Patent ID: 9678438
Date: 2017-06-13
CPC Classifications: G03F

Claim:
1. An illumination system, comprising: an optical integrator comprising an array of optical raster elements configured so that, during use of the illumination system, a light beam is associated with each optical raster element; a condenser configured so that, during use of the illumination system, the condenser superimposes the light beams associated with the optical raster elements in a common field plane which is a mask plane or which is optically conjugate to the mask plane; a modulator configured so that, during use of the illumination system, the modulator modifies a field dependency of an angular irradiance distribution in an illuminated field of the mask plane, the modulator comprising a plurality of modulator units, each modulator unit being: a control device configured so that, during use of the illumination system, the control device controls the modulator units so that, during use of the illumination system: wherein a first angular irradiance distribution is produced at a first portion of the illuminated field and a second angular irradiance distribution at a second portion of the illuminated field, wherein the second angular irradiance distribution is distinct from the first angular irradiance distribution, and the illumination system is a microlithographic illumination system.