Wafer positioner with planar motor and mag-lev fine stage

• US RE41,232 E1
• Filed: 06/24/2004
• Issued: 04/20/2010
• Est. Priority Date: 04/24/2000
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Ebihara, Akimitsu, Novak, W. Thomas, Hazelton, Andrew J.
• Primary Examiner(s): MULLINS, BURTON S
• Application Number:
  US10/876,201
• Time in Patent Office: 2,126 Days
• Field of Search: 318592-593, 250/491.1, 250/491.2, 250/492.22, 355/53, 355/72, 310/12
• US Class Current: 310/12.06
• 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 positioning stage assembly having a coarse stage which includes a planar motor driveable in at least two degrees of freedom, and a fine stage positioned on the coarse stage which is driveable in at least three degrees of freedom with respect to the coarse stage. More preferably, the fine stage is driveable in six degrees of freedom and includes variable reluctance actuators for positioning in three degrees of freedom.

Claims

1. A positioning stage assembly for moving a substrate along a trajectory, the positioning stage assembly comprising:

a coarse stage including a planar motor driveable in at least two degrees of freedom wherein said planar motor comprises a planar magnet array having magnets disposed in a plane and a planar coil array that is interacting interacts with said planar magnet array to produce a first force and a second force differing from said first force;

and

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage;

a control module that controls movement of said fine stage along said trajectory, wherein said control module controls the movement of said coarse stage to follow said fine stage.

2. The positioning stage assembly of claim 1, wherein said fine stage is

driveable in six degrees of freedom with respect to said coarse stage.

3. The positioning stage assembly of claim 1, further comprising at least one pair of electromagnetic actuators coupling said fine stage to said coarse stage for control in at least one of said degrees of freedom with respect to said coarse stage.

4. The positioning stage assembly of claim 3, wherein both actuators of said pair of electromagnetic actuators are mounted adjacent a single side of said fine stage.

5. The positioning stage assembly of claim 4, wherein both of said actuators of said pair are mounted on said coarse stage in close opposition to one another, and a pair of corresponding targets are mounted on said fine stage adjacent one another and within a predefined gap defined by said mounted electromagnetic actuators.

6. The positioning stage assembly of claim 3, wherein said at least one pair of electromagnetic actuators comprises three pairs of electromagnetic actuators coupling said fine stage to said coarse stage for control in said at least three degrees of freedom with respect to said coarse stage.

7. The positioning stage assembly of claim 6, wherein two of said three pairs of electromagnetic actuators are aligned substantially parallel to a first direction, and a third of said three pairs of electromagnetic actuators is aligned in a second direction substantially perpendicular to said first direction.

8. The positioning stage assembly of claim 7, wherein said first and second directions are within a plane which said fine stage substantially lies in.

9. The positioning stage assembly of claim 5, wherein said pair of corresponding targets are peripherally mounted on said fine stage.

10. The positioning stage assembly of claim 3, wherein said electromagnetic actuators comprise variable reluctance actuators.

11. The positioning stage assembly of claim 3, wherein said at least one pair comprises three pairs of electromagnetic actuators interconnecting said fine stage and said coarse stage and actuable to control said fine stage in three degrees of freedom.

12. The positioning stage assembly of claim 11, further comprising three additional electromagnetic actuators mounted between said fine stage and said coarse stage and actuable to control said fine stage in three additional degrees of freedom.

13. The positioning stage assembly of claim 11, wherein said pairs of electromagnetic actuators comprise variable reluctance actuators.

14. The positioning stage assembly of claim 12, whrein wherein said additional electromagnetic actuators comprise voice coil motors.

15. The positioning stage assembly of claim 11, wherein said pairs of electromagnetic actuators comprise variable reluctance actuators and said positioning stage further comprises supplemental vertical supports mounted between said fine stage and said coarse stage.

