Patent Number: 
Section: abstract

There is provided an illumination system for microlithography with wavelengths ≦193 nm. The illumination system includes a primary light source, a first optical component, a second optical component, an image plane, and an exit pupil. The first optical component transforms the primary light source into a plurality of secondary light sources that are imaged by the second optical component in the exit pupil. The first optical component includes a first optical element having a plurality of first raster elements that are imaged into the image plane, producing a plurality of images being superimposed at least partially on a field in the image plane. The second optical component comprises a first optical system that includes at least a third field mirror with positive optical power and a second optical system that includes at least a second field mirror with positive optical power. The first optical system images the plurality of secondary light sources in a plane between the first optical system and the second optical system, forming a plurality of tertiary light sources, and the second optical system images the plurality of tertiary light sources in the exit pupil.