Lithographic systems and processes of making and using same
AssigneeCarl Zeiss SMT GmbH
InventorDirk Juergens
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Abstract
A lithographic system includes a projection system for projecting an object field through a projection system's pupil onto an image field. The projection system includes an optical element located at the projection system's pupil. The projection system's pupil is manipulable with respect to normalized pupil heights by the optical element. Related processes are also disclosed.
Claims20
A process of operating a lithographic system comprising a projection system having an object field and an image field, the projection system comprising an optical element located at a projection system pupil, the process comprising:
- projecting the object field through the projection system and onto the image field;
- and
- manipulating the projection system pupil via the optical element at normalized pupil heights r=ƒ(ρ) to manipulate an exit pupil of an object point at normalized pupil heights ρ,
- wherein ƒ:
- [0,1]→[0,1] is a non-linear function approximating an offence against the sine condition φP with respect to the projection system pupil.
The process of claim 11, wherein the projection system is an immersion projection system.
A process of manufacturing a lithographic system comprising a projection system having an object field and an image field, the projection system comprising an optical element having a surface located at a projection system pupil, the process comprising:
- providing the surface of the optical element with a surface deformation ΣinαiZi(r,φ) to correct the wavefront in the exit pupil ΣiαiZi(ρ,φ),
- wherein r=ƒ(ρ) and ƒ:
- [0,1]→[0,1] is a non-linear function approximating the offence against the sine condition φ between the normalized exit pupil and the normalized projection systems pupil P.
Dependencies are inferred from the claim text.