Projection objective for microlithographic projection exposure apparatus, has lens composed of lens elements which are arranged to follow each other along optical axis, where lens has curved lens surfaces put together by elements

摘要

The objective has a lens (143) composed of a set of lens elements (143a-143d), which are arranged to follow each other along an optical axis (OA) in a mutually adjacent relationship. The lens has a set of curved lens surfaces put together by the lens elements made of intrinsically birefringent material e.g. magnesium spinel. The lens elements are made up of two pairs of lens elements having crystallographic cuts different from each other. The lens elements of each pair have same crystallographic cut and are arranged relative to each other with a rotary offset about the optical axis. Independent claims are also included for the following: (1) a microlithographic projection exposure apparatus with an illumination device (2) a method for microlithographic manufacture of microstructured components.