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US 7,248,667 B2Granted
Illumination system with a grating element
AssigneeCarl Zeiss SMT GmbH
InventorsMarkus Weiss, Wolfgang Singer, Bernd Kleemann
Life of this patent
Estimating the term…
Abstract
An illumination system, particularly for wavelengths ≦100 nm, with an object plane and a field plane, comprises a grating element and a physical diaphragm in a diaphragm plane, which is arranged downstream to the grating element in the beam path from the object plane to the field plane.
Claims40
An illumination system, comprising:
- a light source for providing light having a wavelength ≦100 nm;
- a collector unit for receiving said light and producing a convergent light bundle;
- a field plane;
- a grating element situated in a beam path from said light source to said field plane,
- wherein said grating element diffracts said convergent light bundle and produces a diffracted light bundle;
- a physical diaphragm in a diaphragm plane, situated in said beam path downstream of said grating element, wherein said illumination system forms an intermediate image of said light source that is substantially located in said diaphragm plane;
- and
- a mirror having a plurality of facets situated in said beam path downstream of said physical diaphragm, for illuminating a field in said field plane with images of said plurality of facets that overlap one another.
5 more elements
Illumination system comprising:
- a diffraction grating element;
- and
- a first physical diaphragm in a diaphragm plane after said diffraction grating element, in a beam path from a light source, of light having a wavelength ≦100 nm, to a field plane;
- an optical system, located between said diaphragm plane and said field plane, for forming and illuminating a field in said field plane, wherein said optical system includes a facetted mirror for homogeneously illuminating said field in said field plane;
- and
- a second physical diaphragm in said beam path, after said first physical diaphragm, for suppressing stray light.
3 more elements
Illumination system comprising:
- a diffraction grating element;
- a first physical diaphragm in a beam path between said diffraction grating element and a diaphragm plane;
- and
- a second physical diaphragm in said diaphragm plane;
- and
- an optical system for forming and illuminating a field in a field plane, wherein said optical system is located between said diaphragm plane and said field plane, and includes a facetted mirror for homogeneously illuminating said field in said field plane,
- wherein said diffraction grating element receives light having a wavelength ≦100 nm and produces a light bundle of a kth diffraction order with a focal point at said second physical diaphragm,
- wherein |k|≧1.
5 more elements
Dependencies are inferred from the claim text.