Photolithography methods and systems

Abstract

Lithographic methods are disclosed. In one such method, a pulsed ultraviolet radiation source for producing ultraviolet lithography radiation having a wavelength shorter than about 300 nm at a fluence of less than 10 mJ/cm 2 /pulse and a high purity fused silica lithography glass having a concentration of molecular hydrogen of between about 0.02×10 18 molecules/cm 3 and about 0.18×10 18 molecules/cm 3 are provided. A lithography pattern is formed with the ultraviolet lithography radiation; the lithography pattern is reduced to produce a reduced lithography pattern; and the reduced lithography pattern is projected onto a ultraviolet radiation sensitive lithography medium to form a printed lithography pattern. At least one of the forming, reducing, and projecting steps includes transmitting the ultraviolet lithography radiation through the high purity fused silica lithography glass. Lithography systems and high purity fused silica lithography glass are also described.

1 - 50 . (canceled)  
   
   
       51 . A method for producing a synthetic high purity fused silica glass optical member having a predictably evolving wavefront distortion when exposed to pulsed ultraviolet lithography radiation having a wavelength shorter than about 300 nm at a fluence of less than 10 mJ/cm 2 /pulse, said method comprising limiting molecular hydrogen concentration in the high purity fused silica glass optical member to between about 0.05×10 18  molecules/cm 3  and about 0.5×10 18  molecules/cm 3 .  
   
   
       52 . A method according to  claim 51 , wherein the high purity fused silica glass optical member exhibits negligible negative density changes and/or photorefractive effects.  
   
   
       53 . A method according to  claim 51 , wherein the high purity fused silica glass optical member has a predictably evolving wavefront distortion when exposed to pulsed ultraviolet lithography radiation having a wavelength shorter than about 200 nm at a fluence of less than about 5 mJ/cm 2 /pulse.  
   
   
       54 . A method according to  claim 51 , wherein the high purity fused silica glass optical member has a predictably evolving wavefront distortion when exposed to pulsed ultraviolet lithography radiation having a wavelength shorter than about 200 nm at a fluence of less than about 1.5 mJ/cm 2 /pulse.  
   
   
       55 . A method according to  claim 51 , wherein the high purity fused silica glass optical member has a predictably evolving wavefront distortion when exposed to pulsed ultraviolet lithography radiation produced by an ArF excimer laser at a fluence of less than about 1.5 mJ/cm 2 /pulse.  
   
   
       56 - 76 . (canceled)