Electromagnetic alignment and scanning apparatus

• US 6,246,204 B1
• Filed: 03/02/1999
• Issued: 06/12/2001
• Est. Priority Date: 06/27/1994
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Ebihara, Akimitsu, Novak, Thomas
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US09/260,544
• Time in Patent Office: 833 Days
• Field of Search: 318/566, 318/568.22, 318/611, 318/648, 318/649, 318/652, 318/687, 33/1.M, 744/71.XY, 269/71, 414/935, 414/936
• US Class Current: 318/649
• CPC Class Codes: G03F 7/20 Exposure; Apparatus therefor photographic printing apparatus for making copies G03B27/00
• CPC Class Codes: G03F 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70725 control
• CPC Class Codes: G03F 7/70766 Reaction force control means, e.g. countermass
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position
• CPC Class Codes: G03F 7/709 Vibration, e.g. vibration detection, compensation, suppression or isolation
• CPC Class Codes: G03F 7/70991 Connection with other apparatus, e.g. multiple exposure stations, particular arrangement of exposure apparatus and pre-exposure and/or post-exposure apparatus; Shared apparatus, e.g. having shared radiation source, shared mask or workpiece stage, shared base-plate; Utilities, e.g. cable, pipe or wireless arrangements for data, power, fluids or vacuum
• CPC Class Codes: G03F 9/00 Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically G03F7/22 takes precedence; preparation of photographic masks G03F1/00; within photographic printing apparatus for making copies G03B27/00
• CPC Class Codes: Y10S 414/135 Associated with semiconductor wafer handling
• CPC Class Codes: Y10S 414/136 including wafer orienting means

Abstract

An apparatus capable of high accuracy position and motion control utilizes one or more linear commutated motors to move a guideless stage in one long linear direction and small yaw rotation in a plane. A carrier/follower holding a single voice coil motor (VCM) is controlled to approximately follow the stage in the direction of the long linear motion. The VCM provides an electromagnetic force to move the stage for small displacements in the plane in a linear direction perpendicular to the direction of the long linear motion to ensure proper alignment. One element of the linear commutated motors is mounted on a freely suspended drive assembly frame which is moved by a reaction force to maintain the center of gravity of the apparatus. Where one linear motor is utilized, yaw correction can be achieved utilizing two VCMs.

Claims

1. A scanning exposure apparatus that exposes a pattern onto an object while a stage holding one of said pattern and said object is moved in a scanning direction, comprising:

an exposure device that exposes said pattern onto said object;

a first drive device connected to said stage to move said stage in the scanning direction; and

a balancing portion having a moving member that moves in the scanning direction responsive to the movement of said stage such that a center of gravity of said scanning exposure apparatus does not shift substantially.

2. An exposure apparatus according to claim 1, wherein said first drive device has a first portion connected to said stage and a second portion connected to said moving member.

3. An exposure apparatus according to claim 2, wherein said first portion and said second portion are not in contact with each other.

4. An exposure apparatus according to claim 2, wherein said first portion comprises a coil and said second portion comprises a magnet.

5. An exposure apparatus according to claim 2, wherein the movements of said stage and of said moving member cooperatively follow the law of conservation of momentum.

6. An exposure apparatus according to claim 1, wherein said first drive device comprises a linear motor.

7. An exposure apparatus according to claim 1, further comprising a base structure that movably supports said stage.

8. An exposure apparatus according to claim 7, wherein said moving member is movably supported by said base structure.

9. An exposure apparatus according to claim 7, wherein said stage is movable over a surface of said base structure via a bearing.

10. An exposure apparatus according to claim 9, wherein said bearing is a non-contact bearing that supports said stage on said base structure without contact therebetween.

11. An exposure apparatus according to claim 7, further comprising:

a first non-contact bearing directly between said base structure and said stage; and

a second non-contact bearing directly between said base structure and said moving member,

wherein said first and second non-contact bearings directly support said stage and said moving member, respectively, on said base structure.

