Surface position detecting method, surface position adjusting apparatus and projection exposure apparatus effecting accurate positioning of a substrate

• US 5,998,801 A
• Filed: 03/30/1999
• Issued: 12/07/1999
• Est. Priority Date: 05/09/1996
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Imai, Yuji
• Primary Examiner(s): ALLEN, STEPHONE B
• Application Number:
  US09/281,095
• Time in Patent Office: 252 Days
• Field of Search: 250/548, 250/559.4, 356/375, 356/399-401, 355/53, 355/55
• US Class Current: 250/548
• CPC Class Codes: B23K 20/02 by means of a press ; Diffusion bonding B23K20/001, B23K20/04 take precedence
• CPC Class Codes: B23K 20/023 Thermo-compression bonding
• CPC Class Codes: B23K 2101/38 Conductors
• CPC Class Codes: H01R 43/02 for soldered or welded connections

Abstract

A projection area (exposure area) on a wafer W, in which a mask pattern is transferred, is divided into, for example, four quadrants. A slit or X-shaped pattern is projected by a light-transmitting optical system so that a plurality of images are formed at a regular interval in the projection area on the wafer W. Luminous flux reflected from the images on the wafer W is received by a light-receiver and converted into photoelectric signals. A master controller calculates the focal values of the first through fourth quadrants along the optical axis based on the photoelectric signals. An optimum focal position and a leveling amount are determined based on the focal values of the first through fourth quadrants. Even if there are level differences in the wafer surface, the optimum focal position and the leveling amount can be accurately determined.

Claims

1. A surface position detecting method for detecting a surface position of a projection area on a substrate, a pattern being projected onto the projection area as a pattern image through a projection optical system, the method comprising:

(a) dividing the projection area into four quadrants;

(b) projecting a plurality of patterns to form at least one image in each quadrant of the projection area;

(c) receiving luminous flux reflected from the images;

(d) converting the luminous flux into photoelectric signals;

(e) calculating respective focal values of the four quadrants along a projection optical system optical axis based on the photoelectric signals; and

(f) calculating an optimum focal position along the optical axis and a leveling amount based on the focal values.

2. The surface position detecting method of claim 1, wherein step (f) is practiced by calculating an average value of the focal values of the four quadrants.

3. The surface position detecting method of claim 1, wherein step (f) is practiced by determining a maximum value of the focal values of the four quadrants.

4. The surface position detecting method of claim 1, wherein step (f) is practiced by determining a minimum value of the focal values of the four quadrants.

5. The surface position detecting method of claim 1, wherein step (f) is practiced by calculating an average of a maximum value and a minimum value of the focal values of the four quadrants.

6. The surface position detecting method of claim 1, wherein the leveling amount in step (f) is calculated by:

calculating respective center positions (C1, C2, C3, C4) of the four quadrants based on the image positions in the four quadrants;

calculating distances l1 (l1=|C1-C2|), l2 (l2=|C2-C3|), l3 (l3=|C3-C4|), and l4 (l4=|C4-C1|) between adjacent quadrants based on the center positions (C1, C2, C3, C4) of the four quadrants; and

calculating the leveling amount based on the distances between the adjacent quadrants and the focal values of the four quadrants, the leveling amount (P, R) being expressed as;

space="preserve" listing-type="equation">(P, R)=([{(Z1-Z4)/l4}+{(Z2-Z3)/l2}]/2, [{(Z1-Z2)/l1}+{(Z4-Z3)/l3}]/2).

7. The surface position detecting method of claim 1, wherein the leveling amount in step (f) is calculated by:

calculating respective center positions (C1, C2, C3, C4) of the four quadrants based on the image positions in the four quadrants;

calculating apitching distance lP (lP=|C1-C3|) and a rolling distance lR (lR=|C2-C4|) based on the center positions (C1, C2, C3, C4) of the four quadrants; and

calculating the leveling amount based on the pitching distance lP, the rolling distance lR, and the focal values of the four quadrants, the leveling amount (P, R) being expressed as;

space="preserve" listing-type="equation">(P, R)={(Z1-Z3)/lP, (Z2-Z4)/lR)}.

8. The surface position detecting method of claim 1, wherein the leveling amount in step (f) is calculated by:

detecting Z positions of the images formed on the substrate as position data in the optical-axis direction based on the photoelectric signals;

calculating an approximate plane by statistically processing the position data through least square approximation; and

calculating the leveling amount based on the inclination of the approximate plane.

