Exposure apparatus, microdevice, photomask, method of exposure, and method of production of device

• US 6,842,225 B1
• Filed: 04/11/2000
• Issued: 01/11/2005
• Est. Priority Date: 05/07/1999
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Irie, Nobuyuki
• Primary Examiner(s): FULLER, RODNEY EVAN
• Application Number:
  US09/959,676
• Time in Patent Office: 1,736 Days
• Field of Search: 355/53, 355/67, 355/71
• US Class Current: 355/67
• CPC Class Codes: G03F 7/70066 Size and form of the illuminated area in the mask plane, e.g. reticle masking blades or blinds
• CPC Class Codes: G03F 7/70475 Stitching, i.e. connecting image fields to produce a device field, the field occupied by a device such as a memory chip, processor chip, CCD, flat panel display

Abstract

A stitching type exposure apparatus for successively exposing an image of a pattern of a reticle (Ri) on different areas of a surface of a substrate (4) while overlaying parts of the same, wherein a density filter (Fj) having a light attenuating part for reducing the amount of light of overlaid parts of the image of the pattern in a sloping manner is provided in the vicinity of the reticle (Ri), the density filter (Fj) is held at a filter stage (FS) for adjusting the posture, the posture of the density filter (Fj) is detected by an illumination uniformity sensor (126) on the substrate stage (6), and the posture of the density filter (Fj) is matched with the posture of the reticle (Ri) by the filter stage (FS).

Claims

1. An exposure apparatus which transfers a pattern of a mask onto at least one of different areas with an overlapped peripheral part on a substrate by exposing the at least one area with illumination light irradiated onto the mask, comprising:

a light attenuating member having a filter disposed on an optical path through which the illumination light passes to reduce the amount of light on the overlapped peripheral part, the filter having an attenuating portion of which a light attenuation rate is gradually varied; and

a detection device which detects a posture of the filter at least in a rotation direction.

2. An exposure apparatus as set forth in claim 1, wherein said filter has a light transmitting portion shaped rectangularly, and the attenuating portion is provided at an outside of the light transmitting portion.

3. An exposure apparatus as set forth in claim 2, wherein said detection device includes a sensor for detection of an illumination distribution provided on a substrate stage moving said substrate.

4. An exposure apparatus as set forth in claim 2, wherein:

said filter has a mark for positional measurement; and

said detection device includes a sensor for detecting the position of said mark.

5. An exposure apparatus as set forth in claim 4, wherein said mark is comprised of an aperture or a plurality of slits formed in a light blocking portion of said filter.

6. An exposure apparatus as set forth in claim 2, wherein a stage for moving the mask is controlled so that the posture of said mask becomes matched with the posture of said filter based on the detection results of said detection device.

7. An exposure apparatus as set forth in claim 1, wherein said light attenuating member includes:

a light blocking plate provided so as to be able to advance and retract with respect to the optical path of the illumination light; and

an actuator which drives said light blocking plate.

8. An exposure apparatus as set forth in claim 1, wherein the mask has at least one of a plurality of patterns into which a pattern obtained by enlarging a pattern to be formed on the substrate is divided, and images of the plurality of patterns reduced by a projection optical system are transferred onto the substrate.

9. A photomask produced using an exposure apparatus as set forth in claim 8.

10. An exposure apparatus as set forth in claim 1, wherein said mask is a master mask having at least one of a plurality of patterns into which a pattern obtained by enlarging a pattern to be formed on a working mask is divided, and the substrate is a mask substrate for producing the working mask onto which images of the plurality of patterns reduced by a projection optical system are transferred.

11. A microdevice produced using an exposure apparatus as set forth in claim 1.

12. An exposure apparatus as set forth in claim 1, further comprising an adjusting device which adjusts a relative positional relationship between a distribution of the amount of light defined by said light attenuating member and said pattern or image of said pattern based on the detection results of said detection device.

13. An exposure apparatus as set forth in claim 12, wherein said adjusting device performs at least one of relative movement of said light attenuating member and said mask, and adjustment of optical characteristics of an optical system arranged between said light attenuating member and said mask.

14. An exposure apparatus as set forth in claim 1, wherein said detection device detects a relative positional relationship between said light attenuating member and said mask in a direction along an optical axis substantially perpendicular to the mask.

15. An exposure apparatus as set forth in claim 1, wherein said detection device detects information on position of the filter on a predetermined plane perpendicular to an optical axis of an irradiation system forming the optical path.

