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. 28, 2020
Filed:
Feb. 23, 2018
Sumco Corporation, Tokyo, JP;
Taisuke Mizuno, Saga, JP;
SUMCO CORPORATION, Tokyo, JP;
Abstract
Provided is a method of analyzing metal contamination of a silicon wafer, the method including etching a surface layer region of the silicon wafer by bringing a surface of a silicon wafer to be analyzed into contact with etching gas that includes hydrogen fluoride gas and nitric acid gas; bringing an exposed surface of the silicon wafer, exposed by the etching, into contact with gas generated from a mixed acid including hydrochloric acid and nitric acid; heating the silicon wafer that has been brought into contact with the gas generated from the mixed acid; bringing the exposed surface, exposed by the etching, of the silicon wafer after the heating into contact with a recovery solution; and analyzing a metal component in the recovery solution that has been brought into contact with the exposed surface, exposed by the etching, of the silicon wafer.