Exposure apparatus, exposure method, and device fabricating method

• US 20070070323A1
• Filed: 09/20/2006
• Published: 03/29/2007
• Est. Priority Date: 09/21/2005
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nagasaka, Hiroyuki
• Application Number:
  US11/523,589
• Publication Number:
  US 20070070323A1
• Time in Patent Office: Days
• US Class Current: 355/71
• CPC Class Codes: G02B 13/143 for use with ultraviolet radiation
• CPC Class Codes: G02B 21/33 Immersion oils , or microscope systems or objectives for use with immersion fluids
• 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

An exposure apparatus is provided with an optical element, which has a concave surface from which an exposure light emerges, and a surface, which is provided so that it surrounds the optical path of the exposure light. An interface of a liquid of an immersion region is held between the surface and an object, which is disposed at a position where it can be irradiated by the exposure light.

Claims

1. An exposure apparatus that exposes a substrate through an immersion region, comprising:

an optical element that has a concave surface from which exposure light emerges; and

a surface that is provided to surround an optical path of the exposure light, an interface of a liquid of the immersion region being held between the surface and an object, the object being disposed at a position where the object can be irradiated by the exposure light.

2. An exposure apparatus according to claim 1, wherein at least one of a liquid immersion condition, which is for forming the immersion region, and a surface condition is set so that the interface of the liquid is held between the object and the surface by a surface tension of the liquid.

3. An exposure apparatus according to claim 2, wherein at least one of the liquid immersion condition and the surface condition is set in accordance with an object front surface condition.

4. An exposure apparatus according to claim 3, wherein the front surface condition of the object includes a contact angle condition of the liquid at the front surface of the object.

5. An exposure apparatus according to claim 2, wherein the surface condition includes at least one of a distance condition between the object and the surface, and the contact angle condition of the liquid at the surface.

6. An exposure apparatus according to claim 2, wherein the liquid immersion condition includes a condition related to at least one of a density of the liquid and an amount of the liquid.

7. An exposure apparatus according to claim 6, wherein the condition related to the amount of the liquid includes at least one of a distance condition between the object and a position of the concave surface that is farthest from the object, and a condition related to the size of the immersion region in the radial direction.

8. An exposure apparatus according to claim 1, further comprising:

an adjustment apparatus that adjusts a density of the liquid that is supplied between the concave surface and the object.

9. An exposure apparatus according to claim 2, wherein

the condition of ρ

×

g×

h<

(γ

×

(cos θ

₁+cos θ

₂)/d)+(γ

/R)+P_A is satisfied, wherein

ρ

;

density of the liquid;

g;

gravitational acceleration;

h;

distance between the object and the position of the concave surface that is farthest from the object;

γ

;

surface tension of the liquid;

θ

₁;

contact angle of the front surface of the object with respect to the liquid;

θ

₂;

contact angle of the surface with respect to the liquid;

d;

distance between the object and the surface;

R;

radius of the immersion region; and

P_A;

pressure of the surroundings of the immersion region.

10. An exposure apparatus according to claim 1, wherein the object includes the substrate.

11. An exposure apparatus according to claim 1, wherein the surface is part of a nozzle member that has at least one of a supply port that supplies the liquid and a recovery port that recovers the liquid.

12. An exposure apparatus according to claim 1, wherein the surface is part of a holding member that holds the optical element.

13. An exposure apparatus according to claim 1, wherein the surface is part of the optical element.

14. An exposure apparatus according to claim 1, wherein a refractive index of the liquid with respect to the exposure light is higher than that of the optical element with respect to the exposure light.

15. An exposure apparatus according to claim 1, further comprising:

a projection optical system that projects a pattern image onto the substrate;

wherein,

the optical element that has the concave surface is an element of a plurality of optical elements of the projection optical system that is closest to an image plane of the projection optical system.

16. An exposure method, comprising:

forming an immersion region so that a space between an object and a concave surface of an optical element is filled with a liquid, an interface of the liquid being positioned between the object and a surface, the surface being provided to surround the optical path of exposure light; and

exposing a substrate through the immersion region.

17. An exposure method according to claim 16, wherein at least one of a object front surface condition, a surface condition, and a liquid immersion condition, which is for forming the immersion region, is set so that the interface of the liquid is positioned between the object and the surface by a surface tension of the liquid.

18. An exposure method according to claim 17, wherein

the condition of ρ

×

g×

h<

(γ

×

(cos θ

₁+cos θ

₂)/d)+(γ

/R)+P_A is satisfied, wherein

ρ

;

density of the liquid;

g;

gravitational acceleration;

h;

distance between the object and the position of the concave surface that is farthest from the object;

γ

;

surface tension of the liquid;

θ

₁;

contact angle of the front surface of the object with respect to the liquid;

θ

₂;

contact angle of the surface with respect to the liquid;

d;

distance between the object and the surface;

R;

radius of the immersion region; and

P_A;

pressure of the surroundings of the immersion region.

