Optical simulation of 3D Mask effects

Optical extensions, laid out by Sematech and others, have implications for simulation, calling for new solutions. Phase-shifting masks need new models, to accurately predict the intensity imbalance and to forecast conditions under which defects print. This paper shows areas where the lithographer may expect strong assistance through simulation. The results of a study, using mask modeling for optimizing edge topography of Alternating Phase Shift Mask are presented. The new 3D-simulator (TMASK) configuration of SOLID-CM is used to the study phase errors (CD sensitivity, image log. slope, CD placement), influence of sloped edge profiles and phase defects.