Method for preventing or reducing contamination of an immersion type projection apparatus and an immersion type lithographic apparatus

• US 20070127001A1
• Filed: 12/02/2005
• Published: 06/07/2007
• Est. Priority Date: 12/02/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Van Der Hoeven, Jan Cornelis
• Granted Patent: US 8,125,610 B2
• Time in Patent Office: Days
• US Class Current: 355/53
• CPC Class Codes: G03F 1/82 Auxiliary processes, e.g. cleaning or inspecting
• 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
• CPC Class Codes: G03F 7/70925 Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning

Abstract

A method for preventing or reducing contamination of an immersion type projection apparatus is disclosed. The apparatus includes at least one immersion space that is at least partially filled with a liquid when the apparatus projects a beam of radiation onto a substrate. The method includes rinsing at least part of the immersion space with a rinsing liquid before the apparatus is used to project the beam of radiation onto a substrate.

Claims

1. A method for preventing or reducing contamination of an immersion type projection apparatus, the apparatus comprising at least one immersion space that is at least partially filled with a liquid when the apparatus projects a beam of radiation onto a substrate, the method comprising:

rinsing at least part of the immersion space with a rinsing liquid before the apparatus is used to project the beam of radiation onto a substrate.

2. A method according to claim 1, wherein the rinsing of the immersion space occurs during an idle operational mode of the apparatus.

3. A method according to claim 1, wherein said liquid and said rinsing liquid are the same liquid.

4. A method according to claim 1, wherein the rinsing of the immersion space occurs substantially continuously until the apparatus is used to project radiation onto a substrate.

5. A method according to claim 1, further comprising illuminating at least part of the immersion space and/or the rinsing liquid with ultraviolet radiation.

6. A method according to claim 1, wherein said immersion space at least extends between at least part of a substrate, a dummy substrate or a substrate-shaped object and/or a substrate holder on one side, and a projection system on an opposite side.

7. A method according to claim 6, further comprising:

placing the dummy substrate or the substrate-shaped object on said substrate holder; and

replacing the dummy substrate or the substrate-shaped object a substrate to be illuminated by the projection system after the rinsing has been completed.

8. A method according to claim 1, wherein said immersion space at least extends between a patterning device, a dummy patterning device or a patterning device-shaped object and/or a patterning device holder on one side, and a projection system on opposite side.

9. A method according to claim 8, further comprising:

placing the dummy patterning device or the patterning device-shaped object on said patterning device holder; and

replacing the dummy patterning device or the patterning device-shaped object with a patterning device to be used to pattern radiation before the radiation enters the projection system.

10. A method according to claim 1, wherein the apparatus is a lithographic projection apparatus.

11. A method according to claim 1, further comprising:

varying the location of the immersion space during the rinsing of the immersion space to clean different parts and/or areas of the apparatus.

12. A method for preventing or reducing contamination of a lithographic projection apparatus, the apparatus including a substrate holder constructed to hold a substrate, a patterning device holder constructed to hold a patterning device, a projection system, and an immersion system configured to at least partially fill an immersion space of the apparatus with a liquid, the method comprising:

moving at least one of the immersion system and at least part of the apparatus relative to each other; and

rinsing said at least part of the apparatus with the liquid before the apparatus is used to project a patterned beam of radiation onto a target portion of a substrate.

13. A method according to claim 12, wherein said at least part of the apparatus comprises at least part of the substrate holder.

14. A method according to claim 12, wherein said at least part of the apparatus comprises at least one slit or aperture extending in or near the substrate holder.

15. A method according to claim 12, wherein said at least part of the apparatus comprises at least part of the patterning device holder.

16. A method according to claim 12, wherein said at least part of the apparatus comprises at least one slit or aperture extending in or near the patterning device holder.

17. A method for preventing or reducing contamination of a lithographic projection apparatus, the apparatus including an immersion space, the method comprising:

filling at least part of the immersion space with a rinsing liquid for at least one minute.

18. A method according to claim 17, wherein the filling occurs substantially continuously for at least one day, including at least one idle operational period of the apparatus or a part thereof.

19. A method for preventing or reducing contamination of a lithographic projection apparatus, the apparatus including a substrate holder constructed to hold a substrate, a patterning device holder constructed to hold a patterning device, a projection system, and an immersion space, the method comprising:

filling at least part of the immersion space with a rinsing liquid during an idle time of the apparatus to prevent or reduce substrate contamination during at least one subsequent start-up run of the apparatus.

20. A method according to claim 19, wherein the rinsing liquid consists of ultra pure water.

21. An immersion type lithographic apparatus comprising:

at least one immersion space; and

an immersion system configured to at least partially fill the immersion space with a liquid,

wherein the apparatus is configured to rinse at least part of the immersion space with a rinsing liquid before the apparatus is used to project a patterned beam of radiation onto a substrate.

22. An apparatus according to claim 21, wherein the apparatus is configured to rinse at least part of the immersion space during an idle operational mode of the apparatus.

