Illumination system of a microlithographic projection exposure apparatus with a birefringent element

摘要

The disclosure concerns an illumination system of a microlithographic projection exposure apparatus. The illumination system includes a mirror arrangement which has a plurality of mirror units and at least one element arranged in front of the mirror arrangement in the light propagation direction to produce at least two different states of polarization incident on different mirror units. The mirror units are displaceable independently of each other for altering an angle distribution of the light reflected by the mirror arrangement.

主权项

1. An illumination system, comprising:
a mirror arrangement comprising a plurality of mirror units displaceable independently of each other to alter an angle distribution of light reflected by the mirror arrangement, each mirror unit comprising at least one mirror element; and at least one element that is in front of the mirror arrangement in a propagation direction of the light so that the at least one element is configured to produce at least two different states of polarization incident on different mirror units and/or different mirror elements, wherein:
the at least one element comprises a birefringent element configured to split a partial ray of the light into an ordinary partial ray and an extraordinary partial ray;an entire portion of the partial ray contributes to the ordinary partial ray;the entire portion of the partial ray contributes to the extraordinary partial ray;the ordinary partial ray and the extraordinary partial ray have mutually perpendicular polarization directions;the ordinary partial ray is deflected by the mirror arrangement in a first direction;the extraordinary partial ray is deflected by the mirror arrangement in a second direction different from the first direction; andthe illumination system is configured to be used in a microlithographic projection exposure apparatus.