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:
May. 03, 2011
Filed:
Feb. 04, 2008
Toshiaki Ono, Tokyo, JP;
Masataka Hourai, Tokyo, JP;
Toshiaki Ono, Tokyo, JP;
Masataka Hourai, Tokyo, JP;
Sumco Corporation, Tokyo, JP;
Abstract
A silicon wafer which achieves a gettering effect without occurrence of slip dislocations is provided, and the silicon wafer is subject to heat treatment after slicing from a silicon monocrystal ingot so that a layer which has zero light scattering defects according to the 90° light scattering method is formed in a region at a depth from the wafer surface of 25 μm or more but less than 100 μm, and a layer which has a light scattering defect density of 1×10/cmor more according to the 90° light scattering method is formed in a region at a depth of 100 μm from the wafer surface.