SYNTHETIC QUARTZ GLASS OPTICAL MATERIAL AND OPTICAL MEMBER FOR F 2? EXCIMER LASERS

摘要

An object of the present invention is to provide a synthetic quartz glass optical material having a high optical transmittance for a radiation 157 nm in wavelength emitted from F2 excimer laser and a high resistance against irradiation of a F2 excimer laser radiation, yet having a uniformity suitable for such a fine patterning using a F2 excimer laser, and to provide an optical member using the same. The problems above are solved by a synthetic quartz glass optical material for F2 excimer lasers having an OH group concentration of 0.5 ppm or lower, a fluorine concentration of 0.1 to 2 mol %, a hydrogen molecule concentration of 5x10<16 >molecules/cm<3 >or lower, a difference between the maximum and minimum fluorine concentrations within 20 mol ppm, and a difference between the maximum and minimum refraction indices of 2x10<-5 >or lower.