The fabrication of x-ray masks using proton beam writing

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 νm height and with vertical and smooth sidewalls were fabricated. The smallest size in the absorber pattern is less than 0.5 νm in this work. The masks were used for x-ray lithography with synchrotron radiation, and 870 νm 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. © 2008 IOP Publishing Ltd.