Journal of Vacuum Science & Technology B, Vol.25, No.6, 2064-2067, 2007
Improving electron beam resist sensitivity by preexposure to deep ultraviolet radiation
Electron beam lithography, when combined with optical lithography, is a promising approach to obtain good throughput. A bottleneck for this is resist sensitivity and the concomitant shot-noise limit for resolution. It is possible to obtain increased sensitivity without reducing resolution by preexposing electron beam resist to deep ultraviolet radiation before electron beam patterning. Results show that up to a 30% reduction in required dosage is obtained with this method; the associated trade off in dissolution of unexposed areas and critical dimension sensitivity is minimal. Resolution is also maintained and sub-50 nm lines with good aspect ratio have been demonstrated. (c) 2007 American Vacuum Society.