Patent ID: 8792082

Claim:
An illumination system for a microlithography projection exposure apparatus configured to illuminate an illumination field with light from an assigned light source, comprising: a variable pupil shaping unit comprising a plurality of optical elements configured to receive light from the assigned light source and to generate a light bundle with a basic light distribution in a pupil plane of the illumination system; an array of individual adjustable optical elements, wherein the individual adjustable optical elements are arranged in a two-dimensional raster arrangement and configured to be adjusted to provide a location-dependent two-dimensional transmission function; and a control unit configured to adapt the basic light distribution generated by the pupil shaping unit and the transmission function of the array of individual adjustable optical elements to a mask structure to be illuminated, wherein the array of individual adjustable optical elements is arranged in or in proximity to the pupil plane of the illumination system, or in or in proximity to a plane of the illumination system that is optically conjugate to the pupil plane of the illumination system.