Position measuring system and position measuring method, Movable body apparatus, movable body drive method, exposure apparatus and exposure method, pattern forming apparatus, and device manufacturing method

• US 8,208,128 B2
• Filed: 02/06/2009
• Issued: 06/26/2012
• Est. Priority Date: 02/08/2008
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Makinouchi, Susumu
• Primary Examiner(s): Nguyen, Hung Henry
• Assistant Examiner(s): KREUTZER, COLIN WRIGHT
• Application Number:
  US12/366,934
• Publication Number:
  US 20090262321A1
• Time in Patent Office: 1,236 Days
• Field of Search: 250/492.2, 25055929-5593, 310 1205- 1206, 310/12.19, 318/649, 355/53, 355 67- 68, 355/72, 355/75, 355/77, 356399-401, 356498-500, 356614-616
• US Class Current: 355/72
• CPC Class Codes: G01D 2205/90 Two-dimensional encoders, i.e. having one or two codes extending in two directions
• CPC Class Codes: G01D 5/34746 Linear encoders
• CPC Class Codes: G01D 5/38 by diffraction gratings
• CPC Class Codes: G03F 7/70725 control
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position
• CPC Class Codes: G03F 7/7085 Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load

Abstract

A mirror block on which moving gratings are arranged is fixed to the lower surface of a stage. Fixed gratings are placed on the upper surface of a stage platform that is opposed to the lower surface of the stage. A Y encoder that measures Y positional information of the stage is configured including the moving gratings and the fixed gratings. Similarly, an X encoder that measures X positional information of the stage is configured including the moving gratings and the fixed grating.

Claims

1. A position measuring system that measures positional information of a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other, the system comprising:

a first fixed grating and a second fixed grating that are respectively arranged external to the movable body so as to extend in a direction parallel to the first axis, the first fixed grating having its periodic direction in the direction parallel to the first axis and the second fixed grating having its periodic direction in a direction parallel to the second axis;

an optical member that has a first moving grating and a second moving grating and is attached to the movable body, the first and second moving gratings having their periodic directions in directions corresponding to the periodic directions of the first fixed grating and the second fixed grating respectively; and

a first photodetection system and a second photodetection system that correspond to the first and second fixed gratings respectively, whereby

a first measurement device that measures positional information of the movable body in the direction parallel to the first axis is configured including the first fixed grating, the first moving grating and the first photodetection system, and

a second measurement device that measures positional information of the movable body in the direction parallel to the second axis is configured including the second fixed grating, the second moving grating and the second photodetection system, wherein

a first measurement beam and a second measurement beam, which reach the optical member, are irradiated on the first moving grating and the second moving grating, respectively, the first measurement beam and the second measurement beam reaching the optical member along a first optical path and a second optical path that are parallel to the first axis and correspond to the first fixed grating and the second fixed grating, respectively.

2. The position measuring system according to claim 1, wherein

the optical member has its longitudinal direction in the direction parallel to the second axis, and has a length in the longitudinal direction that is longer than or equal to about a length of the movable body in the direction parallel to the second axis.

3. The position measuring system according to claim 1, wherein

the first and second moving gratings are placed on a surface of the optical member.

4. The position measuring system according to claim 3, wherein

the optical member further has a third moving grating and a fourth moving grating that are respectively placed on another surface that is different from the surface, the third and fourth moving gratings having their periodic directions in directions corresponding to the periodic directions of the first and second fixed gratings, respectively.

5. The position measuring system according to claim 1, wherein

the first and second fixed gratings are placed on a surface that is opposed to the movable body and parallel to the predetermined plane.

6. The position measuring system according to claim 5, wherein the first and second fixed gratings are placed apart in the direction parallel to the second axis.

7. The position measuring system according to claim 1, wherein

the first and second fixed gratings each have a length that is longer than or equal to about a movement stroke of the movable body in the direction parallel to the first axis.

