High purity silicon oxyfluoride glass suitable for use as a photomask
substrates for photolithography applications in the VUV wavelength region
below 190 nm is disclosed with the silicon oxyfluoride glass having a
preferred fluorine content<0.5 weight percent. The inventive silicon
oxyfluoride glass is transmissive at wavelengths around 157 nm, making it
particularly useful as a photomask substrate at the 157 nm wavelength
region. The inventive photomask substrate is a "dry," silicon oxyfluoride
glass which exhibits very high transmittance in the vacuum ultraviolet
(VUV) wavelength region while maintaining the excellent thermal and
physical properties generally associated with high purity fused silica. In
addition to containing fluorine and having little or no OH content, the
inventive silicon oxyfluoride glass suitable for use as a photomask
substrate at 157 nm is also characterized by having less than
1.times.10.sup.17 molecules/cm.sup.3 of molecular hydrogen and low
chlorine levels.
Apropriado de vidro do oxyfluoride do silicone do purity elevado para o uso como carcaças de um photomask para aplicações do photolithography na região do wavelength de VUV abaixo de 190 nm é divulgado com o vidro do oxyfluoride do silicone que tem um índice preferido do fluorine