Beam-forming and illuminating system for a lithography system, lithography system, and method

Patent metadata

Field	Value
Publication number	US-11448968-B2
Application number	US-202017019931-A
Country	US
Kind code	B2
Filing date	Sep 14, 2020
Priority date	Mar 15, 2018
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A beam-forming and illuminating system for a lithography system, such an EUV lithography system, includes an optical element and an adjusting device. The adjusting device is configured so that, during a heat-up phase of the beam-forming and illuminating system, the adjusting device measures a field position and/or a pupil position of the beam-forming and illuminating system and adjusts the orientation and/or position of the optical element based on the measured field position and/or pupil position to keep the optical element in a desired position.

First claim

What is claimed is:

1. A beam-shaping and illumination system having an exposure phase and a heating phase which begins before the exposure phase, the beam-shaping and illumination system comprising:
an optical element; and
an adjustment device, comprising:
a control unit;
a sensor; and
an actuating element configured to adjust an orientation and/or a position of the optical element to keep the optical element in a target location,

wherein the control unit is operatively connected to the sensor and the actuating element so that, during the heating phase and before the exposure phase begins:
a) the sensor is located in an object plane of the beam-shaping and illumination unit along a beam path of the beam-shaping and illumination unit so that the sensor measures the field position and/or the pupil position of the beam-shaping and illumination system; and
b) based on the measured field position and/or pupil position of the beam-shaping and illumination system, the actuating element adjusts an orientation and/or a position of the optical element to keep the optical element in a target location.

2. The beam-shaping and illumination system of claim 1 , further comprising a plurality of optical elements, wherein the adjustment device is configured to adjust an orientation and/or a position of the optical elements relative to one another depending on the measured field position and/or pupil position.

3. The beam-shaping and illumination system of claim 2 , wherein the plurality of optical elements comprises a field facet mirror, a pupil facet mirror, and/or a condenser mirror.

4. The beam-shaping and illumination system of claim 1 , further comprising a bearing device which comprises the actuating element.

5. The beam-shaping and illumination system of claim 4 , wherein the bearing device comprises a hexapod.

6. The beam-shaping and illumination system of claim 4 , wherein the actuating element comprises a piezo element.

7. The beam-shaping and illumination system of claim 4 , wherein the bearing device comprises six bearing units, and each bearing unit comprises a corresponding actuating element.

8. The beam-shaping and illumination system of claim 7 , wherein, for each bearing unit, the bearing unit comprises a spacer configured to change a length of the bearing unit.

9. The beam-shaping and illumination system of claim 7 , wherein the system is configured so that changing a length of the bearing units adjusts the orientation and/or the position of the optical element.

10. The beam-shaping and illumination system of claim 7 , wherein the actuating element is configured to change from an undeflected state to a deflected state, and the actuating element is without current both in the undeflected state and in the deflected state.

11. The beam-shaping and illumination system of claim 7 , wherein for each bearing unit:
the bearing unit comprises:
a first bending decoupling element;
a second bending decoupling element; and
a pin section arranged between the first and second bending decoupling elements; and

the actuating element is between:
the first and second bending decoupling elements;
the first bending decoupling element and the optical element; or
the second bending decoupling element and a base of the beam-shaping and illumination system.

12. A lithography apparatus, comprising:
a beam-shaping and illumination system according to claim 1 .

13. The lithography apparatus of claim 12 , wherein the lithography apparatus is an EUV lithography apparatus.

14. A beam-shaping and illumination system having an exposure phase and a heating phase which begins before the exposure phase, the beam-shaping and illumination system comprising:
an optical element;
an adjustment device, comprising:
a control unit;
a sensor; and
a bearing device comprising six bearing units,

wherein:
for each bearing unit, the bearing unit comprises:
an actuating element controllable by the adjustment device; and
a spacer configured to change a length of the bearing unit;

the system is configured so that changing a length of the bearing units adjusts an orientation and/or a position of the optical element; and
the control unit is operatively connected to the sensor and the bearing device so that, during the heating phase and before the exposure phase begins:
a) the sensor is located in an object plane of the beam-shaping and illumination unit along a beam path of the beam-shaping and illumination unit so that the sensor measures the field position and/or the pupil position of the beam-shaping and illumination system; and
b) based on the measured field position and/or pupil position of the beam-shaping and illumination system, the bearing device adjusts an orientation and/or a position of the optical element to keep the optical element in a target location.

15. A method of operating a beam-shaping and illumination system having an exposure phase and a heating phase which begins before the exposure phase, the method comprising:
during the heating phase and before the exposure phase begins:
a) using a sensor located in an object plane of the beam-shaping and illumination unit along a beam path of the beam-shaping and illumination unit to measure a field position and/or a pupil position of the beam-shaping and illumination system; and
b) based on the measured field position and/or pupil position, adjusting an orientation and/or a position of an optical element of the beam-shaping and illumination system.

16. The method of claim 15 , wherein a) and b) are iteratively performed until the field position and/or the pupil position meet a desired specification.

17. The method of claim 15 , further comprising, before or during b), calculating a correction recipe for the optical element, wherein the optical element is adjusted based on this correction recipe.

18. The method of claim 15 , wherein the method is carried out under vacuum and/or during the operation of an EUV light source of the beam-shaping and illumination system.

19. The method of claim 15 , wherein b) comprises adjusting the orientation and/or the position of the optical element by, in each case, changing a length of bearing units of a bearing device of the optical element.

20. The method of claim 15 , comprising performing the method to attain a thermal equilibrium of the beam-shaping and illumination system.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Holderer Hubert
• Abele Klaus
• Liebaug Björn

Classifications

• G03F7/70891

  Temperature · CPC title

• G03F7/70141 Primary

  Illumination system adjustment, e.g. adjustments during exposure or alignment during assembly of illumination system · CPC title

• G03F7/7085

  Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load · CPC title

• G03F7/70033

  by plasma extreme ultraviolet [EUV] sources · CPC title