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:
Jan. 19, 2010
Filed:
Aug. 15, 2006
Sakae Koyata, Tokyo, JP;
Tomohiro Hashii, Tokyo, JP;
Katsuhiko Murayama, Tokyo, JP;
Kazushige Takaishi, Tokyo, JP;
Takeo Katoh, Tokyo, JP;
Sakae Koyata, Tokyo, JP;
Tomohiro Hashii, Tokyo, JP;
Katsuhiko Murayama, Tokyo, JP;
Kazushige Takaishi, Tokyo, JP;
Takeo Katoh, Tokyo, JP;
Sumco Corporation, Tokyo, JP;
Abstract
A process for producing a silicon wafer comprising a single-wafer etching step of performing an etching by supplying an etching solution through a supplying-nozzle to a surface of a single and a thin-discal wafer obtained by slicing a silicon single crystal ingot and rotating the wafer to spread the etching solution over all the surface of the wafer; and a grinding step of grinding the surface of the wafer, in this order, wherein the etching solution used in the single-wafer etching step is an aqueous acid solution which contains hydrogen fluoride, nitric acid, and phosphoric acid in an amount such that the content of which by weight % at a mixing rate of fluoric acid:nitric acid:phosphoric acid is 0.5 to 40%:5 to 50%:5 to 70%, respectively.