Adjustment arrangement of an optical element
View Patent ↗A arrangement serves for the adjustment of an optical element ( 1 ), in particular of a lens in an optical system, in particular in a projection lens system for semiconductor lithography. The optical element ( 1 ) is mounted in a mount ( 3 ) by means of a number of bearing feet ( 2 ) distributed over the circumference of the optical element ( 1 ) and is selectively deformable by actuators ( 5 ). At least some of the bearing feet ( 2 ) are engaged by the actuators ( 5 ) in a region of the respective bearing foot ( 2 ) in such a way that the respective bearing foot ( 2 ) can be displaced in the direction of the optical axis ( 7 ).
1. An apparatus, comprising:
a mount for positioning an optical element in an optical system, the optical system having an optical axis and the mount comprising at least one bearing for supporting the optical element, the at least one bearing comprising:
a first bearing part configured to contact a surface of the optical element and support the optical element when the optical element is positioned in the mount;
an actuator configured to adjust a force applied in a direction parallel to the optical axis by the first bearing part to the surface of the optical element; and
coupling means for coupling the actuator to the first bearing part.
2. The apparatus of claim 1 , wherein the first bearing part is a lever comprising an engagement surface that contacts the optical element and a pivot point opposite the engagement surface.
3. The apparatus of claim 2 , wherein the mount comprises a frame against which the lever pivots.
4. The apparatus of claim 2 , wherein the coupling means couples the actuator to the lever between the engagement surface and the pivot point.
5. The apparatus of claim 1 , wherein the first bearing part is a U-shaped part, and a first section of the U-shaped part contacts the surface of the optical element and a second section of the U-shaped part is coupled to the coupling means.
6. The apparatus of claim 5 , wherein the mount comprises a frame that extends circumferentially around the optical element when the optical element is positioned in the mount, and a third second of the U-shaped part contacts the frame.
7. The apparatus of claim 6 , wherein the second section of the U-shaped part connects the first section to the third section.
8. The apparatus of claim 1 , wherein the coupling means comprises a pneumatic actuator or a hydraulic actuator.
9. The apparatus of claim 1 , wherein bearing is configured so that the weight of the optical element compresses the coupling means when the optical element is positioned in the mount.
10. The apparatus of claim 1 , wherein the coupling means is positioned between the first bearing part and the actuator.
11. The apparatus of claim 1 , wherein the actuator comprises an adjustable screw.
12. The apparatus of claim 11 , wherein the mount comprises a frame and the adjustable screw is set in the frame in a manner allowing adjustment of the screw in a direction parallel to the optical axis.
13. The apparatus of claim 1 , wherein the optical element is a lens.
14. The apparatus of claim 13 , wherein the surface of the lens contacted by the actuator intersects the optical axis.
15. The apparatus of claim 1 , wherein the mount comprises additional bearings, the bearings being arranged in a distributed manner over a circumference of the optical element.
16. The apparatus of claim 15 , wherein the bearings are arranged to allow introduction of a three-wave deformation to the optical element by actuation of the bearings.
17. The apparatus of claim 15 , wherein the bearings are arranged to allow introduction of an astigmatism to the optical element by actuation of the bearings.
18. The apparatus of claim 15 , wherein the bearings are distributed in relation to each other at an angle of 120° with respect to the optical axis.
19. The apparatus of claim 15 , wherein the additional bearings include adjustable bearings and non-adjustable bearings.
20. The apparatus of claim 19 , wherein the bearings are arranged so that the adjustable bearings alternate with the non-adjustable bearings over the circumference of the optical element.
21. The apparatus of claim 19 , wherein the bearings include three adjustable bearings and three non-adjustable bearings.
22. A projection lens system for a microlithography exposure machine, comprising:
a plurality of optical elements; and
a mount for positioning one of the optical elements in the projection lens system, the projection lens system having an optical axis and the mount comprising at least one bearing for supporting the optical element, the at least one bearing comprising:
a first bearing part configured to contact a surface of the optical element and support the optical element when the optical element is positioned in the mount;
an actuator configured to adjust a force applied in a direction parallel to the optical axis by the first bearing part to the surface of the optical element; and
coupling means for coupling the actuator to the first bearing part.
23. The projection lens system of claim 22 , wherein the mount comprises additional bearings, the bearings being arranged in a distributed manner over a circumference of the optical element.
24. The apparatus of claim 23 , wherein the additional bearings include adjustable bearings and non-adjustable bearings.
25. The apparatus of claim 24 , wherein the bearings are arranged so that the adjustable bearings alternate with the non-adjustable bearings over the circumference of the optical element.
26. The apparatus of claim 24 , wherein the bearings include three adjustable bearings and three non-adjustable bearings.
27. A method, comprising:
providing an optical system comprising an optical element positioned by a mount having at least one adjustable bearing supporting the optical element; and
adjusting a force applied in a direction parallel to the optical axis by the bearing to a surface of the optical element,
wherein the bearing comprises a first bearing part that contacts contact the surface of the optical element and supports the optical element, an actuator, and coupling means for coupling the actuator to the first bearing part, and the force applied to the optical element by the bearing is adjusted by adjusting the actuator.