9. The surface position detecting method of claim 1, wherein step (f) is practiced by:

detecting vertical positions of the images formed on the substrate as position data in the optical-axis direction based on the photoelectric signals; and

using a predetermined range of the position data to calculate the optimum focal position and the leveling amount.

10. The surface position detecting method of claim 1, wherein the optimum focal position is determined by:

receiving luminous flux of the images reflected by the substrate;

converting the luminous flux into photoelectric signals;

detecting the Z positions (ZS1, ZS2, ZS3, . . . , ZSm) of the images on the substrate as position data in the optical axis direction based on the photoelectric signals;

calculating an approximate plane by statistically processing the position data through least square approximation;

calculating a level difference between the approximate plane and the Z position of each of the images to obtain the frequency distribution of the level differences; and

determining the most frequent level position as the optimum focal position.

11. The surface position detecting method of claim 1, wherein step (b) is practiced by projecting the patterns from an oblique direction at a predetermined inclination angle with respect to the optical axis of the projection optical system.

12. The surface position detecting method of claim 1, wherein step (b) is practiced by projecting slit shaped patterns to form at least one slit shaped image in each quadrant of the projection area.

13. The surface position detecting method of claim 1, wherein step (b) is practiced by projecting X-shaped patterns to form at least one X-shaped image in each quadrant of the projection area.

14. A surface position adjusting apparatus for aligning a surface of a substrate with an image plane of a projection optical system, the projection optical system projecting a pattern of a mask onto the surface of the substrate as a pattern image, the surface position adjusting apparatus comprising;

a light-transmitting optical system that projects a plurality of images along at optical path on the substrate;

a light-receiving optical system disposed in said optical path that receives luminous flux reflected from the images on the substrate and converts the luminous flux into photoelectric signals;

a table on which the substrate is mounted;

a driving system coupled with the table that drives the table along the optical axis;

an operation unit communicating with said light-receiving optical system, said operation unit calculating an optimum focal position based on the photoelectric signals; and

a controller communicating with said operation unit and said driving system, said controller controlling said driving system based on said optimum focal position,

wherein said light-receiving optical system comprises a plurality of photosensors corresponding to the number of images, wherein each sensor corresponds to one of the images, said photosensors generating said photoelectric signals, and comprises a senser selector communicating with said photosensors and said operation unit, said sensor selector selecting the photosensors and outputting each of photoelectric signals generated by the selected photosensors to the operation unit.

15. The surface position adjusting apparatus of claim 14, wherein said pattern is a slit shaped pattern forming a slit shaped pattern image on the projection area.

16. The surface position adjusting apparatus of claim 14, wherein said pattern is an X-shaped pattern forming an X-shaped pattern image on the projection area.

17. The surface position adjusting apparatus of claim 14, wherein said operation unit is operable in accordance with a first function to detect Z positions of the images formed on the substrate as position data in the optical axis direction based on the photoelectric signals, a second function to calculate an approximate plane by statistically processing the position data through least square approximation, a third function to calculate a level difference between the approximate plane and the Z position of each image, and a fourth function to obtain a frequency distribution of the level differences and determine a most frequent level position as the optimum focal position.

18. The surface position adjusting apparatus of claim 17, wherein said operation unit is operable to set a threshold value in the frequency distribution, and is operable in accordance with a dust detecting function to identify a level difference exceeding the threshold value as dust.

19. The surface position adjusting apparatus of claim 14, wherein said light transmitting optical system is disposed offset from the substrate, and wherein said images are projected from an oblique direction at a predetermined inclination angle with respect to the optical axis of the projection optical system.

20. The surface position adjusting apparatus of claim 19, wherein said light-transmitting optical system comprises a mirror disposed in said optical path, said mirror directing said images to the projection area on the substrate.

21. The surface position adjusting apparatus of claim 14, wherein said light-transmitting optical system comprises:

a fiber flux guiding light along said optical path; and

a pattern plate disposed in said optical path, said pattern plate having a pattern thereon forming said images.

22. The surface position adjusting apparatus of claim 21, wherein said light-transmitting optical system further comprises a collective lens disposed between said fiber flux and said pattern plate in said optical path and a collimating lens and an illuminating objective lens disposed between said pattern plate and said substrate in said optical path.

