One-dimensional Transverse Superresolution Achieved by Three-zone Dissymmetrical Pupil Filter
非对称三区光瞳滤波器实现一维横向超分辨

Based on the rigorous vector imaging theory of an optical system,taking the optical imaging system with amplification of 1/4 and the x linearly polarized illumination as an example,the transverse electric field expression in focal region was obtained when the x linearly polarized light passes through an optical system with high numerical aperture modulated by a pupil filter.A new kind of dissymmetrical three-zone phase pupil filter was designed by studying in detail such parameters of the three-zone complex pupil filter as the influences of the normalized radiuses of the inner and outer zones,the phase distribution in each zone,and the transmittance t of the first zone on the superresolution gain ratio Gty,the Strehl ratio Sy and the relative intensity ratio of the sidelobe to that of the central lobe Iry in y direction,respectively.According to the simulation results,Gty=0.834 5,Sy=0.408 7,and Iry=0.492 3 are achieved,and the designed phase pupil filter can improve the resolution in transverse y direction by nearly 20% in contrast to that in the optical imaging system without pupil filter.This new kind of three-zone dissymmetrical phase pupil filter with superresolution in a single transverse direction can be effectively applied to the resolution enhancement technology (RET) in an advanced photolithography with the double exposure technique.