Illumination system for EUV projection lithography

Patent metadata

Field	Value
Publication number	US-10310381-B2
Application number	US-201815945879-A
Country	US
Kind code	B2
Filing date	Apr 5, 2018
Priority date	Nov 22, 2013
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

An illumination system for EUV projection lithography has a beam shaping optical unit for generating an EUV collective output beam from an EUV raw beam of a synchrotron-radiation-based light source. An output coupling optical unit serves for generating a plurality of EUV individual output beams from the EUV collective output beam. In each case a beam guiding optical unit serves for guiding the respective EUV individual output beam toward an object field in which a lithography mask is arrangable. The result is an illumination system with which EUV light of a synchrotron-radiation-based light source is guided to the greatest possible extent without losses and at the same time flexibly.

First claim

What is claimed is:

1. A beam shaping optical unit, comprising:
at least two groups of mirrors on which EUV radiation impinges with grazing incidence during use of the beam shaping optical unit,
wherein each mirror group has a common group incidence plane, the group incidence planes of the mirror groups differ from one another, and the beam shaping unit is an EUV lithography beam shaping unit, and
wherein:
the beam shaping optical unit comprises first, second and third groups of mirrors;
all mirrors of the first group of mirrors are in a beam path downstream of a first mirror of the second group of mirrors; and
all the mirrors of the first group of mirrors are upstream of a last mirror of the third group of mirrors.

2. The beam shaping optical unit of claim 1 , wherein the angles of incidence of the EUV radiation on all mirrors of one of the mirror groups are of identical magnitude.

3. The beam shaping optical unit of claim 2 , wherein the angles of incidence of the EUV radiation on at least two mirrors of one of the mirror groups differ.

4. The beam shaping optical unit of claim 3 , wherein, projected onto the common group incidence plane of the group of mirrors with different angles of incidence, a generated EUV collective output beam runs in the same direction as an EUV raw beam that is incident in the beam shaping optical unit.

5. The beam shaping optical unit of claim 2 , wherein, projected onto the common group incidence plane of the group of mirrors with different angles of incidence, a generated EUV collective output beam runs in the same direction as an EUV raw beam that is incident in the beam shaping optical unit.

6. The beam shaping optical unit of claim 1 , wherein the angles of incidence of the EUV radiation on at least two mirrors of one of the mirror groups differ.

7. The beam shaping optical unit of claim 6 , wherein, projected onto the common group incidence plane of the group of mirrors with different angles of incidence, a generated EUV collective output beam runs in the same direction as an EUV raw beam that is incident in the beam shaping optical unit.

8. The beam shaping optical unit of claim 1 , wherein, projected onto the common group incidence plane of the group of mirrors with different angles of incidence, a generated EUV collective output beam runs in the same direction as an EUV raw beam that is incident in the beam shaping optical unit.

9. An illumination system, comprising:
a beam shaping optical unit according to claim 1 ,
wherein the illumination system is an EUV illumination system.

10. The illumination system of claim 9 , wherein the beam shaping optical unit configured to generate an EUV collective output beam from an EUV raw beam of a synchrotron-radiation-based light source.

11. The illumination system of claim 10 , further comprising an output coupling optical unit configured to generate a plurality of EUV individual output beams from the EUV collective output beam.

12. The illumination system of claim 11 , wherein, for each EUV individual output beam, a beam guiding optical unit configured to guide the EUV individual output beam toward an object field in which a lithography mask is arrangable.

13. The illumination system of claim 12 , wherein:
the beam shaping optical unit is configured to generate the EUV collective output beam with an aspect ratio contribution of 1:√{square root over (N)}; and
at least one member selected from the group consisting of the output coupling optical unit and the beam guiding optical unit is configured to subsequently generate a number N of the EUV individual output beams with an aspect ratio contribution of in each case 1:1.

14. The illumination system of claim 9 , further comprising an EUV light source.

15. An apparatus, comprising:
an illumination system comprising a beam shaping optical unit according to claim 1 ; and
a projection optical unit configured to image the object field into an image field,
wherein the apparatus is an EUV lithography projection exposure apparatus.

16. A beam shaping optical unit, comprising:
at least two groups of mirrors on which EUV radiation impinges with grazing incidence during use of the beam shaping optical unit,
wherein each mirror group has a common group incidence plane, the group incidence planes of the mirror groups differ from one another, and the beam shaping unit is an EUV lithography beam shaping unit, and
wherein the angles of incidence of the EUV radiation on at least two mirrors of one of the mirror groups differ.

17. The beam shaping optical unit of claim 16 , wherein, projected onto the common group incidence plane of the group of mirrors with different angles of incidence, a generated EUV collective output beam runs in the same direction as an EUV raw beam that is incident in the beam shaping optical unit.

18. An illumination system, comprising:
a beam shaping optical unit according to claim 16 ,
wherein the illumination system is an EUV illumination system.

19. An apparatus, comprising:
an illumination system comprising a beam shaping optical unit according to claim 16 ; and
a projection optical unit configured to image the object field into an image field,
wherein the apparatus is an EUV lithography projection exposure apparatus.

20. An illumination system, comprising:
a beam shaping optical unit comprising at least two groups of mirrors on which EUV radiation impinges with grazing incidence during use of the beam shaping optical unit,
wherein:
each mirror group has a common group incidence plane, the group incidence planes of the mirror groups differ from one another;
the beam shaping unit is an EUV lithography beam shaping unit;
the illumination system is an EUV illumination system; and
the beam shaping optical unit configured to generate an EUV collective output beam from an EUV raw beam of a synchrotron-radiation-based light source.

21. The illumination system of claim 20 , further comprising an output coupling optical unit configured to generate a plurality of EUV individual output beams from the EUV collective output beam.

22. The illumination system of claim 21 , wherein, for each EUV individual output beam, a beam guiding optical unit configured to guide the EUV individual output beam toward an object field in which a lithography mask is arrangable.

23. The illumination system of claim 22 , wherein:
the beam shaping optical unit is configured to generate the EUV collective output beam with an aspect ratio contribution of 1:√{square root over (N)}; and
at least one member selected from the group consisting of the output coupling optical unit and the beam guiding optical unit is configured to subsequently generate a number N of the EUV individual output beams with an aspect ratio contribution of in each case 1:1.

24. An apparatus, comprising:
an illumination system according to claim 20 ; and
a projection optical unit configured to image the object field into an image field,
wherein the apparatus is an EUV lithography projection exposure apparatus.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Patra Michael
• Mueller Ralf

Classifications

• G03F7/70183 Primary

  Zoom systems for adjusting beam diameter · CPC title

• G03F7/70008 Primary

  Production of exposure light, i.e. light sources · CPC title

• G03F7/702

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

• G03F7/2006 Primary

  using coherent light; using polarised light · CPC title

• G03F7/70191

  Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like · CPC title