Patent ID: 6656860
Filing Date: 2003-12-02
Classification: C03C,G03F

Abstract:
A synthetic silica glass member for use in a photolithography apparatus employing light in a wavelength range of 400 nm or less, whereinupon 1Ã—104 pulse irradiation with an ArF excimer laser at an energy density from 0.1 &mgr;J/cm2Â·p to 200 mJ/cm2Â·p, the loss factor at 193.4 nm measured after irradiation is no greater than 0.0050 cmâˆ’1, the hydrogen molecule concentration is from 1Ã—1016 molecules/cm3 to 1.8Ã—1018 molecules/cm3, wherein for the hydrogen molecule concentration at the geometrical center of gravity of the synthetic silica glass member, the variation width V of the hydrogen molecule concentration at any desired point on a plane including the center is in the range of âˆ’50%&lE;V&lE;+50%, and the loss factor before ultraviolet irradiation is no greater than 0.0020 cmâˆ’1.