Projection optical system, exposure apparatus, and device manufacturing method
AssigneeCanon Kabushiki Kaisha
InventorYuhei Sumiyoshi
Life of this patent
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Abstract
A projection optical system is configured to project an image of an object plane onto an image plane, and includes a first optical element having an aspheric shape that is rotationally asymmetric with respect to an optical axis, a moving unit configured to move the first optical element in a direction perpendicular to the optical axis, and a second optical element fixed on the optical axis, and configured to reduce an optical path length difference caused by an aspheric surface of the first optical element, the second optical element having no aspheric shape complement to the aspheric shape of the first optical element.
Claims12
A projection optical system configured to project an image of an object plane onto an image plane, said projection optical system comprising:
- a first optical element having an aspheric surface that is rotationally asymmetric with respect to an optical axis;
- a moving unit configured to move the first optical element in a direction perpendicular to the optical axis;
- and
- a second optical element having an aspheric surface and fixed on the optical axis,
- wherein the aspheric surface of the second optical element is configured to reduce an aberration due to the aspheric surface of the first optical element when the first optical element is located at a predetermined position,
- wherein the first optical element corrects an aberration of the projection optical system by moving away from the predetermined position in the direction perpendicular to the optical axis, and
- wherein the aspheric surface of the second optical element is not complementary to the aspheric surface of the first optical element.
An exposure apparatus comprising:
- a projection optical system configured to project an image of an original plane onto a substrate plane,
- wherein the projection optical system comprises:
- a first optical element having an aspheric surface that is rotationally asymmetric with respect to an optical axis;
- a moving unit configured to move the first optical element in a direction perpendicular to the optical axis;
- and
- a second optical element having an aspheric surface and fixed on the optical axis,
- wherein the aspheric surface of the second optical element is configured to reduce an aberration due to the aspheric surface of the first optical element when the first optical element is located at a predetermined position,
- wherein the first optical element corrects an aberration of the projection optical system by moving away from the predetermined position in the direction perpendicular to the optical axis, and
- wherein the aspheric surface of the second optical element is not complementary to the aspheric surface of the first optical element.
A device manufacturing method comprising the steps of:
- exposing a substrate using an exposure apparatus;
- and
- developing the substrate that has been exposed,
- wherein the exposure apparatus includes a projection optical system configured to project an image of an original plane onto a substrate plane,
- wherein the projection optical system comprises:
- a first optical element having an aspheric surface that is rotationally asymmetric with respect to an optical axis;
- a moving unit configured to move the first optical element in a direction perpendicular to the optical axis;
- and
- a second optical element having an aspheric surface and fixed on the optical axis,
- wherein the aspheric surface of the second optical element is configured to reduce an aberration due to the aspheric surface of the first optical element when the first optical element is located at a predetermined position,
- wherein the first optical element corrects an aberration of the projection optical system by moving away from the predetermined position in the direction perpendicular to the optical axis, and
- wherein the aspheric surface of the second optical element is not complementary to the aspheric surface of the first optical element.
A projection optical system comprising:
- a first optical element having an aspheric surface that is rotationally asymmetric with respect to an optical axis of the projection optical system;
- and
- a second optical element having an aspheric surface that is not complementary to the aspheric surface of the first optical element,
- wherein the aspheric surface of the second optical element is configured to reduce an aberration due to the aspheric surface of the first optical element when the first optical element is located at a predetermined position, and
- wherein the first optical element corrects an aberration of the projection optical system by moving away from the predetermined position in a direction perpendicular to the optical axis.
An exposure apparatus comprising:
- a projection optical system configured to project an image of an original onto a substrate,
- wherein the projection optical system comprises:
- a first optical element having an aspheric surface that is rotationally asymmetric with respect to an optical axis of the projection optical system;
- and
- a second optical element having an aspheric surface that is not complementary to the aspheric surface of the first optical element,
- wherein the aspheric surface of the second optical element is configured to reduce an aberration due to the aspheric surface of the first optical element when the first optical element is located at a predetermined position, and
- wherein the first optical element corrects an aberration of the projection optical system by moving away from the predetermined position in a direction perpendicular to the optical axis.
A device manufacturing method comprising the steps of:
- exposing a substrate using an exposure apparatus;
- and
- developing the substrate that has been exposed,
- wherein the exposure apparatus includes a projection optical system configured to project an image of an original onto a substrate,
- wherein the projection optical system comprises:
- a first optical element having an aspheric surface that is rotationally asymmetric with respect to an optical axis of the projection optical system;
- and
- a second optical element having an aspheric surface that is not complementary to the aspheric surface of the first optical element,
- wherein the aspheric surface of the second optical element is configured to reduce an aberration due to the aspheric surface of the first optical element when the first optical element is located at a predetermined position, and
- wherein the first optical element corrects an aberration of the projection optical system by moving away from the predetermined position in a direction perpendicular to the optical axis.
Dependencies are inferred from the claim text.