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:
Jul. 02, 2002
Filed:
May. 22, 2000
Applicant:
Inventors:
Yukio Shibano, Nakakubiki-gun, JP;
Hisatoshi Otsuka, Nakakubiki-gun, JP;
Assignee:
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G03F 9/00 ;
U.S. Cl.
CPC ...
G03F 9/00 ;
Abstract
A synthetic quartz glass substrate is prepared by annealing a synthetic quartz glass member having a higher hydroxyl content in a peripheral portion than in a central portion, machining off the peripheral portion of the member, slicing the member into a plate shaped substrate, chamfering and etching the substrate. The synthetic quartz glass substrate has a minimized birefringence and is suited for use as a photomask in photolithography.