Correlation of the vector diffraction effect on the optical lithographic image of a binary mask with magnification of the projection system

We show quantitatively through a computer simulation the effect ofvector diffraction on the image in optical lithography. Thesimulation was made with a new program, and the variation ofdiffraction as the magnification was varied was calculated for variousnumerical apertures and degrees of defocus. The diffraction at themask improves the images of lines across the polarizing direction, andthe diffraction at the lens improves the images of the lines along thepolarizing direction. We investigated the difference between imagesof lines along and across the polarizing direction as the magnificationincreased. Our result shows that the effect of the lens is sodominant that the images of lines along the polarizing direction arealways better.