Simulation and measurement of resist heating in multipass exposure using a50 kV variably shaped beam system

Resist heating in electron-beam lithography was studied. An original heat f unction approach was developed and implemented with the TEMPTATION <(Temp)u nder bar>perature simul<(ation)under bar>) software tool. This software sim ulates heat transfer throughout a multilayer substrate. The heat function a lso allowed simulation of effective dose change due to combined proximity a nd heating effects. Experiments were made using a 50 kV high-throughput, va riably shaped beam system. Exposures were done with single-pass and multipa ss writing using PBS and EBR-900 resists. Lines as wide as 1 mu m broke due to resist heating. EBR-900 resist changed tone to negative because of loca l heating. A comparison of writing results at single-pass, two-pass, and fo ur-pass exposures is presented, as well as exposures at beam current densit ies up to 80 A/cm(2). Comparison of simulated and experimental data is disc ussed.