16. The positioning stage assembly of claim 15, wherein said supplemental vertical supports comprise air bellows.

17. The positioning stage assembly of claim 3, further comprising at least one non-contact vertical support member which levitates said fine stage above said coarse stage.

18. The positioning stage assembly of claim 17, wherein said at least one non-contact vertical support member comprises three non-contact vertical support members for controlling the position of said fine stage in three vertical degrees of freedom.

19.. The positioning stage assembly of claim 18, wherein each said non-contact vertical support member comprises an electromagnetic actuator.

19. The positioning stage assembly of claim 18, wherein each said non-contact vertical support member comprises a voice coil motor having a magnet portion and a coil portion, one of said magnet portion and said coil portion being mounted on said fine stage and the other of said magnet portion and said coil portion being mounted on said coarse stage.

20. The positioning stage assembly of claim 18, further comprising at least one dead weight support that supports a dead weight of said fine stage vertically.

21. The positioning stage assembly of claim 18, further comprising at least one air bearing that is coupled to said coarse stage and vertically supporting supports a dead weight of said coarse stage.

23. The positioning stage assembly of claim 9, further comprising at least one target mount extending from a main surface of said fine stage, said pair of corresponding targets being mounted on said target mount, such that only a resultant force from actuation of said pair of electromagnetic actuators is transferred to said fine stage through said target mount.

24. The positioning stage assembly of claim 1, further comprising a second fine stage driveable in at least three degrees of freedom with respect to said coarse stage and indepenently independently of the other fine stage.

25. The positioning stage assembly of claim 1, wherein said planar motor is driveable in at least three degrees of freedom.

27. The positioning stage assembly of claim 1, wherein said magnets of said magnet array have independent magnetic fields and said planar coil array is positioned adjacent to said planar magnet array, with one of said magnet array and said coil array being fixed and the other being movable with respect thereto.

22. The positioning stage assembly of claim 22, wherein said at least one air bearing comprises three air bearings.

26. The positioning stage assembly of claim 26, wherein said planar motor is driveable in six degrees of freedom.

28. The positioning stage assembly of claim 28, wherein said magnet array is fixed and said coil array is movable with respect to said magnet array.

29. The positioning stage assembly of claim 28, wherein said coil array is fixed and said magnet array is movable with respect to said coil array.

30. A lithography system comprising:

an illumination system that irradiates radiant energy;

a coarse stage that includes a planar motor driveable in at least two degrees of freedom with respect to said radiant energy wherein said planar motor comprises a planar magnet array having magnets disposed in a plane and a planar coil array that is interacting with said planar magnet array to produce a first force and a second force differing from said first force; and

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage.

31. The lithography system of claim 31, wherein said fine stage is driveable in six degrees of freedom with respect to said coarse stage.

32. The lithography system of claim 31, further comprising at least one pair of electromagnetic actuators coupling said fine stage to said coarse stage for control in at least one of said degrees of freedom with respect to said coarse stage.

35. The lithography system of claim 31, further comprising a mask pattern positioned between said illumination system and said fine stage.

40. The lithography system of claim 35, wherein said pair of corresponding targets are peripherally mounted on said fine stage.

55. The lithography system of claim 31, further comprising a second fine stage driveable in at least three degrees of freedom with respect to said coarse stage and independently of the other fine stage.

56. The lithography system of claim 31, wherein said planar motor is driveable in six degrees of freedom.

57. A device manufactured with the lithography system of claim 31.

58. A wafer on which an image has been formed by the lithography system of claim 31.

33. The lithography system of claim 33, wherein both actuators of said pair of electromagnetic actuators are mounted adjacent a single side of said fine stage.

37. The lithography system of claim 33, wherein said at least one pair of electromagnetic actuators comprises three pairs of electromagnetic actuators coupling said fine stage to said coarse stage for control in said at least three degrees of freedom with respect to said coarse stage.

