Electromagnetic alignment and scanning apparatus

• US 6,323,935 B1
• Filed: 01/14/2000
• Issued: 11/27/2001
• 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): Adams, Russell
• Assistant Examiner(s): NGUYEN, HUNG
• Application Number:
  US09/482,686
• Time in Patent Office: 683 Days
• Field of Search: 355/53, 355/72-76, 355/77, 310/12-14, 318/567, 318/649
• US Class Current: 355/53
• 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 microlithographic system for exposing a pattern of a mask onto an object, comprising:

an exposure device disposed between said mask and said object to expose said pattern onto said object;

a stage that moves while holding one of said mask and said object, the stage having a first reflective portion along a first direction;

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

a position detector having a first interferometer system that cooperates with the first reflective portion to detect a position of the stage; and

a balancing portion having a moving member along the first direction that moves in a direction opposite to the direction of movement of said stage without holding either said mask or said object, said moving member being heavier than said entire stage having the first reflective portion, and a length of the moving member being longer than a length of the first reflective portion.

2. A microlithographic system 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. A microlithographic system according to claim 2, wherein said first portion and said second portion are not in contact with each other.

4. A microlithographic system according to claim 2, wherein said first portion comprises a coil and said second portion comprises a magnet.

5. A microlithographic system according to claim 2, wherein the movements of said stage and of said moving member cooperatively follow the law of conservation of momentum.

6. A microlithographic system according to claim 1, wherein said first drive device comprises a linear motor.

7. A microlithographic system according to claim 1, further comprising a base structure that movably supports said stage.

8. A microlithographic system according to claim 7, wherein said moving member is movably supported by said base structure.

9. A microlithographic system according to claim 7, wherein said stage is movable over a surface of said base structure via a bearing.

10. A microlithographic system according to claim 9, wherein said bearing is a non-contact bearing that supports said stage on said base structure without contact therebetween.

11. A microlithographic system according to claim 10, wherein said moving member is heavier than said stage including said non-contact bearing.

12. A microlithographic system 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.

13. A microlithographic system according to claim 12, wherein said first and second non-contact bearings are gas bearings.

14. A microlithographic system according to claim 1, wherein said position detector detects a position of said stage with regard to said first direction during the movement of said stage.

15. A microlithographic system according to claim 1, further comprising a second drive device that moves said stage in a second direction that is different from said first direction.

16. A microlithographic system according to claim 1, wherein said exposure device includes a projection system that projects the pattern onto said object.

17. A microlithographic system according to claim 1, wherein said moving member moves so that a center of gravity of said microlithographic system does not shift.

18. A microlithographic system according to claim 1, wherein the microlithographic system is a scanning exposure apparatus that moves the mask and the object in a scanning manner.

19. A microlithographic system according to claim 1, wherein said balancing portion operates without a drive source.

20. A microlithographic system according to claim 1, wherein said stage holds said mask above an opening defined in said stage.

21. An object on which a pattern has been exposed utilizing the microlithographic system of claim 1.

22. A microlithographic system according to claim 1, wherein the stage has a second reflective portion along a second direction which is different from the first direction, and the position detector has a second interferometer system that cooperates with the second reflective portion.

23. A microlithographic system according to claim 22, wherein said second reflective portion is a corner-cube mirror.

24. A microlithographic system according to claim 22, wherein said position detector detects a position of said stage with regard to the second direction during the movement of said stage.

25. A microlithographic system according to claim 22, further comprising a control system that corrects yaw rotation of said stage based on a detection result of said position detector.

26. A microlithographic system according to claim 25, wherein said control system is connected to said first drive device.

27. A microlithographic system for exposing a pattern of a mask onto an object, comprising:

means for exposing said pattern onto said object;

movable holding means for holding one of said mask and said object, the movable holding means having a reflective portion along a first direction;

first moving means for moving said holding means in the first direction;

position detecting means having an interferometer system that cooperates with the reflective portion to detect a position of the holding means; and

balancing means having a moving member along the first direction for moving in a direction opposite to the direction of movement of said holding means without holding either said mask or said object, said balancing means being heavier than said entire holding means having the reflective portion, and a length of the moving member being longer than a length of the reflective portion.