23. The surface position adjusting apparatus of claim 22, wherein said light-transmitting optical system further comprises a mirror disposed in said optical path between said pattern plate and said substrate, said mirror directing said images to the projection area on said substrate.

24. The surface position adjusting apparatus of claim 14, wherein said light-receiving optical system comprises a plurality of photosensors corresponding to the number of images, wherein each sensor corresponds to one of the images, said photosensors being disposed in said optical path and communicating with said operation unit.

25. The surface position adjusting apparatus of claim 24, wherein said light-receiving optical system further comprises a sensor selection circuit coupled with said plurality of photosensors, said sensor selection circuit activating ones of said photosensors in accordance with instructions from said controller.

26. The surface position adjusting apparatus of claim 25, wherein said light-receiving optical system further comprises a signal processor coupled via said sensor selection circuit with said plurality of photosensors, said signal processor supplying photoelectric signals from said photosensors to said controller.

27. The surface position adjusting apparatus of claim 24, wherein said light-receiving optical system is disposed offset from the substrate, said light-receiving optical system further comprising a mirror disposed in said optical path downstream from the substrate, said mirror directing said images to said photosensors.

28. The surface position adjusting apparatus of claim 27, wherein said mirror comprises a rotational diaphragm coupled with a vibrator unit communicating with said controller.

29. The surface position adjusting apparatus of claim 27, wherein said light-receiving optical system further comprises a collecting objective lens disposed in said optical path between said substrate and said mirror, and an imagery lens disposed in said optical path between said mirror and said photosensors.

30. The surface position adjusting apparatus of claim 14, wherein a projection area on the substrate is divided into four quadrants, said light-transmitting optical system comprising optical structure that projects at least one of said images in each of said quadrants, wherein said operation unit comprises:

a first operation processor communicating with said light-transmitting optical system that calculates Z positions of the images on the substrate as position data in the optical-axis direction based on the photoelectric signals;

a second operation processor communicating with said first operation processor that calculates focal values of the quadrants along the optical axis based on the Z positions of the images;

a third operation processor communicating with said second operation processor that calculates said optimum focal position along the optical axis based on the focal values; and

a fourth operation processor communicating with said second operation processor that calculates a leveling amount based on the focal values.

31. The surface position adjusting apparatus of claim 30, wherein said third and fourth operation processors are operable to determine said optimum focal position and said leveling amount using only a prescribed range of the position data.

32. The surface position adjusting apparatus of claim 30, wherein said third operation processor is operable to calculate an average of the focal values as said optimum focal position.

33. The surface position adjusting apparatus of claim 30, wherein said third operation processor is operable to determine a maximum value of the focal values as said optimum focal position.

34. The surface position adjusting apparatus of claim 30, wherein said third operation processor is operable to determine a minimum value of the focal values as said optimum focal position.

35. The surface position adjusting apparatus of claim 30, wherein said third operation processor is operable to calculate the average of a maximum value and a minimum value of the focal values as the optimum focal position.

36. The surface position adjusting apparatus of claim 30, wherein said third operation processor is operable in a first mode for calculating an average of the focal values as the optimum focal position, a second mode for calculating a maximum value of the focal values as the optimum focal position, a third mode for calculating a minimum value of the focal values as the optimum focal position, and a fourth mode for calculating an average of the maximum value and the minimum value as the optimum focal position, the apparatus further comprising a selector coupled with said third operation processor, said selector enabling selective setting of one of said first through fourth modes.

37. The surface position adjusting apparatus of claim 30, wherein said fourth operation processor is operable in accordance with a first function to calculate center positions (C1, C2, C3, C4) of the quadrants based on the positions of the images formed in the quadrants, a second function to calculate distances l1 (l1=|C1-C2|), l2 (l2=|C2-C3|), l3 (l3=|C3-C4|), and l4 (l4=|C4-C1|) between adjacent quadrants based on the center positions (C1, C2, C3, C4), and a third function to calculate said leveling amount based on the distances between adjacent quadrants and the focal values, said leveling amount (P, R) being expressed as:

space="preserve" listing-type="equation">(P, R)=([{(Z1-Z4)/l4}+{(Z2-Z3)/l2}]/2, [{(Z1-Z2)/l1}+{(Z4-Z3)/l3 }]/2).

38.

