同步辐射光刻光束线的真空系统

THE VACUUM SYSTEM FOR SYNCHROTRON RADIATON LITHOGRAPHY BEAM LINE

第一条同步辐射光刻光束线已在合肥国家同步辐射实验室建成，并刻出了线宽0．2μm的图形。真空系统是光束线的重要组成部分。该真空系统要使镜箱内的压力分别小于6．7×10-8Pa（镜箱内有SR）和2．6×10-7（镜箱内无SR），以免暴露于SR的光学镜面遭受碳污染。一个装有可移动样品架的曝光室坐落在超净室中。曝光室内的压力约为10-4Pa。一个多级差分抽气系统实现了镜箱到曝光室的真空过渡。具有较大截面的差分管必须是良好的光通路。给出了差分抽气系统的计算公式和实验结果。描述了真空联锁系统的组成部分和功能。该光束线的功能还需扩展和提高，真空系统也有值得探讨和改进的问题。

A lithography beam line has been constructed at NSRL. Some lithography pictures with 0. 2 μm lines have been presented. The pressures in the mirror box are less than 6. 7 ×10-8Pa without SR and 2． 6× 10-7Pa with existence of SR respectively for preventing from carbon contamination on the mirror surface. An exposure chamber with movable sample holder is located in a super clean room. The pressure in the chamber is about 10-4Pa. A multistage differential pumping system connects the mirror box with the exposure chamber. The differential tubes with larger section are pathes of SR also. A vacuum interlock sys tem is a necessary part for the beam line. Its component parts and their function are described briefly.Some problerns related to the vacuum system which should be studied and modified are rnentioned.