28. A method of making a microlithographic system for exposing a pattern of a mask onto an object, comprising the steps of:

providing an exposure device between said mask and said object to expose said pattern onto said object;

providing a stage that moves while holding one of said mask and said object, the stage having a first reflective portion along a first direction;

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

providing a position detector having a first interferometer system that cooperates with the reflective portion to detect a position of the stage; and

providing a balancing portion having a moving member along the first direction that moves in a direction opposite to the direction of movement of said stage without holding either said mask or said object, said moving member being heavier than said entire stage having the reflective portion, and a length of the moving member being longer than a length of the first reflective portion.

29. A method according to claim 28, wherein said first drive device has a first portion connected to said stage and a second portion connected to said moving member.

30. A method according to claim 29, wherein said first portion and said second portion do not contact each other.

31. A method according to claim 29, wherein said first portion comprises a coil and said second portion comprises a magnet.

32. A method according to claim 28, wherein the movements of said stage and of said moving member cooperatively follow the law of conservation of momentum.

33. A method according to claim 28, wherein said first drive device comprises a linear motor.

34. A method according to claim 28, wherein a base structure movably supports said stage.

35. A method according to claim 34, wherein said stage is movable over a surface of said base structure via a bearing.

36. A method according to claim 35, 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.

37. A method according to claim 36, wherein said moving member is heavier than said stage including said non-contact bearing.

38. A method according to claim 34, wherein said moving member is movably supported by said base structure.

39. A method according to claim 34, 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 base structure.

40. A method according to claim 39, wherein said first and second non-contact bearings are gas bearings.

41. A method according to claim 28, wherein said position detector detects a position of said stage with regard to said first direction during the movement of said stage.

42. A method according to claim 28, further comprising providing a second drive device that moves said stage in a second direction that is different from said first direction.

43. A method according to claim 28, wherein said exposure device includes a projection system that projects onto said object.

44. A method according to claim 28, wherein said moving member moves so that a center of gravity of said microlithographic system does not shift.

45. A method according to claim 28, wherein said microlithographic system is a scanning exposure apparatus that moves said mask and said object in a scanning manner.

46. A method according to claim 28, wherein said balancing portion operates without a drive source.

47. A method according to claim 28, wherein said stage holds said mask above an opening defined in said stage.

48. An object on which a pattern has been exposed utilizing the microlithographic system made by the method of claim 28.

49. A method according to claim 28, wherein the stage has a second reflective portion along a second direction which is different from the first direction, and the position detector has a second interferometer system that cooperates with the second reflective portion.

50. A method according to claim 49, wherein said second reflective portion is a corner-cube mirror.

51. A method according to claim 49, wherein said position detector detects a position of said stage with regard to the second direction during the movement of said stage.

52. A method according to claim 49, further comprising providing a control system that adjusts yaw rotation of said stage based on a detection result of said position detector.

53. A method according to claim 52, wherein said control system is connected to said first drive device.

54. An exposure method for forming a pattern of a mask onto an object utilizing a microlithographic system, the method comprising the steps of:

moving a stage, which holds one of said mask and said object, in a first direction, the stage having a first reflective portion along the first direction;

measuring a position of the stage by a position detector comprising a first interferometer system that cooperates with the first reflective portion;

moving a balancing portion having a moving member along the first direction in a direction opposite to the direction of movement of said stage without holding either said mask or said object, said balancing portion being heavier than said entire stage having the first reflective portion, and a length of the moving member being longer than a length of the first reflective portion; and

exposing said pattern onto said object.

55. A method according to claim 54, wherein said stage is moved with a first drive device having a first portion connected to said stage and a second portion connected to said balancing portion.

56. A method according to claim 55, wherein said first portion and said second portion do not contact each other.

57. A method according to claim 55, wherein said first portion comprises a coil and said second portion comprises a magnet.

58. A method according to claim 54, wherein the movements of said stage and of said balancing portion cooperatively follow the law of conservation of momentum.

59. A method according to claim 54, wherein said stage is moved by a linear motor.

60. A method according to claim 54, further comprising movably supporting said stage on a base structure.

61. A method according to claim 60, wherein said balancing portion is movably supported by said base structure.

62. A method according to claim 60, wherein said stage is movably supported over a surface of said base structure via a bearing.

63. A method according to claim 62, 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.

64. A method according to claim 63, wherein said balancing portion is heavier than said stage including said non-contact bearing.

65. A method according to claim 60, further comprising:

supporting said stage on said base structure with a first non-contact bearing located directly between said base structure and said stage; and

supporting said balancing portion on said base structure with a second non-contact bearing located directly between said base structure and said balancing portion.