8. The position measuring system according to claim 1, wherein

the first measurement device further includes a third fixed grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis and a third photodetection system corresponding to the third fixed grating, and further measures positional information of the movable body in a rotational direction around a third axis orthogonal to the predetermined plane based on an output of the first photodetection system and an output of the third photodetection system.

9. A movable body apparatus, comprising:

a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other;

the position measuring system according to claim 1 that measures positional information of the movable body within the predetermined plane; and

a drive device that drives the movable body along the predetermined plane based on the positional information of the movable body that has been measured by the position measuring system.

10. The movable body apparatus according to claim 9, wherein

the optical member that constitutes a part of the position measuring system is attached near a center of gravity of the movable body.

11. An exposure apparatus that forms a pattern on an object by irradiating the object with an energy beam, the apparatus comprising:

the movable body apparatus according to claim 9 that drives a movable body that holds the object along a predetermined plane in order to form the pattern.

12. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the exposure apparatus according to claim 11; and

a process of applying processing to the object on which the pattern has been formed.

13. A pattern forming apparatus that forms a pattern on an object, the apparatus comprising:

a movable body that can move while holding the object;

a pattern generating device that forms the pattern on the object; and

the movable body apparatus according to claim 9 that drives the movable body within a predetermined plane.

14. The pattern forming apparatus according to claim 13, wherein

the object has a sensitive layer, and

the pattern generating device forms the pattern by irradiating the sensitive layer with an energy beam.

15. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the pattern forming apparatus according to claim 13; and

a process of applying processing to the object on which the pattern has been formed.

16. A position measuring system that measures positional information of a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other, the system comprising:

a first measurement device which includes a first reference grating that is arranged external to the movable body so as to extend in a direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis, a first diffraction grating that is arranged on the movable body and has its periodic direction in a direction corresponding to the periodic direction of the first reference grating, and a first photodetection system that corresponds to the first reference grating, and which measures positional information of the movable body in the direction parallel to the first axis; and

a second measurement device which includes a second reference grating that is arranged on the movable body and has its periodic direction in a direction parallel to the second axis, a second diffraction grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in a direction corresponding to the periodic direction of the second reference grating, and a second photodetection system that corresponds to the second reference grating, and which measures positional information of the movable body in the direction parallel to the second axis, wherein

a first measurement beam and a second measurement beam, which reach the movable body, are irradiated on the first diffraction grating and the second reference grating, respectively, the first measurement beam and the second measurement beam reaching the movable body along a first optical path and a second optical path that are parallel to the first axis and correspond to the first reference grating and the second diffraction grating, respectively.

17. The position measuring system according to claim 16, wherein

the first diffraction grating and the second reference grating have their longitudinal directions in the direction parallel to the second axis, and each have a length in the longitudinal direction that is longer than or equal to about a length of the movable body in the direction parallel to the second axis.

18. The position measuring system according to claim 16, wherein

the first measurement device further includes a third diffraction grating that is placed at a location different from a location where the first diffraction grating and the second reference grating are arranged on the movable body, and has its periodic direction in a direction corresponding to the periodic direction of the first reference grating, and

the second measurement device further includes a fourth diffraction grating that is placed at a location different from a location where the first diffraction grating and the second reference grating are arranged on the movable body, and has its periodic direction in a direction corresponding to the periodic direction of the second reference grating.

19. The position measuring system according to claim 16, wherein

the first reference grating and the second diffraction grating are placed on a surface that is opposed to the movable body and parallel to the predetermined plane.

20. The position measuring system according to claim 19, wherein

the first reference grating and the second diffraction grating are placed apart in the direction parallel to the second axis.

21. The position measuring system according to claim 16, wherein

the first reference grating and the second diffraction grating each have a length that is longer than or equal to about a movement stroke of the movable body in the direction parallel to the first axis.

22. The position measuring system according to claim 16, wherein

the first measurement device further includes a third reference grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis and a third photodetection system corresponding to the third reference grating, and further measures positional information of the movable body in a rotational direction around a third axis orthogonal to the predetermined plane based on an output of the first photodetection system and an output of the third photodetection system.

