Image formation in extreme ultraviolet lithography and numerical aperture effects

Abstract

The problem of image formation in extreme ultraviolet lithography from the mask to the wafer is studied by physical modeling along with computer simulations. The reflective properties of multilayer mirrors and some of the demands that they impose upon the optical system design for accurate replication of mask patterns is discussed. Numerical aperture size effects in relation to the critical dimension at the wafer is presented along with several illustrative examples.