Method for producing a lens for a lithography apparatus, and measurement system

Patent metadata

Field	Value
Publication number	US-10345547-B2
Application number	US-201715813660-A
Country	US
Kind code	B2
Filing date	Nov 15, 2017
Priority date	May 20, 2015
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

A method for producing a lens for a lithography apparatus is disclosed. A measurement system for ascertaining an optical characteristic of a partial lens for a lithography apparatus is also disclosed.

First claim

What is claimed is:

1. A method, comprising:
a) providing first and second partial lenses, the first partial lens comprising a plurality of optical elements, the second partial lens comprising an optical element, each of the first and second partial lenses having a beam path comprising a non-homocentric embodiment on its entry side or its exit side;
b) transmitting a first light beam along a respective beam path of the first and second partial lenses and capturing the first light beam downstream of the respective partial lens;
c) ascertaining an optical characteristic of a respective partial lens based on the captured first light beam;
d) adjusting the plurality of optical elements of the first partial lens and the optical element of the second partial lens depending on the ascertained optical characteristic, and
e) joining the first and second partial lenses to produce a lens.

2. The method of claim 1 , further comprising capture the first light beam by a capturing device on which the light beam produces a light spot, wherein ascertaining the at least one optical characteristic comprises comparing the light spot to a reference light spot.

3. The method of claim 2 , wherein a position of the light spot is compared to a position of the reference light spot.

4. The method of claim 1 , wherein at least one first and one spaced apart second light beams are transmitted along the respective beam path of the first and second partial lenses and captured downstream of the respective partial lens, and wherein the at least one optical characteristic is ascertained on the basis of the captured first and second light beams.

5. The method of claim 4 , wherein the first and second light beams are captured by a capturing device on which the first and second light beams produce a light spot pattern, and ascertaining the optical characteristic comprises comparing the light spot pattern to a reference light spot pattern.

6. The method of claim 4 , wherein the first and the spaced apart second light beam are produced by virtue of a light source being moved between two positions.

7. The method of claim 6 , wherein the light source is moved between the two positions via a robot.

8. The method of claim 1 , wherein the first and the spaced apart second light beam are produced by virtue of two spaced apart light sources being provided at the same time.

9. The method of claim 1 , wherein the optical characteristic of at least one partial lens is ascertained using a deflectometric measuring method.

10. The method of claim 9 , wherein, for the deflectometric measuring method, at least one light source for producing the at least one first light beam and a mask illuminated thereby are arranged upstream of the at least one partial lens and a capturing device for capturing the at least one first light beam is arranged downstream of the corresponding partial lens.

11. The method of claim 1 , wherein the optical characteristic of at least one partial lens is ascertained using a method for a wavefront measurement.

12. The method of claim 11 , wherein, for the method for a wavefront measurement, at least one light source for producing the at least one first light beam and a mask illuminated thereby are arranged up-stream of the at least one partial lens, provision further being made of a correcting optical unit for correcting the at least one first light beam, and a capturing device for capturing the at least one first, corrected light beam is arranged downstream of the corresponding partial lens.

13. The method of claim 12 , wherein the correcting optical unit comprises a microlens array or a pinhole aperture grid.

14. The method of claim 12 , wherein the correcting optical unit comprises a computer-generated hologram.

15. The method of claim 12 , wherein the correcting optical unit comprises respectively one computer-generated hologram for each light beam.

16. The method of claim 14 , wherein the computer-generated hologram is arranged upstream of the microlens array or the pinhole aperture grid.

17. The method of claim 14 , wherein the computer-generated hologram is configured to parallelize the first and second light beams.

18. The method of claim 14 , wherein the at least one optical characteristic of at least one partial lens is ascertained using the wavefront measuring method without a computer-generated hologram in a first step and with a computer-generated hologram in a second step.

19. The method of claim 2 , wherein the capturing device comprises a ground glass screen or an electronic chip.

20. The method of claim 1 , wherein the plurality of optical elements of the first partial lens and the optical element of the second partial lens are fixed after d).

21. The method of claim 1 , wherein each of the plurality of optical elements of the first partial lens or the optical element of the second partial lens is actuatable between first and second positions or alignment during the operation of the lithography apparatus, wherein c) is carried out in the first and second positions or alignments.

22. The method of claim 1 , wherein an imaging optical characteristic of the produced lens is ascertained after e) at the operating wavelength.

23. The method of claim 22 , wherein post-processing of surfaces or an actuation of one or more of the optical elements of the first or second partial lenses is effectuated depending on the ascertained imaging optical characteristic.

24. The method of claim 1 , wherein an interface in the beam path between the first and second partial lenses subdivides a distance between an optical element of the first partial lens and an optical element of the second partial lens, the distance being longer than the longest distance between every two adjacent optical elements of the first and second partial lenses.

25. The method of claim 1 , wherein at least three partial lenses are provided.

26. The method as of claim 1 , wherein the plurality of optical elements of the first partial lens and/or the optical element of the second partial lens are mirrors and/or lens elements.

27. The method of claim 1 , wherein first and second partial lenses are combined to form a partial lens.

28. The method of claim 27 , wherein a) to e) are repeated with the combined partial lens.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Fritzsche Steffen
• Baier Juergen
• Freimann Rolf

Classifications

• G01M11/0292 Primary

  of objectives by measuring the optical modulation transfer function (photometry G01J) · CPC title

• G01M11/0221

  by determining the optical axis or position of lenses · CPC title

• G02B7/023

  permitting adjustment · CPC title

• G02B7/003 Primary

  Alignment of optical elements (G02B7/001, G02B7/002 take precedence; for mirrors G02B7/1822) · CPC title

• G03F7/7015

  Details of optical elements · CPC title