Exposure Method, Exposure Apparatus, Exposure System and Device Manufacturing Method

• US 20080038675A1
• Filed: 02/18/2005
• Published: 02/14/2008
• Est. Priority Date: 02/20/2004
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nagasaka, Hiroyuki
• Application Number:
  US10/589,962
• Publication Number:
  US 20080038675A1
• Time in Patent Office: Days
• US Class Current: 430/322
• CPC Class Codes: G03F 7/70 Microphotolithographic exposure; Apparatus therefor photo-masks G03F1/00
• 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 7/70458 Mix-and-match, i.e. multiple exposures of the same area using a similar type of exposure apparatus, e.g. multiple exposures using a UV apparatus

Abstract

When exposing a same resist layer of a wafer a plurality of times, at least in one exposure of the plurality of exposures, by filling a space between a projection optical system, which projects an exposure light on the wafer, and the wafer with water by a liquid supply/drainage unit, a substantial wavelength of exposure light that reaches the wafer is made to differ from a substantial wavelength of exposure light in another exposure. Accordingly, exposure with high precision and high throughput can be achieved.

Claims

1. An exposure method in which a plurality of times of exposure is performed on a same photosensitive object wherein

the substantial wavelength of an exposure light in a space between a projection optical system, which projects said exposure light on said photosensitive object, and said photosensitive object is different in at least one exposure in said plurality of times of exposure from another exposure.

2. The exposure method according to claim 1 wherein

in said at least one exposure, said space is in a state filled with a predetermined liquid.

3. The exposure method according to claim 2 wherein

in said another exposure, said space is in a state filled with another liquid of a different type from said predetermined liquid.

4. The exposure method according to claim 3 wherein

said predetermined liquid has refractive index larger than the refractive index of said another liquid.

5. The exposure method according to claim 3 wherein

said another liquid has solubility to a specific material contained within a photosensitive agent of said photosensitive object lower than said predetermined liquid.

6. The exposure method according to claim 2 wherein

in said another exposure, said space is in a state not filled with liquid.

7. The exposure method according to claim 6 wherein

said at least one exposure is performed prior to said another exposure.

8. The exposure method according to claim 6 wherein

said at least one exposure is performed after said another exposure is performed.

9. The exposure method according to claim 1 wherein

a wavelength of an exposure light made to enter said projection optical system in said at least one exposure is different from a wavelength of exposure light in said another exposure.

10. The exposure method according to claim 1 wherein

in said at least one exposure, a phase shift method is used.

11. A device manufacturing method including a lithography process wherein

the exposure method of claim 1 is performed to expose a photosensitive object a plurality of times.

12. An exposure method in which a plurality of times of exposure is performed on a same photosensitive object, said method comprising:

a process in which under a first exposure condition where a substantial wavelength of said exposure light in a space between an optical member and said photosensitive object is a first wavelength, said photosensitive object is exposed by said exposure light of said first wavelength; and

a process in which under a second exposure condition where a substantial wavelength of said exposure light in a space between said optical member and said photosensitive object is a second wavelength different from said first wavelength, said photosensitive object is exposed by said exposure light of said second wavelength.

13. The exposure method according to claim 12 wherein

exposure under said first exposure condition is an immersion exposure performed in a state where said space is filled with a predetermined liquid.

14. The exposure method according to claim 13 wherein

exposure under said second exposure condition is an immersion exposure performed in a state where said space is filled with another liquid different from said predetermined liquid.

15. The exposure method according to claim 14 wherein

said predetermined liquid has a refractive index different from said another liquid.

16. The exposure method according to claim 15 wherein

said predetermined liquid has a refractive index larger than said another liquid.

17. The exposure method according to claim 14 wherein

said another liquid has solubility to a specific material contained within a photosensitive agent of said photosensitive object different from said predetermined liquid.

18. The exposure method according to claim 17 wherein

said another liquid has solubility to said specific material contained within said photosensitive agent of said photosensitive object smaller than said predetermined liquid.

19. The exposure method according to claim 13 wherein

exposure under said second exposure condition is a dry exposure performed in a state where said space is not filled with liquid.

