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

Abstract

A stage device is equipped with a first scale which is placed with a Y-axis direction serving as its longitudinal direction and in which a first grating whose periodic direction is in an X-axis direction is formed and a second scale which is placed with the X-axis direction serving as its longitudinal direction and in which a second grating whose periodic direction is orthogonal to the periodic direction of the first grating is formed, the first scale and the second scale being placed on a plane which a wafer stage faces. Further, on the upper surface of the wafer stage, a plurality of X heads placed at different positions in the X-axis direction and a plurality of Y heads placed at different positions in the Y-axis direction are arranged. An encoder system that has these heads measures positional information of the stage within an XY plane, based on an output of the X head facing the first scale and an output of the Y head facing the second scale.

1 . A movable body drive system that drives a movable body substantially along a predetermined plane, the system comprising:
 a first scale which is placed, with a first direction serving as its longitudinal direction, on a first plane that faces the movable body and is parallel to the predetermined plane, and in which a first grating whose periodic direction is in the first direction or in a second direction perpendicular to the first direction is formed;   a second scale which is placed, with the second direction serving as its longitudinal direction, on the first plane, and in which a second grating whose periodic direction is orthogonal to the periodic direction of the first grating is formed;   a measurement system which has a first head group including a plurality of first heads that are placed at different positions in the second direction on a second plane of the movable body substantially parallel to the predetermined plane and have their measurement directions in the periodic direction of the first grating, and a second head group including a plurality of second heads that are placed at different positions in the first direction on the second plane of the movable body and have their measurement directions in the periodic direction of the second grating, and which computes positional information of the movable body in at least directions of two degrees of freedom within the predetermine plane including the first and second directions based on an output of the first head that faces the first scale and an output of the second head that faces the second scale; and   a drive system that drives the movable body along the predetermined plane based on the positional information that has been computed by the measurement system.   
     
     
         2 . The movable body drive system according to  claim 1 , wherein
 the first scale has a width, which three of the first heads can simultaneously face, in the second direction, and   the measurement system computes positional information of the movable body in directions of three degrees of freedom within the predetermined plane, based on outputs of at least two of the first heads that simultaneously face the first scale and an output of the second head that faces the second scale.   
     
     
         3 . The movable body drive system according to  claim 1 , wherein
 a pair of the first scales are placed at a predetermined distance on the first plane, with the first direction serving as theirs longitudinal directions,   the first head group is placed on the second plane of movable body in an arrangement in which at least one each of the first heads can simultaneously face each of the pair of the first scales when the movable body is located in a predetermined effective area, and   the measurement system computes positional information of the movable body in directions of three degrees of freedom within the predetermined plane, based on outputs of two of the first heads that simultaneously face the pair of the first scales respectively, and an output of the second head that faces the second scale.   
     
     
         4 . The movable body drive system according to  claim 1 , wherein
 a pair of the second scales are placed at a predetermined distance on the first plane, with the second direction serving as their longitudinal directions,   the second head group is placed on the second plane of the movable body in an arrangement in which at least one each of the second heads can simultaneously face each of the pair of the second scales when the movable body is located in the effective area, and   the measurement system computes positional information of the movable body in directions of three degrees of freedom within the predetermined plane, based on outputs of two of the first heads that simultaneously face the pair of the first scales respectively, and outputs of two of the second heads that simultaneously face the pair of the second scales respectively.   
     
     
         5 . The movable body drive system according to  claim 1 , wherein
 the drive system includes a planar motor that drives the movable body along the predetermined plane.   
     
     
         6 . A pattern formation apparatus that forms a pattern on an object, the apparatus comprising:
 a patterning device that generates a pattern on the object; and   the movable body drive system according to  claim 1 , whereby   a movable body, on which the object is mounted, is driven by the movable body drive system, for pattern formation to the object.   
     
     
         7 . The pattern formation apparatus according to  claim 6 , wherein
 the object has a sensitive layer, and the patterning device generates a pattern on the object by exposing the sensitive layer with irradiation of an energy beam.   
     
     
         8 . An exposure apparatus that forms a pattern on an object with irradiation of an energy beam, the apparatus comprising:
 a patterning device that irradiates the object with the energy beam; and   able body drive system according to  claim 1 , whereby   a movable body, on which the object is mounted, is driven by the movable body drive system, for relative movement of the energy beam and the object.   
     
