Measuring apparatus and method, processing apparatus and method, pattern forming apparatus and method, exposure apparatus and method, and device manufacturing method
Position information of a movable body within an XY plane is measured with high accuracy by an encoder system whose measurement values have favorable short-term stability, without being affected by air fluctuations, and also position information of the movable body in a Z-axis direction orthogonal to the XY plane is measured with high accuracy by a surface position measuring system, without being affected by air fluctuations. In this case, since both of the encoder system and the surface position measuring system directly measure the upper surface of the movable body, simple and direct position control of the movable body can be performed.
1. An exposure apparatus that exposes a substrate with illumination light via a projection optical system, the apparatus comprising:
a frame member that supports the projection optical system;
a stage system that has a stage and a drive system, and is capable of moving the substrate in directions of six degrees of freedom, the stage being disposed below the projection optical system and having a holder to hold the substrate, the drive system having a motor to drive the stage, the directions of six degrees of freedom including a first direction and a second direction orthogonal to each other within a predetermined plane and a third direction orthogonal to the predetermined plane, and the predetermined plane being orthogonal to an optical axis of the projection optical system;
a first detection system that is provided at the frame member, away from the projection optical system, the first detection system being capable of setting a predetermined number of detection areas whose positions are different from each other in the first direction and capable of detecting marks of the substrate using detection beams by at least a part of the predetermined number of detection areas, respectively, the predetermined number being not less than three;
a second detection system that is provided at the frame member, away from the projection optical system, and detects positional information of the substrate in the third direction;
a measurement system that has a plurality of sensors, and measures positional information of the stage in the directions of six degrees of freedom, the plurality of sensors each irradiating a grating member with a measurement beam, and the grating member having a reflective grating that is periodic in a direction parallel to the predetermined plane; and
a controller that is coupled to the stage system, and controls the drive system based on measurement information of the measurement system, wherein
the positional information of the stage is measured with the measurement system in each of a first detection operation of detecting the mark with the first detection system, a second detection operation of detecting the substrate with the second detection system, and an exposure operation of the substrate, and
the controller
controls the drive system so that, in the first detection operation, the substrate is moved in the second direction relative to the predetermined number of detection areas in order to detect a plurality of marks of the substrate by at least a part of the predetermined number of detection areas, positions of the plurality of marks being different from each other in the second direction, wherein when performing detection of the plurality of marks whose positions are different from each other in the second direction, the predetermined number at a maximum of the marks can be detected concurrently with the detection areas irradiated with the detection beams from the first detection system, and
controls the drive system so that, in the exposure operation, alignment of the substrate is performed based on detection information of the first detection system and also focus-leveling control of the substrate is performed based on detection information of the second detection system, in the focus-leveling control a relative positional relationship between a pattern image projected via the projection optical system and the substrate being adjusted based on the detection information of the second detection system.
2. The exposure apparatus according to claim 1 , wherein
the stage has a fiducial mark on an upper surface of the stage,
the controller controls the drive system so that the fiducial mark is placed in one of the predetermined number of detection areas, in order to detect the fiducial mark with the first detection system, and
the positional information of the stage is measured with the measurement system in a detection operation of the fiducial mark, and detection information of the fiducial mark is used in the exposure operation.
3. The exposure apparatus according to claim 2 , wherein
the stage has a slit pattern on the upper surface, and
the exposure apparatus further comprises:
an aerial image measuring device that detects, via the slit pattern, a mark image projected via the projection optical system, wherein
the controller controls the drive system so that the mark image is projected on the slit pattern, and
the positional information of the stage is measured with the measurement system in a detection operation of the mark image, and detection information of the mark image is used in the exposure operation.
4. The exposure apparatus according to claim 3 , wherein
measurement information of the measurement system in the detection operation of the mark image and the detection information of the mark image are used for the alignment.
5. The exposure apparatus according to claim 3 , wherein
the controller controls the drive system so that the mark image is detected, via the slit pattern, at each of positions that are different from each other in the third direction, and
the detection information of the mark image is used in the focus-leveling control.
6. The exposure apparatus according to claim 3 , wherein
the stage has the holder provided in a recessed portion on an upper surface of the stage, and
the fiducial mark and the slit pattern are provided at a measurement member disposed in an opening of the upper surface, the opening being different from the recessed portion.
7. The exposure apparatus according to claim 6 , wherein
the stage system has a reference member having a mark that is detectable with the first detection system,
the reference member is placed below the first detection system so that the mark of the reference member is detected with each of the predetermined number of detection areas, and
the controller acquires positional information of the predetermined number of detection areas used in the exposure operation, based on detection information of the mark of the reference member.
