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 and a liquid, the apparatus comprising:
a frame member that supports the projection optical system;
a base member placed below the projection optical system;
a local liquid immersion device that has a nozzle unit arranged surrounding an optical element of the projection optical system and forms a liquid immersion area under the projection optical system with a liquid supplied via the nozzle unit, the optical element contacting the liquid;
a stage system having a stage and a motor to drive the stage, that can move the substrate in directions of six degrees of freedom including a first direction and a second direction orthogonal to each other within a predetermined plane perpendicular to an optical axis of the projection optical system and a third direction orthogonal to the predetermined plane, the stage being placed on the base member and holding the substrate by a holder provided in a depressed part on an upper surface of the stage;
a first measurement system that has a plurality of sensors each irradiating a measurement beam to a grating member having a reflective grating periodic in a direction parallel to the predetermined plane, and that measures positional information of the stage in the third direction;
a second measurement system that is supported by the frame member, distanced from the projection optical system, and measures positional information in the third direction of a substrate held by the stage; and
a controller that, in an exposure operation of the substrate, controls the stage system based on the positional information measured by the first measurement system and the positional information measured by the second measurement system, to adjust a positional relation between a pattern image and the substrate, the pattern image being formed via the projection optical system and the liquid, wherein
a measurement operation of the substrate by the second measurement system is performed before the exposure operation, and
in each of the exposure operation and the measurement operation, positional information of the stage is measured by the first measurement system.
2. The exposure apparatus according to claim 1 , wherein
the first measurement system measures positional information of the stage in the first and the second directions by a sensor that irradiates a measurement beam on the reflective grating and receives a reflected beam from the reflective grating.
3. The exposure apparatus according to claim 2 , further comprising:
a detection system that is supported by the frame member, distanced from the projection optical system, and detects a mark of a substrate held by the stage, wherein
a detection operation of the substrate by the detection system is performed before the exposure operation, and
in the detection operation, positional information of the stage is measured by the first measurement system.
4. The exposure apparatus according to claim 3 , further comprising:
a mask stage system having a mask stage to hold a mask illuminated with the illumination light and a motor to drive the mask stage; and
an encoder system that measures positional information of the mask stage, wherein
in the exposure operation, positional information of the mask stage is measured by the encoder system and positional information of the stage is measured by the first measurement system.
5. The exposure apparatus according to claim 4 , wherein
the nozzle unit is provided at the frame member or another frame member different from the frame member so that a lower surface of the nozzle unit is placed closer to an upper surface of the stage that is placed facing the projection optical system, than to an emitting surface of the optical element.
6. The exposure apparatus according to claim 5 , wherein
the stage holds the substrate by the holder in the depressed part so that a surface of the substrate is substantially flush with the upper surface.
7. The exposure apparatus according to claim 6 , wherein
in the exposure operation, of the plurality of sensors, one sensor used in the measurement is switched to another sensor by a movement of the stage.
8. The exposure apparatus according to claim 7 , wherein
in the exposure operation, of the plurality of sensors, the number of sensors that face the reflective grating is changed by a movement of the stage.
9. The exposure apparatus according to claim 8 , wherein
the controller controls at least one of the mask stage system and the stage system so that a measurement error of the first detection system that occurs due to the grating member is compensated for.
10. A device manufacturing method comprising:
exposing a substrate using the exposure apparatus according to claim 1 ; and
developing the substrate that has been exposed.
11. An exposure method of exposing a substrate with illumination light via a projection optical system and a liquid, the method comprising:
forming, under the projection optical system, a liquid immersion area with a liquid that is supplied via a nozzle unit, by a local liquid immersion device that has the nozzle unit, the nozzle unit being arranged surrounding an optical element of the projection optical system, and the optical element contacting the liquid;
moving a stage that is placed on a base member placed below the projection optical system and holds the substrate by a holder provided in a depressed part on an upper surface of the stage, by a stage system that has the stage and a motor to drive the stage and can move the substrate in directions of six degrees of freedom including a first direction and a second direction orthogonal to each other within a predetermined plane perpendicular to an optical axis of the projection optical system and a third direction orthogonal to the predetermined plane;
measuring positional information of the stage in the third direction, by a first measurement system that has a plurality of sensors each irradiating a measurement beam to a grating member having a reflective grating periodic in a direction parallel to the predetermined plane;
measuring positional information in the third direction of a substrate held by the stage, by a second measurement system supported by a frame member that supports the projection optical system, the second measurement system being distanced from the projection optical system; and
in an exposure operation of the substrate, controlling the stage system based on the positional information measured by the first measurement system and the positional information measured by the second measurement system, to adjust a positional relation between a pattern image and the substrate, the pattern image being formed via the projection optical system and the liquid, wherein
a measurement operation of the substrate by the second measurement system is performed before the exposure operation, and
in each of the exposure operation and the measurement operation, positional information of the stage is measured by the first measurement system.
