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:
Jan. 13, 1987
Filed:
Aug. 21, 1984
Applicant:
Inventors:
Assignees:
Sumitomo Electric Ind., Ltd., Osaka, JP;
Nippon Telegraph & Telephone Public Corp., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B / ;
U.S. Cl.
CPC ...
156603 ; 156D / ; 148187 ;
Abstract
An IC wafer with a uniform distribution of impurities is obtained by a pretreatment comprising annealing a semiconductor substrate at a high temperature for a long period of time and then cooling rapidly before IC processing.