8. The exposure apparatus according to claim 7 , wherein
the reference member is different from the measurement member, and
the first detection system detects the fiducial mark of the stage with a part of the predetermined number of detection areas, and detects the mark of the reference member with all of the predetermined number of detection areas.
9. The exposure apparatus according to claim 8 , wherein
in the reference member, the mark is formed in a predetermined area extending in the first direction so that the mark is almost simultaneously detected with the predetermined number of detection areas.
10. The exposure apparatus according to claim 9 , wherein
the stage system has another stage that is provided with the reference member and is different from the stage, and
the reference member is placed below the first detection system, by another stage, and positional information of the another stage is measured with the measurement system in a detection operation of the mark of the reference member.
11. The exposure apparatus according to claim 3 , wherein
in the first detection system, a distance or a relative positional relationship between the predetermined number of detection areas is variable in at least the first direction.
12. The exposure apparatus according to claim 11 , wherein
in the first detection system, a distance or a relative positional relationship between the predetermined number of detection areas is variable in the second direction.
13. The exposure apparatus according to claim 11 , wherein
in the first detection system, a part of the predetermined number of detection areas is movable, and the part of the predetermined number of detection areas is moved relative to the rest of the predetermined number of detection areas so that a distance or a relative positional relationship between the predetermined number of detection areas is changed.
14. The exposure apparatus according to claim 13 , wherein
the first detection system has a predetermined number of optical systems and a drive section, the predetermined number of optical systems irradiating the predetermined number of detection areas with detection lights, respectively, and the drive section moving a part of the predetermined number of optical systems so that a distance or a relative positional relationship between the predetermined number of detection areas is changed.
15. The exposure apparatus according to claim 14 , wherein
the first detection system has a sensor, the sensor measuring positional information of the optical system that is moved by the drive section.
16. The exposure apparatus according to claim 3 , wherein
in a detection operation of the mark of the substrate in which the substrate is moved in the second direction relative to the predetermined number of detection areas, at least one of the number of the detection areas of the first detection system used in detection of the mark and the number of the marks detected with the first detection system is different at positions that are different from each other in the second direction.
17. The exposure apparatus according to claim 3 , further comprising:
a nozzle unit provided to surround a lens that is disposed closest to an image plane side, of a plurality of optical elements of the projection optical system, the nozzle unit forming a liquid immersion area with a liquid under the projection optical system, wherein
the substrate is exposed via the projection optical system and the liquid of the liquid immersion area,
the mark image is detected, via the liquid of the liquid immersion area and the slit pattern, with the aerial image measuring device, and
the mark of the substrate and the fiducial mark of the stage are detected, not via the liquid, with the first detection system.
18. The exposure apparatus according to claim 17 , wherein
the nozzle unit has a supply opening and a recovery opening for the liquid and a lower surface disposed lower than an emitting surface of the lens, and supplies the liquid to the liquid immersion area via the supply opening and recovers the liquid of the liquid immersion area via the recovery opening.
19. The exposure apparatus according to claim 18 , wherein
the nozzle unit is provided at the frame member or another frame member different from the frame member.
20. The exposure apparatus according to claim 18 , wherein
the stage has the holder provided in a recessed portion on an upper surface of the stage, and holds the substrate in the recessed portion so that a surface of the substrate is substantially flush with the upper surface.
21. The exposure apparatus according to claim 18 , wherein
the first detection system and the second detection system are disposed on one side of the projection optical system in the second direction, away from the projection optical system, and
at least a part of the detection operation of the substrate with the second detection system is performed in parallel with the detection operation of the mark with the first detection system.
22. The exposure apparatus according to claim 18 , wherein
one sensor used in the measurement is switched to another sensor, of the plurality of sensors, according to movement of the stage.
23. The exposure apparatus according to claim 22 , wherein
the number of sensors that face the reflective grating, of the plurality of sensors, is changed according to movement of the stage.
24. The exposure apparatus according to claim 18 , further comprising:
a mask stage system that has a mask stage and another drive system, the mask stage being disposed above the projection optical system and holding a mask illuminated with the illumination light, and the another drive system being different from the drive system and driving the mask stage; and
an encoder system different from the measurement system, that measures positional information of the mask stage, wherein
in the exposure operation, scanning exposure of the substrate in which the mask and the substrate are each moved relative to the illumination light is performed, and during the scanning exposure, the mask stage is moved based on measurement information of the encoder system and the stage is moved based on measurement information of the measurement system.
25. The exposure apparatus according to claim 24 , wherein
the controller controls at least one of the mask stage system and the stage system so that a measurement error of the measurement system that occurs due to the grating member is compensated for.