38. The surface position adjusting apparatus of claim 30, wherein said fourth operation processor is operable in accordance with a first function to calculate center positions (C1, C2, C3, C4) of the quadrants based on the positions of the images formed in the quadrants, a second function to determine a pitching distance lP (lP=|C1-C3|) and a rolling distance lR (lR=|C2-C4|) based on the center positions (C1, C2, C3, C4), and a third function to calculate said leveling amount (P, R)={(Z1-Z3)/lP, (Z2-Z4)/lR)} based on the pitching distance lP, the rolling distance lR, and the focal values.

39. The surface position adjusting apparatus of claim 30, wherein the sensor selector is operable to connect the photosensors corresponding to the quadrants to a calculating unit in the operation unit.

40. A projection exposure apparatus for transferring a pattern formed on a mask through a projection optical system onto a substrate as a pattern image, the projection exposure apparatus comprising:

a light-tramsmitting optical system that projects a plurality of slit images along an optical path within a projection area on the substrate;

a light-receiving optical system disposed in said optical path that receives luminous flux reflected from the slit images on the substrate and converts the luminous flux into photoelectric signals;

a substrate table on which the substrate is mounted;

a driving system coupled with the substrate table that drives the substrate table along the optical axis;

an operation unit communicating with said light-receiving optical system, said operation unit calculating an optimum focal position along the optical axis based on the photoelectric signals; and

a controller communicating with said operation unit and said driving system, said controller controlling said driving system based on said optimum focal position,

wherein said light-receiving optical system comprises a plurality of photosensors corresponding to the number of slit images, wherein each sensor corresponds to one of the slit images, said photosensors generating said photoelectric signals, and comprises a sensor selector communicating with said photosensors and said operation unit, said sensor selector selecting the photosensors and outputting each of photoelectric signals generated by the selected photosensors to the operation unit.

41. The projection exposure apparatus of claim 40, wherein said light-receiving optical system comprises a plurality of photosensors corresponding to the number of slit images wherein each sensor corresponds to one of the slit images, said photosensors generating said photoelectric signals, and wherein the surface position adjusting apparatus further comprises at least four output circuits connected to said operation unit and outputting said photoelectric signals generated by said photosensors, and a sensor selection and connection circuit communicating with said photosensors and said output circuits, said sensor selection and connection circuit selecting the photosensors and connecting each of the selected photosensors to a respective one of the output circuits.

42. The projection exposure apparatus of claim 40, wherein said sensor selector selects slit images that are to be detected as target slit images according to a size of the pattern area on the mask or a chip size on the substrate.

43. The projection exposure apparatus of claim 40, further comprising blinds that define an exposure area on the substrate, wherein said sensor selector selects the slit images positioned within the exposure area as detection targets.

44. A projection exposure apparatus for transferring a pattern formed on a mask through a projection optical system onto a substrate by means of exposure light from a light source, the projection exposure apparatus comprising:

a detecting system that has a plurality of detection points on the substrate to detect positional information of the substrate in a direction of the optical axis of the projection optical system;

a changeable member, disposed between the light source and the mask, that changes an area illummated by the exposure light on the substrate;

a selector, connected to the detecting system and the changeable member, that selects at least one of detection points among the plurality of detection points according to information regarding the changeable member; and

a surface position adjusting member, connected to the selector, that adjusts a surface position of the substrate according to said positional information of the detection points selected by the selector.

45. A projection exposure apparatus according to claim 44, wherein said selector calculates actual exposure area defined by the changeable member as said information regarding the changeable member, and selects the detection points according to the actual exposure area.

46. A projection exposure apparatus according to claim 44, wherein:

said detecting system comprises a light-transmitting optical system that projects a plurality of images at the detection points on the substrate, and a light-receiving optical system that receives the luminous flux reflected from the images on the substrate and converts the luminous flux into photoelectric signals; and

said selector selects photoelectric signals corresponding to the images located within an area illuminated by the exposure light on the substrate.

47. A projection exposure apparatus according to claim 44, wherein:

said substrate is movable in an X direction and a Y direction perpendicular to the X direction with a reference plane perpendicular to the optical axis of the projection optical system; and

said detection system transmits a plurality of slit images at the detection points on the substrate, wherein the slit images incline with respect to the X direction and Y direction.

48. A projection exposure apparatus according to claim 44, wherein:

said selector divides the area illuminated by the exposure light on the substrate into a plurality of divided areas, and calculates surface position of each divided area according to said positional information of the detection points selected by the selector; and

said surface position adjusting member adjusts a surface position of the substrate according to said surface position of each divided area.

