Exposure Method, Exposure Apparatus, Method for Producing Device, and Method for Evaluating Exposure Apparatus

• US 20080212056A1
• Filed: 03/17/2006
• Published: 09/04/2008
• Est. Priority Date: 03/18/2005
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Shiraishi, Kenichi
• Granted Patent: US 8,638,422 B2
• Time in Patent Office: Days
• US Class Current: 355/53
• 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 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70516 Calibration of components of the microlithographic apparatus, e.g. light sources, addressable masks or detectors
• CPC Class Codes: G03F 7/70525 Controlling normal operating mode, e.g. matching different apparatus, remote control or prediction of failure
• CPC Class Codes: G03F 7/70616 Monitoring the printed patterns
• CPC Class Codes: G03F 7/70725 control
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position

Abstract

An exposure method includes a first step for measuring position information of a substrate while controlling a substrate stage to move the substrate stage in a state that an optical path space is filled with a liquid under a predetermined condition; a second step for obtaining a movement control accuracy of the substrate stage based on a result of the measurement; a third step for determining an exposure condition, for exposing the substrate, based on the obtained movement control accuracy; and a fourth step for exposing the substrate based on the determined exposure condition. This makes it possible to satisfactorily expose the substrate at the time of exposing the substrate based on the liquid immersion method.

Claims

1. An exposure method for exposing a substrate while moving the substrate held on a substrate stage with respect to an exposure light beam in a state that an optical path space for the exposure light beam is filled with a liquid, the method comprising:

a first step for measuring position information of the substrate held on the substrate stage while controlling the substrate stage to move the substrate stage in a state that the optical path space is filled with the liquid under a predetermined condition;

a second step for obtaining movement control accuracy of the substrate stage based on a result of the measurement;

a third step for determining, based on the obtained movement control accuracy, an exposure condition for exposing the substrate; and

a fourth step for exposing the substrate based on the determined exposure condition.

2. The exposure method according to claim 1, wherein in the fourth step, the substrate is exposed while synchronously moving the substrate stage and a mask stage, which is capable of moving a mask having a pattern, in a predetermined scanning direction;

and

the movement control accuracy includes a synchronization error between the mask stage and the substrate stage.

3. The exposure method according to claim 2, wherein position information of each of the mask and the substrate is measured while moving the mask stage and the substrate stage in the scanning direction, and the synchronization error is obtained based on a result of the measurement.

4. The exposure method according to claim 2, wherein a predetermined slit area on the mask is illuminated with the exposure light beam;

and

at least one of an average of the synchronization error, in a period of time from an arbitrary point on the substrate enters into the slit area to the arbitrary point exits from the slit area, and a degree of dispersion around the average of the synchronization error is obtained based on the synchronization error.

5. The exposure method according to claim 1, wherein the substrate stage is movable in a predetermined two-dimensional direction;

and

the movement control accuracy includes movement control accuracy in the two-dimensional direction.

6. The exposure method according to claim 1, wherein the substrate stage is movable in a predetermined two-dimensional direction;

and

the movement control accuracy includes movement control accuracy in a direction perpendicular to the two-dimensional direction.

7. The exposure method according to claim 6, wherein the movement control accuracy in the direction perpendicular to the two-dimensional direction includes a position error between a predetermined surface on the substrate stage and a target surface with which the predetermined surface is to be matched.

8. The exposure method according to claim 7, wherein the predetermined surface includes at least one of a surface of the substrate held on the substrate stage and a surface of a member disposed around the substrate held on the substrate stage.

9. The exposure method according to claim 7, wherein in the fourth step, the exposure light beam is irradiated onto the substrate in a state that an optical path space between the substrate and a projection optical system is filled with the liquid;

and

the target surface is determined based on an image plane formed via the projection optical system and the liquid.

10. The exposure method according to claim 1, wherein a liquid immersion area is formed, by filling the optical path space with the liquid, on at least one of a surface of the substrate held on the substrate stage and a surface of a member disposed around the substrate held on the substrate stage.

11. The exposure method according to claim 1, wherein the exposure condition includes a liquid immersion condition for filling the optical path space with the liquid.

12. The exposure method according to claim 11, wherein the liquid immersion condition includes at least one of a supply condition for supplying the liquid to the optical path space and a recovery condition for recovering the liquid.

13. The exposure method according to claim 1, wherein the exposure condition includes a moving condition of the substrate.

14. The exposure method according to claim 13, wherein the moving condition includes at least one of a moving speed, an acceleration/deceleration, and a moving direction of the substrate.

15. The exposure method according to claim 13, wherein the moving condition includes positional relationship between the optical path space and the substrate stage.

16. The exposure method according to claim 1, wherein the exposure condition includes a condition of an object which comes into contact with the liquid.

17. The exposure method according to claim 16, wherein the object includes at least one of the substrate held on the substrate stage and a member disposed around the substrate held on the substrate stage.

