Simulation of chemically amplified resist processes for 150 nm e-beam lithography

A fast simulator for e-beam lithography called SELID, is presented. For the exposure part, an analytical solution based on the Boltzmann transport equation is used instead of Monte Carlo. All-important phenomena (backscattering, generation of secondary electrons) are included in the calculation. The reaction/diffusion effects occurring during post exposure bake in the case of chemically amplified resists (CARs) are taken into account. The results obtained by the simulation are compared successfully with experimental ones for conventional and CARs. The case of substrates consisting of more than one layer is considered in depth as being of great importance in e-beam pattering. By using SELID, forecast of resist profile with considerable accuracy for a wide range of resists, substrates and energies is possible as long as the evaluation of proximity effect parameters.