Projection lens for use in projection exposure system, has arrangement of optical elements arranged between object and image planes, and two imaging groups with lenses made from material with small absorption and/or high heat conductivity

摘要

The lens (18) has an arrangement of optical elements arranged between an object plane (OE) and an image plane (BE), where the arrangement of optical elements is viewed from the object plane and has a dioptric imaging group of optical elements. The arrangement of optical elements has an additional dioptric imaging group of optical elements, which contains a concave mirror. One of lenses of the imaging groups is made from a material with small absorption and/or high heat conductivity, where the lenses are made of calcium fluoride. An independent claim is also included for a projection exposure system for lithography, comprising a lighting device and a projection lens.