Patent ID: 7964522
Filing Date: 2011-06-21
Classification: C03B,C03C,Y02P

Abstract:
1. An F-doped synthetic silica glass material capable of being used in the light path of the lithographic irradiation of a lithographic device operating at a wavelength below 300 nm, comprising, by weight of the glass: from 0.01 to 150 ppm OD; less than 50 ppm of Cl; less than 50 ppb of Na; less than 50 ppb in total of transition metals; and from 0.1 ppm to 5000 ppm of fluorine; and having a polarization-induced birefringence of lower than 7 nm/mm, measured at 633 nm after being subjected to 10 million pulses of linearly polarized pulsed laser beam at 157 nm having a fluence of 250 μJ·cm