Optical element having a coating for influencing heating radiation and optical arrangement

Patent metadata

Field	Value
Publication number	US-10401540-B2
Application number	US-201715405012-A
Country	US
Kind code	B2
Filing date	Jan 12, 2017
Priority date	Aug 19, 2014
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

The disclosure relates to an optical element, including: a substrate, a first coating, which is disposed on a first side of the substrate and is configured for reflecting radiation having a used wavelength (λ EUV ) in the EUV wavelength range, and a second coating, which is disposed on a second side of the substrate, for influencing heating radiation that is incident on the second side of the substrate. The disclosure also relates to an optical arrangement having at least one such optical element.

First claim

What is claimed is:

1. An optical element, comprising:
a substrate having first and second sides;
a first coating supported by the first side of the substrate; and
a second coating supported by the second side of the substrate,
wherein:
the substrate comprises a glass;
the first coating reflects EUV radiation;
the first coating comprises a layer that reflects radiation having a first wavelength;
the second coating comprises an absorbing layer that absorbs radiation having a second wavelength;
the first wavelength is in a range selected from the group consisting of the visible range and the infrared range;
the second wavelength is in a range selected from the group consisting of the visible range and the infrared range;
the second wavelength is different from the first wavelength; and
the optical element is an EUV mirror.

2. The optical element of claim 1 , wherein the second coating further comprises an anti-reflecting layer that suppresses reflection of radiation at the second wavelength, wherein the absorbing layer is between the substrate and the anti-reflection layer.

3. The optical element of claim 2 , wherein at least one of the following holds:
a maximum absorbance of the absorbing layer is at wavelengths of more than 1500 nm; and
a maximum suppression of the anti-reflection layer is at wavelengths of more than 1500 nm.

4. The optical element of claim 1 , wherein the absorbing layer transmits radiation at a third wavelength which is different from the second wavelength.

5. The optical element of claim 4 , wherein the absorbing layer has a maximum transmission at wavelengths less than 1500 nm.

6. The optical element of claim 4 , wherein at least one of the following holds:
the substrate comprises a material that is at least partially transparent for radiation at the first wavelength; and
the substrate comprises a material that is at least partially transparent for radiation at the third wavelength.

7. The optical element of claim 1 , wherein:
the absorbing layer transmits radiation at a third wavelength that is different from the second wavelength; and
the third wavelength is in a range selected from the group consisting of the visible range and in the infrared range.

8. The optical element of claim 7 , wherein:
the second coating further comprises an anti-reflection layer that suppresses reflection of radiation at the second and third wavelengths; and
the absorbing layer is between the substrate and the anti-reflection layer.

9. The optical element of claim 1 , wherein the second coating comprises an anti-reflection layer that suppresses radiation at the second wavelength.

10. The optical element of claim 9 , wherein at least one of the following holds:
a maximum reflectance of the layer of the first coating is in a wavelength range of between 3500 nm and 3700 nm; and
a maximum suppression of reflection of the anti-reflection layer is in a wavelength range of between 3500 nm and 3700 nm.

11. The optical element of claim 1 , wherein the second coating further comprises a polarization-selective layer that:
transmits radiation at the first wavelength in a first polarization state; and
reflects radiation at the first wavelength in a second polarization state different from the first polarization state.

12. The optical element of claim 11 , further comprising a polarization-changing layer, wherein the polarization-changing layer is: a) between the layer of the first coating and the substrate; or b) between the polarization-selective layer and the substrate.

13. The optical element of claim 1 , wherein the second coating transmits radiation at the first wavelength.

14. An arrangement, comprising:
an optical element according to claim 1 ; and
a light source configured to generate radiation at a wavelength in a range selected from the group consisting of visible radiation and infrared radiation,
wherein the second coating is between the light source and the substrate.

15. The arrangement of claim 14 , wherein the arrangement is an EUV lithography apparatus.

16. The arrangement of claim 14 , wherein: the arrangement comprises a plurality of light sources in a gird-type arrangement; and for each light source, the second coating is between the light source and the substrate.

17. The optical element of claim 1 , wherein the glass comprises a material selected from the group consisting of a quartz glass and a silicate glass.

18. The optical element of claim 1 , wherein the optical element is configured so that, during use of the optical element, radiation having the first wavelength that passes through the substrate and impinges on the first coating is reflected back toward the substrate by the first coating.

19. The optical element of claim 1 , wherein the glass comprises a quartz glass.

20. The optical element of claim 1 , wherein the glass comprises a TiO 2 -doped quartz glass.

21. The optical element of claim 1 , wherein the glass comprises a glass ceramic.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Bittner Boris
• Wabra Norbert
• Schmidt Holger
• Schoemer Ricarda
• Schneider Sonja

Classifications

• G03F7/70958

  Optical materials or coatings, e.g. with particular transmittance, reflectance or anti-reflection properties · CPC title

• G03F7/70266

  Adaptive optics, e.g. deformable optical elements for wavefront control, e.g. for aberration adjustment or correction · CPC title

• G02B27/0025

  for optical correction, e.g. distorsion, aberration · CPC title

• G02B7/1815

  with cooling or heating systems (cooling arrangements for laser mirrors H01S3/0401) · CPC title

• G02B5/3075

  for use in the UV (G02B5/3066 takes precedence) · CPC title