20. The exposure method according to claim 19 wherein

said exposure under said first exposure condition is performed prior to said exposure under said second condition.

21. The exposure method according to claim 19 wherein

said exposure under said first exposure is performed after said exposure under said second exposure has been performed.

22. The exposure method according to claim 12 wherein

wavelength of exposure light made to enter said optical member in exposure under said first exposure condition is different from the wavelength of exposure light in exposure under said second exposure condition.

23. The exposure method according to claim 12 wherein

in said exposure under said first exposure condition, a phase shift method is used.

24. The exposure method according to claim 12 wherein

said exposure under said first exposure condition and said exposure under said second exposure condition are severally executed in a different exposure apparatus.

25. The exposure method according to claim 12 wherein

said exposure under said first exposure condition and said exposure under said second exposure condition are severally executed in a same exposure apparatus.

26. A device manufacturing method including a lithography process wherein

the exposure method of claim 12 is performed to expose a photosensitive object a plurality of times.

27. An exposure apparatus that performs a plurality of times of exposure on a same photosensitive object, said apparatus comprising:

a stage that holds said photosensitive object;

a projection optical system that projects an exposure light on said photosensitive object;

an adjustment unit that adjusts a substantial wavelength of said exposure light in a space between said projection optical system and said photosensitive object; and

a control unit that controls said adjustment unit when exposing said photosensitive object a plurality of times so that in at least one exposure of said plurality of times, said substantial wavelength of said exposure light in said space is different from the wavelength in another exposure.

28. The exposure apparatus according to claim 27 wherein

said adjustment unit comprises a liquid supply mechanism that supplies a predetermined liquid so that in a space between said projection optical system and said stage, at least a space between said projection optical system and said photosensitive object on said stage is filled with said liquid, whereby

said control unit controls said adjustment unit so that said liquid supply mechanism supplies said liquid to said space between said projection optical system and said photosensitive object on said stage in said at least one exposure, whereas in said another exposure said liquid supply mechanism does not supply said liquid to said space.

29. The exposure apparatus according to claim 27 wherein

said adjustment unit comprises a liquid supply mechanism that supplies any one liquid of a plurality of types of liquid so that in a space between said projection optical system and said stage, at least a space between said projection optical system and said photosensitive object on said stage is filled with said liquid, whereby

said control unit controls said adjustment unit so that said liquid supply mechanism supplies a predetermined liquid of said plurality of types of liquid to said space between said projection optical system and said photosensitive object on said stage in said at least one exposure, whereas in said another exposure said liquid supply mechanism supplies a liquid different from said predetermined liquid to said space.

30. A device manufacturing method including a lithography process wherein

a device pattern is transferred onto a photosensitive object by using the exposure apparatus according to claim 27.

31. An exposure system that performs exposure on a same photosensitive object a plurality of times, said system comprising:

a first exposure apparatus whose substantial wavelength of an exposure light in a space between a projection optical system, which projects said exposure light on said photosensitive object, and said photosensitive object is a predetermined length; and

a second exposure apparatus whose substantial wavelength of an exposure light in a space between a projection optical system, which projects said exposure light on said photosensitive object, and said photosensitive object is longer than said predetermined length.

32. The exposure system according to claim 31 wherein

in said first exposure apparatus, a predetermined liquid is filled between said projection optical system and said photosensitive object when said exposure light is projected on said photosensitive object.

33. The exposure system according to claim 32 wherein

in said second exposure apparatus, another liquid having a refractive index smaller than said predetermined liquid is filled between said projection optical system and said photosensitive object when said exposure light is projected on said photosensitive object.

34. The exposure system according to claim 32 wherein

in said second exposure apparatus, liquid does not exist between said projection optical system and said photosensitive object when said exposure light is projected on said photosensitive object.

35. The exposure system according to claim 31 wherein

said first exposure apparatus is larger than said second exposure apparatus in number.

36. The exposure system according to claim 31, wherein

oscillation wavelength of a light source emitting said exposure light of said first exposure apparatus is different from oscillation wavelength of a light source emitting said exposure light of said second exposure apparatus.

37. A device manufacturing method including a lithography process wherein

a device pattern is transferred onto a photosensitive object by using the exposure system according to claim 31.