EUV lithography system

Patent metadata

Field	Value
Publication number	US-9448490-B2
Application number	US-201313910912-A
Country	US
Kind code	B2
Filing date	Jun 5, 2013
Priority date	Dec 9, 2010
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

An EUV lithography system 1 comprises an EUV beam path and a monitor beam path 51.
The EUV beam path comprises a mirror system 13 , which has a base and a multiplicity of mirror elements 17 having concave mirror surfaces, the orientation of which relative to the base is respectively adjustable.
The monitor beam path 51 comprises at least one monitor radiation source 53 , a screen 71 , the mirror system 13 , which is arranged in the monitor beam path 51 between the monitor radiation source 53 and the screen 71 , and a spatially resolving detector 77.
In this case, each of a plurality of the mirror elements generates an image of the monitor radiation source in an image plane assigned to the respective mirror elements, distances B between the image planes assigned to the mirror elements and the screen have a maximum distance, distances A between each of the plurality of mirror elements and the image plane assigned to it have a minimum distance, and the maximum distance B is less than half of the minimum distance A.

First claim

The invention claimed is:

1. A system having a first beam path and a second beam path different from the first beam path, the system comprising:
imaging optics in the first beam path, the imaging optics configured to image an object plane into an image plane;
a first mirror system in the first beam path upstream of the object plane, the first mirror system comprising a base and a plurality of mirror elements supported by the base, each mirror element having a mirror surface with an orientation which is adjustable relative to the base;
a second mirror system in the first beam path upstream of the object plane, the second mirror system comprising a base and a plurality of mirror elements supported by the base,
a plurality of radiation sources in the second beam path, each radiation source being arranged between adjacent mirror elements of the second mirror system;
a detector in the second beam path,
wherein:
the first mirror system is in the second beam path between the radiation sources and the detector;
the detector is configured to detect radiation reflected from mirror elements of the first mirror system; and
the system is an EUV lithography system.

2. The system of claim 1 , wherein the second mirror system is upstream of the first mirror system along the first beam path.

3. The system of claim 1 , wherein the second mirror system is downstream of the first mirror system along the first beam path.

4. The system of claim 1 , further comprising a radiation source configured to produce EUV radiation that travels through the system along the first beam path.

5. The system of claim 1 , further comprising:
a screen in the second beam path; and
a detector in the second beam path, the detector being configured to detect in a spatially resolved manner radiation intensities impinging on the screen during use of the system,
wherein:
the first mirror system is in the second beam path between the plurality of radiation sources and the screen;
during use of the system, each mirror element generates an image of the plurality of radiation sources in an image plane corresponding to the mirror element;
there is a maximum distance among the distances between the screen and the image planes of the mirror elements;
there is a minimum distance among the distances between the mirror elements and their respective image planes;
the maximum distance is less than half of the minimum distance.

6. The system of claim 1 , wherein the detector is a plenoptic camera.

7. The system of claim 1 , further comprising a plurality of actuators configured to change the orientation of at least some of the mirror surfaces relative to the base.

8. The system of claim 7 , further comprising a controller configured to control the actuators based on a signal from the detector.

9. The system of claim 1 , wherein:
each mirror surface has a width and a length which is at least five times greater than the width;
each radiation source is configured to generate a separate radiation beam which, during use of the system, impinges on the first mirror system at a location which is away from radiation beams generated by others of the plurality of radiation sources;
during use of the system, each radiation beam impinges on at least one of the mirror elements of the first mirror system; and
during use of the system, a lateral extension of each radiation beam in a longitudinal direction of a mirror element of the first mirror system on which it impinges is less than the length of the mirror element.

10. The system of claim 1 , wherein:
the mirror elements of the first mirror system are arranged in an array so that their mirror surfaces are arranged in a plurality of rows arranged adjacent one another;
centers of the mirror surfaces within the rows are arranged a distance from one another that is less than the lengths of the mirror surfaces; and
centers of the rows are arranged a distance from one another that is greater than or equal to the lengths of the mirror surfaces.

11. The system of claim 1 , wherein each radiation source is configured to emit radiation having a wavelength range, and the wavelength ranges of at least two radiation sources are different from one another.

12. The system of claim 1 , wherein each radiation source is configured to emit radiation having a temporal intensity modulation, and the temporal intensity modulations of at least two radiation sources are different from one another.

13. The system of claim 1 , further comprising:
an interferometer in the second beam path, the interferometer comprising a measuring arm;
a monitor mirror in the second beam path, the monitor mirror being fixed to the base of the first mirror system; and
a hologram arranged in the second beam path between the monitor mirror and the interferometer.

14. A system having a first beam path and a second beam path different from the first beam path, the system comprising:
imaging optics in the first beam path upstream of the object plane, the imaging optics configured to image an object plane into an image plane;
a mirror system in the first beam path upstream of the object plane, the mirror system comprising a base and a plurality of mirror elements supported by the base, each mirror element having a mirror surface with an orientation which is adjustable relative to the base;
a radiation source in the second beam path;
a screen in the second beam path; and
a detector in the second beam path, the detector being configured to detect in a spatially resolved manner radiation intensities impinging on the screen during use of the system,
wherein:
the mirror system is in the second beam path between the radiation source and the screen;
during use of the system, each mirror element generates an image of the radiation source in an image plane corresponding to the mirror element;
there is a maximum distance among the distances between the screen and the image planes of the mirror elements;
there is a minimum distance among the distances between the mirror elements and their respective image planes;
the maximum distance is less than half of the minimum distance; and
the system is an EUV lithography system.

15. The system of claim 14 , wherein the screen comprises a radiation-sensitive layer, and the detector comprises the radiation-sensitive layer.

16. The system of claim 14 , wherein the screen comprises a light-scattering layer, and the system further comprises imaging optics configured to image the light-scattering layer onto a radiation-sensitive layer of the detector.

17. The system of claim 14 , wherein the screen comprises a plurality of lens elements adjacent to one another and a distance from a radiation-sensitive layer of the detector so that, during use of the system, light from the radiation source which impinges on the lens elements traverses the lens elements and impinges on the radiation-sensitive layer.

18. A system, comprising:
imaging optics in the first beam path, the imaging optics being configured to image an object plane into an image plane along a beam path;
a mirror system in the first beam path upstream of the object plane, the imaging optics comprising a plurality of mirror elements supported by a base, each mirror element having an orientation which is adjustable relative to the base;
an interferometer comprising a measuring arm;
a monitor mirror fixed to the base of the mirror system; and
a hologram in a second beam path which is between the monitor mirror and the interferometer,
wherein the system is an EUV lithography system.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Dinger Udo
• Wischmeier Lars
• Hauf Markus
• Kellner Stephan
• Gurevich Igor
• Deguenther Markus

Classifications

• G03F7/70116

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• G03F7/7085

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• G03F7/70483

  Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring · CPC title

• G03F7/708

  Construction of apparatus, e.g. environment aspects, hygiene aspects or materials · CPC title

• G03F7/70075

  Homogenization of illumination intensity in the mask plane by using an integrator, e.g. fly's eye lens, facet mirror or glass rod, by using a diffusing optical element or by beam deflection · CPC title