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. 08, 2012
Filed:
May. 22, 2007
Shuichi Inami, Tokyo, JP;
Shuichi Inami, Tokyo, JP;
Sumco Corporation, Tokyo, JP;
Abstract
An evaluation area of an evaluation object wafer is concentrically divided in a radial direction, an upper limit value to the number of COPs is set in each divided evaluation segment, and an acceptance determination of the single-crystal silicon wafer is made using the upper limit value as a criterion. Thereby, a quantitative and objective COP evaluation can be made, and a proper determination is made based on a clear criterion. The evaluation method of the present invention can sufficiently deal with automation of the COP evaluation (inspection) and the higher-quality wafer in the near future, and the evaluation method can be widely applied to production of the single-crystal silicon wafer and production of a semiconductor device.