41. The lithography system of claim 33, wherein said electromagnetic actuators comprise variable reluctance actuators.

42. The lithography system of claim 33, wherein said at least one pair comprises three pairs of electromagnetic actuators interconnecting said fine stage and said coarse stage and actuable to control said fine stage in three degrees of freedom.

48. The lithography system of claim 33, further comprising at least one non-contact vertical support member which levitates said fine stage above said coarse stage.

34. The lithography system of claim 34, wherein both of said actuators of said pair are mounted on said coarse stage in close opposition to one another, and a pair of corresponding targets are mounted on said fine stage adjacent one another and within a predefined gap defined by said mounted electromagnetic actuators.

36. The lithography system of claim 36, further comprising a lens system positioned between said mask pattern and said fine stage.

38. The positioning stage assembly of claim 38, wherein two of said three pairs of electromagnetic actuators are aligned substantially parallel to a first direction, and a third of said three pairs of electromagnetic actuators is aligned in a second direction substantially perpendicular to said first direction.

39. The lithography system of claim 39, wherein said first and second directions are within a plane which said fine stage substantially lies in.

43. The lithography system of claim 43, further comprising three additional electromagnetic actuators mounted between said fine stage and said coarse stage and actuable to control said fine stage in three additional degrees of freedom.

44. The lithography system of claim 43, wherein said pairs of electromagnetic actuators comprise variable reluctance actuators.

45. The lithography system of claim 44, wherein said additional electromagnetic actuators comprise voice coil motors.

46. The lithography system of claim 43, wherein said pairs of electromagnetic actuators comprise variable reluctance actuators, said lithography system further comprising supplemental vertical supports mounted between said fine stage and said coarse stage.

47. The lithography system of claim 47, wherein said supplemental vertical supports comprise air bellows.

49. The lithography system of claim 49, wherein said at least one non-contact vertical support member comprises three non-contact vertical support members for controlling the position of said fine stage in three vertical degrees of freedom.

50. The lithography system of claim 50, wherein each said non-contact vertical support member comprises an electromagnetic actuator.

51. The lithography system of claim 50, wherein each said non-contact vertical support member comprises a voice coil motor having a magnet portion and a coil portion, one of said magnet portion and said coil portion being mounted on said fine stage and the other of said magnet portion and said coil portion being mounted on said coarse stage.

52. The lithography system of claim 50, further comprising at least one dead weight support that supports a dead weight of said fine stage vertically.

53. The lithography system of claim 50, further comprising at least one air bearing that is coupled to said coarse stage and vertically supporting a dead weight of said coarse stage.

54. The lithography system of claim 54, wherein said at least one air bearing comprises three air bearings.

59. A method of precisely positioning a stage, comprising:

coarse positioning the stage in at least two degrees of freedom, wherein said coarse positioning is driven by a planar motor, said planar motor comprising a planar magnet array having magnets disposed in a plane and a planar coil array that is interacting interacts with said planar magnet array to produce a first force and a second force differing from said first force; and

fine positioning the stage in at least three degrees of freedom with respect to said coarse positioning by inputting opposing forces for moving the stage in opposite directions at the same location on the stage, such that a pulling force for moving the stage in a first direction is inputted at the same side of the stage as a pulling force for moving the stage in a second direction opposite to the first direction, whereby the greater pulling force determines a resultant direction of movement.

60. The method of claim 60, wherein said coarse positioning comprises positioning in at least three degrees of freedom.

62. The method of claim 60, wherein said fine positioning comprises positioning in six degree of freedom with respect to said coarse positioning.

63. The method of claim 60, wherein said fine positioning comprises inputting opposing forces for moving the stage in opposite directions at the same location on the stage, such that a pulling force for moving the stage in a first direction is inputted at the same side of the stage as a pulling force for moving the stage in a second direction opposite to the first direction, whereby the greater pulling force determines a resultant direction of movement.

64. The method of claim 64 60, wherein said inputting comprises inputting magnetic driving forces with no physical contact of the stage by a driver.

