ILLUMINATION SYSTEM OF A MICROLITHOGRAPHIC PROJECTION EXPOSURE APPARATUS

摘要

An illumination system of a microlithographic projection exposure apparatus (10) comprises an optical integrator (52; 152) that includes an array (54c; 154b) of optical raster elements (56; 156). A condenser (72) superimposes the light beams associated with the optical raster elements in a common field plane (71). A modulator (62; 162; 262) modifies a field dependency of an angular irradiance distribution in an illuminated field. Units (60; 160; 260) of the modulator are associated with one of the light beams and are arranged at a position in front of the condenser (72) such that only the associated light beam impinges on a single modulator unit (60). The units are furthermore configured to variably redistribute, without blocking any light, a spatial and/or an angular irradiance distribution of the associated light beams. A control device (66) controls the modulator units (60; 160; 260) if it receives an input command that the field dependency of the angular irradiance distribution in the mask plane (78) shall be modified.