Exposure method and apparatus, maintenance method, and device manufacturing method

• US 20090061331A1
• Filed: 10/23/2008
• Published: 03/05/2009
• Est. Priority Date: 05/22/2006
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nakano, Katsushi
• Application Number:
  US12/289,244
• Publication Number:
  US 20090061331A1
• Time in Patent Office: Days
• US Class Current: 430/30
• CPC Class Codes: G03F 7/70341 Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply chemical composition of immersion liquids G03F7/2041
• 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
• CPC Class Codes: G03F 7/70916 Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps
• CPC Class Codes: G03F 7/70925 Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning
• CPC Class Codes: G03F 9/7088 Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection
• CPC Class Codes: G03F 9/7096 Arrangement, mounting, housing, environment, cleaning or maintenance of apparatus

Abstract

An exposure method for exposing a substrate with an exposure light via an projection optical system and a liquid includes: a first step of optically observing a liquid contact portion which comes into contact with the liquid and storing first image data obtained by the optical observation; a second step of optically observing the liquid contact portion after the liquid contact portion came into contact with the liquid, for example, after the liquid immersion exposure and obtaining second image data obtained by the optical observation; and a third step of comparing the first image data and the second image data to judge whether abnormality of observation objective portion is present or absent. It is possible to efficiently judge whether or not the abnormality of the liquid-contact portion, of the exposure apparatus which performs the exposure by the immersion method, is present or absent.

Claims

1. An exposure method for exposing a substrate with an exposure light via an optical member and a liquid, the exposure method comprising:

a first step of storing first observation information obtained by optically observing a state of at least a part of a detection objective portion of a liquid contact portion which comes into contact with the liquid in a predetermined operation;

a second step of obtaining second observation information by optically observing a state of the detection objective portion after the predetermined operation; and

a third step of comparing the first observation information and the second observation information to judge whether abnormality of the detection objective portion is present or absent.

2. The exposure method according to claim 1, wherein a space between the optical member and the substrate is filled with the liquid to form a liquid immersion space, and the substrate is exposed with the exposure light via the optical member and the liquid.

3. The exposure method according to claim 1, further comprising a fourth step of stopping an exposure operation when the abnormality is present in the third step.

4. The exposure method according to claim 1, wherein the presence or absence of the abnormality, which is judged in the third step, is presence or absence of a foreign matter at the detection objective portion.

5. The exposure method according to claim 1, wherein an alignment sensor of an image processing system is used to detect a position of an alignment mark on the substrate so as to optically observe the state of the detection objective portion.

6. The exposure method according to claim 5, wherein the second step is executed when the position of the alignment mark on the substrate is detected by using the alignment sensor.

7. The exposure method according to claim 1, wherein an image pickup device, which is provided on a stage arranged opposite to the optical member, is used to optically observe the state of the detection objective portion.

8. The exposure method according to claim 1, wherein the liquid contact portion comes into contact with the liquid at least during the exposure of the substrate.

9. The exposure method according to claim 1, wherein the liquid contact portion includes at least a part of a liquid immersion space-forming member which fills a space between the optical member and the substrate to form a liquid immersion space.

10. The exposure method according to claim 9, wherein the detection objective portion includes at least one of a supply port and a recovery port, for the liquid, of the liquid immersion space-forming member.

11. The exposure method according to claim 1, wherein the liquid contact portion includes at least a part of a movable member which is arranged opposite to the optical member.

12. The exposure method according to claim 11, wherein the detection objective portion includes a measuring portion and/or a flat surface of the movable member.

13. The exposure method according to claim 1, wherein the second step is executed after an exposure operation for the substrate.

14. The exposure method according to claim 1, further comprising a step of cleaning the liquid contact portion when the abnormality is present in the third step.

74. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 1;

developing the exposed substrate; and

processing the developed substrate.

15. An exposure method for exposing a substrate with an exposure light via an optical member and a liquid, the exposure method comprising:

detecting information about a state of a liquid contact portion which comes into contact with the liquid in a predetermined operation; and

detecting information about abnormality of the liquid contact portion based on the detected information about the state and reference information about a state of the liquid contact portion before the predetermined operation.

16. The exposure method according to claim 15, wherein the liquid contact portion includes at least one of a liquid immersion space-forming member which forms a liquid immersion space by filling a space between the optical member and the substrate with the liquid, a movable member which is arranged opposite to the optical member, and the optical member.