65. The method of claim 60, A method of precisely positioning a stage, comprising:

coarse positioning the stage in at least two degrees of freedom, wherein said coarse positioning is driven by a planar motor, said planar motor comprising a planar magnet array having magnets disposed in a plane and a planar coil array that interacts with said planar magnet array to produce a first force and a second force differing from said first force; and

wherein said fine positioning comprisesfine positioning the stage in at least three degrees of freedom with respect to said coarse positioning by controlling movements in at least three degrees of freedom of said stage by arranging three input locations on the stage, such that a pulling force for moving the stage in a first direction at each location is inputted at the same side of the stage as a pulling force for moving the stage in a second direction opposite to the first direction.

66. The method of claim 60, further comprising floating said stage with respect to a coarse stage base such that positioning movements of the stage are performed with no physical contact occurring between the stage and the coarse stage base.

68. The method of claim 60, wherein said fine positioning comprises actuating controlling movements in at least three degrees of freedom with variable reluctance actuators.

70. A method for operating a lithography system comprising the method of precisely positioning a stage according to claim 60.

61. The method of claim 61, wherein said coarse positioning comprises positioning in six degrees of freedom.

67. The method of claim 67, wherein said floating comprises electromagnetically biasing the stage with respect to the coarse stage base.

69. The method of claim 69, further comprising fine controlling the stage in three additional degrees of freedom with voice coil motors.

71. A method for making an object including at least the photolithography process, wherein the photolithography process utilizes the method for operating a lithography system of claim 71.

72. A method for making a wafer utilizing the method for operating a lithography system of 71.

73. A method of precisely positioning a substrate along a trajectory, comprising:

coarse positioning two stages independently of one another, each in at least two degrees of freedom, wherein said coarse positioning is driven by a planar motor;

and

fine positioning the two stages independently of one another, each in at least three degrees of freedom with respect to said coarse positioning;

controlling said fine positioning along said trajectory with a control module; and

controlling said coarse positioning with said control module to follow said fine positioning.

74. The method of claim 74, wherein said coarse positioning comprises positioning in at least three degrees of freedom.

76. The method of claim 74, wherein said fine positioning comprises positioning in six degrees of freedom with respect to said coarse positioning.

77. A method for operating a lithography system comprising the method of precisely positioning of claim 74.

75. The method of claim 75, wherein said coarse positioning comprises positioning in six degrees of freedom.

78. A method for making an object including at least the photolithography process, wherein the photolithography process utilizes the method for operating a lithography system of claim 78.

79. A method for making a wafer utilizing the method for operating a lithography system of claim 78.

80. A positioning stage assembly comprising:

a coarse stage including a planar motor driveable in at least two degrees of freedom; and

a fine stage positioned on said coarse stage and driveable in six degrees of freedom with respect to said coarse stage.

81. A positioning stage assembly comprising:

a coarse stage including a planar motor driveable in at least two degrees of freedom;

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage;

at least one pair of electromagnetic actuators coupling said fine stage to said coarse stage for control in at least one of said degrees of freedom with respect to said coarse stage; and

at least one non-contact vertical support member which levitates said fine stage above said coarse stage.

82. A positioning stage assembly comprising:

a coarse stage including a planar motor driveable in at least two degrees of freedom;

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage; and

a second fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage and independently of the other fine stage.

83. A positioning stage assembly form moving a substrate along a trajectory, the positioning stage assembly comprising:

a coarse stage including a planar motor driveable in six degrees of freedom;

and

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage; and

a control module that controls movement of said fine stage along said trajectory, wherein said control module controls the movement of said coarse stage to follow said fine stage.

84. A lithography system comprising:

an illumination system that irradiates radiant energy;

a coarse stage that includes a planar motor driveable in at least two degrees of freedom with respect to said radiant energy;

and

a fine stage positioned on said coarse stage and driveable in six degrees of freedom with respect to said coarse stage; and

a control module that controls movement of said fine stage along a trajectory, wherein said control module controls the movement of said coarse stage to follow said fine stage.