23. A movable body apparatus, comprising:

a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other;

the position measuring system according to claim 16 that measures positional information of the movable body within the predetermined plane; and

a drive device that drives the movable body along the predetermined plane based on the positional information of the movable body that has been measured by the position measuring system.

24. The movable body apparatus according to claim 23, wherein

the first diffraction grating and the second reference grating that constitute a part of the position measuring system are arranged near a center of gravity of the movable body.

25. An exposure apparatus that forms a pattern on an object by irradiating the object with an energy beam, the apparatus comprising:

the movable body apparatus according to claim 23 that drives a movable body that holds the object along a predetermined plane in order to form the pattern.

26. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the exposure apparatus according to claim 25; and

a process of applying processing to the object on which the pattern has been formed.

27. A pattern forming apparatus that forms a pattern on an object, the apparatus comprising:

a movable body that can move while holding the object;

a pattern generating device that forms the pattern on the object; and

the movable body apparatus according to claim 23 that drives the movable body within a predetermined plane.

28. The pattern forming apparatus according to claim 27, wherein

the object has a sensitive layer, and

the pattern generating device forms the pattern by irradiating the sensitive layer with an energy beam.

29. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the pattern forming apparatus according to claim 27; and

a process of applying processing to the object on which the pattern has been formed.

30. A position measuring system that measures positional information of a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other, the system comprising:

a first measurement device which measures positional information of the movable body in a direction parallel to the first axis, by irradiating a first moving grating that is comprised in an optical member attached to the movable body, with a first measurement beam along an optical path that at least partially includes a first optical path parallel to the first axis, irradiating a first fixed grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis, with a diffraction beam generated from the first moving grating, and receiving a diffraction beam generated from the first fixed grating via the optical member; and

a second measurement device which measures positional information of the movable body in a direction parallel to the second axis, by irradiating a second moving grating that is comprised in the optical member, with a second measurement beam along an optical path that at least partially includes a second optical path close to the first optical path and parallel to the first axis, irradiating a second fixed grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the second axis, with a diffraction beam generated from the second moving grating, and receiving a diffraction beam generated from the second fixed grating via the optical member.

31. The position measuring system according to claim 30, wherein

the optical member has its longitudinal direction in the direction parallel to the second axis, and has a length in the longitudinal direction that is longer than or equal to about a length of the movable body in the direction parallel to the second axis.

32. The position measuring system according to claim 30, wherein

the first and second moving gratings have their periodic directions in directions that correspond to the periodic directions of the first and second fixed gratings, respectively.

33. The position measuring system according to claim 30, wherein

the optical member further has a third moving grating and a fourth moving grating that converge diffraction beams generated from the first and second moving gratings, respectively, and

the third and fourth moving gratings have their periodic directions in directions that correspond to the periodic directions of the first and second fixed gratings, respectively.

34. The position measuring system according to claim 30, wherein

the optical member further has a third moving grating and a fourth moving grating that converge diffraction beams generated from the first and second fixed gratings, respectively, and

the third and fourth moving gratings have their periodic directions in directions that correspond to the periodic directions of the first and second fixed gratings, respectively.

35. The position measuring system according to claim 30, wherein

the optical member has a reflection member that deflects the optical paths of the first and second measurement beams toward the first and second fixed gratings, respectively.

36. The position measuring system according to claim 30, wherein

the optical member has a reflection member that deflects optical paths of the diffraction beams generated from the first and second fixed gratings into directions parallel to the first and second optical paths, respectively.

37. The position measuring system according to claim 30, wherein

the first and second optical paths are placed a predetermined distance apart in the direction parallel to the second axis.

38. The position measuring system according to claim 37, wherein

the first and second fixed gratings are placed the predetermined distance apart in the direction parallel to the second axis, on a surface that is opposed to the movable body and parallel to the predetermined plane.

39. The position measuring system according to claim 30, wherein

the first and second fixed gratings each have a length that is longer than or equal to about a movement stroke of the movable body in the direction parallel to the first axis.

