AN EVALUATION OF HIGH ACCELERATION VOLTAGE ELECTRON-BEAM WRITING ON X-RAY MASKS

High acceleration voltage electron beam (EB) writing on X-ray masks wa s evaluated. Normalized dose latitudes of 100 keV for the 0.15 mu m li ne and space (L&S), isolated lines and isolated space patterns were 3. 5, 2.7 and 7.6 times larger than those of 25 keV, respectively. It was also found that the back-scattered electrons extend over a range of 1 0 mu m in 100 keV writing. The maximum mesh size in the pattern area d ensity method for proximity effect correction was evaluated by Monte C arlo simulation. When a +/-10% pattern size error was permitted for a 0.1 mu m line pattern, the 0.3 mu m mesh size in 50 keV writing was ma rkedly improved to 5 mu m at a higher voltage of 100 keV. Reducing the beam size by half from 60 nm (2 sigma) in 100 keV writing also increa ses the mesh size from 0.4 to 5 mu m. Moreover, the fine W-Ti patterns of 0.06-0.14 mu m were formed using 100 keV Gaussian EB writing and e lectron cyclotron resonance (ECR) etching systems, where good linearit y and linewidth deviations within 9 nm (3 sigma) were obtained.