Movable body system, pattern formation apparatus, exposure apparatus and exposure method, and device manufacturing method

• US 20100321666A1
• Filed: 08/25/2010
• Published: 12/23/2010
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Shibazaki, Yuichi
• Granted Patent: US 8,514,373 B2
• Time in Patent Office: Days
• US Class Current: 355/72
• CPC Class Codes: G01D 5/266 by interferometric means G01D5/353 takes precedence
• CPC Class Codes: G01D 5/305 controlling the movement of a following part
• CPC Class Codes: G03F 7/70758 Drive means, e.g. actuators, motors for long- or short-stroke modules or fine or coarse driving
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position

Abstract

A laser beam emitted by an encoder main body enters a wafer table via a PBS from the outside, and reaches a grating at a point that is located right under exposure area, and is diffracted by the grating. Then, by receiving interference light of a first polarized component that has returned from the grating and a second polarized component reflected by the PBS, positional information of the wafer table is measured. Accordingly, because the first polarized component, which has passed through PBS passes through the wafer table until it is synthesized with the second polarized component again, does not proceed through the atmosphere outside, position measurement of the wafer table can be performed with high precision without the measurement beam being affected by the fluctuation of the atmosphere around the wafer table.

Claims

1. An exposure apparatus that exposes a substrate with an illumination beam via an optical system, the apparatus comprising:

a stage system, on a front surface side of which the substrate is mounted, which has a holding member where a grating is placed and a movable member where the holding member is mounted, on its rear surface side, and which moves the substrate in a predetermined plane orthogonal to an optical axis of the optical system; and

an encoder system which has an optical member placed on a rear surface side of the holding member, and measures positional information of the holding member via the optical member, the optical member emitting a measurement beam to irradiate the grating and a reflected beam from the grating entering the optical member, wherein

a measurement point on which the measurement beam is irradiated is set within an exposure area on which the illumination beam is irradiated via the optical system.

2. The exposure apparatus according to claim 1, wherein

the measurement point is set at a center of the exposure area or in the vicinity of the center.

3. The exposure apparatus according to claim 1, wherein

the measurement point is set at a predetermined point where the holding member should be positioned or in the vicinity of the point.

4. The exposure apparatus according to claim 1, wherein

the encoder system measures positional information of the holding member in different directions by irradiating a plurality of the measurement beams on the grating via the optical member.

5. The exposure apparatus according to claim 4, wherein

the plurality of the measurement beams include measurement beams the measurement points of which are at different positions within the exposure area.

6. The exposure apparatus according to claim 5, wherein

the plurality of the measurement beams include measurement beams the measurement points of which are placed symmetrically with respect to an exposure center within the exposure area.

7. The exposure apparatus according to claim 1, wherein

the holding member has the grating placed on its one surface substantially parallel to the predetermined plane.

8. The exposure apparatus according to claim 7, wherein

the holding member has the grating arranged on its rear surface.

9. The exposure apparatus according to claim 1, further comprising:

a base member at which the movable member is placed; and

a planar motor that drives the movable member supported by levitation above the base member.

10. The exposure apparatus according to claim 9, wherein

the holding member is mounted on the movable member so as to be finely movable.

11. The exposure apparatus according to claim 1, further comprising:

a base member at which the movable member is placed, wherein

the optical member is placed lower than an upper surface of the base member.

12. The exposure apparatus according to claim 11, wherein

the movable member is supported by levitation above the base member and is moved by a planar motor.

13. The exposure apparatus according to claim 12, wherein

the movable member is supported by levitation by a magnetic force.

14. The exposure apparatus according to claim 11, wherein

the base member has a light-transmitting section, which the measurement beam passes through, on its upper surface.

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

a support section on which the optical system is mounted, wherein

the optical member is supported by the support section.

16. The exposure apparatus according to claim 15, further comprising:

a base member that is supported by suspension by the support section, wherein

the optical member is arranged at the base member.

17. The exposure apparatus according to claim 16, wherein

the base member has a light-transmitting section which, the measurement beam passes through, on its upper surface.

18. The exposure apparatus according to claim 1, wherein

the holding member has a protective member that covers the grating.

19. The exposure apparatus according to claim 18, wherein

the protective member includes a thin film.

20. A device manufacturing method, comprising:

exposing a substrate using the exposure apparatus according to claim 1; and

developing the exposed substrate.

