Projection objective
AssigneeCarl Zeiss SMT GmbH
InventorsJohannes Zellner, Hans-Juergen Mann, Wilhelm Ulrich
Life of this patent
Estimating the term…
Abstract
The disclosure relates a projection objective for imaging an object field in an object plane into an image field in an image plane. The disclosure also relates to a microlithographic projection exposure apparatus including such a projection objective. The disclosure further relates to methods of using such a projection exposure apparatus to fabricate microstructured or nanostructured components, such as highly integrated semiconductor components. In addition, the disclosure relates to components fabricated by such methods.
Claims21
A projection objective configured to image radiation from an object field in an object plane to an image field in an image plane along an optical path, the projection objective comprising:
- a grazing incidence mirror configured to provide a first bundle-guiding element, the grazing incidence mirror being downstream of the object plane along the optical path;
- and
- a normal incidence mirror disposed downstream of the grazing incidence mirror in the optical path,
- wherein:
- the grazing incidence mirror is closer to the object plane along the optical path than any other mirror in the projection objective;
- and
- the projection objective is a microlithographic projection objective.
A projection objective configured to image radiation from an object field in an object plane to an image field in an image plane along an optical path, the projection objective comprising:
- a first mirror configured that the radiation impinges at grazing incidence along the optical path, the first mirror being downstream of the object plane along the optical path;
- and
- a second mirror that the radiation impinges at a substantially normal angle along the path of the radiation, the second mirror being disposed downstream of the first mirror in the optical path,
- wherein:
- the first mirror is closer to the object plane along the optical path than any other mirror in the projection objective;
- and
- the projection objective is a microlithographic projection objective;
- a portion of the radiation that passes through a center of a pupil of the projection objective assigned to a central field point impinges on the first mirror at an angle of incidence of at least 70°;
- and
- all individual rays of the radiation in the optical path that impinge on the second mirror do so at an angle of incidence that is less than 30°.
Dependencies are inferred from the claim text.