Exposure apparatus, exposure method, and method for producing device

• US 8,373,843 B2
• Filed: 04/19/2007
• Issued: 02/12/2013
• Est. Priority Date: 06/10/2004
• 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
• Primary Examiner(s): Kim, Peter B
• Application Number:
  US11/785,722
• Publication Number:
  US 20070195301A1
• Time in Patent Office: 2,126 Days
• Field of Search: 355/30, 355/53, 355/55, 355/67, 250/548, 438/795, 430/302
• 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

Abstract

A lithographic apparatus includes a substrate table to hold a substrate and a projection system to project a patterned radiation beam onto a target portion of the substrate. A liquid supply system at least partly fills a space between the projection system and the substrate with a liquid, and has a liquid confinement structure to at least partly confine the liquid within the space. An outlet removes a mixture of liquid and gas passing through a gap between the liquid confinement structure and the substrate. An evacuation system draws the mixture through the outlet, and includes a separator tank to separate liquid from gas in the mixture and a separator tank pressure controller, connected to a non-liquid-filled region of the separator tank, to maintain a stable pressure within the non-liquid-filled region.

Claims

1. A lithographic apparatus comprising:

a projection system which projects a patterned radiation beam onto a target portion of a substrate;

a liquid supply system which at least partly fills a space between the projection system and the substrate with a liquid, the liquid supply system comprising a liquid confinement member with which the liquid is confined within the space, the liquid confinement member having a liquid supply inlet on a lower surface thereof, the substrate being moved below the liquid confinement member, and a surface of the substrate being opposite to an undersurface of the liquid confinement member during the projection;

an outlet which removes liquid, the outlet removing the liquid from on the surface of the substrate facing the outlet such that the liquid on the surface of the substrate covers only a portion of the surface of the substrate during the projection, and the liquid supply inlet being disposed closer to a path of the patterned radiation beam from the projection system than the outlet; and

an evacuation system which draws the liquid through the outlet, the evacuation system comprising a tank and a tank pressure controller which maintains a stable pressure within the tank, the liquid on the surface of the substrate being drawn through the outlet by the stable pressure within the tank during the projection.

2. The lithographic apparatus according to claim 1, wherein the evacuation system further comprises a liquid pump which pumps the liquid from the tank.

3. The lithographic apparatus according to claim 1, wherein the evacuation system comprises:

a pumping line connected to a pump which pumps the liquid; and

a vacuum line connectable to a vacuum facility which pumps gas,

wherein the pumping and vacuum lines are connected to the tank.

4. The lithographic apparatus according to claim 3, wherein the pumping line is connected to a lower, liquid filled portion of the tank, and the vacuum line is connected to an upper, non-liquid-filled portion of the tank.

5. The lithographic apparatus according to claim 3, wherein the pump maintains a vacuum level within the tank via the pumping line and extracts liquid from a lower liquid filled portion of the tank.

6. The lithographic apparatus according to claim 1, wherein the outlet includes a porous member disposed facing the substrate.

7. The lithographic apparatus according to claim 1, wherein the outlet surrounds the target portion of the substrate subjected to the patterned radiation beam.

8. A device manufacturing method, comprising:

projecting a patterned beam of radiation, using a projection system, through a liquid onto a substrate;

providing the liquid to a space between the projection system of a lithographic apparatus and the substrate, the liquid being confined to the space by a liquid confinement member, the liquid confinement member having a liquid supply inlet on a lower surface thereof, the substrate being moved below the liquid confinement member, and a surface of the substrate being opposite to an undersurface of the liquid confinement member during the projection;

removing liquid through an outlet from on the surface of the substrate facing the outlet to a tank such that the liquid covers only a portion of the surface of the substrate during the projection, the liquid supply inlet being disposed closer to a path of the patterned radiation beam from the projection system than the outlet; and

maintaining a stable pressure within the tank, the liquid on the surface of the substrate being drawn through the outlet by the stable pressure within the tank.

9. A lithographic apparatus comprising:

a projection system including an optical member, which projects a patterned radiation beam onto a substrate;

a liquid supply inlet via which a liquid is supplied, the substrate being moved below the liquid supply inlet and the liquid being supplied via the liquid supply inlet onto a surface of the substrate facing the liquid supply inlet during the projection;

an outlet through which the liquid supplied via the inlet is removed, the outlet removing the liquid from on the surface of the substrate such that liquid on the surface of the substrate covers only a portion of the surface of the substrate during the projection, the liquid supply inlet being disposed closer to a path of the patterned radiation beam from the projection system than the outlet; and

an evacuation system including a tank, that draws the liquid through the outlet to the tank in which a pressure is stabilized, the evacuation system including a pumping line that is connected to a lower, liquid filled portion in the tank, and a vacuum line that is connected to an upper, non-liquid filled portion in the tank, the liquid on the surface of the substrate being drawn through the outlet by the stabilized pressure in the tank.

10. The lithographic apparatus according to claim 9, wherein the evacuation system further comprises a liquid pump which pumps liquid from the tank via the pumping line.