18. The exposure method according to claim 16, wherein the condition of the object includes a condition concerning a contact angle with the liquid.

19. The exposure method according to claim 16, wherein the condition of the object includes a condition concerning a film on a surface of the object.

20. The exposure method according to claim 1, wherein the exposure condition includes a blowing condition for blowing a gas toward the optical path space from an outer side of the optical path space.

21. The exposure method according to claim 1, wherein the first step and the second step are performed a plurality of times while changing the predetermined condition.

22. The exposure method according to claim 1, wherein the predetermined condition includes at least one of a liquid immersion condition for filling the optical path space with the liquid, a moving condition of the substrate, a condition of an object which comes into contact with the liquid, and a blowing condition for blowing a gas toward the optical path space from an outer side of the optical path space.

23. A method for producing a device, comprising:

exposing a substrate by using the exposure method as defined in claim 1;

developing the exposed substrate; and

processing the developed substrate.

24. An exposure apparatus which exposes a substrate through a liquid while filling a predetermined optical path space for an exposure light beam with the liquid, the apparatus comprising:

a substrate stage which moves the substrate while holding the substrate in a state that the optical path space is filled with the liquid under a predetermined condition;

a control unit which controls movement of the substrate stage; and

a measuring unit which measures position information of the substrate held by the substrate stage;

wherein the control unit obtains movement control accuracy of the substrate stage based on the position information of the substrate measured by the measuring unit when the substrate is being moved by the substrate stage, and the control unit determines an exposure condition based on the obtained movement control accuracy.

25. The exposure apparatus according to claim 24, further comprising a mask stage which is capable of moving a mask having a pattern,

wherein the control unit controls the mask stage and the substrate stage to expose the substrate while synchronously moving the mask stage and the substrate stage in a predetermined scanning direction;

and the movement control accuracy includes a synchronization error between the mask stage and the substrate stage.

26. The exposure apparatus according to claim 25, wherein the measuring unit measures position information of each of the mask and the substrate while moving the mask stage and the substrate stage in the scanning direction;

and the control unit obtains the synchronization error based on a result of the measurement.

27. The exposure apparatus according to claim 25, wherein when a predetermined slit area on the mask is illuminated by the exposure light beam, the control unit obtains, based on the synchronization error, at least one of an average of the synchronization error, in a period of time from an arbitrary point on the substrate enters into the slit area to the arbitrary point exits from the slit area, and a degree of dispersion around the average of the synchronization error.

28. The exposure apparatus according to claim 24, wherein the substrate stage is movable in a predetermined two-dimensional direction;

and

the movement control accuracy includes movement control accuracy in the two-dimensional direction or in a direction perpendicular to the two-dimensional direction.

29. The exposure apparatus according to claim 24, further comprising a projection optical system,

wherein the exposure light beam is irradiated onto the substrate in a state that an optical path space between the substrate and the projection optical system is filled with the liquid.

30. The exposure apparatus according to claim 24, further comprising a device which blows a gas toward the optical path space from an outer side of the optical path space.

31. The exposure apparatus according to claim 24, wherein the exposure condition includes at least one of a liquid immersion condition, a moving condition of the substrate, a condition of an object which comes into contact with the liquid, and a blowing condition for blowing a gas toward the optical path space from an outer side of the optical path space.

32. The exposure apparatus according to claim 24, wherein the predetermined condition includes at least one of a liquid immersion condition, a moving condition of the substrate, a condition of an object which comes into contact with the liquid, and a blowing condition for blowing a gas toward the optical path space from an outer side of the optical path space.

33. A method for producing a device using the exposure apparatus as defined in claim 24.

34. An evaluation method for evaluating control accuracy of an exposure apparatus which has a substrate stage capable of moving a substrate and which exposes the substrate while moving the substrate with respect to an exposure light beam in a state that an optical path space for the exposure light beam is filled with a liquid, the method comprising:

a first step for measuring position information of the substrate while controlling the substrate stage to move the substrate stage in a state that the optical path space is filled with the liquid under a predetermined condition; and

a second step for evaluating movement control accuracy of the substrate stage based on a result of the measurement.

35. An evaluation method for evaluating control accuracy of an exposure apparatus which has a substrate stage capable of moving a substrate and which exposes the substrate through a liquid while moving the substrate with respect to an exposure light beam, the method comprising:

a text-exposure step for text-exposing, under a predetermined exposure condition, a predetermined pattern onto the substrate through the liquid while moving the substrate stage;

a measurement step for measuring an exposure pattern test-exposed on the substrate; and

an evaluation step for evaluating movement control accuracy of the substrate stage from a result of the measurement of the exposure pattern.

36. The evaluation method according to claim 35, wherein the substrate is exposed through the liquid while synchronously moving the substrate and a mask having the predetermined pattern in a predetermined scanning direction;

and

the predetermined pattern includes a pattern extending in a direction orthogonal to the scanning direction.