Exposure apparatus, exposure method, and method for producing device

• US 20090021709A1
• Filed: 10/12/2005
• Published: 01/22/2009
• Est. Priority Date: 10/13/2004
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nagasaka, Hiroyuki
• Application Number:
  US11/665,073
• Publication Number:
  US 20090021709A1
• Time in Patent Office: Days
• US Class Current: 355/53
• 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

Abstract

An exposure apparatus fills an optical path space on a side of an image plane of a projection optical system with liquid and exposes a substrate via the projection optical system and the liquid. The exposure apparatus has a measurement unit which measures an optical property of the liquid. According to the measurement result, it is possible to adjust the optical characteristic of the liquid by a liquid mixing unit. Thus, it is possible to maintain the exposure accuracy at a desired state when performing immersion exposure.

Claims

1. An exposure apparatus which exposes a substrate through a liquid, comprising:

a projection optical system; and

a measuring device which measures optical property of the liquid.

2. The exposure apparatus according to claim 1, wherein the optical property includes at least one of a refractive index and a light transmittance of the liquid.

3. The exposure apparatus according to claim 1, further comprising a liquid supply mechanism which supplies the liquid to a side of an image plane of the optical system,

wherein the measuring device optically measures the optical property of a liquid supplied by the liquid supply mechanism.

4. The exposure apparatus according to claim 1, wherein the liquid supply mechanism has a supply passage in which the liquid flows, and the measuring device optically measures optical the property of the liquid flowing in the supply passage.

5. The exposure apparatus according to claim 1, further comprising an adjusting mechanism which performs an adjustment of an exposure condition based on the result of measurement by the measuring device.

6. The exposure apparatus according to claim 5, wherein the adjustment includes an adjustment of the optical property of the liquid.

7. The exposure apparatus according to claim 6, wherein the adjustment of the optical property of the liquid includes a mixing of a predetermined substance with the liquid.

8. The exposure apparatus according to claim 6, comprising a mixing device which mixes a plurality of liquids,

wherein the liquid prepared by the mixing device fills an optical path space, and the adjustment of the optical property of the liquid includes an adjustment of a mixing ratio of the plurality of liquids.

9. The exposure apparatus according to claim 8, wherein the plurality of liquids have mutually different optical property.

10. The exposure apparatus according to claim 8, further comprising a storage device which stores in advance a relationship between the mixing ratio and the optical property of the liquid mixed at the mixing ratio,

wherein the mixing device performs mixing based on information stored in the storage device.

11. The exposure apparatus according to claim 5, wherein the adjustment includes an adjustment of the positional relationship between a surface of the substrate and a position of an image plane formed via the projection optical system and the liquid.

12. The exposure apparatus according to claim 11, further comprising a storage device which stores in advance a relationship between the optical property of the liquid and the position of the image plane formed via the projection optical system and the liquid,

wherein the adjusting mechanism performs adjustment based on information stored in the storage device.

13. The exposure apparatus according to claim 11, further comprising a substrate stage which is movable while holding the substrate,

wherein the adjusting mechanism includes a stage adjusting device which adjusts a position of the substrate stage.

14. The exposure apparatus according to claim 5, wherein the adjusting mechanism includes an image formation characteristic adjusting device which adjusts an image formation characteristic.

15. The exposure apparatus according to claim 5, wherein the adjustment includes a temperature adjustment of the liquid.

16. The exposure apparatus according to claim 5, wherein the measuring device includes a first measuring instrument which measures the liquid and a second measuring instrument which measures the liquid which has been adjusted based on a result of measurement by the first measuring instrument.

17. The exposure apparatus according to claim 16, wherein the optical property of the liquid is adjusted based on the result of measurement by the first measuring instrument, and

a positional relationship between a position of an image plane of the projection optical system and a surface of the substrate is adjusted based on a result of measurement by the second measuring instrument.

18. The exposure apparatus according to claim 3, further comprising a liquid recovery mechanism which recovers the liquid on the side of the image plane of the projection optical system and returns at least a part of the liquid which has been recovered to the liquid supply mechanism for reuse.

