Monte Carlo study of high performance resists for SCALPEL nanolithography

Abstract The semiconductor community continues to push the limits of device dimensions by exploring new high-resolution lithography technology. As part of the SCALPEL lithography resist program, our goal is to be able to print sub-100 nm structures at doses that will permit high throughput, reduce wafer heating and still maintain good process latitude. Using 100 KV exposures on a SCALPEL tool, 100 nm structures were printed at exposure dose of 5.8 μC/cm 2 (and 80 nm isolated trenches at 5.4 μC/cm 2 ) in positive resists. In negative resists, isolated 100 nm were printed at a dose of 6.8 μC/cm 2 , and 80 nm structures at 7.2 μC/cm 2 were resolved as well. These results are well below the 10 μC/cm 2 minimum dose requirement for high throughput. Monte Carlo simulations were used as means to understand energy absorption mechanisms of these e-beam optimized resists, DUV and 193 nm resists. Atomic composition was found to factor in improved resist ionization. The resin (or low-Z elements) is found to account for more than 99% of ionization events during exposure.