40. A movable body apparatus, comprising:

a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other;

the position measuring system according to claim 30 that measures positional information of the movable body within the predetermined plane; and

a drive device that drives the movable body along the predetermined plane based on the positional information of the movable body that has been measured by the position measuring system.

41. The movable body apparatus according to claim 40, wherein

the optical member that constitutes a part of the position measuring system is attached near a center of gravity of the movable body.

42. The movable body apparatus according to claim 40, wherein

the position measuring system further comprises

a third measurement device which measures positional information of the movable body in the direction parallel to the first axis, by irradiating the first moving grating, with a third measurement beam along an optical path that at least partially includes a third optical path close to the first optical path and parallel to the first axis, irradiating a third fixed grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis, with a diffraction beam generated from the first moving grating, and receiving a diffraction beam generated from the third fixed grating via the optical member.

43. The movable body apparatus according to claim 42, wherein

the first and third optical paths are placed an equal distance apart from the second optical path, on one side and the other side in the direction parallel to the second axis, respectively.

44. An exposure apparatus that forms a pattern on an object by irradiating the object with an energy beam, the apparatus comprising:

the movable body apparatus according to claim 40 that drives a movable body that holds the object along a predetermined plane in order to form the pattern.

45. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the exposure apparatus according to claim 44; and

a process of applying processing to the object on which the pattern has been formed.

46. A pattern forming apparatus that forms a pattern on an object, the apparatus comprising:

a movable body that can move while holding the object;

a pattern generating device that forms the pattern on the object; and

the movable body apparatus according to claim 40 that drives the movable body within a predetermined plane.

47. The pattern forming apparatus according to claim 46, wherein

the object has a sensitive layer, and

the pattern generating device forms the pattern by irradiating the sensitive layer with an energy beam.

48. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the pattern forming apparatus according to claim 46; and

a process of applying processing to the object on which the pattern has been formed.

49. A position measuring method of measuring positional information of a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other, the method comprising:

a first measurement process of measuring positional information of the movable body in a direction parallel to the first axis, by irradiating a first moving grating that is comprised in an optical member attached to the movable body and has its periodic direction in a direction corresponding to a periodic direction of a first fixed grating, with a first measurement beam along an optical path parallel to the first axis, irradiating the first fixed grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis, with a diffraction beam generated from the first moving grating, and receiving a diffraction beam generated from the first fixed grating, with a first photodetection system via the optical member; and

a second measurement process of measuring positional information of the movable body in a direction parallel to the second axis, by irradiating a second moving grating that is comprised in the optical member and has its periodic direction in a direction corresponding to a periodic direction of a second fixed grating, with a second measurement beam along an optical path parallel to the first axis, irradiating the second fixed grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the second axis, with a diffraction beam generated from the second moving grating, and receiving a diffraction beam generated from the second fixed grating, with a second photodetection system via the optical member.

50. The position measuring method according to claim 49, wherein

the optical member has its longitudinal direction in the direction parallel to the second axis, and has a length in the longitudinal direction that is longer than or equal to about a length of the movable body in the direction parallel to the second axis.

51. The position measuring method according to claim 49, wherein

the first and second moving gratings are placed on a surface of the optical member.

52. A movable body drive method, comprising:

a process of measuring positional information of a movable body within a predetermined plane including a first axis and a second axis that are orthogonal to each other by using the position measuring method according to claim 49, the movable body moving along the predetermined plane; and

a process of driving the movable body along the predetermined plane based on the positional information of the movable body that has been measured.

53. An exposure method of forming a pattern on an object by irradiating the object with an energy beam, the method comprising:

driving a movable body that holds the object along a predetermined plane by using the movable body drive method according to claim 52 in order to form the pattern.

54. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the exposure method according to claim 53; and

a process of applying processing to the object on which the pattern has been formed.

