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:
Jun. 30, 2015
Filed:
Jan. 15, 2010
Shigeru Maida, Joetsu, JP;
Hisatoshi Otsuka, Joetsu, JP;
Shigeru Maida, Joetsu, JP;
Hisatoshi Otsuka, Joetsu, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
Disclosed is a method of producing a synthetic quartz glass for excimer laser by depositing on a target silica particulates obtained by subjecting a silica raw material to vapor-phase hydrolysis or oxidative decomposition in an oxyhydrogen flame in a vacuum sintering furnace to form a porous silica base material, vitrifying the porous silica base material, and subjecting the vitrified material to hot forming, an annealing treatment and a hydrogen doping treatment, wherein the vitrification of the porous silica base material includes: (a) a step of holding a vacuum pressure at or below 20.0 Pa in a temperature range from 400° C., inclusive, to 900° C., exclusive; (b) a step of holding a vacuum pressure at or below 10.0 Pa in a temperature range from 900° C., inclusive, to 1100° C., exclusive; and (c) a step of holding a vacuum pressure at or below 3.0 Pa in a temperature range from 1100° C. to a transparent-vitrification temperature.