Illumination optimization for specific mask patterns

摘要: A method and apparatus for microlithography. The include optimizing illumination modes based on characteristics of a specific mask pattern. is optimized by determining an appropriate mode diffraction orders the reticle, autocorrelation projection optic. By elimination parts pattern which have no influence modulation, excess DC light can be reduced, thereby improving depth focus. Optimization patterns includes addition sub-resolution features to reduce pitches discretize probability density function space width.