Illumination system for a microlithography projection exposure installation

Abstract

An illumination system for a microlithography projection exposure installation is used to illuminate an illumination field with the light from a primary light source ( 11 ). The illumination system has a light distribution device ( 25 ) which receives light from the primary light source and, from this light, produces a two-dimensional intensity distribution which can be set variably in a pupil-shaping surface ( 31 ) of the illumination system. The light distribution device has at least one optical modulation device ( 20 ) having a two-dimensional array of individual elements ( 21 ) that can be controlled individually in order to change the angular distribution of the light incident on the optical modulation device. The device permits the variable setting of extremely different illuminating modes without replacing optical components.

1 . An illumination system for a microlithography projection exposure installation for illuminating an illumination field with light from a primary light source, comprising:
 a light distribution device which receives light from the primary light source and which produces a two-dimensional intensity distribution in a pupil-shaping surface of the illumination system,   wherein the light distribution device variably sets the two-dimensional intensity distribution,   wherein the light distribution device comprises at least one optical modulation device which controllably changes the angular distribution of the light incident on the optical modulation device, and   wherein a space between the optical modulation device and the pupil-shaping surface is free of optical components.   
     
     
         2 . The illumination system according to  claim 1 , wherein a distance between the optical modulation device and the pupil-shaping surface is so great that the pupil-shaping surface lies in the far-field region of the optical modulation device.