Exposure method, exposure apparatus, and method for producing device

• US 20080297751A1
• Filed: 05/27/2008
• Published: 12/04/2008
• Est. Priority Date: 05/29/2007
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Shibazaki, Yuichi
• Granted Patent: US 8,164,736 B2
• Time in Patent Office: Days
• US Class Current: 355/53
• CPC Class Codes: G03F 7/70258 Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
• 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 7/70425 Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning
• CPC Class Codes: G03F 7/70633 Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
• CPC Class Codes: G03F 7/70733 Handling masks and workpieces, e.g. exchange of workpiece or mask, transport of workpiece or mask
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position
• CPC Class Codes: G03F 7/70783 Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight
• 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 7/70875 Temperature, e.g. temperature control of masks or workpieces via control of stage temperature
• CPC Class Codes: G03F 9/7084 Position of mark on substrate, i.e. position in (x, y, z) of mark, e.g. buried or resist covered mark, mark on rearside, at the substrate edge, in the circuit area, latent image mark, marks in plural levels

Abstract

An exposure method includes measuring coordinates of alignment marks before and after exposing a first wafer to determine a fluctuation amount of a parameter of the alignment; measuring coordinates of alignment marks before exposing a second wafer to determine a parameter of the alignment; and aligning and exposing the second wafer based on a parameter obtained by correcting the parameter with the fluctuation amount determined for the first wafer. A high overlay accuracy can be obtained even when the alignment information is gradually changed, for example, due to the linear expansion and contraction of the substrate during the exposure of the substrate.

Claims

1. An exposure method for exposing a substrate via a pattern with an exposure light by illuminating the pattern with the exposure light, the exposure method comprising:

performing measurement of alignment information of a first substrate before and after exposure of the first substrate; and

correcting alignment information of a second substrate before exposure of the second substrate, based on a result of the measurement.

2. The exposure method according to claim 1, wherein the measurement includes detecting a mark on the first substrate.

3. The exposure method according to claim 2, wherein the mark includes a mark which is formed on the first substrate before the exposure.

4. The exposure method according to claim 1, wherein the alignment information measured each before and after the exposure of the first substrate includes position information about a plurality of marks on the first substrate, and the plurality of the marks detected after the exposure of the first substrate include at least one of the plurality of the marks detected before the exposure of the first substrate.

5. The exposure method according to claim 1, wherein the first substrate is held by a movable member during the exposure, the first substrate is moved based on the alignment information before the exposure, and the alignment information measured after the exposure is measured before the first substrate is released from the movable member.

6. The exposure method according to claim 1, wherein at least a part of a measuring operation for measuring the alignment information of the first substrate and a part of a measuring operation for measuring the alignment information of the second substrate are performed concurrently with an exposure operation.

7. The exposure method according to claim 1, wherein a part of areas of the first substrate is exposed, and then an area, which is different from the part of the areas, is exposed while measuring alignment information of at least one area among the part of areas which have been exposed.

8. The exposure method according to claim 1, wherein all areas of the first substrate are exposed, and then the measurement of the alignment information after the exposure is started.

9. The exposure method according to claim 1, wherein the alignment information includes arrangement information of a plurality of areas on the substrate, the arrangement information being obtained based on position information about a plurality of marks on the substrate.

10. The exposure method according to claim 9, wherein the position information is obtained by detecting the marks simultaneously at a plurality of positions on the substrate.

11. The exposure method according to claim 1, wherein the substrate is exposed via the pattern and a projection optical system;

and

the alignment information includes focus position information of the projection optical system.

12. The exposure method according to claim 1, wherein the substrate is exposed with the exposure light via the pattern and a liquid in a liquid immersion area.

69. 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.

13. An exposure method for exposing a substrate via a pattern with an exposure light by illuminating the pattern with the exposure light, the exposure method comprising:

a first step of performing measurement of alignment information of a first substrate before exposure of the first substrate;

a second step of exposing the first substrate via the pattern while performing alignment for the first substrate based on a result of the measurement in the first step;

a third step of performing measurement of alignment information of the first substrate after the exposure of the first substrate; and

a fourth step of determining a fluctuation amount of the alignment information measured in the third step with respect to the alignment information measured in the first step.

