Abstract
We have developed a simplified method of fabricating x-ray masks for deep x-ray lithography by using proton beam writing (PBW) without subsequent soft x-ray copying steps. Combining direct PBW and subsequent electroplating, x-ray masks with gold absorber patterns of up to 11 mu m height and with vertical and smooth sidewalls were fabricated. The smallest size in the absorber pattern is less than 0.5 mu m in this work. The masks were used for x-ray lithography with synchrotron radiation, and 870 mu m SU-8 structures with smooth sidewalls were produced. This fabrication method is promising to be an important alternative to conventional methods for x-ray mask making.