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:
Sep. 22, 2026
Filed:
Feb. 21, 2022
Shin-etsu Handotai Co., Ltd., Tokyo, JP;
Kota Fujii, Nishigo-mura, JP;
Tatsuo Abe, Shirakawa, JP;
SHIN-ETSU HANDOTAI CO., LTD., Tokyo, JP;
Abstract
A method of cleaning a silicon wafer in which the silicon wafer is roughened, including: forming an oxide film on the silicon wafer by SC1 cleaning, SC2 cleaning, or ozone water cleaning; cleaning the silicon wafer on which the oxide film is formed by using any one of: a diluted aqueous solution of ammonium hydroxide having an ammonium hydroxide concentration of 0.051% by mass or less; or a diluted aqueous solution containing ammonium hydroxide and hydrogen peroxide water and having an ammonium hydroxide concentration of 0.051% by mass or less and a hydrogen peroxide concentration of 0.2% by mass or less, the hydrogen peroxide concentration being four times or less the ammonium hydroxide concentration, to roughen front and rear faces of the silicon wafer.