26. A device manufacturing method, comprising:
exposing a substrate using the exposure apparatus according to claim 1 ; and
developing the substrate that has been exposed.
27. An exposure method of exposing a substrate with illumination light via a projection optical system, the method comprising:
below a first detection system capable of setting a predetermined number of detection areas whose positions are different from each other in a first direction within a predetermined plane, moving the substrate relative to the predetermined number of detection areas in a second direction orthogonal to the first direction within the predetermined plane so that a plurality of marks of the substrate whose positions are different from each other in the second direction are detected using detection beams by at least a part of the predetermined number of detection areas, respectively, the predetermined number being not less than three, the first detection system being provided at a frame member to be away from the projection optical system, the frame member supporting the projection optical system, and the predetermined plane being orthogonal to an optical axis of the projection optical system;
detecting positional information of the substrate in a third direction orthogonal to the predetermined plane, with a second detection system that is provided at the frame member, away from the projection optical system;
measuring positional information of the stage in directions of six degrees of freedom, with a measurement system that has a plurality of sensors, the directions of six degrees of freedom including the first direction, the second direction and the third direction, the plurality of sensors each irradiating a grating member with a measurement beam, and the grating member having a reflective grating that is periodic in a direction parallel to the predetermined plane; and
controlling movement of the stage based on measurement information of the measurement system, wherein
when performing detection of the plurality of marks whose positions are different from each other in the second direction, the predetermined number at a maximum of the marks can be detected concurrently with the detection areas irradiated with the detection beams from the first detection system,
the positional information of the stage is measured with the measurement system in each of a first detection operation of detecting the mark with the first detection system, a second detection operation of detecting the substrate with the second detection system, and an exposure operation of the substrate, and
the stage is moved so that, in the exposure operation, alignment of the substrate is performed based on detection information of the first detection system and also focus-leveling control of the substrate is performed based on detection information of the second detection system, in the focus-leveling control a relative positional relationship between a pattern image projected via the projection optical system and the substrate being adjusted based on the detection information of the second detection system.
28. The exposure method according to claim 27 , wherein
in order to detect a fiducial mark of the stage with the first detection system, the stage is moved so that the fiducial mark is placed in one of the predetermined number of detection areas, and
the positional information of the stage is measured with the measurement system in a detection operation of the fiducial mark, and detection information of the fiducial mark is used in the exposure operation.
29. The exposure method according to claim 28 , wherein
in order to detect, via a slit pattern of the stage, a mark image projected via the projection optical system, the stage is moved so that the mark image is projected on the slit pattern, and
the positional information of the stage is measured with the measurement system in a detection operation of the mark image, and detection information of the mark image is used in the exposure operation.
30. The exposure method according to claim 29 , wherein
measurement information of the measurement system in the detection operation of the mark image and the detection information of the mark image are used for the alignment.
31. The exposure method according to claim 29 , wherein
the stage is moved so that the mark image is detected, via the slit pattern, at each of positions that are different from each other in the third direction, and
the detection information of the mark image is used in the focus-leveling control.
32. The exposure method according to claim 29 , wherein
the substrate is held in a recessed portion on an upper surface of the stage, and
the fiducial mark and the slit pattern are provided at a measurement member disposed in an opening of the upper surface, the opening being different from the recessed portion.
33. The exposure method according to claim 32 , wherein
in order to acquire positional information of the predetermined number of detection areas used in the exposure operation, a reference member is placed below the first detection system so that a mark of the reference member is detected with each of the predetermined number of detection areas.
34. The exposure method according to claim 33 , wherein
the reference member is different from the measurement member, and
the fiducial mark of the stage is detected with a part of the predetermined number of detection areas, and the mark of the reference member is detected with all of the predetermined number of detection areas.
35. The exposure method according to claim 34 , wherein
in a detection operation of the reference member with the first detection system, the mark of the reference member is almost simultaneously detected with the predetermined number of detection areas.
36. The exposure method according to claim 35 , wherein
the reference member is placed below the first detection system, by another stage that is provided with the reference member and is different from the stage, and in a detection operation of the mark of the reference member, positional information of the another stage is measured with the measurement system.
37. The exposure method according to claim 29 , wherein
a distance or a relative positional relationship between the predetermined number of detection areas is adjusted in at least the first direction.
38. The exposure method according to claim 37 , wherein
a distance or a relative positional relationship between the predetermined number of detection areas is adjusted in the second direction.
39. The exposure method according to claim 29 , wherein
in a detection operation of the mark of the substrate in which the substrate is moved in the second direction relative to the predetermined number of detection areas, at least one of the number of the detection areas of the first detection system used in detection of the mark and the number of the marks detected with the first detection system is different at positions that are different from each other in the second direction.
