SYNTHETIC QUARTZ GLASS MATERIAL FOR OPTICAL USE AND METHOD FOR EVALUATING SYNTHETIC QUARTZ GLASS FOR OPTICAL USE

摘要

PROBLEM TO BE SOLVED: To provide a synthetic quartz glass material for an optical use whose refractive index variation caused by irradiating it with ultraviolet pulse laser beams having the same laser energy density as that at mounting in an aligner for semiconductor is very small and to provide a method for evaluating synthetic quartz glass for an optical use. SOLUTION: The ultraviolet pulse laser beams having oscillation wavelength of 150 nm or more and 220 nm or less are used for the synthetic quartz glass material for the optical use within a range of 0.01 mJ/cm2or more and 0.3 mJ/cm2or less as an energy density per 1 pulse. When continuous light irradiated from an ultraviolet lamp having a light-emitting range of 150-300 nm irradiates the quartz glass at the illuminance of 0.01 mW/cm2or more and 100 mW/cm2or less, the refractive index at the irradiated part with the light from the ultraviolet lamp is reduced. When the total irradiation energy per unit area at the irradiated part with light from the ultraviolet lamp is expressed as A kJ/cm2and the refractive index variation at the irradiated part with light from the ultraviolet lamp is expressed as B, the range of the value B/A is denoted as -1×10-6≤B/A≤-1×10-7. COPYRIGHT: (C)2005,JPO&NCIPI