66. A method according to claim 65, wherein said first and second non-contact bearings are gas bearings.

67. A method according to claim 54, wherein said position detector detects a position of said stage with regard to said first direction during the movement of said stage.

68. A method according to claim 54, further comprising moving said stage in a second direction that is different from said first direction.

69. A method according to claim 54, wherein said pattern is exposed by projecting the pattern optically.

70. A method according to claim 54, wherein said balancing portion moves so that a center of gravity of said microlithographic system does not shift.

71. A method according to claim 54, wherein the microlithographic system is a scanning exposure apparatus that moves the mask and the object during exposure.

72. A method according to claim 54, wherein said balancing portion operates without a drive source.

73. A method according to claim 54, wherein said stage holds said mask.

74. A method according to claim 54, wherein the stage has a second reflective portion along a second direction which is different from the first direction, and the position detector has a second interferometer system that cooperates with the second reflective portion.

75. A method according to claim 74, wherein said second reflective portion is a corner-cube mirror.

76. A method according to claim 74, wherein said position detector detects a position of said stage with regard to the second direction during the movement of said stage.

77. A method according to claim 74, further comprising adjusting yaw rotation of said stage based on a detection result of said position detector.

78. A microlithographic system that exposes a pattern of a mask onto an object, comprising:

an exposure device disposed between the mask and the object to expose the pattern onto the object;

a stage that holds the mask;

a first electromagnetic driver connected to the stage to move the stage in a first direction;

a second electromagnetic driver connected to the stage to move the stage in a second direction different from the first direction, a moving distance of the stage in the second direction by the second electromagnetic driver being shorter than a moving distance of the stage in the first direction by the first electromagnetic driver; and

a balancing portion having a moving member that moves in a direction opposite to the direction of movement of the stage by the first electromagnetic driver without holding either the mask or the object, the balancing portion being heavier than the stage.

79. A microlithographic system according to claim 78, further comprising a position detector having an interferometer system and a reflective portion of the stage to detect a position of the stage.

80. A microlithographic system according to claim 79, wherein the position detector detects a position of said stage with respect to the first direction during the movement of the stage.

81. A microlithographic system according to claim 79, wherein the position detector detects a position of the stage with respect to the second direction during the movement of the stage.

82. A microlithographic system according to claim 79, of further comprising a control system that corrects yaw rotation of the stage based on a detection result of the position detector.

83. A microlithographic system according to claim 79, wherein the balancing portion is heavier than the entire stage having the reflective portion.

84. A microlithography system according to claim 79, wherein a length of the moving member with regard to the first direction is longer than a length of the reflective portion with regard to the first direction.

85. A microlithographic system according to claim 78, wherein at least one of the first electromagnetic driver and the second electromagnetic driver comprises a linear motor.

86. A microlithographic system according to claim 78, wherein the microlithographic system is a scanning exposure apparatus that moves the mask and the object in a scanning manner.

87. An exposure method that forms a pattern of a mask onto an object utilizing a microlithographic system, the method comprising the steps of:

moving a stage, that holds said mask, in a first direction by a first electromagnetic actuator and in a second direction different from said first direction by a second electromagnetic actuator, a moving distance of the stage in the second direction by the second electromagnetic actuator being shorter than a moving distance of the stage in the first direction by the first electromagnetic actuator;

moving a balancing portion in a direction opposite to the first direction of movement of said stage without holding either said mask or said object;

said balancing portion being heavier than said stage; and

exposing said pattern onto said object.

88. A method according to claim 87, further comprising detecting a position of the stage with a position detector, the position detector comprising an interferometer system and a reflective portion of the stage.

89. A method according to claim 88, wherein the position detector detects a position of the stage with respect to the first direction during the movement of the stage.

90. A method according to claim 88, wherein the position detector detects a position of the stage with respect to the second direction during the movement of the stage.

91. A method according to claim 88, further comprising correcting yaw rotation of the stage based on a detection result of the position detector.

92. A method according to claim 88, wherein the balancing portion is heavier than the entire stage having the reflective portion.

93. A method according to claim 88, wherein the length of the balancing portion with regard to the first direction is longer than a length of the reflective portion with regard to the first direction.

94. A method according to claim 87, wherein at least one of the first and second electromagnetic actuators is a linear motor.

95. A method according to claim 87, wherein the microlithographic system is a scanning exposure apparatus that moves the mask and the object in a scanning manner.