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. 16, 2011
Filed:
Aug. 27, 2010
Akio Koike, Tokyo, JP;
Yasutomi Iwahashi, Tokyo, JP;
Shinya Kikugawa, Tokyo, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
The present invention provides a TiO—SiOglass whose coefficient of linear thermal expansion upon irradiation with high EUV energy light is substantially zero, which is suitable as an optical member of an exposure tool for EUVL. The present invention relates to a TiO-containing silica glass having a halogen content of 100 ppm or more; a fictive temperature of 1,100° C. or lower; an average coefficient of linear thermal expansion in the range of from 20 to 100° C. of 30 ppb/° C. or lower; a temperature width ΔT, in which a coefficient of linear thermal expansion is 0±5 ppb/° C., of 5° C. or greater; and a temperature, at which a coefficient of linear thermal expansion is 0 ppb/° C., falling within the range of from 30 to 150° C.