40. The exposure method according to claim 29 , wherein
a liquid immersion area is formed with a liquid under the projection optical system, by a nozzle unit provided to surround a lens that is disposed closest to an image plane side, of a plurality of optical elements of the projection optical system,
the substrate is exposed via the projection optical system and the liquid of the liquid immersion area, and the mark image is detected via the liquid of the liquid immersion area and the slit pattern, and
the mark of the substrate and the fiducial mark of the stage are detected, not via the liquid, with the first detection system.
41. The exposure method according to claim 40 , wherein
the nozzle unit has a supply opening and a recovery opening for the liquid and a lower surface disposed lower than an emitting surface of the lens, and supplies the liquid to the liquid immersion area via the supply opening and recovers the liquid of the liquid immersion area via the recovery opening.
42. The exposure method according to claim 41 , wherein
the nozzle unit is provided at the frame member or another frame member different from the frame member.
43. The exposure method according to claim 41 , wherein
the substrate is held in a recessed portion on an upper surface of the stage so that a surface of the substrate is substantially flush with the upper surface.
44. The exposure method according to claim 41 , wherein
the first detection system and the second detection system are disposed on one side of the projection optical system in the second direction, away from the projection optical system, and
at least a part of the detection operation of the substrate with the second detection system is performed in parallel with the detection operation of the mark with the first detection system.
45. The exposure method according to claim 41 , wherein
one sensor used in the measurement is switched to another sensor, of the plurality of sensors, according to movement of the stage.
46. The exposure method according to claim 45 , wherein
the number of sensors that face the reflective grating, of the plurality of sensors, is changed according to movement of the stage.
47. The exposure method according to claim 41 , wherein
a mask illuminated with the illumination light is held by a mask stage disposed above the projection optical system, and positional information of the mask stage is measured by an encoder system different from the measurement system, and
in the exposure operation, scanning exposure of the substrate in which the mask and the substrate are each moved relative to the illumination light is performed, and during the scanning exposure, the mask stage is moved based on measurement information of the encoder system and the stage is moved based on measurement information of the measurement system.
48. The exposure method according to claim 47 , wherein
at least one of the mask stage and the stage is moved so that a measurement error of the measurement system that occurs due to the grating member is compensated for.
49. A device manufacturing method, comprising:
exposing a substrate using the exposure method according to claim 27 ; and
developing the substrate that has been exposed.
50. A making method of an exposure apparatus that exposes a substrate with illumination light via a projection optical system, the method comprising:
supporting the projection optical system with a frame member;
providing a stage system that has a stage and a drive system, and is capable of moving the substrate in directions of six degrees of freedom, the stage being disposed below the projection optical system and having a holder to hold the substrate, the drive system having a motor to drive the stage, the directions of six degrees of freedom including a first direction and a second direction orthogonal to each other within a predetermined plane and a third direction orthogonal to the predetermined plane, and the predetermined plane being orthogonal to an optical axis of the projection optical system;
providing a first detection system at the frame member to be away from the projection optical system, the first detection system being capable of setting a predetermined number of detection areas whose positions are different from each other in the first direction and capable of detecting marks of the substrate using detection beams by at least a part of the predetermined number of detection areas, respectively, and the predetermined number being not less than three;
providing a second detection system at the frame member to be away from the projection optical system, the second detection system detecting positional information of the substrate in the third direction;
providing a measurement system that has a plurality of sensors, and measures positional information of the stage in the directions of six degrees of freedom, the plurality of sensors each irradiating a grating member with a measurement beam, and the grating member having a reflective grating that is periodic in a direction parallel to the predetermined plane; and
providing a controller that controls the drive system based on measurement information of the measurement system, wherein
the positional information of the stage is measured with the measurement system in each of a first detection operation of detecting the mark with the first detection system, a second detection operation of detecting the substrate with the second detection system, and an exposure operation of the substrate, and
the controller
controls the drive system so that, in the first detection operation, the substrate is moved in the second direction relative to the predetermined number of detection areas in order to detect a plurality of marks of the substrate by at least a part of the predetermined number of detection areas, positions of the plurality of marks being different from each other in the second direction, wherein when performing detection of the plurality of marks whose positions are different from each other in the second direction, the predetermined number at a maximum of the marks can be detected concurrently with the detection areas irradiated with the detection beams from the first detection system, and
controls the drive system so that, in the exposure operation, alignment of the substrate is performed based on detection information of the first detection system and also focus-leveling control of the substrate is performed based on detection information of the second detection system, in the focus-leveling control a relative positional relationship between a pattern image projected via the projection optical system and the substrate being adjusted based on the detection information of the second detection system.