This paper presents an approach to designing all-reflective, projection cameras for EUV lithography. We make a comparison of fourmirror cameras with numerical apertures ranging from 0.1 to 0.2 and ring-field widths from 1.0 to 3.6 mm. Additionally, we present two theoretical models that allow for the phase change introduced by multilayer coatings
Scott A. Lerner, Jose M. Sasian, Michael R. Descour, "Design approach and comparison of projection cameras for EUV lithography," Opt. Eng. 39(3) (1 March 2000)