Source Optimization under Thick Mask Model

Source optimization(SO) is a key method of resolution enhancement technology. However, as the technique node enters 45 nm and below, the influence of thick mask effect has become apparent. The result of source optimization considering the mask as a thin film is inaccurate. In this paper, we propose a source optimization model considering thick mask structure. We establish the theoretical model of source optimization with gradient method and compressive sensing(CS) method. The typical masks of 45nm, 28nm and 22nm were selected for simulation. The optimized source provides better imaging performance, while the simulation speed has been improved by using CS method.