Exposure apparatus and device manufacturing method

• US 8,218,127 B2
• Filed: 02/04/2009
• Issued: 07/10/2012
• Est. Priority Date: 07/09/2003
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation, Nikon Engineering Co. Ltd. (Nikon Corporation)
• Original Assignee: Nikon Corporation, Nikon Engineering Co. Ltd. (Nikon Corporation)
• Inventors: Nagasaka, Hiroyuki, Okuyama, Takeshi
• Primary Examiner(s): Nguyen, Hung Henry
• Application Number:
  US12/320,771
• Publication Number:
  US 20090153820A1
• Time in Patent Office: 1,252 Days
• Field of Search: 355/30, 355/53, 355/67, 250/548
• 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
• CPC Class Codes: G03F 7/70883 of optical system

Abstract

An exposure apparatus exposes a substrate by forming a liquid immersion region on the substrate, and projecting a pattern image onto the substrate via a projection optical system and a liquid that forms the liquid immersion region. The exposure apparatus includes a projection optical system having a plurality of optical elements, by which a pattern image is projected onto a substrate via a liquid to expose the substrate and a liquid recovery system that recovers the liquid along with a gas and has a separator that separates the recovered liquid and the recovered gas.

Claims

1. An exposure apparatus comprising:

a projection optical system having a plurality of optical elements, by which an exposure light is projected;

a liquid retaining member having an opening through which the exposure light is projected, and having a liquid recovery outlet;

a liquid recovery system having a separator that separates one of a gas and a liquid from the other, which are collected via the liquid recovery outlet; and

a substrate holding member having a holding portion on which a substrate to be exposed is held,

wherein;

a liquid immersion area is formed under the projection optical system by supplying the liquid and by collecting, via the liquid recovery outlet of the liquid retaining member, the supplied liquid along with the gas, and

the substrate holding member is movable under and relative to the projection optical system and the liquid retaining member to expose the substrate on the holding portion with the exposure light through the liquid of the liquid immersion area which covers a portion of an upper surface of the substrate.

2. The apparatus according to claim 1, wherein

the separator is arranged between the liquid recovery outlet and a vacuum system.

3. The apparatus according to claim 2, wherein

the liquid recovery outlet is arranged to surround a projection region where the exposure light is projected.

4. The apparatus according to claim 3, further comprising:

a liquid supply system that supplies liquid onto the substrate and has a liquid supply inlet that supplies the liquid between the projection region and the liquid recovery outlet.

5. The apparatus according to claim 4, wherein

the substrate is exposed while moving the substrate in a scanning direction, and

the liquid supply inlet is arranged on at least both sides of the projection region.

6. The apparatus according to claim 5, wherein:

the liquid retaining member includes a buffer space on a supply flow passage through which the liquid is supplied to the liquid supply inlet.

7. The apparatus according to claim 1, wherein

the liquid recovery outlet is configured to surround a projection region to which the exposure light is projected, and

the liquid recovery outlet collects the liquid from above the substrate during the projection.

8. The apparatus according to claim 7, wherein

the separator includes a tank.

9. The apparatus according to claim 8, wherein

the vacuum system is connected to an upper gas portion in the tank.

10. The apparatus according to claim 8, wherein

the separator includes a discharging flow passage which is connected to a lower liquid portion in the tank.

11. The apparatus according to claim 10, wherein

the separator includes a valve provided at the discharging flow passage.

12. The apparatus according to claim 8, wherein

the liquid recovery system includes a recovery flow passage provided between the liquid recovery outlet and the tank of the separator, and

the recovery flow passage is connected to an upper gas portion in the tank.

13. The apparatus according to claim 1, wherein

the separator includes a tank.

14. The apparatus according to claim 13, wherein

a vacuum system is connected to an upper gas portion in the tank.

15. The apparatus according to claim 14, wherein

the separator includes a discharging flow passage which is connected to a lower liquid portion in the tank.

16. The apparatus according to claim 13, wherein

the separator includes a discharging flow passage which is connected to a lower liquid portion in the tank.

17. The apparatus according to claim 16, wherein

the separator includes a valve provided at the discharging flow passage.

18. The apparatus according to claim 17, wherein

the discharging flow passage is opened or closed by the valve.

