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:
Nov. 14, 2000
Filed:
Mar. 05, 1999
Norihiko Tsuchiya, Setagaya-Ku, JP;
Hiroshi Matsushita, Funabashi, JP;
Kabushiki Kaisha Toshiba, Kawasaki-shi, JP;
Abstract
The average density and scattered light intensity or the average density and average size of void defects contained in a surface region in a predetermined depth of a semiconductor wafer sample are measured. An ingot whose a semiconductor wafer sample satisfies D.times.Is.ltoreq.a predetermined value between the measured average density D and scattered light intensity Is or satisfies D.times.L.sup.3 .ltoreq.fixed value between the measured average density D and average size L is extracted and wafers cut from the ingot are annealed. The semiconductor wafers having few residual defects in a surface region wherein devices are to be formed can be obtained.