Fabrication of X-ray masks using the silicon direct write electron-beam lithography process and complementary electron-sensitive resists

In order to meet the long term goals of the International Technology Roachmap For Semiconductor,,. it is important to demonstrate that X-ray masks can be fabricated at resolutions kell below the 100 nm barrier, This paper presents results on the use of conventional electron-sensitive resists and the silicide direct write electron beam lithography Process for the fabrication of X-ray masks with sub-100 nm resolution. By optimizing the deposition of the thin films using conventional evaporators. the SiDWEL process was able to achieve linewidths of less than 40nm and line spacing of than 100nm The silicide patterns formed by the SiDWEL process are sufficiently, resistant to plasma etching to directly transfer the patterns to the tantalum absorber. To improve the turnover time for mask fabrication. different writing schemes were studied, including combining the SiDWEL process with QSR-4. a novel negative resist designed specifically for this application.