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:
Jul. 27, 1999
Filed:
Feb. 01, 1996
Applicant:
Inventors:
Yasukazu Mukogawa, Hyogo, JP;
Yasuhiro Kimura, Hyogo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428409 ; 428426 ; 428428 ; 428446 ; 428700 ;
Abstract
A monocrystalline silicon wafer is improved so as not to cause enhanced oxidation at the time of forming a gate oxide film. The monocrystalline silicon wafer includes a monocrystalline silicon substrate. The monocrystalline silicon substrate has potassium concentration of at most 2.times.10.sup.11 atoms/cm.sup.2 at an outer surface thereof.