Patent ID: 6835683
Filing Date: 2004-12-28
Classification: C03B,C03C,G02B,G03F

Abstract:
A silica glass member wherein when a composition thereof is expressed by SiOx, x is not less than 1.85 nor more than 1.95, wherein a concentration of hydrogen molecules included therein is not less than 1Ã—1016 molecules/cm3 nor more than 5Ã—1018 molecules/cm3, and wherein a difference Aâˆ’B between an absorption coefficient A immediately before an end of irradiation with 1Ã—104 pulses of ArF excimer laser light in an average one-pulse energy density of 2 mJ/cm2 and an absorption coefficient B at 600 seconds after a stop of the irradiation with the ArF excimer laser light is not more than 0.005 cmâˆ’1.