Lithography apparatus with flexibly supported optical system

• US 20090033895A1
• Filed: 07/30/2007
• Published: 02/05/2009
• Est. Priority Date: 07/30/2007
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Watson, Douglas C., Phillips, Alton H., Coakley, Scott, Binnard, Michael B.
• Application Number:
  US11/882,027
• Publication Number:
  US 20090033895A1
• Time in Patent Office: Days
• US Class Current: 355/53
• CPC Class Codes: G03F 7/70833 Mounting of optical systems, e.g. mounting of illumination system, projection system or stage systems on base-plate or ground
• CPC Class Codes: G03F 7/709 Vibration, e.g. vibration detection, compensation, suppression or isolation

Abstract

A lithography apparatus includes a projection optical system that projects an image of a pattern, a first support member, a second support member that is flexibly coupled to the first support member by a first flexible coupling device such that the second support member is suspended from the first support member, and a second flexible coupling device that flexibly couples the projection optical system to the second support structure. This arrangement is capable of improving the vibration characteristics of the projection optical system.

Claims

1. A lithography apparatus comprising:

a projection optical system that projects an image of a pattern;

a first support member;

a second support member coupled to the first support member and supporting at least one metrology component; and

a flexible coupling device that flexibly couples the projection optical system to the second support member.

2. The lithography apparatus according to claim 1, wherein the flexible coupling device is disposed between the second support member and the projection optical system such that the weight of the projection optical system is transferred to the second support member.

3. The lithography apparatus according to claim 2, wherein the flexible coupling device inhibits vibrations from passing between the second support member and the projection optical system.

4. The lithography apparatus according to claim 2, wherein the flexible coupling device is a passive vibration isolation system.

5. The lithography apparatus according to claim 2, wherein the flexible coupling device is an active vibration isolation system.

6. The lithography apparatus according to claim 1, further comprising a support member flexible coupling device that flexibly couples the second support member to the first support member.

7. The lithography apparatus according to claim 6, wherein the support member flexible coupling device suspends the second support member from the first support member.

8. The lithography apparatus according to claim 7, wherein the support member flexible coupling device includes a plurality of suspension members that extend between the first support member and the second support member.

9. The lithography apparatus according to claim 8, wherein each of the suspension members is stiff in an axial direction and flexible in directions orthogonal to the axial direction.

10. The lithography apparatus according to claim 8, wherein each of the suspension members is a wire.

11. The lithography apparatus according to claim 10, wherein each of the wires is rotatably attached to the second support member.

12. The lithography apparatus according to claim 8, wherein each of the suspension members is a rod.

13. The lithography apparatus according to claim 12, wherein each of the rods is rotatably attached to the second support member.

14. The lithography apparatus according to claim 8, wherein each of the suspension members is a chain.

15. The lithography apparatus according to claim 14, wherein each of the chains is rotatably attached to the second support member.

16. The lithography apparatus according to claim 8, wherein each of the suspension members is directly attached to the first support member.

17. The lithography apparatus according to claim 8, further comprising a mounting device between each of the suspension members and the first support member, the mounting device having a stiffness in the axial direction that is less stiff than a stiffness of the suspension members in the axial direction.

18. The lithography apparatus according to claim 17, wherein the mounting device includes a piston supported by gas so as to absorb vibrations in the axial direction.

19. The lithography apparatus according to claim 1, wherein the at least one metrology component includes a measuring unit attached to the second support member.

20. The lithography apparatus according to claim 19, wherein the measuring unit measures a positional relationship between the projection optical system and a predetermined member.

21. The lithography apparatus according to claim 20, further comprising a stage for supporting an object, and wherein the measuring unit measures a positional relationship between the projection optical system and the stage.

22. The lithography apparatus according to claim 21, wherein the stage is a substrate stage.

23. The lithography apparatus according to claim 21, wherein the stage is a reticle stage.

24. The lithography apparatus according to claim 1, wherein the first support member is a frame.

25. The lithography apparatus according to claim 24, further comprising a reticle stage supported on the frame.

26. A lithography apparatus comprising:

a projection optical system that projects an image of a pattern;

a first support member;

a metrology frame to which is mounted a measuring unit that measures a positional relationship between the projection optical system and a predetermined member;

a first flexible coupling device that flexibly couples the metrology frame to the first support member; and

a second flexible coupling device that flexibly couples the projection optical system to the metrology frame.

27. The lithography apparatus according to claim 26, wherein the first flexible coupling device suspends the metrology frame from the first support member.

28. The lithography apparatus according to claim 26, wherein the second flexible coupling device is disposed between an upward-facing surface of the metrology frame and a downward-facing surface of the projection optical system such that the weight of the projection optical system is transferred to the metrology frame.

