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:
Oct. 04, 2022
Filed:
Apr. 10, 2018
Nissan Chemical Corporation, Tokyo, JP;
Hiroaki Sakaida, Funabashi, JP;
Eiichiro Ishimizu, Funabashi, JP;
NISSAN CHEMICAL CORPORATION, Tokyo, JP;
Abstract
There are provided a polishing composition that gives, in the step of polishing a wafer, a flat polished surface having a reduced height difference between a central region and a peripheral region (laser mark region) of the wafer, and a method for producing a wafer using the polished composition. A polishing composition comprising water, silica particles, an alkaline substance, and an amphoteric surfactant of formula (1): wherein Ris a Calkyl group, or a Calkyl group containing an amide group; Rand Rare each independently a Calkyl group; and Xis a Canionic organic group containing a carboxylate ion or a sulfonate ion. Silica particles in the form of an aqueous dispersion of silica particles having a mean primary particle diameter of 5 to 100 nm may be used. A method for producing a wafer, wherein in the step of polishing a wafer, polishing is performed until a height difference between a central region and a peripheral region of the wafer becomes 100 nm or less.