasebe, Chiba, JP;
Katsuhiko Nakai, Chiba, JP;
Hikaru Sakamoto, Chiba, JP;
Wataru Ohashi, Chiba, JP;
Taizo Hoshino, Yamaguchi, JP;
Toshio Iwasaki, Yamaguchi, JP;
Wacker NSCE Corporation, Tokyo, JP;
Abstract
A silicon semiconductor substrate is obtained by deriving a silicon semiconductor substrate from a silicon single crystal grown by the Czochralski method from a molten silicon containing not less than 1×10 atoms/cm and not more than 1.5×10 atoms/cm of nitrogen and heat-treating the silicon semiconductor substrate at a temperature of not less than 1000° C. and not more than 1300° C. for not less than one hour and is characterized by the fact that the density of crystal defects measuring not less than 0.1 &mgr;m as reduced to diameter is not more than 10 pieces/cm at least in the region reaching a depth of 1 &mgr;m from the surface of the substrate and the nitrogen content at the center of thickness of the silicon semiconductor substrate is not less than 1×10 atoms/cm and not more than 1×10 atoms/cm .