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:
Dec. 27, 2022
Filed:
Aug. 02, 2018
Globalwafers Japan Co., Ltd., Niigata, JP;
GLOBALWAFERS JAPAN CO., LTD., Niigata, JP;
Abstract
A method of evaluating metal contamination by measuring the amount of metal contaminants to a silicon wafer in a rapid thermal processing apparatus includes steps of obtaining a Si single crystal grown by the Czochralski method at a pulling rate of 1.0 mm/min or lower, the crystal having oxygen concentration of 1.3×10atoms/cmor less, slicing silicon wafers from the Si single crystal except regions of 40 mm toward the central portion from the head of the single crystal and 40 mm toward the central portion from the tail, heat-treating the silicon wafer with a rapid thermal processing apparatus and transferring contaminants from members in a furnace of the rapid thermal processing apparatus to the silicon wafer, and measuring a lifetime of the silicon wafer to which contaminants are transferred.