55. A position measuring method of measuring positional information of a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other, the method comprising:

a first measurement process of measuring positional information of the movable body in a direction parallel to the first axis, by irradiating a first diffraction grating that is arranged on the movable body and has its periodic direction in a direction corresponding to a periodic direction of a first reference grating, with a first measurement beam along an optical path parallel to the first axis, irradiating the first reference grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis, with a diffraction beam generated from the first diffraction grating, and receiving a diffraction beam generated from the first reference grating, with a first photodetection system; and

a second measurement process of measuring positional information of the movable body in a direction parallel to the second axis, by irradiating a second reference grating that is arranged on the movable body and has its periodic direction in a direction parallel to the second axis, with a second measurement beam along an optical path parallel to the first axis, irradiating a second diffraction grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in a direction corresponding to the periodic direction of the second reference grating, with a diffraction beam generated from the second reference grating, and receiving a diffraction beam generated from the second diffraction grating, with a second photodetection system.

56. The position measuring method according to claim 55, wherein

the first diffraction grating and the second reference grating have their longitudinal directions in the direction parallel to the second axis, and each have a length in the longitudinal direction that is longer than or equal to about a length of the movable body in the direction parallel to the second axis.

57. The position measuring method according to claim 55, wherein

the first reference grating and the second diffraction grating are placed on a surface that is opposed to the movable body and parallel to the predetermined plane.

58. A movable body drive method, comprising:

a process of measuring positional information of a movable body within a predetermined plane including a first axis and a second axis that are orthogonal to each other by using the position measuring method according to claim 55, the movable body moving along the predetermined plane; and

a process of driving the movable body along the predetermined plane based on the positional information of the movable body that has been measured.

59. An exposure method of forming a pattern on an object by irradiating the object with an energy beam, the method comprising:

driving a movable body that holds the object along a predetermined plane by using the movable body drive method according to claim 58 in order to form the pattern.

60. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the exposure method according to claim 59; and

a process of applying processing to the object on which the pattern has been formed.

61. A position measuring method of measuring positional information of a movable body that moves along a predetermined plane including a first axis and a second axis that are orthogonal to each other, the method comprising:

a first measurement process of measuring positional information of the movable body in a direction parallel to the first axis, by irradiating a first moving grating that is comprised in an optical member attached to the movable body, with a first measurement beam along an optical path that at least partially includes a first optical path parallel to the first axis, irradiating a first fixed grating that is arranged external to the movable body so as to extend in a direction parallel to the first axis and has its periodic direction in the direction parallel to the first axis, with a diffraction beam generated from the first moving grating, and receiving a diffraction beam generated from the first fixed grating via the optical member; and

a second measurement process of measuring positional information of the movable body in a direction parallel to the second axis, by irradiating a second moving grating that is comprised in the optical member, with a second measurement beam along an optical path that at least partially includes a second optical path close to the first optical path and parallel to the first axis, irradiating a second fixed grating that is arranged external to the movable body so as to extend in the direction parallel to the first axis and has its periodic direction in the direction parallel to the second axis, with a diffraction beam generated from the second moving grating, and receiving a diffraction beam generated from the second fixed grating via the optical member.

62. The position measuring method according to claim 61, wherein

the optical member has a reflection member that deflects the optical paths of the first and second measurement beams toward the first and second fixed gratings, respectively.

63. The position measuring method according to claim 61, wherein

the optical member has a reflection member that deflects optical paths of the diffraction beams generated from the first and second fixed gratings into directions parallel to the first and second optical paths, respectively.

64. A movable body drive method, comprising:

a process of measuring positional information of a movable body within a predetermined plane including a first axis and a second axis that are orthogonal to each other by using the position measuring method according to claim 61, the movable body moving along the predetermined plane; and

a process of driving the movable body along the predetermined plane based on the positional information of the movable body that has been measured.

65. An exposure method of forming a pattern on an object by irradiating the object with an energy beam, the method comprising:

driving a movable body that holds the object along a predetermined plane by using the movable body drive method according to claim 64 in order to form the pattern.

66. A device manufacturing method, comprising:

a process of forming a pattern on an object by using the exposure method according to claim 65; and

a process of applying processing to the object on which the pattern has been formed.