14. The exposure method according to claim 13, further comprising:

a fifth step of determining a correction amount, with respect to the alignment information before the exposure, based on the fluctuation amount determined in the fourth step;

a sixth step of performing measurement of alignment information of a second substrate before the exposure of the second substrate; and

a seventh step of exposing the second substrate via the pattern while performing alignment for the second substrate based on alignment information obtained by correcting a result of the measurement performed in the sixth step using the correction amount determined in the fifth step.

15. The exposure method according to claim 14, wherein the fifth step includes a step of adjusting the correction amount for the alignment information before the exposure depending on positions of a plurality of areas, on the second substrate, each of which is to be exposed with the pattern.

16. The exposure method according to claim 13, wherein the alignment information includes arrangement information of a plurality of areas disposed on the substrate, the arrangement information being obtained based on a result of measurement of position information about a plurality of marks on the substrate.

17. The exposure method according to claim 16, wherein the arrangement information is obtained by detecting the marks simultaneously at a plurality of positions on the substrate.

18. The exposure method according to claim 13, wherein in the first step, the alignment information is measured while moving the first substrate in a predetermined direction;

and in the third step, the alignment information is measured while moving the first substrate in a direction opposite to the predetermined direction.

19. The exposure method according to claim 13, wherein in the first step, the first substrate is moved in a predetermined direction while detecting marks simultaneously at a plurality of positions which are different with respect to a direction intersecting the predetermined direction.

20. The exposure method according to claim 16, wherein the alignment information includes information about a positional relationship between an image of the pattern to be formed via a projection optical system and an alignment system which measures the position information of the mark on the substrate and information about a fluctuation amount of a measured value obtained by the alignment system.

21. The exposure method according to claim 13, wherein the substrate is exposed via the pattern and a projection optical system;

and

the alignment information includes focus position information of the projection optical system.

22. The exposure method according to claim 13, wherein in the third step, before the exposure is completed for the first substrate, the measurement of the alignment information is started.

23. The exposure method according to claim 13, wherein in the third step, after the exposure is completed for the first substrate, the measurement of the alignment information is started.

70. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 13;

developing the exposed substrate; and

processing the developed substrate.

24. An exposure method for exposing a substrate with an exposure light, the exposure method comprising:

performing exposure of a first substrate with the exposure light, and then performing detection of a mark disposed on the first substrate after the exposure; and

performing exposure of a second substrate by using a result of the detection of the mark.

25. The exposure method according to claim 24, wherein the mark includes a mark which is formed on the first substrate before the exposure.

26. The exposure method according to claim 24, wherein the mark, which is detected after the exposure, includes at least one of a plurality of marks detected before the exposure to obtain position information used for the exposure of the first substrate.

27. The exposure method according to claim 24, wherein the first substrate is held by a movable member during the exposure;

and the mark is detected before the first substrate is released from the movable member.

28. The exposure method according to claim 24, wherein a plurality of marks are detected for each of the first and second substrates before the exposure;

and

a result of the detection is used during the exposure for each of the first and second substrates.

29. The exposure method according to claim 24, wherein at least a part of an operation for detecting the mark of the first substrate or the second substrate is performed concurrently with an exposure operation.

30. The exposure method according to claim 29, wherein a part of an operation for detecting the mark before the exposure is performed concurrently with the exposure operation.

31. The exposure method according to claim 29, wherein an operation for detecting the mark is started for the first substrate before the exposure operation for the first substrate is completed.

32. The exposure method according to claim 24, wherein the substrate is exposed with the exposure light via a pattern and a liquid in a liquid immersion area.

71. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 24;

developing the exposed substrate; and

processing the developed substrate.

33. An exposure method for exposing a substrate with an exposure light, the exposure method comprising:

performing detection of a mark of a first substrate both before and after exposure of the first substrate with the exposure light; and

determining alignment information of a second substrate by using a result of the detection after the exposure.

