Lithographic apparatus and device manufacturing method

• US 7,733,459 B2
• Filed: 08/24/2004
• Issued: 06/08/2010
• Est. Priority Date: 08/29/2003
• Status: Expired due to Fees

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Stavenga, Marco Koert, Verhagen, Martinus Cornelis Maria, Jacobs, Johannes Henricus Wilhelmus, Seuntiens-Gruda, Lejla, Donders, Sjoerd Nicolaas Lambertus, Jansen, Hans, Streefkerk, Bob, Loopstra, Erik Roelof, Mertens, Jeroen Johannes Sophia Maria, Dierichs, Marcel Mathijs Theodore Marie
• Primary Examiner(s): Kim; Peter B
• Application Number:
  US10/924,192
• Publication Number:
  US 20050078286A1
• Time in Patent Office: 2,114 Days
• Field of Search: 355/30, 355/53, 355/55, 355/77, 355/72, 359/380, 359/886, 210/188, 210/321.6, 210/650, 210/640
• US Class Current: 355/30
• CPC Class Codes: B01D 19/0031 by filtration
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: C02F 1/04 by distillation or evaporation
• CPC Class Codes: C02F 1/20 by degassing, i.e. liberation of dissolved gases degasification of liquids in general B01D19/00; arrangement of degassing apparatus in boiler feed supply F22D
• CPC Class Codes: C02F 1/28 by sorption using ion-exchange C02F1/42; sorbent compositions B01J
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 1/32 with ultraviolet light
• CPC Class Codes: C02F 1/42 by ion-exchange ion-exchange in general B01J
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 2103/40 from the manufacture or use of photosensitive materials
• CPC Class Codes: G03F 7/2041 in the presence of a fluid, e.g. immersion; using fluid cooling means
• 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 7/70866 of mask or workpiece

Abstract

In a lithographic projection apparatus, a liquid supply system maintains liquid in a space between the projection system and the substrate. The liquid supply system may further include a de-mineralizing unit, a distillation unit, a de-hydrocarbonating unit, a UV radiation source, and/or a filter configured to purify the liquid. A gas content reduction device may be provided to reduce a gas content of the liquid. A chemical may be added to the liquid using an adding device to inhibit lifeform growth and components of the liquid supply system may be made of a material which is non-transparent to visible light such that growth of lifeforms may be reduced.

Claims

1. A lithographic projection apparatus comprising:

an illumination system configured to condition a radiation beam;

a support constructed to hold a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam;

a substrate table constructed to hold a substrate;

a projection system configured to project the patterned radiation beam onto a target portion of the substrate; and

a liquid supply system configured to at least partly fill a space between the projection system and the substrate with a liquid, the liquid supply system comprising a liquid purifier configured to purify the liquid and to maintain optical properties of the liquid in the space substantially constant,

wherein the liquid is water or an aqueous solution and the liquid purifier is configured to purify the water or aqueous solution such that it has the following properties (a) to (c) in the space for exposure;

(a) a particle content of no more than 2 particles having a dimension of 50 nm or greater per ml of liquid;

(b) a dissolved oxygen concentration of 15 ppb or less; and

(c) a silica content of 500 ppt or less.

2. The apparatus according to claim 1, wherein the liquid purifier comprises a distillation unit.

3. The apparatus according to claim 1, wherein the liquid purifier comprises a de-hydrocarbonating unit configured to reduce a hydrocarbon content of the liquid.

4. The apparatus according to claim 1, wherein the liquid purifier comprises a demineralizer.

5. The apparatus according to claim 4, wherein the demineralizer comprises a reverse osmosis unit, an ion exchanger or a de-ionization unit.

6. The apparatus according to claim 1, wherein the liquid purifier comprises a filter.

7. The apparatus according to claim 6, wherein the filter is dynamically isolated from one or more other components in the liquid supply system.

8. The apparatus according to claim 1, wherein the liquid supply system includes a re-circulation mechanism configured to re-use liquid in the space without purifying the liquid for a re-use.

9. The apparatus according to claim 1, wherein the liquid supply system includes a re-circulation mechanism configured to re-use liquid in the space and the liquid is partly or fully purified for a re-use.