12. An exposure apparatus according to claim 11, wherein said first and second non-contact bearings are gas bearings.

13. An exposure apparatus according to claim 1, further comprising a position detector that detects a position of said stage.

14. An exposure apparatus according to claim 13, wherein said position detector comprises a reflective surface of said stage.

15. An exposure apparatus according to claim 14, wherein said reflective surface is a corner-cube mirror.

16. An exposure apparatus according to claim 13, wherein said position detector detects a position of said stage with regard to said scanning direction during the movement of said stage.

17. An exposure apparatus according to claim 13, wherein said position detector detects a position of said stage with regard to a direction that is different from said scanning direction during the movement of said stage.

18. An exposure apparatus according to claim 13, further comprising a control system that corrects yaw rotation of said stage based on a detection result of said position detector.

19. An exposure apparatus according to claim 18, wherein said control system is connected to said first drive device.

20. An exposure apparatus according to claim 13, wherein said position detector comprises an interferometer system.

21. An exposure apparatus according to claim 1, further comprising a second drive device that moves said stage in a direction that is different from said scanning direction.

22. An exposure apparatus according to claim 1, wherein said exposure device includes a projection system that projects said pattern onto said object.

23. An exposure apparatus according to claim 22, wherein said stage is located above said projection system.

24. An exposure apparatus according to claim 22, wherein said projection system projects the pattern optically.

25. An exposure apparatus according to claim 1, wherein said exposure device includes said stage, which holds a mask that defines said pattern.

26. An exposure apparatus according to claim 25, wherein said stage holds said mask above an opening defined in said stage.

27. An exposure apparatus according to claim 1, wherein said balancing portion operates without a drive source.

28. An object on which a pattern has been exposed utilizing the scanning exposure apparatus of claim 1.

29. A scanning exposure apparatus that exposes a pattern onto an object while a stage holding one of said pattern and said object is moved in a scanning direction, comprising:

means for exposing said pattern onto said object;

means for moving said stage in the scanning direction; and

balancing means for moving in the scanning direction responsive to the movement of said stage such that a center of gravity of said scanning exposure apparatus does not shift substantially.

30. A method of making a scanning exposure apparatus that exposes a pattern onto an object while a stage holding one of said pattern and said object is moved in a scanning direction, comprising the steps of:

providing an exposure device that exposes said pattern onto said object;

providing a first drive device that is connected to said stage to move said stage in the scanning direction; and

providing a balancing portion having a moving member that moves in the scanning direction responsive to the movement of said stage such that a center of gravity of said scanning exposure apparatus does not shift substantially.

31. A method according to claim 30, wherein said first drive device has a first portion connected to said stage and a second portion connected to said moving member.

32. A method according to claim 31, wherein said first portion and said second portion do not contact each other.

33. A method according to claim 31, wherein said first portion comprises a coil and said second portion comprises a magnet.

34. A method according to claim 30, wherein the movements of said stage and of said moving member cooperatively follow the law of conservation of momentum.

35. A method according to claim 30, wherein said first drive device comprises a linear motor.

36. A method according to claim 30, wherein a base structure movably supports said stage.

37. A method according to claim 36, wherein said moving member is movably supported by said base structure.

38. A method according to claim 36, wherein said stage is movable over a surface of said base structure via a bearing.

39. A method according to claim 38, wherein said bearing is a non-contact bearing that supports said stage on said base structure without contact between said stage and said base structure.

40. A method according to claim 36, further comprising:

providing a first non-contact bearing directly between said base structure and said stage; and

providing a second non-contact bearing directly between said base structure and said moving member,

wherein said first and second non-contact bearings directly support said stage and said moving member, respectively, on said basic structure.

41. A method according to claim 40, wherein said first and second non-contact bearings are gas bearings.

42. A method according to claim 30, further comprising providing a position detector that detects a position of said stage.

