Abstract: Improving graphics quality is one of the important factors for fabrication of high precision and high aspect ratio microstructure. For investigating the pattern transfer accuracy of proximity UV-lithography, a theoretical model is constructed based on partial coherent light theory. The intensity distribution on the photo resist surface is attained and the related lithography profile is simulated. A compensation method which employs the genetic algorithm (GA) is studied to optimize photo mask. The strategy of the method is to modulate the optic field distribution by adjusting the pattern of the photo-mask. The evaluation strategy is proposed based on the simulation profile. The profile character is classified and limited to reduce the searching space. With the GA method, an optimum mask pattern is achieved. The simulation results show that the graphics distortion of photoresist is reduced obviously and the study provides a new approach to improving the graphics quality in lithography.

Key words: Coherent light, Genetic algorithm, Mask optimization, Proximity UV-lithography, Shape distortion