| 摘要 |
An optical member is provided for used by a photolithography projection system that has a sub-200 nm wavelength vacuum ultraviolet light source. The optical member includes silica glass that has an ArF excimer laser-induced bulk attenuation coefficient DELTA gamma that substantially satisfies the equation, DELTA gamma = ks . epsilon <2> . P<1> when an ArF excimer laser with an energy density less than or equal to about 200 mJ/cm<2> per pulse is used for illumination, where ks is less than about 9.1 x 10<-13> cm<-1>, epsilon is per pulse energy density, P is pulse count, and ks is a proportionality constant. <IMAGE> |