12. The exposure method according to claim 11 , wherein
positional information of the stage in the first and the second directions is measured by a sensor of the first measurement system that irradiates a measurement beam on the reflective grating and receives a reflected beam from the reflective grating.
13. The exposure method according to claim 12 , wherein
a mark of a substrate held by the stage is detected by a detection system that is supported by the frame member, distanced from the projection optical system,
a detection operation of the substrate by the detection system is performed before the exposure operation, and
in the detection operation, positional information of the stage is measured by the first measurement system.
14. The exposure method according to claim 13 , wherein
by a mask stage system having a mask stage to hold a mask illuminated with the illumination light and a motor to drive the mask stage, the mask is moved, and
in the exposure operation, positional information of the mask stage is measured by an encoder system different form the first measurement system and positional information of the stage is measured by the first measurement system.
15. The exposure method according to claim 14 , wherein
the nozzle unit is provided at the frame member or another frame member different from the frame member so that a lower surface of the nozzle unit is placed closer to an upper surface of the stage that is placed facing the projection optical system, than to an emitting surface of the optical element.
16. The exposure method according to claim 15 , wherein
the substrate is held by the holder in the depressed part so that a surface of the substrate is substantially flush with the upper surface of the stage.
17. The exposure method according to claim 16 , wherein
in the exposure operation, of the plurality of sensors, one sensor used in the measurement is switched to another sensor by a movement of the stage.
18. The exposure method according to claim 17 , wherein
in the exposure operation, of the plurality of sensors, the number of sensors that face the reflective grating is changed by a movement of the stage.
19. The exposure method according to claim 18 , wherein
at least one of the mask stage system and the stage system is controlled so that a measurement error of the first detection system that occurs due to the grating member is compensated for.
20. A device manufacturing method comprising:
exposing a substrate using the exposure method according to claim 11 ; and
developing the substrate that has been exposed.
21. A method of making an exposure apparatus that exposes a substrate with illumination light via a projection optical system and a liquid, the method comprising:
supporting the projection optical system with a frame member;
placing a base member below the projection optical system;
providing a local liquid immersion device that has a nozzle unit arranged surrounding an optical element of the projection optical system and forms a liquid immersion area under the projection optical system with a liquid supplied via the nozzle unit, the optical element contacting the liquid;
providing a stage system having a stage and a motor to drive the stage, that can move the substrate in directions of six degrees of freedom including a first direction and a second direction orthogonal to each other within a predetermined plane perpendicular to an optical axis of the projection optical system and a third direction orthogonal to the predetermined plane, the stage being placed on the base member and holding the substrate by a holder provided in a depressed part on an upper surface of the stage;
providing a first measurement system that has a plurality of sensors each irradiating a measurement beam to a grating member having a reflective grating periodic in a direction parallel to the predetermined plane, and that measures positional information of the stage in the third direction;
providing a second measurement system that is supported by the frame member, distanced from the projection optical system, and measures positional information in the third direction of a substrate held by the stage; and
providing a controller that, in an exposure operation of the substrate, controls the stage system based on the positional information measured by the first measurement system and the positional information measured by the second measurement system, to adjust a positional relation between a pattern image and the substrate, the pattern image being formed via the projection optical system and the liquid, wherein
a measurement operation of the substrate by the second measurement system is performed before the exposure operation, and
in each of the exposure operation and the measurement operation, positional information of the stage is measured by the first measurement system.