Illumination system with field mirrors for producing uniform scanning energy
AssigneeCarl Zeiss SMT GmbH
InventorsWolfgang Singer, Joachim Hainz, Hans-Joachim Frasch, Johannes Wangler, Joachim Wietzorrek, Jörg Schultz
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Abstract
This invention relates to an Ilumination system for scanning lithography especially for wavelengths≦193 nm, particularly EUV lithography, for the illumination of a slit, comprising at least one field mirror or at least one field lens and being characterized in that at least one of the field mirror(s) or the field lens(es) has (have) an aspheric shape.
Claims33
An illumination system for scanning lithography, comprising:
- a component that alters a direction of propagation of a light beam,
- wherein said component is selected from the group consisting of a field mirror and a field lens, and
- wherein said component (a) has an aspheric surface upon which said light beam is incident, and (b) is corrected in an aplanatic manner such that a σ-variation in an exit pupil of the illumination system is less than 10%.
An illumination system for scanning lithography for wavelengths ≦193 nm, for illuminating a slit, comprising:
- at least one field mirror or at least one field lens,
- wherein at least one of said field mirror(s) or said field lens(es) has (have) an inclined aspheric shape, and is corrected in an aplanatic manner such that a σ-variation in an exit pupil of the illumination system is less than 10%.
A projection exposure system for scanning-microlithography, comprising:
- an illumination system having a component that alters a direction of propagation of a light beam, wherein said component is selected from the group consisting of a field mirror and a field lens, and has an aspheric surface upon which said light beam is incident, and wherein said illumination system has an exit pupil with σ-variations of less than 10%;
- a support system for holding a mask to be illuminated by the illumination system;
- a projection objective for imaging said mask to an image plane of said projection objective;
- and
- a support system for holding a light-sensitive subject in said image plane.
Dependencies are inferred from the claim text.