Patent ID: 8717541

Claim:
A field facet mirror configured to transmit a structure of an object arranged in an object field into an image field, the field facet mirror comprising: a plurality of field facets including first and second field facets, wherein: field facets next to one another are disposed in a base plane of the field facet mirror; each of the plurality of field facets comprises a reflection surface; the reflection surface of the first field facet has a first projection onto the base plane; the first projection has first edge which is the longest edge of the first projection; the first field facet has a first axis which passes through a center of the first edge and a center of the first projection; the reflection surface of the second field facet has a second projection onto the base plane; the second projection has second edge which is the longest edge of the second projection; the second field facet has a second axis which passes through a center of the second edge and a center of the second projection; the first and second axes are rotated with respect to one another by more than 1° about an axis perpendicular to the base plane of the field facet mirror; and the field facet mirror is configured to be used in an illumination optics of a projection exposure apparatus for EUV microlithography.