Exposure Apparatus, Exposure Method, And Method For Producing Device

• US 20080212043A1
• Filed: 10/12/2005
• Published: 09/04/2008
• Est. Priority Date: 10/13/2004
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nagasaka, Hiroyuki
• Granted Patent: US 7,852,456 B2
• Time in Patent Office: Days
• US Class Current: 355/30
• CPC Class Codes: G03F 7/70341 Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply chemical composition of immersion liquids G03F7/2041
• CPC Class Codes: G03F 7/70916 Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps

Abstract

An exposure apparatus fills an optical path space of an exposure light beam with a liquid, and exposes a substrate by irradiating the substrate with the exposure light beam via a projection optical system and the liquid. A first optical element of the projection optical system is provided with a removing device for removing foreign matters in a space inside of the concave surface portion. Immersion exposure is performed by permitting the exposure light beam to excellently reach an image plane via the projection optical system and the liquid.

Claims

1. An exposure apparatus which exposes a substrate by radiating an exposure light beam onto the substrate through a liquid, the exposure apparatus comprising:

a projection optical system which includes a plurality of optical elements, at least one of the plurality of optical elements having a concave surface portion making contact with the liquid; and

a removing device which removes a foreign matter in a space inside of the concave surface portion.

2. The exposure apparatus according to claim 1, wherein the concave surface portion is formed on a lower surface of the first optical element which is included in the plurality of optical elements and which is disposed closest to an image plane of the projection optical system, and an optical path space, which is formed between the first optical element and an object arranged on a side of an image plane of the projection optical system, is filled with the liquid.

3. The exposure apparatus according to claim 2, wherein the removing device removes the foreign matter which present in the liquid arranged in the space inside of the concave surface portion and which has a specific gravity smaller than that of the liquid.

4. The exposure apparatus according to claim 1, wherein the foreign matter includes a bubble.

5. The exposure apparatus according to claim 1, wherein the removing device has a suction port which sucks the foreign matter.

6. The exposure apparatus according to claim 5, wherein the suction port is arranged at a highest position in the space inside of the concave surface portion or a position in the vicinity thereof.

7. The exposure apparatus according to claim 5, wherein the suction port is provided at a position opposed to the concave surface portion.

8. The exposure apparatus according to claim 5, wherein the suction port is provided outside an optical path for the exposure light beam.

9. The exposure apparatus according to claim 5, wherein the removing device has a driving mechanism which moves the suction port relative to the concave surface portion.

10. The exposure apparatus according to claim 9, wherein the removing device performs suction in a state in which the suction port is moved closer to the concave surface portion by a predetermined distance.

11. The exposure apparatus according to claim 1, wherein the removing device is provided on a movable member which is movable on a side of an image plane of the projection optical system.

12. The exposure apparatus according to claim 11, wherein the movable member includes at least one of a first movable member movable while holding the substrate, and a second movable member provided with a measuring device which performs measuring operation in relation to an exposure process.

13. The exposure apparatus according to claim 1, further comprising:

a nozzle member which has at least one of a supply port which supplies the liquid and a recovery port which recovers the liquid, wherein;

the removing device is provided for the nozzle member.

14. The exposure apparatus according to claim 1, further comprising:

a detection device which detects whether or not the foreign matter is present; and

a control device which controls operation of the removing device on the basis of a detection result of the detection device.

15. The exposure apparatus according to claim 1, further comprising a liquid supply mechanism which supplies the liquid, wherein the liquid supply mechanism has a mixing device which mixes a plurality of types of liquids, and the liquid supply mechanism supplies a mixed liquid mixed in the mixing device.

16. The exposure apparatus according to claim 2, wherein a refractive index of the liquid is higher than a refractive index of the first optical element.

17. The exposure apparatus according to claim 2, wherein a numerical aperture of the projection optical system is higher than a refractive index of the first optical element.

18. The exposure apparatus according to claim 1, wherein the concave surface portion is a curved surface.

19. The exposure apparatus according to claim 1, wherein the liquid includes at least one of glycerol and isopropanol.

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

20. An exposure apparatus which exposes a substrate by radiating an exposure light beam onto the substrate through a liquid, the exposure apparatus comprising:

a projection optical system which includes a plurality of optical elements and which has the first optical element included in the plurality of optical elements and disposed closest to an image plane of the projection optical system, the first optical element having a concave surface portion which makes contact with the liquid, wherein;

a refractive index of the liquid with respect to the exposure light beam is higher than a refractive index of the first optical element.

21. The exposure apparatus according to claim 20, wherein a numerical aperture of the projection optical system is larger than the refractive index of the first optical element.

22. The exposure apparatus according to claim 20, further comprising:

a liquid supply mechanism which supplies the liquid, wherein;

the liquid supply mechanism includes a mixing device which mixes a plurality of types of liquids and supplies a liquid which is prepared by the mixing device.