43. A method according to claim 42, wherein said position detector comprises a reflective surface of said stage.

44. A method according to claim 43, wherein said reflective surface is a corner-cube mirror.

45. A method according to claim 42, wherein said position detector detects a position of said stage with regard to said scanning direction during the movement of said stage.

46. A method according to claim 42, wherein said position detector detects a position of said stage with regard to a direction that is different from said scanning direction during the movement of said stage.

47. A method according to claim 42, further comprising providing a control system that adjusts yaw rotation of said stage based on a detection result of said position detector.

48. A method according to claim 47, wherein said control system is connected to said first drive device.

49. A method according to claim 42, wherein said position detector comprises an interferometer system.

50. A method according to claim 30, further comprising providing a second drive device that moves said stage in a direction that is different from said scanning direction.

51. A method according to claim 30, wherein said exposure device includes a projection system that projects said pattern onto said object.

52. A method according to claim 51, wherein said stage is located above said projection system.

53. A method according to claim 51, wherein said projection system projects the pattern optically.

54. A method according to claim 30, wherein said exposure device includes said stage, which holds a mask that defines said pattern.

55. A method according to claim 54, wherein said stage holds said mask above an opening defined in said stage.

56. A method according to claim 30, wherein said moving member operates without a drive source.

57. An object on which a pattern has been exposed utilizing the scanning exposure apparatus made by the method of claim 30.

58. An exposure method for forming a pattern of a mask on an object utilizing a scanning exposure apparatus, the method comprising the steps of:

moving a stage that holds one of said mask and said object in a scanning direction;

moving a balancing portion in the scanning direction responsive to the movement of said stage such that a center of gravity of said scanning exposure apparatus does not shift substantially; and

exposing said pattern onto said object while said stage is moved in said scanning direction.

59. A method according to claim 58, wherein said stage is moved by a first drive device having a first portion connected to said stage and a second portion connected to said balancing portion.

60. A method according to claim 59, wherein said first portion and said second portion do not contact each other.

61. A method according to claim 59, wherein said first portion comprises a coil and said second portion comprises a magnet.

62. A method according to claim 58, wherein the movements of said stage and of said balancing portion cooperatively follow the law of conservation of momentum.

63. A method according to claim 58, wherein said stage is moved by a first drive device that comprises a linear motor.

64. A method according to claim 58, further comprising movably supporting said stage on a base structure.

65. A method according to claim 64, wherein said balancing portion is movably supported by said base structure.

66. A method according to claim 64, wherein said stage is movable over a surface of said base structure via a bearing.

67. A method according to claim 66, wherein said bearing is a non-contact bearing that supports said stage on said base structure without contact between said stage and said base structure.

68. A method according to claim 58, further comprising detecting a position of said stage with a position detector.

69. A method according to claim 68, wherein said position detector comprises a reflective surface of said stage.

70. A method according to claim 69, wherein said reflective surface is a corner-cube mirror.

71. A method according to claim 68, wherein said position detector detects a position of said stage with regard to said scanning direction during the movement of said stage.

72. A method according to claim 68, wherein said position detector detects a position of said stage with regard to a direction that is different from said scanning direction during the movement of said stage.

73. A method according to claim 68, further comprising adjusting yaw rotation of said stage based on a detection result of said position detector.

74. A method according to claim 68, wherein said position detector comprises an interferometer system.

75. A method according to claim 58, further comprising moving said stage in a direction that is different from said scanning direction.

76. A method according to claim 58, wherein said exposing step includes projecting said pattern onto said object utilizing a projection optical system.

77. A method according to claim 76, wherein said stage is located above said projection optical system.

78. A method according to claim 58, wherein said stage holds said mask.

79. A method according to claim 78, wherein said stage holds said mask above an opening defined in said stage.

80. A method according to claim 58, wherein said balancing portion operates without a drive source.