To minimize the adverse effects of polarization aberrations in the projection optical system, methods to compensate the polarization aberrations are required for high resolution lithography. In this paper, we propose a symmetric polarization aberration compensation method based on scalar aberration control for lithographic projection lens. This method focuses on the compensation of polarization aberrations induced by radially symmetric retardances. The foundation of the compensation method is the linear relationship between conventional even aberration and polarization aberration induced by radially symmetric retardances. The compensation accuracy is dependent on the even aberration adjustment accuracy of the projection lens and the sensitivity of the mask pattern to even aberrations. By this polarization aberration compensation method, the lithographic process window can be improved obviously.

Date Published: 13 March 2012
PDF: 7 pages
Proc. SPIE 8326, Optical Microlithography XXV, 83262T (13 March 2012); doi: 10.1117/12.917909

Published in SPIE Proceedings Vol. 8326:
Optical Microlithography XXV
Will Conley, Editor(s)