19. An exposure method according to claim 16, wherein the object includes the substrate.

20. A device fabricating method, wherein an exposure method according to claim 16 is used.

21. An exposure apparatus that exposes a substrate by radiating exposure light onto the substrate, comprising:

a projection optical system that projects a pattern image onto the substrate and that comprises a first optical element, the first optical element having a first surface that the exposure light impinges and a second surface from which the exposure light emerges;

wherein,

the first surface and the second surface are substantially concentric and are spherical surfaces; and

the first optical element is an element of a plurality of optical elements of the projection optical system that is closest to an image plane of the projection optical system.

22. An exposure apparatus according to claim 21, further comprising:

a support apparatus that rotatably supports the first optical element with a center of curvature of the first surface and the second surface as a center of rotation.

23. An exposure apparatus according to claim 21, wherein the space between the substrate and the second surface of the first optical element is filled with a liquid through which the exposure light passes.

24. An exposure apparatus according to claim 23, wherein a refractive index of the liquid with respect to the exposure light is higher than that of the first optical element with respect to the exposure light.

25. An exposure apparatus according to claim 23, wherein a numerical aperture of the projection optical system is greater than a refractive index of the first optical element with respect to the exposure light.

26. An exposure apparatus according to claim 23, wherein the space between the first optical element and a second optical element that, after the first optical element, is the element that is closest to the image plane, is also filled with a liquid.

27. An exposure apparatus according to claim 23, wherein the substrate is exposed while moving the first optical element and the substrate relative to one another in a state wherein the liquid is filled between the second surface of the first optical element and the substrate.

28. An exposure apparatus according to claim 23, further comprising:

a support apparatus that rotatably supports the first optical element with a center of curvature of the first surface and the second surface of the first optical element as a center of rotation.

29. An exposure apparatus according to claim 28, wherein

the substrate is exposed while moving the first optical element and the substrate relative to one another in a first direction;

and

the support apparatus rotatably supports the first optical element about an axis that passes through the center of curvature and that is parallel to a second direction, which intersects the first direction.

30. An exposure apparatus according to claim 23, further comprising:

a third surface that is disposed on the outer side of the second surface with respect to the optical axis of the first optical element;

wherein,

the liquid is held between the second surface and the substrate, and between the substrate and at least part of the third surface.

31. An exposure apparatus according to claim 30, wherein the third surface is provided to oppose the substrate front surface.

32. An exposure apparatus according to claim 30, wherein the third surface is formed to be substantially perpendicular to the optical axis of the first optical element and to surround the second surface.

33. An exposure apparatus according to claim 30, further comprising:

a fourth surface, which is provided on the outer side of the third surface with respect to the optical axis of the first optical element and that faces the optical axis.

34. An exposure apparatus according to claim 33, wherein the fourth surface is provided at a position that is closer to the substrate front surface than that of the third surface.

35. An exposure apparatus according to claim 33, wherein the fourth surface is provided in order to reduce the force of the liquid that acts upon the second surface of the first optical element.

36. An exposure apparatus according to claim 33, wherein the fourth surface is provided so that the pressure of the liquid that acts upon the second surface of the first optical element is smaller than the pressure of the liquid that acts upon the third surface.

37. An exposure apparatus according to claim 33, wherein a member that has the fourth surface is a member that is separate from the member that has the third surface.

38. An exposure apparatus according to claim 30, wherein a member that has the third surface includes a member that supports the first optical element.

39. An exposure apparatus that exposes a substrate by radiating exposure light onto the substrate, comprising:

an optical element that has a concave surface part from which the exposure light emerges;

a lower surface that is provided to surround the concave surface part; and

a side surface that is provided on the outer side of the lower surface with respect to the optical axis of the optical element and that faces the optical axis.

40. An exposure apparatus according to claim 39, wherein

the concave surface part of the optical element is a curved surface that is concave in a direction away from the substrate;

a liquid is filled between the concave surface part and the substrate; and

the side surface is provided so that the pressure of the liquid that acts upon the concave surface part decreases in a direction that intersects the optical axis direction of the optical element.

41. An exposure apparatus according to claim 40, wherein the side surface is provided so that the pressure of the liquid that acts upon the concave surface part in a direction that intersects the optical axis direction of the optical element falls below the pressure of the liquid that acts upon the lower surface in the optical axis direction of the optical element.

42. An exposure apparatus according to claim 39, further comprising:

a support member that supports the optical element;

wherein,

the lower surface is formed in the optical element or the support member.

43. An exposure apparatus according to claim 42, wherein the member that has the side surface is a member that is separate from the optical element and the support member.

44. An exposure method that exposes a substrate by radiating exposure light onto the substrate, comprising:

radiating the exposure light to an optical element, the optical element opposing a front surface of the substrate and having a concave surface part from which the exposure light emerges; and

irradiating the substrate with the exposure light in a state in which a liquid is filled between the concave surface part of the optical element and a front surface of the substrate;

wherein

the liquid is contacted with a lower surface, which is provided to surround the concave surface part, and a side surface, which is provided on the outer side of the lower surface with respect to the optical axis of the optical element and that faces the optical axis.

45. An exposure method according to claim 44, wherein

the concave surface part of the optical element is a curved surface that is convex in a direction away from the substrate;

and

the side surface is disposed so that the pressure of the liquid that acts upon the concave surface part decreases in a direction that intersects the optical axis direction of the optical element.

46. A device fabricating method, wherein an exposure method according to claim 45 is used.