17. The exposure method according to claim 16, wherein information about a state of the movable member is detected by a mark-detecting system which detects a mark on the substrate.

18. The exposure method according to claim 17, wherein the detected information about the movable member includes information about a measuring portion and/or a flat surface of the movable member.

19. The exposure method according to claim 17, wherein the movable member includes at least one of a first stage which holds the substrate and a second stage which is movable independently from the first stage.

20. The exposure method according to claim 16, wherein the information about the state is detected by a detector which is arranged opposite to the liquid immersion space-forming member and/or the optical member.

21. The exposure method according to claim 15, wherein judgment is made whether an exposure operation is to be stopped or continued depending on the information about the abnormality.

22. The exposure method according to claim 15, wherein judgment is made whether or not maintenance is required for the liquid contact portion depending on the information about the abnormality.

23. The exposure method according to claim 22, wherein the maintenance includes cleaning and/or exchange of the liquid contact portion.

24. The exposure method according to claim 15, wherein the reference information is detected before at least the predetermined operation.

25. The exposure method according to claim 15, wherein the reference information includes at least information about a state of the liquid contact portion before the contact portion comes into contact with the liquid.

26. The exposure method according to claim 15, wherein the predetermined operation includes at least an exposure operation for the substrate.

91. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 15;

developing the exposed substrate; and

processing the developed substrate.

27. An exposure apparatus which exposes a substrate with an exposure light via an optical member and a liquid, the exposure apparatus comprising:

an optical device which optically observes a state of at least a part of a detection objective portion of a liquid contact portion which comes into contact with the liquid;

a storage device which stores observation information obtained by the optical device; and

a controller which compares a plurality of pieces of the observation information obtained by observing the detection objective portion a plurality of times by the optical device to judge whether abnormality of the detection objective portion is present or absent.

28. The exposure apparatus according to claim 27, wherein a space between the optical member and the substrate is filled with the liquid to form a liquid immersion space, and the substrate is exposed with the exposure light via the optical member and the liquid.

29. The exposure apparatus according to claim 27, wherein the controller stops an exposure operation when the abnormality of the detection objective portion is present.

30. The exposure apparatus according to claim 27, wherein the optical device includes an alignment sensor of an image processing system which detects a position of an alignment mark on the substrate.

31. The exposure apparatus according to claim 27, further comprising a stage which is arranged opposite to the optical member, wherein the optical device includes an image pickup device which is provided on the stage.

32. The exposure apparatus according to claim 27, wherein the optical device includes a fluorescence microscope which detects fluorescence emitted when the exposure light is irradiated onto the detection objective portion.

33. The exposure apparatus according to claim 27, wherein the optical device includes a spectrometer.

34. The exposure apparatus according to claim 27, wherein the liquid contact portion comes into contact with the liquid at least during the exposure of the substrate.

35. The exposure apparatus according to claim 27, wherein the liquid contact portion includes at least a part of a liquid immersion space-forming member which fills a space between the optical member and the substrate with the liquid to form a liquid immersion space.

36. The exposure apparatus according to claim 35, wherein the detection objective portion includes at least one of a supply port and a recovery port, for the liquid, of the liquid immersion space-forming member.

37. The exposure apparatus according to claim 27, wherein the liquid contact portion includes at least a part of a measuring member arranged opposite to the optical member.

38. The exposure apparatus according to claim 37, further comprising a stage which is provided with the measuring member.

39. The exposure apparatus according to claim 27, further comprising a cleaning member which cleans the detection objective portion.

86. A method for producing a device, comprising:

exposing a substrate by using the exposure apparatus as defined in claim 27;

developing the exposed substrate; and

processing the developed substrate.

40. An exposure apparatus which exposes a substrate with an exposure light via an optical member and a liquid, the exposure apparatus comprising:

an optical device which detects information about a state of a liquid contact portion which comes into contact with the liquid in a predetermined operation; and

a controller which detects information about abnormality of the liquid contact portion based on the detected information about the state and reference information about a state of the liquid contact portion before the predetermined operation.

41. The exposure apparatus according to claim 40, further comprising a movable member which is arranged opposite to the optical member, wherein the liquid contact portion includes at least one of the movable member and the optical member.

