Illuminating arrangement including a zoom objective incorporating two axicons
AssigneeCarl-Zeiss-Stiftung
InventorsJohannes Wangler, Gerald Richter
Life of this patent
Estimating the term…
Abstract
An illumination system for an optical system such as a microlithographic projection exposure system includes a zoom lens 2 for varying the degree of coherence .sigma. and two axicons (22, 23) with an adjustable distance therebetween. The distance can preferably be reduced to zero. The illumination system provides continuous, conventional illumination with a variable degree of coherence .sigma. and annular illumination or multipole illumination with different geometries with low losses of light.
Claims19
An illuminating arrangement for an optical system such as a microlithographic projection exposure apparatus, the illuminating arrangement comprising:
- a light source for emitting illuminating light along an optical axis;
- a zoom objective mounted on said optical axis and defining a light-entry surface and a light-exit surface and said zoom objective having at least one zoom lens;
- a first displacement drive for shifting said zoom lens along said axis for varying the degree of coherence .sigma. of said illuminating light
- two axicons integrated within said zoom objective between said light-entry surface and said light-exit surface;
- and,
- a second displacement drive for shifting said two axicons relative to each other along said optical axis for adjusting the distance therebetween.
An illuminating arrangement for an optical system such as a microlithographic projection exposure apparatus, the illuminating arrangement comprising:
- a light source for emitting illuminating light along an optical axis;
- a zoom objective mounted on said optical axis and having first and second zoom lenses for transmitting said light;
- a first displacement drive for shifting one of said lenses along said axis to adjust the coherence factor .sigma. of said light transmitted by said lenses;
- two axicons arranged in said zoom objective;
- a second displacement drive for shifting said two axicons relative to each other along said optical axis for adjusting the distance therebetween;
- and,
- said axicons having respective contact surfaces which come into mutual contact engagement when said distance is reduced to a minimum;
- at least one of said axicons having a boundary surface opposite the contact surface thereof;
- and, said boundary surface being curved.
An illuminating arrangement for an optical system such as a microlithographic projection exposure apparatus, the illuminating arrangement comprising:
- a light source for emitting illuminating light along an optical axis;
- a zoom objective mounted on said optical axis having first and second zoom lenses for transmitting light;
- a first displacement drive for shifting one of said zoom lenses along said axis to adjust the coherence factor .sigma. of said light transmitted by said lenses;
- two axicons integrated within said zoom objective;
- and,
- a second displacement drive for shifting said two axicons relative to each other along said optical axis for adjusting the distance therebetween.
Dependencies are inferred from the claim text.