| 摘要 |
The invention relates to a method for producing a blank from titanium-doped, highly silicic-acidic glass having a specified flourine content for use in EUV lithography, wherein the thermal expansion coefficient over the operating temperature remains at zero as stably as possible. The course of the thermal expansion coefficient of Ti-doped silica glass depends on a plurality of influencing factors. In addition to the absolute titanium content, the distribution of the titanium is of significant importance, as is the ratio and distribution of additional doping elements, such as fluorine. According to the invention a method comprises a synthesis process wherein fluorine-doped TiO2-SiO2-soot particles are generated and processed further via consolidation and vitrifying into the blank, characterized in that the synthesis process comprises a method step wherein, by means of flame hydrolysis of input substances containing silicon and titanium, TiO2-SiO2-soot particles are formed and a subsequent method step wherein the TiO2-SiO2-soot particles are exposed to a reagent containing a fluorine in a moving powder bed and converted to the fluorine-doped TiO2-SiO2-soot particles. |