23. An apparatus according to claim 21, wherein the apparatus is configured to provide an object in said immersion space and/or in an adjoining position with respect to the immersion space during the rinsing of that space, and to remove said object before the apparatus is used to project a radiation beam onto a target portion of a substrate.

24. An apparatus according to claim 23, further comprising at least one storage space or compartment to store said object when the apparatus is used to project a radiation beam onto a target portion of the substrate.

25. An apparatus according to claim 21, wherein the apparatus is configured to rinse the immersion space with said liquid.

26. An apparatus according to claim 21, wherein the apparatus is configured to rinse the immersion space substantially continuously until the apparatus projects a radiation beam onto a substrate.

27. An apparatus according to claim 21, further comprising at least one ultra violet radiation source configured to illuminate the immersion space with ultraviolet radiation during the rinsing of that space, before the apparatus is used to project a radiation beam onto a target portion of a substrate.

28. An apparatus according to claim 21, wherein said immersion space extends between at least part of a substrate, a dummy substrate, a substrate-shaped object and/or a substrate holder on one side and part of a projection system of the apparatus on an opposite side.

29. An apparatus according to claim 28, wherein the apparatus is configured to place the dummy substrate or the substrate-shaped object on said substrate holder, and to subsequently rinse the respective immersion space.

30. An apparatus according to claim 28, wherein said apparatus is configured to have the immersion space at least reach or include an outer contour of the substrate, the dummy substrate or the substrate-shaped object, being held by said substrate holder, during the rinsing.

31. An apparatus according to claim 21, wherein the apparatus is configured to rinse at least an area extending along an edge of a substrate, a dummy substrate or a substrate-shaped object, being held by a substrate holder, using said immersion space and said rinsing liquid.

32. An apparatus according to claim 21, wherein the apparatus is configured to rinse at least part of a surface of the substrate holder and/or one or more components that are located on that surface using said immersion space and said rinsing liquid.

33. An apparatus according to claim 32, wherein said components are selected from the group consisting of an edge seal member, a sensor, a positioning device, and a mirror element.

34. An apparatus according to claim 21, further comprising at least two substrate holders, wherein said immersion space extends between at least part of at least one of the substrate holders on one side and a projection system on an opposite side, and wherein the apparatus is configured to move each substrate holder to a first position and to a respective second position, away from said projection system.

35. An apparatus according to claim 34, wherein the apparatus is configured to subsequently move said substrate holders to said first position, to be at least partially rinsed in or near that position by said rinsing liquid.

36. An apparatus according to claim 34, further comprising at least one cleaning device configured to at least partially clean at least one of the substrate holders when that substrate holder is in said second position.

37. An apparatus according to claim 34, wherein the apparatus is configured to determine which of said substrate holders is most likely to be contaminated and to rinse or clean the substrate holder that has been found to be most likely contaminated, first.

38. An apparatus according to claim 21, wherein said immersion space at least extends between a patterning device and/or patterning device holder on one side and a projection system on an opposite side.

39. An apparatus according to claim 38, wherein the apparatus is configured to place a dummy patterning device or a patterning device-shaped object on said patterning device holder, and to subsequently rinse the immersion space.

40. An apparatus according to claim 28, wherein the apparatus is configured to move said substrate holder with respect to said projection system during the rinsing, such that the position of the immersion space changes with respect to the substrate holder during the rinsing.

41. An apparatus according to claim 21, wherein the apparatus is configured to start said rinsing automatically after a predetermined amount of idle time of the apparatus.

42. An apparatus according to claim 21, wherein the apparatus is configured to start said rinsing automatically after a predetermined number of substrate exposures.

43. An apparatus according to claim 21, wherein the apparatus is configured to determine or estimate whether at least part of said apparatus has reached a certain threshold amount of contamination, and to rinse said apparatus part when it has been determined or estimated that said apparatus part has reached the threshold amount of contamination.

44. An apparatus according to claim 21, further comprising a computer control to control said rinsing.

45. An immersion type lithographic apparatus, including at least one storage space or compartment to store at least one dummy substrate or substrate-shaped object in-situ.

46. An immersion type lithographic apparatus, including at least one storage space or compartment to store at least one dummy patterning device or patterning device-shaped object in-situ.

47. A computer program containing one or more sequences of machine-readable instructions configured to carry out a method for preventing or reducing contamination of an immersion type projection apparatus when the computer program is being executed by a computer, the apparatus comprising at least one immersion space that is at least partially filled with a liquid when the apparatus projects a beam of radiation onto a substrate, the method comprising rinsing at least part of the immersion space with a rinsing liquid before the apparatus is used to project the beam of radiation onto a substrate.

48. A method for preventing or reducing contamination of a lithographic projection apparatus comprising a space that is to be provided with a liquid through which a beam of radiation can be transmitted, the method comprising:

operating the lithographic apparatus; and

subsequently rinsing at least part of the space with a rinsing liquid.

49. A method according to claim 48, wherein said liquid and said rinsing liquid are the same liquid.