10. The apparatus according to claim 1, wherein the liquid supply system further comprises a circulation mechanism configured to provide liquid from the liquid purifier to the space.

11. The apparatus according to claim 1, wherein the particle content of the liquid is no more than 0.5 particles having a dimension of 50 nm or greater per ml of liquid, the silica content of the liquid is 100 ppt or less, or both.

12. The apparatus according to claim 1, wherein the liquid supply system comprises an ultra-violet source configured to irradiate the liquid prior to entry into the space.

13. The apparatus according to claim 1, wherein the liquid supply system comprises a container or enclosure non-transparent to visible light surrounding the liquid supply system.

14. The apparatus according to claim 1, wherein the liquid supply system comprises conduits which are non-transparent to visible light configured to supply the liquid from a liquid source to the space.

15. The apparatus according to claim 1, wherein the liquid supply system comprises a device configured to add a lifeform-growth inhibiting chemical to the liquid.

16. The lithographic projection apparatus of claim 1, wherein the liquid purifier comprises a degassing unit having a membrane upstream from and not in contact with the space.

17. The apparatus according to claim 1, further comprising a particle counter.

18. The apparatus according to claim 1, wherein the electrical conductivity of the liquid is from 0.055 microSiemens/cm to 0.5 microSiemens/cm.

19. The apparatus according to claim 1, wherein a content of organic compounds of the liquid is less than 5 ppb.

20. The apparatus according to claim 1, wherein a content of organic compounds of the liquid is less than 1 ppb.

21. The apparatus according to claim 1, wherein a dissolved oxygen concentration of the liquid is 5 ppb or less.

22. A lithographic projection apparatus comprising:

an illumination system configured to condition a radiation beam;

a support constructed to hold a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam;

a substrate table constructed to hold a substrate;

a projection system configured to project the patterned radiation beam onto a target portion of the substrate; and

a liquid supply system configured to at least partly fill a space between the projection system and the substrate with a liquid, the liquid being water or an aqueous solution having the following properties (a) to (c) in the space for exposure;

(a) a particle content of no more than 2 particles having a dimension of 50 nm or greater per ml of liquid;

(b) a dissolved oxygen concentration of 15 ppb or less; and

(c) a silica content of 500 ppt or less.

23. The apparatus according to claim 22, wherein the particle content of the liquid is no more than 0.5 particles having a dimension of 50 nm or greater per ml of liquid, the silica content of the liquid is 100 ppt or less, or both.

24. The apparatus according to claim 22, wherein the liquid supply system comprises a liquid containment system containing the liquid.

25. The lithographic projection apparatus of claim 22, further comprising a liquid purifier including a degassing unit having a membrane upstream from and not in contact with the space.

26. The apparatus according to claim 22, further comprising a particle counter.

27. The apparatus according to claim 22, wherein the liquid has a particle content of no more than 0.5 particles having a dimension of 50 nm or greater per ml of liquid.

28. The apparatus according to claim 22, wherein the electrical conductivity of the liquid is from 0.055 microSiemens/cm to 0.5 microSiemens/cm.

29. The apparatus according to claim 22, wherein a content of organic compounds of the liquid is less than 5 ppb.

30. The apparatus according to claim 22, wherein a content of organic compounds of the liquid is less than 1 ppb.

31. The apparatus according to claim 22, wherein a dissolved oxygen concentration of the liquid is 5 ppb or less.

32. A lithographic projection apparatus, comprising:

an illumination system configured to condition a radiation beam;

a support constructed to hold a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam;

a substrate table constructed to hold a substrate;

a projection system configured to project the patterned radiation beam onto a target portion of the substrate;

a liquid supply system configured to at least partly fill a space between the projection system and the substrate with a liquid, the liquid being water or an aqueous solution having the following properties (a) to (c) in the space for exposure;

(a) a particle content of no more than 2 particles having a dimension of 50 nm or greater per ml of liquid;

(b) a dissolved oxygen concentration of 15 ppb or less; and

(c) a silica content of 500 ppt or less; and

a measurement device configured to measure a property of the liquid indicative of contamination.