19. The apparatus according to claim 13, wherein

the liquid recovery system includes a recovery flow passage provided between the liquid recovery outlet and the tank of the separator, and

the recovery flow passage is connected to an upper gas portion in the tank.

20. A device manufacturing method comprising:

exposing a substrate using the exposure apparatus according to claim 1; and

processing the exposed substrate.

26. The apparatus according to claim 2, wherein the separator is arranged between the liquid retaining member and the vacuum system.

27. The apparatus according to claim 26, wherein the liquid recovery system has a conduit via which the liquid retaining member is connected to the separator.

28. The apparatus according to claim 2, wherein the liquid recovery outlet is connectable to the vacuum system via a flow passage provided in the liquid retaining member.

29. The apparatus according to claim 28, wherein the separator includes a tank.

30. The apparatus according to claim 29, wherein the separator separates the liquid from the gas by gravity.

31. The apparatus according to claim 29, wherein the vacuum system is connectable to an upper gas portion in the tank.

32. The apparatus according to claim 31, wherein the separator includes a discharging passage which is connected to a lower liquid portion in the tank.

33. The apparatus according to claim 32, wherein the separator includes a valve provided at the discharging flow passage by which the discharging flow passage is opened or closed.

34. The apparatus according to claim 1, wherein the retaining member has a lower surface provided around the opening, and the liquid recovery outlet is provided at the lower surface.

35. The apparatus according to claim 34, wherein the liquid recovery outlet is provided such that the liquid recovery outlet surrounds the opening.

36. The apparatus according to claim 35, wherein the liquid recovery outlet surrounds the opening discontinuously.

37. The apparatus according to claim 35, wherein the liquid retaining member has a liquid supply inlet from which the liquid is supplied.

38. The apparatus according to claim 37, wherein the liquid supply inlet is provided at the lower surface of the liquid retaining member.

39. The apparatus according to claim 37, wherein the liquid supply inlet is provided between the opening and the liquid recovery outlet.

40. The apparatus according to claim 39, wherein the liquid supply inlet includes first and second portions provided on both sides of the opening.

41. The apparatus according to claim 39, wherein the liquid supply inlet and the liquid recovery outlet are provided such that the liquid recovery outlet surrounds the liquid supply inlet.

42. The apparatus according to claim 34, wherein the liquid retaining member is disposed such that the lower surface of the liquid retaining member and a lower surface of the projection optical system are formed in a plane.

43. The apparatus according to claim 1, wherein the optical elements of the projection optical system include a final optical element which comes into contact with the liquid of the liquid immersion area, and the liquid retaining member is disposed such that a gap is formed between the liquid retaining member and the final optical element.

21. An exposure method comprising:

forming a liquid immersion area under a projection optical system which projects an exposure light, by supplying a liquid via a liquid supply inlet and by collecting the supplied liquid along with a gas via a liquid recovery outlet;

moving the substrate under and relative to the projection optical system, the liquid supply inlet and the liquid recovery outlet, to expose the substrate with the exposure light through the liquid of the liquid immersion area which covers a portion of an upper surface of the substrate; and

separating one of the liquid and the gas from the other which are collected via the liquid recovery outlet during the exposure.

22. The exposure method according to claim 21, wherein

the collected liquid is moved to a tank of a separator.

23. The exposure method according to claim 22, further comprising:

sucking the gas from an upper gas portion in the tank.

24. The exposure method according to claim 22, further comprising:

discharging the liquid from a lower liquid portion in the tank.

25. A device manufacturing method comprising:

exposing a substrate using the exposure method defined in claim 21; and

processing the exposed substrate.

44. The method according to claim 21, wherein:

the liquid recovery outlet is provided such that the liquid recovery outlet surrounds a path of the exposure light and such that the upper surface of the substrate faces the liquid recovery port, and

the liquid immersion area is formed by collecting the liquid from the liquid recovery outlet such that the liquid immersion area covers a portion of the upper surface of the substrate.

45. The method according to claim 44, wherein:

the liquid supply inlet is provided between the liquid recovery outlet and the path of the exposure light, and

the liquid immersion area is formed by supplying the liquid from the liquid supply inlet and by collecting the liquid from the liquid recovery outlet such that the liquid immersion area covers the portion of the upper surface of the substrate.