The 193nm immersion lithographic machine has already achieved 22nm node and beyond, and its illuminator has become a polarized and off-axis illumination system. Illumination modes and polarization modes can be formed by different diffraction optical elements and polarization optical elements. This paper proposes a model including a micromirror array and a variable retarder array for forming freeform illumination mode and polarization mode. They can be achieved by controlling the retardations of the variable retarders and two-dimensional tilt angles of the micromirrors. The principles of the model are analyzed, and some equations are acquired. Circular illumination mode, tangential polarization modes have been obtained in the simulation experiments. The simulation results show the model is feasible for the 193 nm immersion lithography machine.

Date Published: 12 April 2013
PDF: 8 pages
Proc. SPIE 8683, Optical Microlithography XXVI, 868329 (12 April 2013); doi: 10.1117/12.2011517

Published in SPIE Proceedings Vol. 8683:
Optical Microlithography XXVI
Will Conley, Editor(s)