Impact of non-uniform polarized illumination on hyper-NAlithography

摘要

Conventional top-hat model of polarized illumination loses its accuracy in lithography simulation which cannot meet therequirements of 45nm node lithography and beyond. The simulation error of top-hat model in evaluating lithographyperformance cannot be neglected anymore. In this paper, we apply a Gaussian model to represent the non-uniformdegree of polarization (NU-DOP) distribute across the pupil and evaluate its impact on the CD uniformity under variousconditions. The result shows that the model can accurately evaluate the non-uniform property of polarized illuminator.When the mean NU-DOP approaches to 1, the effect of non-uniformity becomes more pronounced. Furthermore, thenon-uniform of DOP distribution causes more CD error at defocus position.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.