ILLUMINATION OPTICAL UNIT FOR PROJECTION LITHOGRAPHY

摘要

An illumination optical unit for projection lithography serves for illuminating an object field. A first transmission optical unit serves to guide illumination light emanating from a light source. An illumination-predetermining facet mirror is disposed downstream of the first transmission optical unit and comprises a multiplicity of illumination-predetermining facets. The facet mirror generates a predetermined illumination of the object field via an arrangement of illuminated illumination-predetermining facets. This results in an illumination of an illumination pupil of the illumination optical unit, which predetermines an illumination angle distribution in the object field. The illumination pupil has an envelope deviating from a circular form. The illumination pupil is subdivided into sub-pupil regions, which are present arranged in a line-by-line and/or column-by-column manner.

主权项

1. An optical unit configured to illuminate an object field, the optical unit comprising:
a first transmission optical unit configured to guide illumination light from a light source; and a facet mirror downstream of the first transmission optical unit, the facet mirror comprising a multiplicity of facets, the facet mirror configured to generate a illumination of the object field via an arrangement of facets, wherein:
the optical unit is configured so that, during use of the optical unit, an illumination pupil having a maximum extent of the optical unit is illuminated with an envelope deviating from a circular form so as to determine an illumination angle distribution in the object field;the illumination pupil is subdivided into a plurality of sub-pupil regions which are arranged in a line-by-line and/or column-by-column manner; andthe optical unit is a microlithography illumination optical unit.