11. The lithographic apparatus according to claim 10, wherein the pressure within the tank is stabilized by maintaining a liquid level in the tank.

12. The lithographic apparatus according to claim 11, further comprising a liquid level sensor which detects the liquid level in the tank, wherein the liquid pump is controlled based on a detection result of the liquid level sensor.

13. The lithographic apparatus according to claim 9, wherein the pressure within the tank is stabilized by maintaining a liquid level in the tank.

14. The lithographic apparatus according to claim 13, further comprising a liquid level sensor which detects the liquid level in the tank, wherein the liquid level is adjusted based on a detection result of the liquid level sensor.

15. The lithographic apparatus according to claim 9, further comprising a liquid level sensor which detects the liquid level in the tank, wherein the pressure within the tank is stabilized using the liquid level sensor.

16. The lithographic apparatus according to claim 9, wherein the evacuation system includes a recovery line which is connected to the outlet and the tank.

17. The lithographic apparatus according to claim 16, wherein the recovery line is connected to the upper non-liquid filled portion in the tank.

18. The lithographic apparatus according to claim 9, wherein vacuum is provided to the tank via the vacuum line.

19. A device manufacturing method comprising:

exposing a substrate by projecting a patterned beam using the projection system of the lithographic apparatus according to claim 9; and

processing the exposed substrate.

20. The lithographic apparatus according to claim 9, further comprising a nozzle member having an opening though which the patterned radiation beam is projected.

21. The lithographic apparatus according to claim 20, wherein the opening of the nozzle member is disposed below the optical member of the projection system.

22. The lithographic apparatus according to claim 20, wherein:

the nozzle member has the supply inlet,

the nozzle member has a lower surface which surrounds the opening, and

the supply inlet is disposed radially outward of the lower surface with respect to the opening.

23. The lithographic apparatus according to claim 22, wherein the supply inlet is disposed such that the liquid supply inlet surrounds the opening.

24. The lithographic apparatus according to claim 22, wherein the nozzle member has the outlet which is disposed radially outward of the lower surface with respect to the opening.

25. The lithographic apparatus according to claim 24, wherein the outlet is disposed such that the outlet surrounds the opening.

26. The lithographic apparatus according to claim 25, wherein the liquid supply inlet is disposed between the lower surface and the outlet.

27. The lithographic apparatus according to claim 26, wherein the outlet is arranged in a quadrilateral.

28. The lithographic apparatus according to claim 26, wherein the optical member of the projection system has a lower end surface and a side surface extending upwardly and radially outwardly from the lower end surface, and wherein a gap is formed between the nozzle member and the side surface of the optical element.

29. The lithographic apparatus according to claim 26, wherein a gap is formed between a first surface of the optical element of the projection system and a second surface of the nozzle member, and wherein the second surface of the nozzle member is liquid-repellent with respect to the liquid.

30. A lithographic method comprising:

providing a liquid to a space between a projection system of a lithographic apparatus and a substrate, the liquid being confined within the space using a liquid confinement member, the liquid confinement member having a liquid supply inlet on a lower surface thereof;

projecting a patterned beam of radiation, using the projection system, through the liquid onto the substrate, the substrate being moved below the liquid confinement member and a surface of the substrate being opposite to the lower surface of the liquid confinement member during the projection;

removing liquid through an outlet from on the surface of the substrate facing the outlet to a tank by providing vacuum to the tank via a vacuum line that is connected to an upper, non-liquid filled portion in the tank such that the liquid in the space covers only a portion of the surface of the substrate during the projection, the liquid supply inlet being disposed closer to a path of the patterned radiation beam from the projection system than the outlet; and

extracting liquid from the tank via a pumping line that is connected to a lower, liquid filled portion in the tank;

wherein a pressure within the tank is stabilized and the liquid on the surface of the substrate is drawn through the outlet by the stabilized pressure in the tank during the projection.

31. The lithographic method according to claim 30, wherein the liquid is extracted from the tank using a liquid pump that is connected to the pumping line.

32. The lithographic method according to claim 31, wherein the pressure within the tank is stabilized by maintaining a liquid level in the tank.

33. The lithographic method according to claim 32, further comprising detecting the liquid level in the tank, wherein the liquid pump is controlled based on the detected liquid level.

34. The lithographic method according to claim 30, wherein the pressure within the tank is stabilized by maintaining a liquid level in the tank.

35. The lithographic method according to claim 34, further comprising detecting the liquid level in the tank, wherein the liquid level in the tank is adjusted based on the detected liquid level.

36. The lithographic method according to claim 30, further comprising detecting the liquid level in the tank, wherein the pressure in the tank is stabilized based on the detected liquid level.

37. The lithographic method according to claim 30, wherein the liquid on the substrate is drawn to the tank through the outlet via a recovery line.

38. The lithographic method according to claim 37, wherein the recovery line is connected to the upper non-liquid filled portion in the tank.

39. The lithographic method according to claim 30, wherein vacuum is provided to the tank via the vacuum line.