42. The exposure apparatus according to claim 41, wherein the optical device includes a mark-detecting system which detects a mark on the substrate, and information about a state of the movable member is detected by the mark-detecting system.

43. The exposure apparatus according to claim 41, wherein the optical device detects information about a measuring portion and/or a flat surface of the movable member.

44. The exposure apparatus according to claim 41, wherein the movable member includes at least one of a first stage which holds the substrate and a second stage which is movable independently from the first stage.

45. The exposure apparatus according to claim 40, further comprising a liquid immersion space-forming member which fills a space between the optical member and the substrate with the liquid to form a liquid immersion space, and the liquid contact portion includes the liquid immersion space-forming member.

46. The exposure apparatus according to claim 45, wherein the optical device includes a detector which is arranged opposite to the liquid immersion space-forming member and/or the optical member.

47. The exposure apparatus according to claim 40, wherein the optical device includes at least one of an image pickup device, a fluorescence microscope, and a spectrometer.

48. The exposure apparatus according to claim 40, wherein the controller judges whether an exposure operation is to be stopped or continued depending on the information about the abnormality.

49. The exposure apparatus according to claim 40, further comprising a maintenance member which is usable to perform maintenance for the liquid contact portion, wherein the controller judges whether or not the maintenance is required depending on the information about the abnormality.

50. The exposure apparatus according to claim 49, wherein the maintenance member includes a cleaning member which cleans the liquid contact portion.

51. The exposure apparatus according to claim 40, wherein the reference information is detected before at least the predetermined operation.

52. The exposure apparatus according to claim 40, wherein the reference information includes at least information about a state of the liquid contact portion before the liquid contact portion comes into contact with the liquid.

94. A method for producing a device, comprising:

exposing a substrate by using the exposure apparatus as defined in claim 40;

developing the exposed substrate; and

processing the developed substrate.

53. A maintenance method for an exposure apparatus which exposes a substrate with an exposure light via an optical member and a liquid, the maintenance method comprising:

detecting information about a state of a liquid contact portion which comes into contact with the liquid in a predetermined operation; and

detecting information about abnormality of the liquid contact portion based on the detected information about the state and reference information about a state of the liquid contact portion before the predetermined operation.

54. The maintenance method according to claim 53, wherein the liquid contact portion includes at least one of a liquid immersion space-forming member which forms a liquid immersion space by filling a space between the optical member and the substrate with the liquid, a movable member which is arranged opposite to the optical member, and the optical member.

55. The maintenance method according to claim 54, wherein the detected information about the state includes information about a measuring portion and/or a flat surface of the movable member.

56. The maintenance method according to claim 54, wherein the detected information about the state includes information about a liquid recovery portion of the liquid immersion space-forming member.

57. The maintenance method according to claim 53, wherein judgment is made whether or not maintenance is required for the liquid contact portion depending on the information about the abnormality.

58. The maintenance method according to claim 57, wherein the maintenance includes cleaning and/or exchange of the liquid contact portion.

59. An exposure method for exposing a substrate with an exposure light through a liquid, the exposure method comprising:

a first step of supplying the liquid to only a part of an area on the substrate;

a second step of recovering at least a part of the liquid supplied in the first step and inspecting a state of the recovered liquid;

a third step of inspecting a state of a film of the substrate; and

a fourth step of judging whether abnormality is present or absent in the substrate based on at least one of inspection results obtained in the second step and the third step.

60. The exposure method according to claim 59, wherein the substrate is arranged opposite to an optical member through which the exposure light passes, the liquid is supplied to a space between the optical member and the substrate, and the substrate is exposed with the exposure light via the optical member and the liquid.

61. The exposure method according to claim 59, further comprising a fifth step of stopping the exposure of the substrate when the abnormality is present in the fourth step.

62. The exposure method according to claim 59, wherein the film of the substrate includes a film which is formed of a photosensitive material.

63. The exposure method according to claim 59, wherein the film of the substrate includes a top coat which is coated on a photosensitive material.

64. The exposure method according to claim 59, wherein presence or absence of exfoliation of the film of the substrate is inspected in the third step.

65. The exposure method according to claim 59, wherein the area on the substrate, to which the liquid is supplied in the first step, includes at least a part of an edge portion of the substrate.

66. The exposure method according to claim 59, wherein the third step includes a step of inspecting the state of the film on the substrate in a dry state.

