Patent Number: 
Section: abstract

There is provided an illumination system for microlithography with wavelengths≦193 nm that 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 element and the second optical element are reflective. 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 first optical component includes a collector unit and a second optical element having a plurality of second raster elements. The illumination system also includes a first optical axis between the collector unit and the first optical element, a second optical axis between the first optical element and the second optical element, and a third optical axis between the second optical element and the second optical component. A directional vector of the first optical axis and a directional vector of the second optical axis define a plane and wherein the first and second optical elements are tilted to cause a crossing of the projection of the third optical axis in to the plane and the first optical axis.