Synthesized silica glass optical member and method for manufacturing the same

Abstract

A method for manufacturing a synthesized silica glass optical member, the method comprising: providing a porous silica glass body; heating the porous' silica glass body in an atmosphere containing hydrogen or oxygen, and sintering the porous silica glass body in an atmosphere containing fluorine compound. Furthermore, a synthesized silica glass optical member manufactured by the method.

What is claimed is:  
     
         1 . A method for manufacturing a synthesized silica glass optical member, said method comprising: 
 providing a porous silica glass body;    heating the porous silica glass body in an atmosphere containing hydrogen; and    sintering the porous silica glass body in an atmosphere containing a fluorine compound.    
     
     
         2 . The method according to  claim 1 , wherein a temperature of said heating is within a range from 500° C. to a critical temperature below which the porous silica glass body does not shrink.  
     
     
         3 . The method according to  claim 2 , wherein a temperature of said heating is 1250° C. or below.  
     
     
         4 . The method according to claims, wherein said heating precedes said sintering.  
     
     
         5 . The method according to  claim 1 , wherein said providing the glass body includes forming glass particles by flame hydrolysis of a raw material.  
     
     
         6 . A method for manufacturing a synthesized silica glass optical member, said method comprising: 
 providing a porous silica glass body;    heating the porous silica glass body in an atmosphere containing oxygen; and    sintering the porous silica glass body in an atmosphere containing a fluorine compound.    
     
     
         7 . The method according to  claim 6 , wherein a temperature of said heating is within a range from 500° C. to a critical temperature below which the porous silica glass body does not shrink.  
     
     
         8 . The method according to  claim 7 , wherein a temperature of said heating is 1250° C. or below.  
     
     
         9 . The method according to  claim 6 , wherein said heating precedes said sintering.  
     
     
         10 . The method according to  claim 6 , wherein said providing the glass body includes forming glass particles by flame hydrolysis of a raw material.  
     
     
         11 . The method according to any one of claims  1 - 10 , wherein the fluorine compound comprises SiF 4 .  
     
     
         12 . A synthesized silica glass optical member manufactured by a method according to any one of claims  1 - 11 .  
     
     
         13 . A method for a lithography using a photo mask, in which the photo mask utilizes a glass optical member, said method comprising: 
 providing a porous silica glass body for the glass optical member;    heating the porous silica glass body in an atmosphere containing hydrogen; and    sintering the porous silica glass body in an atmosphere containing a fluorine compound.    
     
     
         14 . The method according to  claim 13 , further comprises providing a light source of the lithography having a wavelength of 400 nm or less.  
     
     
         15 . The method according to  claim 14 , wherein the light source includes an F 2  excimer laser a light source.  
     
     
         16 . A method for a lithography using a photo mask, in which the photo mask utilizes a glass optical member, said method comprising: 
 providing a porous silica glass body for the glass optical member;    heating the porous silica glass body in an atmosphere containing oxygen; and    sintering the porous silica glass body in an atmosphere containing a fluorine compound.    
     
     
         17 . The method according to  claim 16 , further comprises providing a light source of the lithography having a wavelength of 400 nm or less.  
     
     
         18 . The method according to  claim 17 , wherein the light source includes an F 2  excimer laser a light source.