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:
Aug. 07, 2018
Filed:
Jul. 13, 2015
Shin-etsu Handotai Co., Ltd., Tokyo, JP;
Michito Sato, Nishigo-mura, JP;
SHIN-ETSU HANDOTAI CO., LTD., Tokyo, JP;
Abstract
A final polishing method using a polishing agent that contains colloidal silica, ammonia, and hydroxyethyl cellulose in which the colloidal silica has a primary particle size of 20 nm or more and less than 30 nm, the hydroxyethyl cellulose has a weight average molecular weight of 400,000 to 700,000, and the polishing agent satisfies 1.5≤D/D≤2.5 where Dis a particle size having a cumulative volume percentage of 95% of particles contained in the polishing agent, and Dis a particle size having a cumulative volume percentage of 95% of the colloidal silica in case of dispersing the colloidal silica in water with a concentration identical to a colloidal silica concentration in the polishing agent, and using a polishing pad that exhibits a contact angle of 60° or more 100 seconds after dropping pure water to the polishing pad that has been subjected to seasoning and then dried.