Lithography apparatus and method for producing a mirror arrangement

Patent metadata

Field	Value
Publication number	US-9459538-B2
Application number	US-201414534644-A
Country	US
Kind code	B2
Filing date	Nov 6, 2014
Priority date	Jun 1, 2012
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A lithography apparatus is disclosed, having at least one mirror arrangement which includes a mirror substrate including a front side with a reflecting surface, a side wall, which extends along a circumference of the mirror substrate from a rear side of the mirror substrate, and mounting elements to mount the mirror arrangement on a structural element of the lithography apparatus. The rear side of the mirror substrate and an inner side of the side wall delimit a cavity. Each of the mounting elements is connected to the mirror arrangement at a connection surface. The relation S/D>0.5 is satisfied at least one of the connection surfaces, wherein D denotes a thickness of the side wall at the connection surface and S denotes the length of the shortest path through the mirror material from the centroid of the connection surface to the rear side of the mirror substrate.

First claim

The invention claimed is:

1. An apparatus, comprising:
a mirror arrangement, comprising:
a mirror substrate having a front side comprising a reflecting surface; and
a side wall extending along a circumference of the mirror substrate from a rear side of the mirror substrate, the side wall and the mirror substrate defining a cavity; and

mounting elements configured to mount the mirror arrangement to a structural element of a lithography apparatus,
wherein:
for each mounting element, the mounting element is connected to the mirror arrangement at a connection surface; and
S/D>0.5 at a connection surface, where D is a thickness of the side wall at the connection surface, S is equal to T−M, T is a length of a shortest path through the mirror material from a centroid of the connection surface to the front side of the mirror substrate, and M is a thickness of the mirror substrate.

2. The apparatus of claim 1 , wherein S is the length of the shortest path through the mirror material from the centroid of the connection surface to the rear side of the mirror substrate.

3. The apparatus of claim 1 , wherein S/D>1.

4. The apparatus of claim 1 , wherein S/A>1 where A is an extent of the connection surface on the side wall.

5. The apparatus of claim 1 , wherein S/A>1.5 where A is an extent of the connection surface on the side wall.

6. The apparatus of claim 1 , wherein the connection surfaces of the mounting elements are on an outer side of the side wall, or the connection surfaces of the mounting elements are on an inner side of the side wall.

7. The apparatus of claim 1 , wherein the cavity has an opening at the rear side of the mirror arrangement.

8. The apparatus of claim 1 , wherein the cavity is closed.

9. The apparatus of claim 1 , further comprising a cover element joined to the side wall so that the mirror substrate, the side wall and the cover element define the cavity.

10. The apparatus of claim 9 , wherein the cover element has an opening.

11. The apparatus of claim 10 , wherein an internal diameter of the opening of the cover element is less than half a diameter of the mirror substrate.

12. The apparatus of claim 1 , wherein an extent of the connection surface in a direction of an optical axis of the mirror arrangement is less than a depth of the cavity.

13. The apparatus of claim 1 , wherein an elevation is a distance from an edge of the rear side of the mirror substrate, and an annular groove is between the side wall and the elevation.

14. The apparatus of claim 13 , wherein a height of the elevation is from 0.1 to 0.8 times a depth of the cavity.

15. The apparatus of claim 14 , wherein an extent of the connection surface in a direction of the optical axis of the mirror arrangement, a height of the elevation and D are substantially equal.

16. The apparatus of claim 1 , wherein the side wall is integral with the mirror substrate.

17. The apparatus of claim 1 , further comprising a cover element joined to the side wall so that the mirror substrate, wherein:
the side wall and the cover element define the cavity; and
the mirror substrate, the side wall and the cover element are integral.

18. The apparatus of claim 1 , wherein the side wall is annular.

19. A lithography apparatus, comprising:
a structural element; and
the apparatus of claim 1 ,
wherein the mounting elements mount the mirror arrangement to the structural element.

20. The lithography apparatus of claim 19 , wherein the lithography apparatus is an EUV lithography apparatus.

21. An apparatus, comprising:
a mirror arrangement, comprising:
a mirror substrate having a front side comprising a reflecting surface; and a side wall extending along a circumference of the mirror substrate from a rear side of the mirror substrate, the side wall and mirror substrate defining a cavity; and mounting elements configured to mount the mirror arrangement to a structural element of the lithography apparatus, wherein:
for each mounting element, the mounting element is connected to the minor arrangement at a connection surface; and normals on the connection surface extend through the cavity, and wherein an entire surface area of the rear side of the mirror substrate is exposed in a region inside of the side wall.

22. A lithography apparatus, comprising:
a structural element; and
the apparatus of claim 21 ,
wherein the mounting elements mount the mirror arrangement to the structural element.

23. The lithography apparatus of claim 22 , wherein the lithography apparatus is an EUV lithography apparatus.

24. The apparatus of claim 1 , wherein an entire area of the rear side of the mirror substrate is unsupported in a region inside of the side wall.

25. The apparatus of claim 1 , wherein an entire surface area of the rear side of the mirror substrate is exposed in a region inside of the side wall.

26. The apparatus of claim 21 , wherein an entire area of the rear side of the mirror substrate is unsupported in a region inside of the side wall.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Schaffer Dirk
• Clauss Wilfried
• Chung Hin-Yiu Anthony

Classifications

• G02B7/182

  for mirrors · CPC title

• G03F7/70825

  Mounting of individual elements, e.g. mounts, holders or supports (workpiece or mask holders G03F7/707) · CPC title

• G02B5/0891

  Ultraviolet [UV] mirrors (apparatus for microlithography exposure G03F7/70; X-ray multilayer structures G21K1/06) · CPC title

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title

• G03F7/702 Primary

  Reflective illumination, i.e. reflective optical elements other than folding mirrors, e.g. extreme ultraviolet [EUV] illumination systems · CPC title