We have designed what we believe to be new hybrid-type attenuated phase-shift masks for extreme-ultraviolet optical lithography by use of a Fabry–Perot interference filter. The designs for the attenuated phase-shift masks show a smaller step height for less geometric shadow effects than additive- and subtractive-type attenuated phase-shift masks, a contrast higher than 94% for both deep-ultraviolet and extreme-ultraviolet wavelength regimes, and a 180° phase-shift in the extreme-ultraviolet wavelength regime.
© 2008 Optical Society of America
Original Manuscript: August 3, 2007
Manuscript Accepted: October 5, 2007
Published: November 27, 2007
Hee Young Kang and Chang Kwon Hwangbo, "Optical design of hybrid-type attenuated phase-shift masks for extreme-ultraviolet lithography by use of a Fabry-Perot interference filter," Appl. Opt. 47, C75-C78 (2008)