TIO2-CONTAINING SILICA GLASS AND OPTICAL MEMBER FOR LITHOGRAPHY USING THE SAME

摘要

The present invention is to provide a TiO2—SiO2 glass 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 TiO2-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.