Importance

Loading Importance Indicators...

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 plurality of first raster elements are rectangular. The field is a segment of an annulus, and the second optical component includes a first field mirror with negative optical power for shaping the field to the segment of the annulus and a second field mirror with positive optical power. Each of a plurality of rays intersects the first field mirror with an incidence angle greater than 70° and each of the plurality of rays intersects the second field mirror with an incidence angle of less than 25°.

Loading the Abstract Image...

First Claim