Imaging optical unit and projection exposure apparatus for projection lithography comprising such an imaging optical unit
AssigneeCarl Zeiss SMT GmbH
InventorsHans-Juergen Rostalski, Sascha Migura, Thomas Schicketanz
Life of this patent
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Abstract
An imaging optical unit (7) serves for imaging an object field (4) in an object plane (5) into an image field (8) in an image plane (9). The imaging optical unit (7) has a plurality of components (M1 to M6, GI) which guide imaging light (3). The imaging optical unit (7) is embodied as a pupil-obscured system. The imaging optical unit (7) has at least one mirror (GI) for grazing incidence of the imaging light (3). The result is an imaging optical unit having a handleable combination of low imaging aberrations and compact construction.
Claims23
1-13. (canceled)
An optical unit configured to image light along a path from an object field in an object plane into an image field in an image plane, the optical unit comprising:
- a plurality of components configured to guide the light along the path, the plurality of components comprising a grazing incidence mirror,
- wherein the imaging optical unit is a pupil-obscured system.
An optical unit configured to image light along a path from an object field in an object plane into an image field in an image plane, the optical unit comprising:
- a plurality of mirrors configured to guide the light along the path, the plurality of mirrors comprising a grazing incidence mirror,
- wherein the imaging optical unit is a pupil-obscured system.
The imaging optical unit of claim 33, wherein the compensation mirror comprises a multilayer reflectivity coating having a layer thickness distribution which varies over a reflection surface of the compensation mirror.
Dependencies are inferred from the claim text.