Field facet system and lithography apparatus

Patent metadata

Field	Value
Publication number	US-12353137-B2
Application number	US-202318318342-A
Country	US
Kind code	B2
Filing date	May 16, 2023
Priority date	Nov 25, 2020
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

A field facet system for a lithography apparatus comprises: an optical element which comprises an elastically deformable facet portion having a light-reflecting optically active surface; and at least one actuating element for introducing a bending moment into the facet portion to deform the facet portion to change a radius of curvature of the optically active surface. The facet portion is curved in an arched manner in a plan view of the optically active surface. The rigidity of the facet portion as viewed along a longitudinal direction of the facet portion is variable so that a normal vector oriented perpendicularly to the optically active surface tilts exclusively about a spatial direction when the bending moment is introduced into the facet portion.

First claim

What is claimed is:

1. A field facet system, comprising:
an optical element comprising an elastically deformable facet portion, the elastically deformable facet portion comprising a light-reflecting optically effective surface; and
an actuating element configured to introduce a bending moment into the facet portion to deform the facet portion to change a radius of curvature of the optically effective surface,
wherein:
the facet portion is arcuately curved in a plan view of the optically effective surface; and
the facet portion has a variable stiffness along a longitudinal direction of the facet portion so that a normal vector perpendicular to the optically effective surface tilts exclusively about a spatial direction when the bending moment is introduced into the facet portion.

2. The field facet system of claim 1 , wherein the facet portion has a variable modulus of elasticity along the longitudinal direction.

3. The field facet system of claim 1 , wherein a cross section of the facet portion has a variable polar section modulus along the longitudinal direction.

4. The field facet system of claim 3 , wherein the cross section is trapezoidal.

5. The field facet system of claim 4 , wherein:
the cross section comprises a first width facing the optically effective surface;
the cross section comprises a second width facing away from the optically effective surface; and
the first width is greater than the second width.

6. The field facet system of claim 5 , wherein the first width is constant along the longitudinal direction, and the second width is variable along the longitudinal direction.

7. The field facet system of claim 6 , wherein the cross section comprises a variable height along the longitudinal direction.

8. The field facet system of claim 5 , wherein the cross section comprises a variable height along the longitudinal direction.

9. The field facet system of claim 3 , wherein the facet portion comprises first and second ends, and the facet portion is mirror-symmetric with respect to a plane of symmetry arranged centrally between the first and second end regions.

10. The field facet system of claim 9 , wherein the cross section is smallest in the plane of symmetry.

11. The field facet system of claim 10 , wherein the cross section increases in size proceeding from the plane of symmetry in a direction of the first end region and in a direction of the second and region.

12. The field facet system of claim 11 , further comprising first and second actuating elements, wherein the first actuating element is configured to introduce a first bending moment in the first end, the second actuating element is configured to introduce a second bending moment in the second end, and the first bending moment is opposite the second bending moment.

13. The field facet system of claim 10 , further comprising first and second actuating elements, wherein the first actuating element is configured to introduce a first bending moment in the first end, the second actuating element is configured to introduce a second bending moment in the second end, and the first bending moment is opposite the second bending moment.

14. The field facet system of claim 9 , further comprising first and second actuating elements, wherein the first actuating element is configured to introduce a first bending moment in the first end, the second actuating element is configured to introduce a second bending moment in the second end, and the first bending moment is opposite the second bending moment.

15. The field facet system of claim 3 , wherein the facet portion has a variable modulus of elasticity along the longitudinal direction.

16. The field facet system of claim 1 , wherein the normal vector tilts exclusively about a first spatial direction when the bending moment is introduced into the facet portion.

17. The field facet system of claim 16 , wherein the bending moment acts about the first spatial direction.

18. The field facet system of claim 17 , wherein:
a second spatial direction is perpendicular to the first spatial direction;
a third spatial direction perpendicular to both the first and second spatial directions; and
the facet portion deforms exclusively in a plane spanned by the second and third spatial directions when the bending moment is introduced.

19. The field facet system of claim 16 , wherein:
in a second spatial direction is perpendicular to the first spatial direction;
a third spatial direction perpendicular to both the first and second spatial directions; and
the facet portion deforms exclusively in a plane spanned by the second and third spatial directions when the bending moment is introduced.

20. An apparatus, comprising:
a field facet system according to claim 1 , wherein the apparatus is a lithography apparatus.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Schmittner Arno
• Anderl Willi
• Lippoldt Stefan
• Rosseels Joram
• Janssen Rob Wilhelmus Maria

Classifications

• G03F7/7015

  Details of optical elements · CPC title

• G03F7/70116

  Off-axis setting using a programmable means, e.g. liquid crystal display [LCD], digital micromirror device [DMD] or pupil facets · CPC title

• G02B26/0825

  the reflecting element being a flexible sheet or membrane, e.g. for varying the focus (flexible mirrors for cosmetic use A45D42/24) · CPC title

• G02B26/06

  for controlling the phase of light (G02B26/08 takes precedence {, measuring optical phase difference G01J9/00}) · CPC title

• G02B17/0848

  off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements · CPC title