Polarization Aberration Compensation Method By Adjusting Illumination Partial Coherent Factors In In Immersion Lithography

As the numerical aperture (NA) increasing and process factor k(1) decreasing in 193nm immersion lithography, polarization aberration (PA) of projection optics leads to image quality degradation seriously. Therefore, this work proposes a new scheme for compensating polarization aberration. By simulating we found that adjusting the illumination source partial coherent factors sigma(out) is an effective method for decreasing the PA induced pattern critical dimension (CD) error while keeping placement error (PE) within an acceptable range. Our simulation results reveal that the proposed method can effectively compensate large PA in actual optics.