Structure integrating gas support bearing and a planar electromagnetic drive and levitation system

• US 20040155534A1
• Filed: 02/07/2003
• Published: 08/12/2004
• Est. Priority Date: 02/07/2003
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Engwall, Mats Anders
• Application Number:
  US10/360,985
• Publication Number:
  US 20040155534A1
• Time in Patent Office: Days
• US Class Current: 310/12
• CPC Class Codes: F16C 29/025 Hydrostatic or aerostatic this type of bearing for rotary parts F16C32/06
• CPC Class Codes: F16C 32/0618 via porous material
• CPC Class Codes: F16C 32/0666 of bearing pads
• 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: G03F 7/70816 Bearings
• CPC Class Codes: H02K 2201/18 Machines moving with multiple degrees of freedom
• CPC Class Codes: H02K 41/031 of the permanent magnet type
• CPC Class Codes: H02K 7/08 Structural association with bearings

Abstract

A combination (231) that creates a fluid film bearing that maintains a stage frame (202) spaced apart from a base frame (204), includes a pad assembly (232) secured to one of the frames (202)(204) and a bearing fluid source (234). The pad assembly (232) includes a porous region (238). The fluid source (234) directs a fluid into the pad assembly (232) so that the fluid is released from the porous region (238) to create the fluid film bearing that maintains the stage frame (202) apart from the base frame (204). The combination (231) is used with a mover (206) having a conductor assembly (218) that is secured to one of the frames (202)(204) and a magnet assembly (216) that is secured to the other one of the frames (202)(204).

Claims

1. A combination that creates a fluid bearing that maintains a stage frame spaced apart from a base frame, the combination comprising:

a pad assembly secured to one of the frames, the pad assembly including a porous region; and

a bearing fluid source that directs a fluid into the pad assembly so that the fluid is released from the porous region to create the fluid bearing that maintains at least a portion of the stage frame apart from the base frame.

2. The combination of claim 1 wherein the pad assembly includes a pad fluid channel that is in fluid communication with the bearing fluid source and the porous region.

3. The combination of claim 2 wherein the pad fluid channel includes a first pad passageway and a second pad passageway that branches away from the first pad passageway.

4. The combination of claim 3 wherein the pad fluid channel includes a plurality of second pad passageways, and a cross-sectional area of the first pad passageway is larger than a cross-sectional area of one of the second pad passageways.

5. The combination of claim 1 wherein the porous region includes a plurality of pores that are between approximately 10 microns and 300 microns.

6. The combination of claim 1 wherein the porous region includes a plurality of pores that are between approximately 100 microns and 200 microns.

7. The combination of claim 1 wherein the pad assembly includes a plurality of spaced apart porous regions.

8. A mover assembly including a magnet assembly, a conductor assembly, and the combination of claim 1.

9. The mover assembly of claim 8 wherein the pad assembly is positioned directly between the magnet assembly and the conductor assembly.

10. The mover assembly of claim 8 wherein the magnet assembly is secured to one of the frames and the conductor assembly is secured to the other frame.

11. The mover assembly of claim 10 wherein the conductor assembly is secured directly to the pad assembly.

12. The mover assembly of claim 10 wherein the magnet assembly is secured directly to the pad assembly.

13. A stage assembly including a stage frame, a base frame and the mover assembly of claim 8.

14. The stage assembly of claim 13 wherein the base frame includes a bearing passageway that is in fluid communication with the bearing fluid source and the porous region.

15. The stage assembly of claim 13 wherein the base frame includes a vacuum passageway that is fluid communication with a vacuum source to create a vacuum between the frames.

16. The stage assembly of claim 13 wherein the base frame includes an upper surface that extends closer to the stage frame than the pad assembly.

17. An exposure apparatus including the stage assembly of claim 13 and an illumination system.

18. A wafer on which an image has been formed by the exposure apparatus of claim 17.

19. A device on which an image has been formed by the exposure apparatus of claim 17.

20. A stage assembly for moving a device relative to a mounting base, the stage assembly comprising:

a stage frame that retains the device;

a base frame that is secured to the mounting base; and

a mover combination that moves the stage frame relative to the base frame and supports the stage frame away from the base frame, the mover combination including a magnet assembly that is secured to one of the frames, a conductor assembly that is secured to the other frame, and a bearing fluid source;

wherein one of the assemblies of the mover combination includes a porous region and the bearing fluid source directs a fluid into the porous region so that the fluid is released from the porous region to create the fluid bearing that maintains at least a portion of the stage frame apart from the base frame.

21. The stage assembly of claim 20 wherein the porous region is positioned adjacent to the magnet assembly.

22. The stage assembly of claim 20 wherein the magnet assembly is secured to the stage frame and the conductor assembly is secured to the base frame.

23. The stage assembly of claim 20 wherein the porous region is integrated directly into the conductor assembly.

24. The stage assembly of claim 20 wherein the porous region is integrated directly into the magnet assembly.

25. The stage assembly of claim 20 wherein the porous region includes a first pad passageway and a second pad passageway that branches away from the first pad passageway.

26. The stage assembly of claim 20 wherein the porous region includes a plurality of pores that are between approximately 10 microns and 300 microns.

27. The stage assembly of claim 20 wherein the porous region includes a plurality of pores that are between approximately 100 microns and 200 microns.

28. The stage assembly of claim 20 wherein the base frame includes a vacuum passageway that is fluid communication with a vacuum source to create a vacuum between the frames.

29. An exposure apparatus including the stage assembly of claim 20 and an illumination system.

30. A wafer on which an image has been formed by the exposure apparatus of claim 29.

31. A device on which an image has been formed by the exposure apparatus of claim 29.

32. A method for maintaining a stage frame spaced apart from a base frame, the method comprising the steps of:

securing a pad assembly to one of the frames, the pad assembly including a porous region; and

directing a fluid from a bearing fluid source into the pad assembly so that the fluid is released from the porous region to create the fluid bearing that maintains at least a portion of the stage frame apart from the base frame.

33. The method of claim 32 wherein the step of directing a fluid includes the step of directing fluid into a pad fluid channel of the pad assembly that is in fluid communication with the bearing fluid source.

34. The method of claim 32 wherein the pad fluid channel includes a first pad passageway and a second pad passageway that branches away from the first pad passageway.

35. The method of claim 34 wherein the pad fluid channel includes a plurality of second pad passageways, and a cross-sectional area of the first pad passageway is larger than a cross-sectional area of one of the second pad passageways.

36. The method of claim 32 wherein the porous region includes a plurality of pores that are between approximately 10 microns and 300 microns.

37. The method of claim 32 wherein the porous region includes a plurality of pores that are between approximately 100 microns and 200 microns.

38. A method for manufacturing a stage assembly that moves a device, the method comprising the steps providing a stage frame that retains the device, providing a base frame, and maintaining the stage frame spaced apart from the base frame by the method of claim 32.

39. The method of claim 38 further comprising the step of moving the stage frame relative to the base frame with a mover.

40. The method of claim 39 wherein the step of moving includes the steps of securing a magnet assembly to one of the frames and securing a conductor assembly to the other one of the frames.

41. The method of claim 40 further comprising the step of creating a vacuum between the frames.

42. A method of making an exposure apparatus that forms an image formed on a first object on a second object, the method comprising the steps of:

securing one of the objects to the stage assembly made by the method of claim 38;

and

providing an irradiation apparatus that irradiates the first object.

43. A method of making a device utilizing the exposure apparatus made by the method of claim 42.

44. A method for making a wafer utilizing the exposure apparatus made by the method of claim 42.