Projection lens system of a microlithographic projection exposure installation
View Patent ↗A microlithographic projection exposure apparatus comprises a projection objective which images an object onto an image plane and has a lens with a curved surface. In the projection objective there is a liquid or solid medium which directly adjoins the curved surface over a region which is usable for imaging the object. The projection exposure apparatus also has an adjustable manipulator for reducing an image field curvature which is caused by heating of the medium during the projection operation.
1. A microlithographic projection exposure apparatus, comprising:
a) a projection objective, which
during use of the projection exposure apparatus is capable of imaging an object onto an image plane and
has a lens with a curved surface,
b) a liquid or solid medium which
directly adjoins the curved surface over a region which during use of the projection exposure apparatus is capable of being used to image the object, and
c) an adjustable manipulator which during use of the projection exposure apparatus, is capable of reducing an image field curvature which is caused by heating of the medium during the projection operation,
wherein the manipulator comprises at least one aspherical lens which is shaped so that it represents a different vertex radius in the event of a swiveling movement about a swivel axis perpendicular to an optical axis.
2. The microlithographic projection exposure apparatus of claim 1 , wherein the at least one aspherical lens has a spherical surface with a center of curvature which lies on the swivel axis.
3. The microlithographic projection exposure apparatus of claim 1 , wherein the lens is the last lens on the image side of the projection objective, and the medium is an immersion medium which is arranged between the last lens on the image side and the image plane.
4. The microlithographic projection exposure apparatus of claim 1 , wherein, during use, the manipulator changes the refractive power of an optical element other than the medium.
5. The projection microlithographic exposure apparatus of claim 4 , wherein the optical element is arranged in or in immediate proximity to an intermediate image of the projection objective.
6. A microlithographic projection exposure apparatus, comprising:
a) a projection objective, which
during use of the projection exposure apparatus is capable of imaging an object onto an image plane and
has a lens with a curved surface,
b) a liquid or solid medium which
directly adjoins the curved surface over a region which during use of the projection exposure apparatus is capable of being used to image the object, and
c) an adjustable manipulator which during use of the projection exposure apparatus, is capable of reducing an image field curvature which is caused by heating of the medium during the projection operation,
wherein the manipulator comprises at least one aspherical lens which is shaped so that it represents a different vertex radius in the event of a swiveling movement about a swivel axis perpendicular to an optical axis, and
wherein the swivel axis lies outside the at least one aspherical lens.
7. The microlithographic projection exposure apparatus of claim 6 , wherein the at least one aspherical lens has an aspherical surface which is shaped so that its curvature on a section line formed with a plane surface changes continuously along the section line and perpendicularly thereto.
8. The microlithographic projection exposure apparatus of claim 6 , wherein the lens is the last lens on the image side of the projection objective, and the medium is an immersion medium which is arranged between the last lens on the image side and the image plane.
9. The microlithographic projection exposure apparatus of claim 6 , wherein, during use, the manipulator changes the refractive power of an optical element other than the medium.
10. The projection microlithographic exposure apparatus of claim 9 , wherein the optical element is arranged in or in immediate proximity to an intermediate image of the projection objective.
11. A microlithographic projection exposure apparatus, comprising:
a) a projection objective, which
during use of the projection exposure apparatus is capable of imaging an object onto an image plane and
has a lens with a curved surface,
b) a liquid or solid medium which
directly adjoins the curved surface over a region which during use of the projection exposure apparatus is capable of being used to image the object, and
c) an adjustable manipulator which during use of the projection exposure apparatus, is capable of reducing an image field curvature which is caused by heating of the medium during the projection operation,
wherein the manipulator comprises at least one aspherical lens which is shaped so that it represents a different vertex radius in the event of a swiveling movement about a swivel axis perpendicular to an optical axis,
wherein the swivel axis lies outside the at least one aspherical lens, and
wherein the at least one aspherical lens has a spherical surface with a center of curvature which lies on the swivel axis.
12. The microlithographic projection exposure apparatus of claim 11 , wherein the lens is the last lens on the image side of the projection objective, and the medium is an immersion medium which is arranged between the last lens on the image side and the image plane.
13. The microlithographic projection exposure apparatus of claim 11 , wherein, during use, the manipulator changes the refractive power of an optical element other than the medium.
14. The projection microlithographic exposure apparatus of claim 13 , wherein the optical element is arranged in or in immediate proximity to an intermediate image of the projection objective.
15. A microlithographic projection exposure apparatus, comprising:
a) a projection objective, which
during use of the projection exposure apparatus is capable of imaging an object onto an image plane and
has a lens with a curved surface,
b) a liquid or solid medium which
directly adjoins the curved surface over a region which during use of the projection exposure apparatus is capable of being used to image the object, and
c) an adjustable manipulator which during use of the projection exposure apparatus, is capable of reducing an image field curvature which is caused by heating of the medium during the projection operation,
wherein the manipulator comprises at least one aspherical lens which is shaped so that it represents a different vertex radius in the event of a swiveling movement about a swivel axis perpendicular to an optical axis, and
wherein the at least one aspherical lens has an aspherical surface which is shaped so that its curvature on a section line formed with a plane surface changes continuously along the section line and perpendicularly thereto.
16. The microlithographic projection exposure apparatus of claim 15 , wherein the at least one aspherical lens has a spherical surface with a center of curvature which lies on the swivel axis.
17. The microlithographic projection exposure apparatus of claim 15 , wherein the swivel axis lies outside the at least one aspherical lens, and the at least one aspherical lens has a spherical surface with a center of curvature which lies on the swivel axis.
18. The microlithographic projection exposure apparatus of claim 15 , wherein the lens is the last lens on the image side of the projection objective, and the medium is an immersion medium which is arranged between the last lens on the image side and the image plane.
19. The microlithographic projection exposure apparatus of claim 15 , wherein, during use, the manipulator changes the refractive power of an optical element other than the medium.
20. The projection microlithographic exposure apparatus of claim 19 , wherein the optical element is arranged in or in immediate proximity to an intermediate image of the projection objective.