Monte Carlo study of High performance resists for SCALPEL nanolithography

The semiconductor community continues to push the limits of device dimensio ns 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 heat ing and still maintain good process latitude. Using 100 KV exposures on a S CALPEL tool, 100 nn structures were printed at exposure dose of 5.8 mu C/cm (2) (and 80 nm isolated trenches at 5.4 mu C/cm(2)) in positive resists. In negative resists, isolated 100 nm were printed at a dose of 6.8 mu C/cm(2) , and 80 nm structures at 7.2 mu C/cm(2) were resolved as well. These resul ts are well below the 10 mu C/cm(2) minimum dose requirement for high throu ghput. Monte Carlo simulations were used as means to understand energy abso rption 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 ionizat ion events during exposure.