34. The exposure method according to claim 33, wherein a result of the detection before the exposure is also used to determine the alignment information.

35. The exposure method according to claim 33, wherein the alignment information is determined based on a scaling information of a scaling of the first substrate obtained from the result of the detection.

36. The exposure method according to claim 35, wherein the scaling information includes a fluctuation information of the scaling, of the first substrate, due to the exposure.

37. The exposure method according to claim 33, wherein the result of the detection is used to correct arrangement information of a plurality of areas disposed on the second substrate, the arrangement information being obtained from position information about a plurality of marks of the second substrate.

38. The exposure method according to claim 33, wherein a plurality of marks are detected before the exposure;

and

the mark, which is detected after the exposure, includes at least one of the plurality of the marks detected before the exposure.

39. The exposure method according to claim 33, wherein the first substrate is held by a movable member during the exposure;

and

the detection of the mark after the exposure is performed before the first substrate is released from the movable member.

40. The exposure method according to claim 33, wherein a plurality of marks are detected for each of the first and second substrates before the exposure of each of the first and second substrates, and a result of the detection of the marks before the exposure is used during the exposure of each of the first and second substrates.

41. The exposure method according to claim 33, wherein at least a part of a detection operation for detecting the mark of the first substrate or the second substrate is performed concurrently with an exposure operation.

42. The exposure method according to claim 41, wherein a part of an operation for detecting the mark before the exposure is performed concurrently with the exposure operation.

43. The exposure method according to claim 41, wherein the detection operation for detecting the mark of the first substrate is started before the exposure operation for the first substrate is completed.

44. The exposure method according to claim 33, wherein the substrate is exposed with the exposure light via a pattern and a liquid in a liquid immersion area.

72. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 33;

developing the exposed substrate; and

processing the developed substrate.

45. An exposure apparatus which exposes a substrate via a pattern with an exposure light by illuminating the pattern with the exposure light, the exposure apparatus comprising:

a measuring device which measures alignment information of the substrate;

a controller which controls exposure of the substrate while performing alignment for the substrate based on a result of the measurement performed by the measuring device; and

a calculating device which determines a fluctuation amount of alignment information measured after exposure of a predetermined substrate by the measuring device with respect to alignment information measured before the exposure of the predetermined substrate by the measuring device.

46. The exposure apparatus according to claim 45, wherein the calculating device determines, based on the fluctuation amount, a correction amount with respect to the alignment information measure by the measuring device;

and

when the correction amount is determined, the controller exposes the substrate via the pattern while performing alignment for the substrate based on alignment information obtained by correcting the result of the measurement performed by the measuring device by using the correction amount.

47. The exposure apparatus according to claim 46, wherein the calculating device adjusts the correction amount of the alignment information based on the fluctuation amount, depending on positions of a plurality of areas on the substrate each of which is to be exposed with the pattern.

48. The exposure apparatus according to claim 45, wherein the measuring device includes an alignment system which detects a mark formed on the substrate.

49. The exposure apparatus according to claim 48, wherein the alignment system measures the mark simultaneously at a plurality of positions on the substrate.

50. The exposure apparatus according to claim 48, wherein the alignment information includes information about a positional relationship between the alignment system and an image of the pattern to be formed via a projection optical system and information about the fluctuation amount of a measured value obtained by the alignment system.

51. The exposure apparatus according to claim 45, wherein the substrate is exposed via the pattern and a projection optical system;

and

the measuring device includes a device which measures focus information of the projection optical system.

52. The exposure apparatus according to claim 45, further comprising a movable member which holds the substrate,

wherein before the movable member release holding of the substrate, the measuring device executes the measurement after the exposure of the substrate.

53. The exposure apparatus according to claim 52, wherein the measurement after the exposure of the substrate is executed on a movement route, of the movable member, at a portion of the movement route located between an exposure position at which the exposure light is irradiated and an unloading position at which the substrate is unloaded from the movable member.