49. A projection exposure apparatus according to claim 44, wherein said selector obtains level difference information of the substrate based on the positional information of the detection points selected by the selector.

50. A projection exposure apparatus according to claim 44, wherein the changeable member is arranged in a plane conjugate with a pattern of the mask.

51. A projection exposure apparatus according to claim 50, wherein said changeable member comprises a movable member, disposed in the optical path of the exposure light, that changes position in the optical path, and a driving member driving the movable member.

52. A projection exposure apparatus according to claim 51, wherein said driving member moves the movable member between a first position and a second position to change the area illuminated by the exposure light on the substrate.

53. A projection exposure apparatus according to claim 51, wherein said movable member comprises a blind member masking at least a part of the exposure light.

54. A projection exposure apparatus according to claim 44, further comprising an optical member disposed between the light source and the mask, wherein the area illuminated by the exposure light is defined by the changeable member and the optical member.

55. A projection exposure apparatus according to claim 54, wherein the optical member is apart from the changeable member in a direction along an optical path of the exposure light.

56. A projection exposure apparatus according to claim 54, wherein the changeable member is arranged in a plane conjugate with a pattern of the mask.

57. A projection exposure apparatus according to claim 54, wherein the optical member is fixed, and wherein the changeable member includes a movable member that moves relative to the optical member.

58. A projection exposure apparatus according to claim 57, wherein the moveable member is disposed in a plane conjugate with a patten of the mask, and wherein the optical member is apart from the movable member in a direction along an optical path of the exposure light.

59. A projection exposure apparatus according to claim 44, wherein said selector selects at least one of detection points located within an area illuminated by the exposure light on the substrate.

60. A projection exposure apparatus according to claim 59, wherein:

said selector comprises a main control system; and

said main control system controls the changeable member and the selection of the detection points.

61. A projection exposure apparatus according to claim 60, wherein:

said changeable member comprises a blind member masking the exposure light; and

said main control system controls the changeable member according to masking information of the blind member.

62. A projection exposure apparatus according to claim 60, wherein said main control system calculates an optimum focal position of the substrate according to the positonal information of the detection points selected by the selector.

63. A projection exposure apparatus according to claim 62, wherein said surface position adjusting member adjusts focal position of the substrate according to the optimum focal position.

64. A projection exposure apparatus according to claim 60, wherein said main control system calculates a leveling amount of the substrate surface according to the positional information of the detection points selected by the selector.

65. A projection exposure apparatus according to claim 64, wherein said surface position adjusting member adjusts an inclination of the substrate surface according to the leveling amount.

66. A projection exposure apparatus according to claim 64, wherein said leveling amount comprises a pitching amount and a rolling amount of the substrate surface.

67. A projection exposure method for transferring a pattern formed on a mask through a projection optical system onto a substrate by means of an exposure light, the projection exposure method comprising:

selecting at least one of detection points among a plurality of detection points according to information regarding a changeable member that changes an area illuminated by the exposure light on the substrate, wherein the plurality of detection points effects detection of positional information of the substrate in a direction of the optical axis of the projection optical system; and

adjusting a surface position of the substrate according to said positional information of the detection points selected in said selecting step.

68. A projection exposure method according to claim 67, wherein said detecting step comprises:

projecting a plurality of images at the detection points on the substrate;

receiving the luminous flux reflected from the images on the substrate and converting the luminous flux into photoelectric signals; and

selecting photoelectric signals corresponding to the images located within an area illuminated by the exposure light on the substrate.

69. A projection exposure method according to claim 67, further comprising dividing the area illuminated by the exposure light on the substrate into four quadrants, and calculating surface position of each quadrant according to said positional information of the detection points selected in the selecting step.

70. A projection exposure method according to claim 67, wherein said selecting step comprises calculating and exposure area defined by the changeable member as said information regarding the changeable member, and selecting the detection points according to the actual exposure area.

71. A projection exposure method according to claim 67, wherein said substrate is movable in the X direction and Y direction perpendicular to the X direction within a reference plane perpendicular to the optical axis of the projection optical system, wherein said detecting step comprises transmitting a plurality of slit images at the detection points on the substrate, and wherein the slit image inclines with respect to the X direction and Y direction.

72. A projection exposure method according to claim 67, wherein said selecting step comprises dividing the area illuminated by the exposure light on the substrate into a plurality of divided areas, and calculating surface position of each divided area according to said positonal information of the selected detection points, and wherein said adjusting step adjusts a surface position of the substrate according to said surface position of each divided area.

