SYNTHETIC QUARTZ GLASS MEMBER FOR ArF EXCIMER LASER LITHOGRAPHY

摘要

PROBLEM TO BE SOLVED: To provide a synthetic quartz glass member for an ArF excimer laser having high homogeneity, high transmitting properties for ArF excimer laser light and excellent resistance against laser light. SOLUTION: This synthetic quartz glass member consists of high purity synthetic quartz glass and has a laminar structure in which striae in three directions and inner stains are thermally and mechanically removed. This member is to be used for ArF excimer laser lithography and has the following properties. The refractive index distributionΔn in the plane perpendicular to the optical axis is h1×10-6, and the refractive index distributionΔn in the plane parallel to the optical axis is <=5×10-6. The glass has <=2 nm/cm double refraction, >=2×1017 molecules/cm3 hydrogen molecule density, and >=99.8% inner transmittance for 193.4 nm wavelength.