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:
Apr. 03, 2018
Filed:
Aug. 27, 2015
Sumco Corporation, Tokyo, JP;
Shinya Fukushima, Saga, JP;
Tsuyoshi Kubota, Saga, JP;
SUMCO CORPORATION, Tokyo, JP;
Abstract
An aspect of the present invention relates to a method of evaluating metal contamination in a boron-doped p-type silicon wafer, which comprises measuring over time by a microwave photoconductive decay method a recombination lifetime following irradiation with light of a silicon wafer being evaluated and obtaining information on change over time of the recombination lifetime, and comparing the information on change over time of the recombination lifetime that has been obtained with reference information on change over time that has been obtained by calculation or actual measurement of a recombination lifetime of an Fe-contaminated boron-doped p-type silicon wafer to determine whether or not metal contamination other than Fe is present in the silicon wafer being evaluated.