29. The lithography apparatus according to claim 28, wherein the second flexible coupling device inhibits vibrations from passing between the metrology frame and the projection optical system.

30. The lithography apparatus according to claim 28, wherein the second flexible coupling device is a passive vibration isolation system.

31. The lithography apparatus according to claim 28, wherein the second flexible coupling device is an active vibration isolation system.

32. The lithography apparatus according to claim 26, wherein the first flexible coupling device is stiff in an axial direction and less stiff in directions orthogonal to the axial direction.

33. The lithography apparatus according to claim 32, wherein the first flexible coupling device includes a plurality of suspension members that extend between the first support member and the metrology frame.

34. The lithography apparatus according to claim 33, wherein each of the suspension members is stiff in an axial direction and flexible in directions orthogonal to the axial direction.

35. The lithography apparatus according to claim 33, wherein each of the suspension members is a wire.

36. The lithography apparatus according to claim 35, wherein each of the wires is rotatably attached to the second support member.

37. The lithography apparatus according to claim 33, wherein each of the suspension members is a rod.

38. The lithography apparatus according to claim 37, wherein each of the rods is rotatably attached to the second support member.

39. The lithography apparatus according to claim 33, wherein each of the suspension members is a chain.

40. The lithography apparatus according to claim 39, wherein each of the chains is rotatably attached to the second support member.

41. The lithography apparatus according to claim 33, wherein each of the suspension members is directly attached to the first support member.

42. The lithography apparatus according to claim 33, further comprising a mounting device between each of the suspension members and the first support member, the mounting device having a stiffness in the axial direction that is less stiff than a stiffness of the suspension members in the axial direction.

43. The lithography apparatus according to claim 42, wherein the mounting device includes a piston supported by gas so as to absorb vibrations in the axial direction.

44. The lithography apparatus according to claim 26, further comprising a stage for supporting an object, and wherein the measuring unit measures a positional relationship between the projection optical system and the stage.

45. The lithography apparatus according to claim 44, wherein the stage is a substrate stage.

46. The lithography apparatus according to claim 44, wherein the stage is a reticle stage.

47. The lithography apparatus according to claim 26, wherein the first support member is a frame.

48. The lithography apparatus according to claim 47, further comprising a reticle stage supported on the frame.

49. A lithography apparatus comprising:

a projection optical system that projects an image of a pattern;

a first support member;

a second support member;

a first flexible coupling having at least three flexible suspension members that flexibly couple the second support member to the first support member such that the second support member is suspended from the first support member; and

a second flexible coupling having at least three vibration isolation mounts disposed between the projection optical system and the second support member to flexibly couple the projection optical system to the second support member.

50. The lithography apparatus according to claim 49, wherein the at least three vibration isolation mounts of the second flexible coupling device are passive vibration isolation mounts.

51. The lithography apparatus according to claim 49, wherein the at least three vibration isolation mounts of the second flexible coupling device are active vibration isolation mounts.

52. The lithography apparatus according to claim 49, wherein each of the suspension members is stiff in an axial direction and flexible in directions orthogonal to the axial direction.

53. The lithography apparatus according to claim 52, wherein each of the suspension members is a wire.

54. The lithography apparatus according to claim 53, wherein each of the wires is rotatably attached to the second support member.

55. The lithography apparatus according to claim 49, wherein each of the suspension members is a rod.

56. The lithography apparatus according to claim 55, wherein each of the rods is rotatably attached to the second support member.

57. The lithography apparatus according to claim 49, wherein each of the suspension members is a chain.

58. The lithography apparatus according to claim 57, wherein each of the chains is rotatably attached to the second support member.

59. The lithography apparatus according to claim 49, further comprising a mounting device between each of the suspension members and the first support member, the mounting device having a stiffness in the axial direction that is less stiff than a stiffness of the suspension members in the axial direction.

60. The lithography apparatus according to claim 59, wherein each of the mounting devices is a vibration isolation member.

61. The lithography apparatus according to claim 60, wherein each of the mounting devices is a passive vibration isolation member.

62. The lithography apparatus according to claim 60, wherein each of the mounting devices is an active vibration isolation member.

63. The lithography apparatus according to claim 49, further comprising a measuring unit attached to the second support member.

64. The lithography apparatus according to claim 63, wherein the measuring unit measures a positional relationship between the projection optical system and a predetermined member.

65. The lithography apparatus according to claim 64, further comprising a stage for supporting an object, and wherein the measuring unit measures a positional relationship between the projection optical system and the stage.

66. The lithography apparatus according to claim 65, wherein the stage is a substrate stage.

67. The lithography apparatus according to claim 65, wherein the stage is a reticle stage.