19. The exposure apparatus according to claim 1, further comprising a reporting device which reports a result of measurement by the measuring device.

20. The exposure apparatus according to claim 1, wherein a refractive index of the liquid with respect to an exposure light beam is greater than that of a first optical element disposed closest to an image plane of the projection optical system, the first optical element being included in a plurality of optical elements of the projection optical system.

21. The exposure apparatus according to claim 1, an optical path on a side of an image plane of the projection optical system is filled with the liquid, and the substrate is exposed via the projection optical system and the liquid.

22. The exposure apparatus according to claim 16, further comprising a temperature controller which adjusts a temperature of the liquid which has been adjusted based on the result of measurement by the first measuring instrument.

36. The exposure apparatus according to claim 1, wherein an optical path on a side of an image plane of the projection optical system is filled with the liquid, and the substrate is exposed via the projection optical system and the liquid.

38. A method for producing a device using the exposure apparatus as defined in claim 1.

23. An exposure apparatus which exposes a substrate through a liquid, comprising:

a projection optical system;

a liquid supply mechanism which supplies the liquid to a side of an image plane of the projection optical system; and

a mixing device which is provided in the liquid supply mechanism and mixes a plurality of liquids,

wherein the liquid supply mechanism supplies the liquid mixed by the mixing device.

24. The exposure apparatus according to claim 23, wherein the mixing device mixes the plurality of liquids which have mutually different optical property.

25. The exposure apparatus according to claim 23, comprising a measuring device which measures the liquid mixed by the mixing device.

26. The exposure apparatus according to claim 25, wherein the measuring device measures optical property of the liquid.

27. The exposure apparatus according to claim 24, wherein the optical property includes at least one of an refractive index and a light transmittance of the liquid.

28. The exposure apparatus according to claim 23, wherein the mixing device mixes a liquid which is supplied to the side of the image plane of the projection optical system according to optical characteristics of a first optical element disposed closest to the image plane of the projection optical system, the first optical element being included in a plurality of optical elements of the projection optical system.

29. The exposure apparatus according to claim 28, wherein the mixing device mixes the liquid so that the liquid has a refractive index greater than that of the first optical element.

30. The exposure apparatus according to claim 28, wherein the mixing device mixes the liquid so that the liquid has a refractive index substantially equal to that of the first optical element.

31. The exposure apparatus according to claim 23, comprising a liquid recovery mechanism which recovers the liquid supplied by the liquid supply mechanism,

wherein the liquid recovery mechanism returns the liquid which has been recovered to the liquid supply mechanism.

32. The exposure apparatus according to claim 31, wherein the liquid recovery mechanism returns a part of the liquid which has been recovered.

33. The exposure apparatus according to claim 31, wherein the liquid recovery mechanism includes a process device which performs a predetermined process for the liquid which has been recovered, and returns the liquid which has been treated by the treatment device to the liquid supply mechanism.

34. The exposure apparatus according to claim 33, wherein the treatment device cleans the liquid which has been recovered.

35. The exposure apparatus according to claim 31, wherein the liquid supply mechanism again supplies the liquid returned from the liquid recovery mechanism to the side of the image plane of the projection optical system.

37. The exposure apparatus according to claim 25, further comprising a controller which adjusts a mixing ratio of the plurality of liquids in the mixing device according to a result of measurement by the measuring device.

53. A method for producing a device using the exposure apparatus as defined in claim 23.

39. An exposure method for exposing a substrate with an image of a predetermined pattern through a liquid, comprising:

measuring optical property of the liquid before supplying the liquid to an area in which the image of the predetermined pattern is formed;

adjusting exposure conditions; and

exposing the substrate with the image of the predetermined pattern through the liquid.

40. The exposure method according to claim 39, wherein the optical property includes at least one of a refractive index and a light transmittance of the liquid.

41. The exposure method according to claim 39, wherein the exposure conditions include at least one of image formation characteristic of the image of the predetermined pattern and the optical property of the liquid.

42. The exposure method according to claim 39, comprising re-supplying the liquid to the area in which the image of the predetermined pattern is formed, after supplying the liquid to the area and recovering the liquid from the area;

and measuring the optical property of the liquid after being recovered and before being re-supplied.