73. A projection exposure method according to claim 67, further comprising obtaining level difference information of the substrate based on the positional information of the selected detection points.

74. A projection exposure method according to claim 67, wherein said detection points are formed at a regular interval over the entire area illuminated by the exposure light on the substrate.

75. A projection exposure method according to claim 67, wherein said information regarding the changeable member comprises information regarding a pattern size of the mask.

76. A projection exposure method according to claim 67, wherein said information regarding the changeable member comprises information regarding a chip size of the substrate.

79. A projection exposure method according to claim 67, further comprising calculating an optimum focal position of the substitute according to the positional information of the detection points selected in the selecting step.

80. A projection exposure method according to claim 79, wherein said adjusting step comprises adjusting focal position of the substrate according to the optimum focal position.

81. A projection exposure method according to claim 67, further comprising calculating a leveling amount of the substrate surface according to the positional information of the detection points selected in the selecting step.

82. A projection exposure method according to claim 81, wherein said adjusting step comprises adjusting an inclination of the substrate surface according to the leveling amount.

83. A projection exposure method according to claim 82, wherein said leveling amount comprises a pitching amount and a rolling amount of the substrate surface.

84. A projection exposure method according to claim 67, wherein the chargeable member is arranged in a plane conjugate with a pattern of the mask.

85. A projection exposure method according to claim 84, wherein said changeable member comprises a movable member, disposed in the optical path of the exposure light that changes position in the path, and wherein said selecting step comprises driving the movable member.

86. A projection exposure apparatus according to claim 84, wherein the movable member is movable between a first position and a second position to change the area illuminated by the exposure light on the substrate.

87. A projection exposure method according to claim 85, wherein said movable member comprises a blind member masking at least a part of the exposure light.

88. A projection exposure method according to claim 67, wherein the area illuminated by the exposure light is defined by the changeable member and the optical member which is disposed between the light source and the mask.

89. A projection exposure method according to claim 88, wherein the optical member is apart from the changeable member in a direction along an optical path of the exposure light.

90. A projection exposure method according to claim 88, wherein the changeable member is arranged in a plane conjugate with a pattern of the mask.

77. A projection exposure method according to clam 67, wherein said selecting step comprises selecting at least one of detection points located within an area illuminated by the exposure light on the substrate.

78. A projection exposure method according to claim 77, wherein said changeable member comprises a blind member masking the exposure light, and wherein said selecting step comprises controlling the changeable member according to masking information of the blind member.

91. A projection exposure method according to clam 88, wherein the optical member is fixed, and wherein the changeable member includes a movable member which moves relative to the optical member.

92. A projection exposure method according to claim 91, wherein the movable member is disposed in a plane conjugate with a pattern of the mask, and wherein the optical member is apart from the movable member in a direction along an optical path of the exposure light.

93. A projection exposure method according to claim 92, wherein the optical member is a field stop with a rectangular aperture, and wherein the movable member defines the vertical length of the rectangular aperture.

94. A projection exposure method according to claim 92, wherein said selecting step comprises selecting at least one of detection points located within an area illuminated by the exposure light on the substrate.

95. A projection exposure method according to claim 94, wherein said changeable member comprises a blind member masking the exposure light, and wherein said selecting step comprises controlling the changeable member according to masking information of the blind member.

96. A projection exposure method according to claim 95, further comprising calculating an optimum focal position of the substrate according to the positional information of the detection points selected in the selecting step.

97. A projection exposure method according to claim 95, further comprising calculating a leveling amount of the substrate surface according to the positional information of the detection points selected in the selecting step.

98. A method for making a projection exposure apparatus for transferring a pattern formed on a mask through a projection optical system onto a substrate by means of an exposure light from a light source, the method comprising:

providing a detecting system that has a plurality of detection points on the substrate to detect positional information of the substrate in a direction of the optical axis of the projection optical system;

providing a changeable member, disposed between the light source and the mask, that changes an area illuminated by the exposure light on the substrate;

providing a selector, connected to the detecting system and the movable member, that selects at least one of detection points among the plurality of detection points according to information regarding the movable member; and

providing a surface position adjusting member, connected to the selector, that adjusts a surface position of the substrate according to said positional information of the detection points selected by the selector.