16. An exposure apparatus as set forth in claim 15, wherein said detection device detects information on position of the filter in a direction along the optical axis.

17. An exposure apparatus as set forth in claim 16, wherein said detection device detects information on tilt of the filter.

18. An exposure apparatus as set forth in claim 15, wherein the irradiation system includes an illumination system which irradiates the illumination light onto the mask, and the filter is disposed at a predetermined distance from a conjugate plane with a pattern plane of the mask in a part of the illumination system.

19. An exposure apparatus as set forth in claim 18, wherein said detection device detects optical characteristics on the part of the illumination system.

36. A exposure apparatus as set forth in claim 15, wherein said filter is arranged away from a pattern surface of said mask or a conjugate plane of said pattern surface by a predetermined distance.

20. An exposure apparatus which transfers a pattern of a mask onto at least one of different areas with an overlapped peripheral part on a substrate by exposing the at least one area with illumination light irradiated onto the mask, comprising:

an illumination system disposed on an optical path through which the illumination light passes to illuminate the mask with th illumination light; and

a light attenuating member having a filter provided in a vicinity of the mask to reduce an amount of light on the overlapped peripheral part, the filter having an attenuating portion of which a light attenuation rate is gradually varied.

21. An exposure apparatus as set forth in claim 20, wherein said filter is held detachably on a mask stage for moving said mask.

22. An exposure apparatus as set forth in claim 20, wherein said filter has a light transmitting portion shaped retangularly, and the attenuating portion is provided at an outside of the light transmitting portion.

23. An exposure apparatus as set forth in claim 20, further comprising an adjusting device which detects position information of said light attenuating member and adjusts a relative positional relationship with said pattern.

24. An exposure apparatus as set forth in claim 20, wherein said light attenuating member includes:

a light blocking plate provided so as to be able to advance and retract with respect to the optical path of the illumination light; and

a drive device which drives said light blocking plate during exposure so that said overlapped peripheral part has a slanted amount of light.

25. An exposure apparatus as set forth in claim 20, wherein the mask has at least one of a plurality of patterns into which a pattern obtained by enlarging a pattern to be formed on the substrate is divided, and images of the plurality of patterns reduced by a projection optical system are transferred onto the substrate.

26. A microdevice produced using an exposure apparatus as set forth in claim 20.

27. An exposure apparatus which transfers a pattern of a mask onto at least one of different areas with an overlapped peripheral part on a substrate by exposing the at least one area with illumination light irradiated onto the mask, comprising:

a light attenuating member having a filter disposed on an optical path through which the illumination light passes to reduce an amount of light on the overlapped peripheral part, the filter having an attenuating portion of which a light attenuation rate is gradually varied; and

an adjusting device which adjusts posture of the filter so as to align the filter with the mask.

28. An exposure apparatus as set forth in claim 27, wherein said filter is provided in a vicinity of the mask.

29. An exposure apparatus as set forth in claim 27, wherein said filter has a light transmitting portion shaped retangularly, and the attenuating portion is provided at an outside of the light transmitting portion.

30. An exposure apparatus as set forth in claim 27, wherein said adjusting device includes a detection device for detecting a relative positional relationship between a distribution of the amount of light defined by said light attenuating member and said pattern or image of the same.

31. An exposure apparatus as set forth in claim 27, wherein said light attenuating member includes:

a light blocking plate provided so as to be able to advance and retract with respect to the optical path of the illumination light; and

a drive device which drives said light blocking plate during exposure so that said overlapped peripheral part has a slanted amount of light.

32. An exposure apparatus as set forth in claim 27, wherein the mask has at least one of a plurality of patterns into which a pattern obtained by enlarging a pattern to be formed on the substrate is divided, and images of the plurality of patterns reduced by a projection optical system are transferred onto the substrate.

33. A microdevice produced using an exposure apparatus as set forth in claim 27.

34. An exposure apparatus which transfers a pattern of a mask onto at least one of different areas with an overlapped peripheral part on a substrate by exposing the at least one area with illumination light irradiated onto the mask, comprising:

a light attenuating member having an optical device in an optical path through which the illumination light passes to reduce an amount of light on the overlapped peripheral part so that a distribution of the amount of light formed on the substrate by the exposure of each area has sloped portion on the overlapped peripheral part of each area, of which the amount of light is gradually decreased; and

an adjusting device which adjusts a relative positional relationship on the substrate between the sloped portion of the distribution and the transferred pattern.

