Mirror

Patent metadata

Field	Value
Publication number	US-9678439-B2
Application number	US-201514623882-A
Country	US
Kind code	B2
Filing date	Feb 17, 2015
Priority date	Sep 17, 2012
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Mirror having a fragmented total surface area, wherein the fragmentation forms an aperiodic arrangement.

First claim

The invention claimed is:

1. A mirror, comprising:
a fragmented total surface area, comprising:
a multiplicity of first regions which arranged aperiodically, each of the first regions having a diameter in the range from one millimeter to 20 millimeters; and
a second region which is a radiation-reflecting region,

wherein each of the first regions is structurally delimited from the second region, and each of the first regions is circumferentially surrounded by the second region.

2. The mirror of claim 1 , wherein at least 10% of the first regions of the mirror are offset by at least half of their diameter compared to an arrangement in which all the first regions are on vertices of a lattice.

3. The mirror of claim 1 , wherein, compared to an arrangement in which all the first regions are on vertices of a lattice, the first regions of the mirror are offset by at most half an of an average distance between neighboring vertices of the lattice.

4. The mirror of claim 1 , wherein the first regions are homogeneously distributed so that a local density of the first regions in regions having a diameter of less than 50% of a diameter of the mirror has a deviation of at most 30% from an average density of the first regions over the entire mirror.

5. The mirror of claim 1 , wherein the mirror comprises at least 100 first regions.

6. The mirror of claim 1 , wherein a total surface area of the multiplicity of first regions comprises at most 30% of a total surface area of the mirror.

7. The mirror of claim 1 , wherein the first regions are radiation-transmissive.

8. The mirror of claim 7 , wherein at least 10% of the first regions of the mirror are offset by at least half of their diameter compared to an arrangement in which all the first regions are on vertices of a lattice.

9. The mirror of claim 7 , wherein, compared to an arrangement in which all the first regions are on vertices of a lattice, the first regions of the mirror are offset by at most half an of an average distance between neighboring vertices of the lattice.

10. The mirror of claim 7 , wherein the first regions are homogeneously distributed so that a local density of the first regions in regions having a diameter of less than 50% of a diameter of the mirror has a deviation of at most 30% from an average density of the first regions over the entire mirror.

11. The mirror of claim 7 , wherein the mirror comprises at least 100 first regions.

12. The mirror of claim 1 , wherein:
the mirror comprises a multiplicity of second regions;
each of the second regions is a radiation-reflecting region;
each of the first regions is structurally delimited from each of the second regions, and
each of the first regions is circumferentially surrounded by the multiplicity of second regions.

13. The mirror of claim 12 , wherein the first regions are radiation-transmissive.

14. A component, comprising:
a mirror according to claim 1 ; and
an adjusting device configured to adjust the mirror,
wherein the component is an optical component.

15. The component of claim 14 , wherein the component comprises a second mirror according to claim 1 , and the adjusting device is configured to exchange the mirrors.

16. A unit, comprising:
a mirror according to claim 1 ,
wherein the optical unit is a projection optical unit configured to image an object field into an image field, and the unit is an optical unit.

17. A system, comprising:
an illumination optical unit configured to illuminate an object field with illumination radiation; and
a projection optical unit configured to image the object field into an image field, the projection optical unit comprising a mirror according to claim 1 ,
wherein the system is an optical system.

18. The system of claim 17 , wherein the first regions are arranged in a beam path of the illumination optical unit, and the second region is arranged in a beam path of the projection optical unit.

19. The system of claim 18 , wherein the system has an object-side numerical aperture (NAO) and a chief ray angle (CRA), and arcsin (NAO)≧CRA.

20. An apparatus, comprising:
a radiation source;
an illumination optical unit configured to illuminate an object field with illumination radiation; and
a projection optical unit configured to image the object field into an image field, wherein
the projection optical unit comprises a mirror according to claim 1 , and the apparatus is a microlithography projection exposure apparatus.

21. A method of operating a microlithography projection exposure apparatus comprising an illumination optical unit and a projection optical unit, the method comprising:
using the illumination optical unit to illuminate an object field with illumination radiation; and
using the projection optical unit to image the object field into a light sensitive coating,
wherein the projection optical unit comprises a mirror according to claim 1 .

22. The mirror of claim 1 , wherein the second region is an EUV-radiation-reflecting region.

23. A method, comprising:
i) selecting a start design of a mirror which comprises an arrangement of a number of first regions on vertices of a lattice;
ii) selecting a fitness function for assessing an imaging quality of a projection optical unit comprising a mirror with the start design;
iii) selecting a target value and a termination criterion;
iv) varying the arrangement of the first regions according to an algorithm until the target value or the termination criterion is reached; and
based on i)-iv), making a mirror;
disposing the mirror in a projection optical unit of a microlithography projection exposure apparatus, the microlithography projection exposure apparatus further comprising an illumination optical unit;
using the illumination optical unit to illuminate an object field with illumination radiation; and
using the projection optical unit to image the object field into a light sensitive coating,
wherein the mirror comprises:
a fragmented total surface area, comprising:
a multiplicity of first regions which arranged aperiodically, each of the first regions having a diameter in the range from one millimeter to 20 millimeters; and
a second region which is a radiation-reflecting region, and

wherein each of the first regions is structurally delimited from the second region, and each of the first regions is circumferentially surrounded by the second region.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Saenger Ingo
• Ruoff Johannes
• Endres Martin
• Eisenmann Thomas

Classifications

• G03F7/70066 Primary

  Size and form of the illuminated area in the mask plane, e.g. reticle masking blades or blinds · CPC title

• G03F7/70083

  Non-homogeneous intensity distribution in the mask plane · CPC title

• G03F7/70233

  Optical aspects of catoptric systems, i.e. comprising only reflective elements, e.g. extreme ultraviolet [EUV] projection systems · CPC title

• G02B5/09

  Multifaceted or polygonal mirrors {, e.g. polygonal scanning mirrors; Fresnel mirrors} · CPC title

• G02B7/182

  for mirrors · CPC title