21. An exposure method of exposing a substrate with an illumination beam via an optical system, the method comprising:

moving the substrate in a predetermined plane orthogonal to an optical axis of the optical system, by a stage system on a front surface side of which the substrate is mounted and which has a holding member where a grating is placed and a movable member where the holding member is mounted, on its rear surface side; and

measuring positional information of the holding member, by an encoder system having an optical member which is placed on a rear surface side of the holding member and emits a measurement beam to irradiate the grating, and which a reflected beam from the grating enters; and

positioning the substrate with respect to the illumination beam by moving the holding member based on the positional information that has been measured, wherein

a measurement point on which the measurement beam is irradiated is set within an exposure area on which the illumination beam is irradiated via the optical system.

22. The exposure method according to claim 21, wherein

the measurement point is set at a center of the exposure area or in the vicinity of the center.

23. The exposure method according to claim 21, wherein

the measurement point is set at a predetermined point where the holding member should be positioned or in the vicinity of the point.

24. The exposure method according to claim 21, wherein

positional information of the holding member in different directions is measured by irradiating a plurality of the measurement beams on the grating via the optical member.

25. The exposure method according to claim 24, wherein

the plurality of the measurement beams include measurement beams the measurement points of which are at different positions within the exposure area.

26. The exposure method according to claim 25, wherein

the plurality of the measurement beams include measurement beams the measurement points of which are placed symmetrically with respect to an exposure center within the exposure area.

27. The exposure method according to claim 21, wherein

the holding member has the grating placed on its one surface substantially parallel to the predetermined plane.

28. The exposure method according to claim 27, wherein

the holding member has the grating arranged on its rear surface.

29. The exposure method according to claim 21, wherein

the movable member is supported by levitation above a base member and is moved by a planar motor.

30. The exposure method according to claim 29, wherein

the holding member is finely movable with respect to the movable member.

31. The exposure method according to claim 21, wherein

the optical member is placed lower than an upper surface of a base member at which the movable member is placed.

32. The exposure method according to claim 31, wherein

the movable member is supported by levitation above the base member and is moved by a planar motor.

33. The exposure method according to claim 32, wherein

the movable member is supported by levitation by a magnetic force.

34. The exposure method according to claim 31, wherein

the measurement beam is irradiated on the grating via a light-transmitting section arranged on an upper surface of the base member.

35. The exposure method according to claim 21, wherein

the optical member is supported by a support section on which the optical system is mounted.

36. The exposure method according to claim 35, wherein

the optical member is arranged at a base member that is supported by suspension by the support section.

37. The exposure method according to claim 36, wherein

the measurement beam is irradiated on the grating via a light-transmitting section arranged on an upper surface of the base member.

38. The exposure method according to claim 21, wherein

the grating is covered with a protective member.

39. The exposure method according to claim 38, wherein

the protective member includes a thin film.

40. A device manufacturing method, comprising:

exposing a substrate using the exposure method according to claim 21; and

developing the exposed substrate.

41. A manufacturing method of an exposure apparatus that exposes a substrate with an illumination beam via an optical system, the method comprising:

providing a stage system, on a front surface side of which the substrate is mounted, which has a holding member where a grating is placed and a movable member where the holding member is mounted, on its rear surface side, and which moves the substrate in a predetermined plane orthogonal to an optical axis of the optical system; and

providing an encoder system which has an optical member placed on a rear surface side of the holding member, and measures positional information of the holding member via the optical member, the optical member emitting a measurement beam to irradiate the grating and a reflected beam from the grating entering the optical member, wherein

a measurement point on which the measurement beam is irradiated is set within an exposure area on which the illumination beam is irradiated via the optical system.

42. The manufacturing method according to claim 41, wherein

the measurement point is set at a center of the exposure area or in the vicinity of the center.

43. The manufacturing method according to claim 41, wherein

the measurement point is set at a predetermined point where the holding member should be positioned or in the vicinity of the point.

44. The manufacturing method according to claim 41, wherein

the optical member irradiates the grating with a plurality of the measurement beams that include measurement beams the measurement points of which are at different positions within the exposure area.

45. The manufacturing method according to claim 41, wherein

the holding member has the grating placed on its one surface substantially parallel to the predetermined plane.

46. The manufacturing method according to claim 41, further comprising:

providing a base member at which the movable member is placed; and

providing a planar motor that moves the movable member supported by levitation above the base member.

47. The manufacturing method according to claim 41, wherein

the optical member is placed lower than an upper surface of the base member at which the movable member is placed.

48. The manufacturing method according to claim 41, further comprising:

providing a support section on which the optical system is mounted, wherein the optical member is supported by the support section.

49. The manufacturing method according to claim 41, wherein

the grating is covered with a protective member.