23. The exposure apparatus according to claim 20, wherein the first optical element is formed of silica glass or calcium fluoride.

24. The exposure apparatus according to claim 20, wherein the refractive index of the liquid with respect to the exposure light beam is not less than 1.5.

35. A method for producing a device, including using the exposure apparatus as defined in claim 20.

26. An exposure method which exposes a substrate by radiating an exposure light beam onto the substrate via a liquid and an optical element having a concave Surface portion which makes contact with the liquid, the exposure method including:

removing a foreign matter from the liquid in a space inside of the concave surface portion of the optical element; and

exposing the substrate by radiating the exposure light beam onto the substrate via the optical element and the liquid.

27. The exposure method according to claim 26, wherein the substrate is exposed after removing the foreign matter, or the substrate is exposed while removing the foreign matter.

28. The exposure method according to claim 26, further including detecting the foreign matter present in the liquid in the space inside of the concave surface portion of the optical element.

29. The exposure method according to claim 28, wherein the foreign matter is removed in accordance with a result of detection of the foreign matter.

30. The exposure method according to claim 26, wherein a refractive index of the liquid is higher than a refractive index of the optical element with respect to the exposure light beam.

34. A method for producing a device, including:

exposing a substrate by the exposure method as defined in claim 26;

developing the exposed substrate; and

processing the developed substrate.

31. An exposure method for exposing a substrate by radiating an exposure light beam onto the substrate via a liquid and an optical element having a concave Surface portion which makes contact with the liquid, the exposure method including:

supplying the liquid to a space between the substrate and the concave surface portion of the optical element, the liquid having a refractive index higher than a refractive index of the optical element; and

exposing the substrate by radiating the exposure light beam onto the substrate via the optical element and the liquid.

32. The exposure method according to claim 31, wherein the exposure light beam is radiated onto the substrate through the liquid by a projection optical system which includes the optical element and which has a numerical aperture higher than the refractive index of the optical element.

33. The exposure method according to claim 31, wherein the refractive index of the liquid with respect to the exposure light beam is not less than 1.5.

36. A method for producing a device, including:

exposing a substrate by the exposure method as defined in claim 31;

developing the exposed substrate; and

processing the developed substrate.

37. A lithographic projection apparatus, comprising:

a projection system configured to project a patterned beam of radiation into an image field that is positioned off the optical axis of the projection system and onto a target portion of a substrate, the projection system comprising a concave refractive lens adjacent the substrate through which the patterned beam is projected; and

a liquid supply system configured to provide a liquid to a space between the substrate and the lens.

38. The apparatus according to claim 37, wherein the projection system is a catadioptric system.

39. The apparatus according to claim 37, wherein the lens is cut-away on the opposite side of the optical axis from the image field.

40. The apparatus according to claim 39, wherein the liquid supply system is an arranged to provide liquid from a position adjacent the cutaway of the lens.

41. The apparatus according to claim 37, wherein the lens is asymmetric about a plane containing the optical axis.

42. The apparatus according to claim 41, wherein the liquid supply system is arranged to provide liquid from a position at or near the optical axis.

43. The apparatus according to claim 37, wherein the lens has a first side edge on a first side of the optical axis and a second side edge on a second side of the optical axis, the first side edge being nearer the optical axis than is the second side edge and the image field being on the second side of the optical axis.

44. The apparatus according to claim 43, wherein the liquid supply system is arranged to provide liquid from a position near the first side edge.

45. The apparatus according to claim 37, wherein the lens extends substantially only to a position that will be traversed by the beam.

46. The apparatus according to claim 37, wherein the lens is provided with a through-hole opening at or near the highest point of its concave side such that liquid can be provided through the through-hole.

47. A device manufacturing method, comprising:

projecting an image of a pattern through a liquid onto a target portion of a substrate using a projection system, the projection system comprising a concave refractive lens adjacent the substrate through which the image is projected and the image field of the projection system being off-axis.

48. The method according to claim 47, wherein the projection system is a catadioptric system.

49. The method according to claim 47, wherein the lens is cut-away on the opposite side of the optical axis from the image field.

50. The method according to claim 49, comprising providing liquid from a position adjacent the cutaway of the lens.

51. The method according to claim 47, wherein the lens is asymmetric about a plane containing the optical axis.

52. The method according to claim 51, comprising providing liquid from a position at or near the optical axis.

53. The method according to claim 47, wherein the lens has a first side edge on a first side of the optical axis and a second side edge on a second side of the optical axis, the first side edge being nearer the optical axis than is the second side edge and the image field being on the second side of the optical axis.

54. The method according to claim 53, comprising providing liquid from a position near the first side edge.

55. The method according to claim 47, wherein the lens extends substantially only to a position that will be traversed by the image.

56. The method according to claim 47, wherein the lens is provided with a through-hole opening at or near the highest point of its concave side and comprising providing liquid through the through-hole.