Patent ID: 8873023

Claim:
An illumination system configured to illuminate an object field with illumination light, the illumination system comprising: a first raster arrangement comprising a first plurality of bundle-forming raster elements arranged in or adjacent to a first plane of the illumination system, the first plurality of bundle-forming raster elements configured to generate a raster arrangement of secondary light sources; a transmission optics configured to superimpose transmission of the illumination light of the secondary light sources into the object field, the transmission optics comprising a second raster arrangement comprising a second plurality of bundle-forming raster elements; wherein: each bundle-forming raster element of the first plurality of bundle-forming raster elements is allocated to a corresponding bundle-forming raster element of the second plurality of bundle-forming raster elements to guide a partial bundle of an entire bundle of the illumination light; at least one of first and second raster arrangements comprises at least two types of bundle-forming raster elements which have different bundle-influencing effects; the bundle-forming raster elements of the first and second raster arrangements correspond to each other so that, for each bundle-forming raster element of one of the raster element types, there is an individual free distance between the bundle-forming raster element and its corresponding bundle-forming raster element of the other raster arrangement; and the illumination system is a microlithography illumination system.