43. The exposure method according to claim 42, further comprising adjusting a component or a temperature of the liquid after being recovered and before being re-supplied.

44. The exposure method according to claim 43, further comprising measuring the optical property of the liquid after adjusting the component or the temperature of the liquid.

52. A method for producing a device comprising:

exposing a substrate by the exposure method as defined in claim 39;

developing the substrate which has been exposed; and

processing the substrate which has been developed.

45. An exposure method for exposing a substrate with an image of a predetermined pattern through a liquid, comprising:

mixing a plurality of liquids;

measuring optical property of the liquid before or after the mixing of the plurality of liquids; and

exposing the substrate through the liquid which has been mixed.

46. The exposure method according to claim 45, further comprising adjusting a mixing ratio of the plurality of liquids based on a result of optical measurement of the liquid before the mixing.

47. The exposure method according to claim 45, further comprising adjusting an image formation characteristic of the predetermined pattern based on a result of optical measurement of the liquid after the mixing.

48. The exposure method according to claim 45, comprising adjusting a temperature of the liquid which has been mixed.

49. The exposure method according to claim 45, wherein the image of the predetermined pattern is projected onto the substrate by an optical element, the liquid is supplied in a space between the substrate and the optical element, and a refractive index of the liquid is not less than a refractive index of the optical element.

50. The exposure method according to claim 45, comprising re-supplying the liquid which has been mixed to an area in which the image of the predetermined pattern is formed, after supplying the liquid to the area and recovering the liquid from the area;

measuring the optical property of the liquid after being recovered and before being re-supplied; and

adjusting a mixing ratio of the plurality of liquids based on a result of measurement of the optical property of the liquid after being recovered and before being re-supplied.

54. A method for producing a device comprising:

exposing a substrate by the exposure method as defined in claim 45;

developing the substrate which has been exposed; and

processing the substrate which has been developed.

51. An exposure method for exposing a substrate with an image of a predetermined pattern through a liquid, comprising:

mixing a plurality of liquids;

adjusting an image formation characteristic of the image of the predetermined pattern so that a desired image of the predetermined pattern is obtained; and

exposing the substrate through the liquid has been mixed.

55. A method for producing a device comprising:

exposing a substrate by the exposure method as defined in claim 51;

developing the substrate which has been exposed; and

processing the substrate which has been developed.

56. An exposure apparatus comprising:

a projection optical system for projecting a pattern of a reticle onto a plate to be exposed, via a liquid that is filled in a space between the projection optical system and the plate; and

a measuring apparatus for measuring a refractive index of the liquid,

wherein said measuring apparatus includes;

a cell for accommodating the liquid and transmitting a light; and

a detector for detecting an incident position of the light refracted by the liquid in the cell.

57. An exposure apparatus according to claim 56, further comprising an optical element, provided between the cell and the detector, for transforming a change of a refracting angle of the light by the liquid into a change of the incident position detected by the detector.

58. An exposure apparatus according to claim 56, wherein said light is emitted from a light source and is an exposure light used for exposure of the plate.

59. An exposure apparatus according to claim 56, further comprising a temperature controller for controlling a temperature of the liquid supplied to the space, based on a measurement result by the measuring apparatus.

60. An exposure apparatus according to claim 56, further comprising a concentration controller for controlling a concentration of the liquid supplied to the space, based on a measurement result by the measuring apparatus.

61. An exposure apparatus according to claim 56, further comprising an aberration controller for reducing an aberration of the projection optical system.

62. An exposure apparatus according to claim 56, wherein said liquid is an aqueous solution or an organic material.

63. An exposure apparatus according to claim 56, wherein said detector is a position sensitive detector.

64. An exposure method comprising the steps of:

calculating a change of a refractive index of a liquid using an exposure apparatus according to claim 56;

adjusting at least one of a projection optical system and the liquid based on a calculated change of the refractive index; and

exposing a plate using the projection optical system and the liquid, after said adjusting step.

65. A device fabrication method comprising the steps of:

exposing a plate to be exposed using an exposure apparatus according to claim 56; and

performing a development process for the plate exposed.