Analytical analysis for impact of polarization aberration of projection lens on lithographic imaging quality

摘要

In high-NA and hyper-NA lithography systems, the polarization aberration of projection lens leads to imaging degradations. Typically, numerical simulations are used to explore the relationship. In this paper, analytical analysis for the impact of polarization aberration of projection lens on the aerial image of alternating phase-shift mask (Alt-PSM) is realized. The analytical expressions of image placement error (IPE) and best focus shift (BFS) caused by polarization aberration are derived from the intensity of aerial image. The derived expressions match simulation results extremely well, and can be used to understand more fully the detrimental impact of polarization aberration on lithographic imaging quality. The linear relationships between IPE and odd items of Pauli-Zernike polarization aberrations, as well as that between BFS and even items of Pauli-Zernike polarization aberrations are established, using linear polarization illumination. The accuracy of the linear relationships is assessed by the least square method.