Synthetic quartz glass member for use in ArF excimer laser lithography

摘要

A synthetic glass member for use in excimer laser lithography, having superior homogeneity, high transmittance for ArF excimer laser beams and an excellent resistance against lasers is made from high purity synthetic quartz glass, and it is characterized in that layered structures, striae in three directions and internal strains are thermally and mechanically removed, the distribution of refractive index ( DELTA n) in a plane orthogonal to the optical axis is up to about 1 x 10<-6>, the distribution of refractive index ( DELTA n) in a plane parallel to the optical axis is up to about 5 x 10<-6>, the birefringence is up to about 2 nm/cm, the hydrogen molecule concentration is at least about 2 x 10<17> molecules/cm<3>, and the internal transmittance is at least about 99.8% at a wavelength of 193.4 nm.