35. An exposure apparatus as set forth in claim 34, wherein said light attenuating member includes a filter, and said adjusting device includes a drive device which moves at least one of the mask and said filter.

37. An exposure apparatus as set forth in claim 34, wherein said adjusting device adjusts optical characteristics of an optical system arranged between the mask and said light attenuating member.

38. An exposure apparatus as set forth in claim 34, further comprises a detection device which detects a distribution of the amount of light defined by said light attenuating member or a mark pattern provided at said light attenuating member to obtain positional information of said light attenuating member.

39. An exposure apparatus as set forth in claim 34, wherein the mask has at least one of a plurality of patterns into which a pattern obtained by enlarging a pattern to be formed on the substrate is divided, and images of the plurality of patterns reduced by a projection optical system are transferred onto the substrate.

40. A microdevice produced using an exposure apparatus as set forth in claim 34.

41. An exposure apparatus as set forth in claim 34, wherein:

the optical device is provided in an illumination system which irradiates the illumination light onto the mask; and

the adjusting device adjusts the relative positional relationship in accordance with a change in relative position between the optical device and the pattern on the mask.

42. An exposure apparatus as set forth in claim 34, wherein said adjusting device includes a detection device which detects position information of the optical device in an irradiation system forming the optical path.

43. An exposure apparatus as set forth in claim 42, wherein the position information includes information on rotation of the optical device on a predetermined plane perpendicular to an optical axis of the irradiation system.

44. An exposure apparatus as set forth in claim 43, wherein the position information includes information on position of the optical device in a direction along the optical axis on the irradiation system.

45. An exposure apparatus as set forth in claim 44, wherein the position information includes information on tilt of the optical device.

46. An exposure apparatus as set forth in claim 42, wherein the irradiation system includes an illumination system which irradiates the illumination light onto the mask, and the optical device is disposed at a predetermined distance from a conjugate plane with a pattern plane of the mask in a part of the illumination system.

47. An exposure apparatus as set forth in claim 46, wherein said detection device detects optical characteristics on the part of the illumination system disposed between the optical device and the mask.

48. An exposure apparatus as set forth in claim 47, wherein said adjusting device adjusts at least one of the optical device and the illumination system based on information detected by said detection device to adjust the relative positional relationship.

49. An exposure method of transferring a pattern of a mask onto at least one of different areas with an overlapped peripheral part on a substrate by exposing the at least one area with illumination light irradiated onto the mask comprising:

reducing an amount of light on the overlapped peripheral part so that a distribution of the amount of light formed on the substrate by the exposure of each area has a sloped portion on the overlapped peripheral part of each area, of which the amount of light is gradually decreased; and

adjusting a relative positional relationship on the substrate between the sloped portion of the distribution and the transferred pattern.

50. A photomask produced using an exposure method as set forth in claim 49.

51. A method of producing a device including a step of transferring onto a photosensitive substrate a circuit pattern formed on a photomask as set forth in claim 50.

52. An exposure method as set forth in claim 49, wherein:

the amount of the illumination light is reduced at an up stream side of the mask; and

the relative positional relationship is adjusted in accordance with a change in position of the pattern.

53. An exposure method as set forth in claim 49, wherein position information of an optical device setting the distribution of the amount of light in an irradiation system through which the illumination light passes is detected to adjust the relative positional relationship.

54. An exposure method as set forth in claim 53, wherein the position information includes information on rotation of the optical device on a predetermined plane perpendicular to an optical axis of the irradiation system.

55. An exposure method as set forth in claim 54, wherein the position information includes information on position of the optical device in a direction along the optical axis of the irradiation system.

56. An exposure method as set forth in claim 55, wherein the position information includes information on tilt of the optical device.

57. An exposure method as set forth in claim 53, wherein the irradiation system includes an illumination system which irradiates the illumination light onto the mask, and the optical device is disposed at a predetermined distance from a conjugate plane with a pattern plane of the mask in a part of the illumination system.

58. An exposure method as set forth in claim 57, wherein optical characteristics of the part of the illumination system disposed between the optical device and the mask are detected.

59. An exposure method as set forth in claim 58, wherein at least one of the optical device and the part of the illumination system is adjusted based on the detected information to adjust the relative positional relationship.