54. The exposure apparatus according to claim 53, wherein the measurement before the exposure of the substrate is executed on the movement route, of the movable member, at a portion of the movement route located between the exposure position and a loading position at which the substrate is loaded into the movable member.

55. The exposure apparatus according to claim 45, wherein the measurement before the exposure of the substrate is executed while the substrate is moved with respect to the measuring device in a predetermined direction;

and

the measurement after the exposure of the substrate is executed while the substrate is moved with respect to the measuring device in a direction opposite to the predetermined direction.

56. The exposure apparatus according to claim 53, wherein the measuring device includes a plurality of detecting areas which are arranged at positions different with respect to a direction intersecting the predetermined direction, and is capable of simultaneously detecting different marks on the substrate.

57. The exposure apparatus according to claim 45, wherein a liquid immersion area is formed with a liquid on the substrate during the exposure of the substrate, and the substrate is exposed with the exposure light through the liquid in the liquid immersion area.

58. An exposure apparatus which exposes a substrate with an exposure light, the exposure apparatus comprising:

a mark-detecting system which performs detection of a mark of the substrate; and

a controller which controls exposure of another substrate, that is to be exposed next to the substrate, by using a result of the detection of the mark of the substrate obtained by the mark-detecting system after exposure of the substrate.

59. The exposure apparatus according to claim 58, further comprising a movable member which holds the substrate, wherein the mark-detecting system executes the detection of the mark after the exposure of the substrate before the movable member releases holding of the substrate.

60. The exposure apparatus according to claim 59, wherein the detection of the mark of the substrate after the exposure is executed on a movement route, of the movable member, at a portion of the movement route located between an exposure position at which the exposure light is irradiated and an unloading position at which the substrate is unloaded from the movable member.

61. The exposure apparatus according to claim 59, wherein the detection of the mark of the substrate is detected before the exposure of the substrate, and a result the detection of the mark before the exposure of the substrate is also used to control the exposure of the another substrate that is to be exposed next to the substrate.

62. The exposure apparatus according to claim 58, wherein the detection of the mark of the substrate is executed before the exposure of the substrate, and is executed while the substrate is moved with respect to the mark-detecting system in a predetermined direction;

and

the detection of the mark of the substrate after the exposure is executed while the substrate is moved with respect to the mark-detecting system in a direction opposite to the predetermined direction.

63. The exposure apparatus according to claim 58, wherein a liquid immersion area is formed with a liquid on the substrate during the exposure of the substrate, and the substrate is exposed with the exposure light through the liquid in the liquid immersion area.

64. An exposure apparatus which exposes a substrate with an exposure light, the exposure apparatus comprising:

a mark-detecting system which performs detection of a mark of the substrate; and

a controller which determines alignment information of another substrate, that is to be exposed next to the substrate, by using a result of the detection of the mark of the substrate obtained each before and after the exposure by the mark-detecting system.

65. The exposure apparatus according to claim 64, further comprising a movable member which holds the substrate;

wherein the mark-detecting system executes the detection of the mark after the exposure of the substrate before the movable member releases holding of the substrate.

66. The exposure apparatus according to claim 65, wherein the mark-detecting system is arranged, with respect to a first direction, between an exposure position at which the exposure light is irradiated and an exchange position at which the substrate is exchanged, the mark-detecting system having a plurality of detection areas located at different positions with respect to a second direction intersecting the first direction, and being capable of simultaneously detecting a plurality of different marks on the substrate.

67. The exposure apparatus according to claim 66, wherein the detection of the mark of the substrate before the exposure is executed while the movable member is moved with respect to the mark-detecting system in the first direction;

and

the detection of the mark of the substrate after the exposure is executed while the movable member is moved with respect to the mark-detecting system in a direction opposite to the first direction.

68. The exposure apparatus according to claim 65, wherein a liquid immersion area is formed with a liquid on the substrate during the exposure of the substrate;

and the substrate is exposed with the exposure light through the liquid in the liquid immersion area.