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. 07, 1999
Filed:
Aug. 11, 1997
Applicant:
Inventors:
Shoichi Takamizawa, Nishishirakawa, JP;
Norihiro Kobayashi, Annaka, JP;
Assignee:
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
438476 ; 438680 ; 438471 ; 438778 ; 438788 ; 438D / ; 257D / ; 148D / ; 148D / ;
Abstract
In a silicon wafer having a CVD film formed on one main face and having the other main face mirror-polished, the components and/or composition of the CVD film change in the thicknesswise direction of the film. This makes it possible to provide a silicon wafer having a thin film provided on the back surface, which thin film has excellent and persistent gettering capability that can remove a greater variety of types of elements and can prevent autodoping.