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:
Mar. 31, 1998
Filed:
Jul. 29, 1996
Toshihiro Tsuchiya, Nishigou-mura, JP;
Kouichi Tanaka, Nishigou-mura, JP;
Kiromasa Hashimoto, Nishigou-mura, JP;
Kouji Morita, Nishigou-mura, JP;
Tsutomu Takaku, Nishigou-mura, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
The invention concerns a process of polishing wafers, in which a silicon wafer held on a wafer support plate rotatable under a predetermined applied pressure, is polished by mechanochemical polishing in a plurality of polishing steps with an abrasive material interposed between the wafer and a polishing pad cloth applied to a polishing surface plate moved relative to the wafer support plate at a predetermined relative speed. Quality comparable to that of wafers obtainable by a prior art three-step polishing process can be obtained with a two-step wafer polishing step comprising a primary polishing step and a final polishing step. The primary polishing step is performed by setting a high polishing pressure of 300 to 700 g/cm.sup.2 and a reference relative speed of 50 to 150 m/min., and quick increase of the relative speed to 2 to 4 times and quick reduction of the polishing pressure down to 1/2 to 1/10 are caused in a final stage of the primary polishing step. The final polishing step is performed by setting a reference polishing pressure of 100 to 400 g/cm.sup.2 and a reference relative speed of 50 to 150 m/min., and in its final stage the relative speed is quickly reduced to 1/2 to 1/5.