INDIVIDUAL MIRROR FOR CONSTRUCTING A FACETED MIRROR, IN PARTICULAR FOR USE IN A PROJECTION EXPOSURE SYSTEM FOR MICROLITHOGRAPHY

• US 20110273694A1
• Filed: 06/29/2011
• Published: 11/10/2011
• Est. Priority Date: 01/09/2009
• Status: Active Grant

• Current Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Original Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Inventors: Muehlberger, Norbert, Bach, Florian, Werber, Armin
• Granted Patent: US 9,013,676 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors
• CPC Class Codes: G03F 7/70075 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

Abstract

An individual mirror is used to construct a facet mirror. A mirror body of the individual mirror is configured to be tiltable relative to a rigid carrier body about at least one tilting axis of a tilting joint. The tilting joint is configured as a solid-body joint. The solid-body joint, perpendicular to the tilting axis, has a joint thickness S and, along the tilting axis, a joint length L. The following applies: L/S>50. The result is an individual mirror to construct a facet mirror, which can be reproduced and is precisely adjustable and simultaneously ensures adequate heat removal, in particular, heat produced by residually absorbed useful radiation, which is reflected by the individual mirror, by dissipation of the heat by the mirror body.

Claims

1. A system, comprising:

a mirror configured to be used in a microlithography facet mirror, the mirror comprising;

a rigid carrier body;

a mirror body configured to be tiltable relative to the rigid carrier body about a tilting axis;

an actuator configured to control tilting of the mirror body about the tilting axis, the actuator comprising;

a first joint body;

a second joint body;

a movement electrode movably connected to the first joint body; and

a counter-electrode rigidly connected to the second joint body; and

a dielectric between the movement electrode and the counter-electrode,

wherein;

in a contact face portion, the movement electrode contacts the dielectric layer;

in a spacing face portion, a continuously increasing space is present between the movement electrode and the counter-electrode in a force-free state; and

the movement electrode is connected to the first joint body in the spacing face portion.

2. The system of claim 1, comprising at least three actuators, wherein each actuator has a movement electrode.

3. The system of claim 1, wherein the movement electrode is curved.

4. The system of claim 1, wherein the movement electrode has a rectangular base face.

5. The system of claim 1, wherein the movement electrode has a spiral base face.

6. The system of claim 1, comprising a voltage input device configured to apply a bias voltage to the movement electrode and the counter-electrode when the actuator is in a neutral position between the movement electrode and the counter-electrode.

16. The system of claim 1, wherein the mirror body has a reflection face with a size of at least 1 mm×

1 mm.

17. The system of claim 1, wherein the mirror body has a reflection face, and the tilting axis extends in a plane of the reflection face or parallel thereto.

18. The system of claim 1, wherein the tilting joint is to the side of a reflection face of the mirror body.

19. The system of claim 1, wherein the mirror body has a reflection face, and the tilting joint is centrally below the reflection face.

20. The system of claim 1, comprising an actuator comprising at least two electrodes arranged separately from one another on the rigid carrier body.

21. The system of claim 1, comprising an actuator comprising four electrodes arranged separately from one another on the rigid carrier body.

22. The system of claim 21, wherein the four electrodes are arranged quadrant-wise.

23. A facet mirror, comprising a plurality of systems according to claim 1, wherein the facet mirror is an EUV lithography facet mirror.

24. The facet mirror of claim 23, wherein each mirror provides a mirror illumination channel configured to guide illumination radiation to an object field, and each mirror has a mirror face configured so that each mirror illumination channel illuminates a portion of the object field which is smaller than the object field.

25. An illumination system, comprising:

a first facet mirror comprising a plurality of systems according to claim 1,

wherein the illumination optical system is a microlithography illumination optical system.

26. A projection exposure system, comprising:

an illumination system, comprising a facet mirror comprising a plurality of systems according to claim 1; and

a projection optical system,

wherein the projection exposure system is a microlithography projection exposure system.

27. The projection exposure system of claim 26, further comprising an EUV radiation source.

28. A method, comprising:

a) providing a microlithography projection exposure system, comprising;

an illumination system, comprising a facet mirror comprising a plurality of systems according to claim 1; and

a projection optical system

b) using the microlithography projection exposure system to project at least a portion of a reticle onto a region of a light-sensitive layer.

7. A system, comprising:

a mirror configured to be used in a microlithography facet mirror, the mirror comprising;

a rigid carrier body;

a tilting joint; and

a mirror body configured to be tiltable relative to the rigid carrier body about a tilting axis of the tilting joint,

wherein;

the tilting joint is a solid-body joint;

the solid-body joint has a thickness perpendicular to the tilting axis;

the solid-body joint has a length along the tilting axis; and

a ratio of the length to the thickness is greater than 50.

8. The system of claim 7, wherein the mirror body is tiltable relative to the carrier body about two tilting axes of two tilting joints, and the two tilting axes are not parallel to each other.

9. The system of claim 8, wherein a first of the two tilting joints is arranged between the mirror body and an intermediate body, and a second of the two tilting joints is between the intermediate body and the carrier body.

10. The system of claim 8, wherein:

the two tilting joints are solid-body joints;

for each of the two solid-body joints, the solid body joint has a thickness perpendicular to its tilting axis;

for each of the two solid-body joints, the solid body joint has a length along its tilting axis; and

for each of the two solid-body joints, a ratio of the length to the thickness is greater than 50.

11. The system of claim 7, wherein the tilting joint is divided into a plurality of separate solid-body joint potions along the tilting axis.

12. The system of claim 7, comprising an actuator configured to control tilting of mirror body about the tilting axis, the actuator comprising:

a first electrode rigidly connected to a first joint body of the tilting joint; and

a first counter-electrode rigidly connected to a second joint body of the tilting joint.

13. The system of claim 12, wherein there is a force-free spacing of 100 μ

m between the first electrode and the first counter-electrode.

14. The system of claim 12, comprising additional electrodes between the first electrode and the first counter-electrode, wherein the additional electrodes together with the first counter-electrode provide an electrode stack, and respective adjacent electrodes are tiltable relative to one another about a second tilting joint.

15. The system of claim 7, comprising an actuator configured to control tilting of mirror body about the tilting axis, the actuator comprising:

a movement electrode movably connected to a first joint body of the tilting joint;

a counter-electrode rigidly connected to a second joint body of the tilting joint; and

a dielectric between the movement electrode and the counter-electrode,

wherein;

in a contact face portion, the movement electrode contacts the dielectric layer;

in a spacing face portion, a continuously increasing space is present between the movement electrode and the counter-electrode in a force-free state; and

the movement electrode is connected to the first joint body in the spacing face portion.