| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce a quartz glass optical member having excellent stability for irradiation of UV laser, especially excimer laser such as KrF and ArF. SOLUTION: The quartz glass is produced in the following processes. The starting source material obtd. from halogenated silicons, alkoxysilanes, alkylakoxysilanes or the like is subjected to oxidation heat treatment in the temp. range between >=600 deg.C and <=1500 deg.C to decrease the hydrogen concn. to <=5×1016 molecules/cm3 as well as to decrease reducible defects. Then the quartz glass is kept at the temp. range between >=200 deg.C and <=600 deg.C in a hydrogen-contg. atmosphere to control the hydrogen concn. to >=1×1017 molecules/cm3. Further, the quartz glass is treated to produce uniform distribution of the hydrogen concn. at the temp. range between >=300 deg.C and <=800 deg.C in an atmosphere of air, inert gas, hydrogen, mixture gas of hydrogen and inert gas, or mixture gas of air and inert gas. Thus, the quartz glass optical member having stable and excellent durability against laser can be obtd.</p> |
