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. 11, 2011
Filed:
Aug. 24, 2010
Akio Koike, Tokyo, JP;
Yasutomi Iwahashi, Tokyo, JP;
Shinya Kikugawa, Tokyo, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
The present invention is to provide a TiO—SiOglass whose coefficient of linear thermal expansion at the time of irradiating with high EUV energy light becomes substantially zero when used as an optical member of an exposure tool for EUVL. The present invention relates to a TiO-containing silica glass, having a fictive temperature of 1,000° C. or lower, a OH concentration of 600 ppm or higher, a temperature at which the coefficient of linear thermal expansion becomes 0 ppb/° C. of from 40 to 110° C., and an average coefficient of linear thermal expansion in the temperature range of 20 to 100° C., of 50 ppb/° C. or lower.