Low mass six degree of freedom stage for lithography tools

• US 20080024749A1
• Filed: 05/18/2007
• Published: 01/31/2008
• Est. Priority Date: 05/18/2006
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Williams, Mark, Phillips, Alton
• Application Number:
  US11/804,734
• Publication Number:
  US 20080024749A1
• Time in Patent Office: Days
• US Class Current: 355/72
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70758 Drive means, e.g. actuators, motors for long- or short-stroke modules or fine or coarse driving
• CPC Class Codes: H02K 2201/18 Machines moving with multiple degrees of freedom
• CPC Class Codes: H02K 41/03 Synchronous motors; Motors moving step by step; Reluctance motors H02K41/035 takes precedence

Abstract

A reticle or wafer stage mover with six degrees of freedom, a low mass coarse stage, and the ability to move an object in a scanning direction in a lithography tool. The mover includes a coarse stage and a fine stage configured to support the object and supported by the coarse stage. A set of actuators is provided to move the fine stage in six degrees of freedom. All of the actuators contribute to accelerating the object and the fine stage in the scanning direction. With all the actuators generating the necessary force to move the fine stage, a single large actuator to push the fine stage in the scanning direction is eliminated. The size or mass of the coarse stage is therefore reduced. All of the actuators are also capable of generating a second force in either the X or Z directions. The actuators therefore also enable the fine stage and the object it supports to be positioned in six degrees of freedom, as well as moved in the scanning direction.

Claims

1. An apparatus, comprising:

a mover configured to support and move an object in a scanning direction in a lithography tool, the mover including;

a coarse stage; and

a fine stage configured to support the object and supported by the coarse stage, the fine stage movable in six degrees of freedom by a set of actuators,

wherein, all of the actuators contribute to accelerating the object and the fine stage in the scanning direction.

2. The apparatus of claim 1, wherein a first subset of the set of actuators is configured to generate forces to move the fine stage in the scanning direction and the vertical direction.

3. The apparatus if claim 2, wherein there are at least three actuators in the first subset of actuators.

4. The apparatus of claim 1, further comprising a second subset of the set of actuators, the second subset of actuators configured to generate forces in the scanning direction and in a direction perpendicular to the scanning direction.

5. The apparatus of claim 4, where in the second subset of actuators consists of one of the following:

(i) at least one actuator;

(ii) two actuators;

or

(iii) two or more actuators.

6. The apparatus of claim 1, wherein the set of actuators comprises a set of stators.

7. The apparatus of claim 6, wherein the set of stators are located on the coarse stage.

8. The apparatus of claim 1, wherein the fine stage is surrounded by the coarse stage.

9. The apparatus of claim 1, further comprising one or more counter-mass elements positioned adjacent the coarse stage to absorb reaction forces generated by moving the coarse and/or fine stage.

10. The apparatus of claim 1, further comprising one or more reaction frame elements positioned adjacent the coarse stage to absorb reaction forces generated by moving the coarse and/or fine stage.

11. The apparatus of claim 1, further comprising a second set of actuators, wherein one or more of the second set of actuators is configured to generate a force configured to move the coarse stage in the scanning direction.

12. The apparatus of claim 11, wherein one or more of the second set of actuators is configured to generate a force configured to move the coarse stage perpendicular to the scanning direction.

13. The apparatus of claim 11, wherein one or more of the second set of actuators is configured to generate a force configured to rotate the coarse stage about a vertical axis.

14. The apparatus of claim 1, wherein the fine stage is configured to support and position a second object.

15. The apparatus of claim 1, further comprising:

a second fine stage configured to support a second object, the second fine stage movable in six degrees of freedom by a second set of actuators,

wherein all of the actuators of the second set contribute to accelerating the second object and the second fine stage in the scanning direction.

16. The apparatus of claim 15, wherein the second fine stage is supported by the coarse stage.

17. The apparatus of claim 15, further comprising a second coarse stage, wherein the second fine stage is supported by the second coarse stage.

18. The apparatus of claim 1, wherein the set of actuators comprise a set of permanent magnets located on fine stage and set of stators located on the coarse stage, wherein the set of permanent magnets and the set of stators cooperate together to move the fine stage in six degrees of freedom.

19. The apparatus of claim 18, wherein the set of stators comprise a set of coils.

20. The apparatus of claim 1, wherein the object is a semiconductor wafer and the mover is a wafer stage in a lithography tool.

21. The apparatus of claim 1, wherein the object is a reticle and the mover is a reticle stage in a lithography tool.

22. The apparatus of claim 1, further comprising:

a patterning element which defines a pattern;

a radiation source;

a projection optical system to project radiation from the radiation source through the patterning element to project the pattern onto the object supported by the mover.

23. The apparatus of claim 1, wherein the object is a reticle, which defines a pattern, wherein the mover is configured to move the reticle.

24. The apparatus of claim 23, further comprising:

a radiation source;

a projection optical system configured to project radiation from the radiation source through the reticle to project the pattern onto a second object supported by a second mover.

25. The apparatus of claim 24, wherein the apparatus is a lithography tool.

26. The apparatus of claim 25, wherein the lithography tool is an immersion lithography tool.

27. An apparatus comprising:

a mover configured to support and move an object in a scanning direction in a lithography tool, the mover including;

a coarse stage having one or more coarse stage actuators, the coarse stage actuators comprising one or more coarse stage movers; and

a fine stage configured to support the object and supported by the coarse stage, the fine stage further including one or more fine stage actuators including one or more fine stage actuators,

wherein the one or more coarse stage movers and the one or more fine stage movers share one or more stators respectively.

28. The apparatus of claim 27, wherein each of the one or more coarse stage movers is either a permanent magnet or a permanent magnet array.

29. The apparatus of claim 27, wherein each of the one or more fine stage movers is either a permanent magnet or a permanent magnet array.

30. The apparatus of claim 27, wherein each of the shared stators is a coil array.

31. The apparatus of claim 27, wherein a first of the actuators is oriented in a vertical plane with respect to the fine and the coarse stages and a second of the actuators is oriented in a horizontal plane with respect to the fine and the coarse stages.

32. The apparatus of claim 27, wherein the one or more coarse stage actuators and the one or more fine stage actuators move both the coarse stage and the fine stage in the X, Y and O directions respectively.

33. The apparatus of claim 27, wherein the fine stage further comprises one or more VCMs for positioning the fine stage in the Z, θ

_x, and θ

_z) directions.

34. The apparatus of claim 27, wherein the mover is either a reticle stage or a wafer stage in a lithography tool.