67. The exposure method according to claim 66, wherein the third step includes a measuring step of measuring uneven thickness of the film of the substrate.

68. The exposure method according to claim 67, further comprising a sixth step of exfoliating the film of the substrate when the uneven thickness measured in the third step exceeds an allowable range.

69. The exposure method according to claim 59, wherein the exposure is started for the substrate through the liquid when the abnormality is absent in the fourth step.

92. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 59;

developing the exposed substrate; and

processing the developed substrate.

70. An exposure method for exposing a substrate with an exposure light via an optical member and a liquid, the exposure method comprising:

filling a space between the optical member and an object with the liquid to form a liquid immersion space and recovering the liquid in the liquid immersion space;

detecting information about the recovered liquid; and

detecting information about abnormality of a liquid contact portion which comes into contact with the liquid, based on the detected information about the recovered liquid.

71. The exposure method according to claim 70, wherein the object includes the substrate.

72. The exposure method according to claim 70, wherein information about a foreign matter in the recovered liquid is detected.

73. The exposure method according to claim 70, wherein judgment is made whether an exposure operation is to be stopped or continued depending on the information about the abnormality.

93. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 70;

developing the exposed substrate; and

processing the developed substrate.

75. An exposure apparatus which exposes a substrate with an exposure light through a liquid, the exposure apparatus comprising:

a liquid supply system which supplies the liquid to only a part of an area on the substrate;

a first detector which detects a state of a liquid obtained by recovering the liquid supplied by the liquid supply system;

a second detector which detects a state of a film of the substrate; and

a controller which judges whether abnormality of the substrate is present or absent based on at least one of detection results obtained by the first detector and the second detector.

76. The exposure apparatus according to claim 75, wherein the first detector includes a particle counter.

77. The exposure apparatus according to claim 75, wherein the second detector includes an alignment sensor.

78. The exposure apparatus according to claim 75, wherein the controller starts liquid immersion exposure when there is no abnormality as judged from the detection results obtained by both of the first detector and the second detector.

79. The exposure apparatus according to claim 75, wherein the controller judges whether the abnormality of the substrate is present or absent based on the detection results obtained by both of the first detector and the second detector.

80. The exposure apparatus according to claim 75, further comprising a stage which holds the substrate, wherein the state of the film is detected at a circumferential edge portion of the substrate by the second detector while moving the stage.

95. A method for producing a device, comprising:

exposing a substrate by using the exposure apparatus as defined in claim 75;

developing the exposed substrate; and

processing the developed substrate.

81. An exposure apparatus which exposes a substrate with an exposure light via an optical member and a liquid, the exposure apparatus comprising:

a liquid immersion mechanism which forms a liquid immersion space by filling a space between the optical member and an object with the liquid and which recovers the liquid in the liquid immersion space;

a detecting device which detects information about the recovered liquid; and

a controller which detects information about abnormality of a liquid contact portion which comes into contact with the liquid, based on the detected information about the recovered liquid.

82. The exposure apparatus according to claim 81, wherein the object includes the substrate.

83. The exposure apparatus according to claim 81, wherein the detecting device detects information about a foreign matter in the recovered liquid.

84. The exposure apparatus according to claim 83, wherein the detecting device includes a particle counter.

85. The exposure apparatus according to claim 81, wherein the controller judges whether an exposure operation is to be stopped or continued depending on the information about the abnormality.

96. A method for producing a device, comprising:

exposing a substrate by using the exposure apparatus as defined in claim 81;

developing the exposed substrate; and

processing the developed substrate.

87. An exposure method for exposing a substrate with an exposure light via an optical member and a liquid, the exposure method comprising:

detecting information about a state of a liquid contact portion which comes into contact with the liquid in a predetermined operation; and

detecting information about abnormality of the liquid contact portion based on the detected information about the state.

88. The exposure method according to claim 87, wherein the detected information about the state includes information obtained by detecting the liquid contact portion with a fluorescence microscope.

89. An exposure apparatus which exposes a substrate with an exposure light via an optical member and a liquid, the exposure apparatus comprising:

an optical device which detects information about a state of a liquid contact portion which comes into contact with the liquid in a predetermined operation; and

a controller which detects information about abnormality of the liquid contact portion, based on the detected information about the state.

90. The exposure apparatus according to claim 89, wherein the optical device includes a fluorescence microscope.