33. The apparatus of claim 32, wherein the property is one or more properties selected from the group consisting of:

electrical conductivity, pH, TOC, particles, oxygen, total silica, and bubbles.

34. The apparatus of claim 32, wherein the property is particles.

35. The apparatus of claim 34, further comprising a liquid purifier configured to purify the liquid such that it has the particle content of no more than 2 particles having a dimension of 50 nm or greater per ml of liquid.

36. The apparatus of claim 32, wherein the measurement device is one or more measurement devices selected from the group consisting of:

an electrical conductivity measurement device, a pH sensor, a TOC analyzer, a particle counter, an oxygen sensor, a total silica measurement device, and a bubble measurement device.

37. The apparatus of claim 32, wherein the liquid supply system comprises a liquid confinement structure configured to at least partly confine the liquid within the space and the measurement device is configured to measure the property of the liquid in a flow path between the liquid confinement structure and a gas content reduction device configured to reduce the gas content of the liquid.

38. The apparatus of claim 32, wherein the measurement device is located downstream in a flow path of the liquid from (i) a demineralizer, or (ii) a distillation unit, or (iii) a de-hydrocarbonating unit, or (iv) a source configured to provide UV radiation to the liquid, or (v) any combination selected from (i)-(iv).

39. The apparatus of claim 32, wherein the measurement device is configured to measure the property of the liquid off-line from the flow of the liquid to the space.

40. The apparatus of claim 32, further comprising a liquid purifier configured to purify the liquid such that it has the following properties (a) to (d):

(a) a content of organic compounds of 5 ppb or less;

(b) the particle content of no more than 2 particles having a dimension of 50 nm or greater per ml of liquid;

(c) a dissolved oxygen concentration of 15 ppb or less; and

(d) the silica content of 500 ppt or less.

41. The apparatus of claim 40, wherein the content of organic compounds of the liquid is 1 ppb or less, the particle content of the liquid is no more than 0.5 particles having a dimension of 50 nm or greater per ml of liquid, the dissolved oxygen concentration of the liquid is 5 ppb or less, the silica content of the liquid is 100 ppt or less, or any combination of the foregoing.

42. The apparatus of claim 32, further comprising a liquid purifier configured to purify the liquid such that it has an electrical conductivity of from 0.055 microSiemens/cm to 0.5 microSiemens/cm.

43. A lithographic projection apparatus, comprising:

an illumination system configured to condition a radiation beam;

a support constructed to hold a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam;

a substrate table constructed to hold a substrate;

a projection system configured to project the patterned radiation beam onto a target portion of the substrate;

a liquid supply system configured to at least partly fill a space between the projection system and the substrate with a liquid, the liquid being water or an aqueous solution having the following properties (a) to (c) in the space for exposure;

(a) a particle content of no more than 2 particles having a dimension of 50 nm or greater per ml of liquid;

(b) a dissolved oxygen concentration of 15 ppb of less; and

(c) a silica content of 500 ppt or less;

a liquid purifier configured to purify the liquid;

a gas content reduction device configured to reduce the gas content of the liquid; and

a measurement device configured to measure the presence of particles in the liquid.

44. The apparatus of claim 43, wherein the liquid purifier is configured to purify the liquid such that it has a particle content of no more than 0.5 particles having a dimension of 50 nm or greater per ml of liquid.

45. The apparatus of claim 43, wherein the measurement device is located downstream in a flow path of the liquid from the gas content reduction device.

46. The apparatus of claim 43, wherein the measurement device comprises a particle counter.

47. The apparatus of claim 43, wherein the gas content reduction device comprises a membrane configured to be in contact with the liquid to separate gas from the liquid, the membrane not in contact with the space.

48. The apparatus of claim 43, wherein the liquid purifier comprises a distillation unit, or a de-hydrocarbonating unit configured to reduce the hydrocarbon content of the liquid, or a demineralizer, or any combination of the foregoing.

49. The apparatus of claim 43, wherein the liquid supply system includes a re-circulation mechanism configured to re-use liquid in the space without purifying the liquid for a re-use.

50. The apparatus of claim 43, wherein the liquid supply system includes a re-circulation mechanism configured to re-use liquid in the space and the liquid is partly or fully purified for a re-use.