99. A method for making a projection exposure apparatus according to claim 98, wherein said selector calculates an actual exposure area defined by the changeable member as said information regarding the changeable member, and selects the detection points according to the actual exposure area.

100. A method for making a projection exposure apparatus according to claim 98, wherein:

said detecting system comprises a light-transmitting optical system that projects a plurality of images at the detection points on the substrate, and a light-receiving optical system that receives the limits flux reflected from the images on the substrate and converts the luminous flex into photoelectric signals; and

said selector selects photoelectric signals corresponding to the images located within a area illuminated by the exposure light on the substrate.

101. A method for making a projection exposure apparatus according to claim 98, wherein:

said substrate is movable in an X direction and a Y direction perpendicular to the X direction within a reference plane perpendicular to the optical axis of the projection optical system; and

said detection system transmits a plurality of slit images at the detection points on the substrate, wherein the slit images incline with respect to the X direction and Y direction.

102. A method for making a projection exposure apparatus according to claim 98, wherein:

said selector divides the area illuminated by the exposure light on the substrate into four quadrants and calculates surface position of each quadrant according to said positional information of the detection points selected by the selector; and

said surface position adjusting member adjusts a surface position of the substrate according to said surface position of each quadrant.

103. A method for making a projection exposure apparatus according to claim 98, wherein said selector obtains level difference information of the substrate based on the positional information of the detection points selected by the selector.

104. A method for making a projection exposure apparatus according to claim 98, wherein the changeable member is arranged in a plane conjugate with a pattern of the mask.

105. A method for making a projection exposure apparatus according to claim 104, wherein said changeable member comprises a movable member, disposed in the optical path of the exposure light, that changes position in the optical path, and a driving member driving the movable member.

106. A method for making a projection exposure apparatus according to claim 105, wherein said driving member moves the movable member between a first position and a second position to change the area illuminated by the exposure light on the substrate.

107. A method for making a projection exposure apparatus according to claim 105, wherein said movable member comprises a blind member masking at least a part of the exposure light.

108. A method for making a projection exposure apparatus according to claim 98, further comprising an optical member disposed between the light source and the mask, wherein the area illuminated by the exposure light is defined by the changeable member and the optical member.

109. A method for making a projection exposure apparatus according to claim 108, wherein the changeable member is arranged in a plane conjugate with a pattern of the mask.

110. A method for making a projection exposure apparatus according to claim 108, wherein the optical member is apart from the changeable member in a direction along an optical path of the exposure light.

113. A method for making a projection exposure apparatus according to claim 98, wherein said selector selects at least one of detection points located within an area illuminated by the exposure light on the substrate.

114. A method for making a projection exposure apparatus according to claim 113, wherein:

said selector comprises a main control system; and

said main control system controls the changeable member and the selection of the detection points.

115. A method for making a projection exposure apparatus according to claim 114, wherein:

said changeable member comprises a blind member masking the exposure light; and

said main control system controls the changeable member according to masking information of the blind member.

116. A method for making a projection exposure apparatus according to claim 114, wherein said main control system calculates an optimum focal position of the substrate according to the position information of the detection points selected by the selector.

117. A method for making a projection exposure apparatus according to claim 116, wherein said surface position adjusting member adjusts a focal position of the substrate according to the optimum focal position.

118. A method for making a projection exposure apparatus according to claim 114, wherein said main control system calculates a leveling amount of the substrate surface according to the positional information of the detection points selected by the selector.

119. A method for making a projection exposure apparatus according to claim 118, wherein said surface position adjusting member adjusts an inclination of the substrate surface according to the leveling amount.

120. A method for making a projection exposure apparatus according to claim 118, wherein said a leveling amount comprises a pitching amount and a rolling amount of the substrate surface.

111. A method for making a projection exposure apparatus according to clam 108, wherein the optical member is fixed, and wherein the changeable member includes a movable member that moves relative to the optical member.

112. A method for making a projection exposure apparatus according to claim 111, wherein the movable member is disposed in a plane conjugate with a pattern of the mask, and wherein the optical member is apart from the movable member in a direction along an optical path of the exposure light.

121. A projection exposure method for transferring a pattern formed on a mask through a projection optical system onto a shot area on a substrate, the projection exposure method comprising:

transmitting at least one of luminous flux on a plurality of chip areas respectively within the shot area; and

detecting positional information of each of the chip areas in the direction of an optical axis of the projection optical system by detecting the luminous flux from the substrate.