85. A lithography system comprising:

an illumination system that irradiates radiant energy;

a coarse stage that includes a planar motor driveable in at least two degrees of freedom with respect to said radiant energy;

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage;

at least one pair of electromagnetic actuators coupling said fine stage to said coarse stage for control in at least one of said degrees of freedom with respect to said course stage; and

at least one non-contact vertical support member which levitates said fine stage above said coarse stage.

86. A lithography system comprising:

an illumination system that irradiates radiant energy;

a coarse stage that includes a planar motor driveable in at least two degrees of freedom with respect to said radiant energy;

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage; and

a second fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage and independently of the other fine stage.

87. A lithography system comprising:

an illumination system that irradiates radiant energy;

a coarse stage that includes a planar motor driveable in six degrees of freedom with respect to said radiant energy; and

a fine stage positioned on said coarse stage and driveable in at least three degrees of freedom with respect to said coarse stage.

88. A method of precisely positioning a stage, comprising:

coarse positioning the stage in at least two degrees of freedom, wherein said coarse positioning is driven by a planar motor; and

fine positioning the stage in six degrees of freedom with respect to said coarse positioning.

89. A positioning stage assembly for moving a substrate along a trajectory, the positioning stage assembly comprising:

a moving device including a planar motor driveable in at least two degrees of freedom wherein said planar motor comprises a planar magnet array having magnets disposed in a plane and a planar coil array that interacts with said planar magnet array to produce a first force and a second force differing from said first force;

a stage positioned on said moving device and driveable in at least one degree of freedom in common with said at least two degrees of freedom in which said planar motor is driveable, with respect to said moving device; and

a control module that controls movement of said stage to follow said trajectory, wherein said control module controls the movement of said moving device to follow said stage.

90. The positioning stage assembly of claim 90, wherein said stage is driveable in three degrees of freedom with respect to said moving device.

91. The positioning stage assembly of claim 90, wherein said stage is driveable in six degrees of freedom with respect to said moving device.

92. The positioning stage assembly of claim 90, further comprising a second stage driveable in at least one degree of freedom with respect to said moving device and independently of the other stage.

93. A lithography system comprising:

illuminating means for irradiating radiant energy;

driving means for driving a moving member, said driving means including a planar motor driveable at least along an X-axis and along a Y-axis with respect to said radiant energy wherein said planar motor comprises a planar member having magnetic means for generating magnetic flux and disposed in a plane, and a planar coil array that interacts with said magnetic means to produce a first force and a second force differing from said first force;

actuating means for actuating a stage, said actuating means positioned on said moving member and driveable at least along one of said X-axis and said Y-axis with respect to said moving member;

controlling means for controlling said actuating means to follow a trajectory, wherein said controlling means controls said driving means to follow said actuating means.

94. A lithography system comprising:

an illumination system that irradiates radiant energy;

a positioning system that comprises a planar motor including a first member and a plurality of second members that interact with said first member to produce a driving force, wherein each of said plurality of second members is movable in at least two degrees of freedom with respect to said first member and said radiant energy, and independently of the other second members;

wherein each of said plurality of second members has a stage mounted thereon, each said stage movable in at least one degree of freedom with respect to said second member that each said stage is mounted on; and

a control system that controls movement of each said stage to follow a trajectory, said control system controlling movement of each said second member to follow the movement of each said stage.

95. The lithography system of claim 95, wherein said stage is movable in at least three degrees of freedom with respect to said second member that each said stage is mounted on.

96. A process for manufacturing a device including the steps of providing a substrate and transferring an image onto the substrate with the lithography system of claim 95.

97. A process for manufacturing a wafer including the steps of providing a substrate and transferring an image onto the substrate with the lithography system of claim 95.