Projection lens for use in projection illumination system in semiconductor microlithography, has correction elements e.g. plane parallel plates, arranged in region, which is optically closed for pupil levels

摘要

The lens has an optical arrangement of optical elements (32a-32d) along a light propagation direction between an object level (O) and an image level (B). The arrangement has pupil levels (P1, P2) and correction elements e.g. plane parallel plates (40a, 40b), for correcting thermally induced aberration. The correction elements are arranged in a region, which is optically closed for the pupil levels. The correction elements are deformable, optically changeable, de-centralizable and warmable, where the correction elements are directly adjacent to each other. An independent claim is also included for a method for correcting thermally induced aberration of a projection lens for the lithography.