     
         9 . A device manufacturing method, comprising:
 exposing an object using the exposure apparatus according to  claim 8 ; and   developing the exposed object.   
     
     
         10 . An exposure method of exposing an object with an energy beam, the method comprising:
 holding the object with a movable body; and   driving the movable body by the movable body drive system according to  claim 1  and exposing the object with the energy beam.   
     
     
         11 . A movable body drive system that drives a movable body substantially along a predetermined plane, the system comprising:
 a scale which is placed, with a first direction serving as its longitudinal direction, on a first plane that faces the movable body and is parallel to the predetermined plane, and in which a two-dimensional grating whose periodic directions are in the first direction and in a second direction perpendicular to the first direction is formed;   a measurement system which has a plurality of two-dimensional heads that are placed at different positions in the second direction on a second plane of the movable body substantially parallel to the predetermined plane and have their measurement directions in the first and second directions, and which computes positional information of the movable body in at least directions of two degrees of freedom within the predetermine plane including the first and second directions based on an output of the two-dimensional head that faces the scale; and   a drive system that drives the movable body along the predetermined plane based on the positional information that has been computed by the measurement system.   
     
     
         12 . The movable body drive system according to  claim 11 , wherein
 the scale has a width, which three of the two-dimensional heads can simultaneously face, in the second direction, and   the measurement system computes positional information of the movable body in directions of three degrees of freedom within the predetermined plane, based on outputs of at least two of the two-dimensional heads that simultaneously face the scale.   
     
     
         13 . The movable body drive system according to  claim 11 , wherein
 the drive system includes a planar motor that drives the movable body along the predetermined plane.   
     
     
         14 . A pattern formation apparatus that forms a pattern on an object, the apparatus comprising:
 a patterning device that generates a pattern on the object; and   the movable body drive system according to  claim 11 , whereby   a movable body, on which the object is mounted, is driven by the movable body drive system, for pattern formation to the object.   
     
     
         15 . The pattern formation apparatus according to  claim 14 , wherein
 the object has a sensitive layer, and the patterning device generates a pattern on the object by exposing the sensitive layer with irradiation of an energy beam.   
     
     
         16 . An exposure apparatus that forms a pattern on an object with irradiation of an energy beam, the apparatus comprising:
 a patterning device that irradiates the object with the energy beam; and   the movable body drive system according to  claim 11 , whereby   a movable body, on which the object is mounted, is driven by the movable body drive system, for relative movement of the energy beam and the object.   
     
     
         17 . A device manufacturing method, comprising:
 exposing an object using the exposure apparatus according to  claim 16 ; and   developing the exposed object.   
     
     
         18 . An exposure method of exposing an object with an energy beam, the method comprising:
 holding the object with a movable body; and   driving the movable body by the movable body drive system according to  claim 11  and exposing the object with the energy beam.   
     
     
         19 . An exposure method of exposing an object held by a movable body that moves substantially along a predetermined plane, with an energy beam, wherein
 a first scale and a second scale are placed on a first plane that faces the movable body and is parallel to the predetermined plane, the first scale being placed with a first direction serving as its longitudinal direction and having a first grating formed therein whose periodic direction is in the first direction or in a second direction perpendicular to the first direction, and the second scale being placed with the second direction serving as its longitudinal direction, and having a second grating formed therein whose periodic direction is orthogonal to the periodic direction of the first grating,   the method comprises:   a measurement process of computing positional information of the movable body in at least directions of two degrees of freedom within the predetermine plane including the first and second directions, based on an output of a first head that faces the first scale and an output of a second head that faces the second scale, from among a first head group including a plurality of the first heads that are placed at different positions in the second direction on a second plane of the movable body substantially parallel to the predetermined plane and have their measurement directions in the periodic direction of the first grating, and a second head group including a plurality of the second heads that are placed at different positions in the first direction on the second plane of the movable body and have their measurement directions in the periodic direction of the second grating; and   a drive process of driving the movable body along the predetermined plane based on the positional information that has been computed in the measurement process.   
     
     
         20 . The exposure method according to  claim 19 , wherein
 the first scale has a width, which three of the first heads can simultaneously face, in the second direction, and   in the measurement process, positional information of the movable body in directions of three degrees of freedom within the predetermined plane is computed, based on outputs of at least two of the first heads that simultaneously face the first scale and an output of the second head that faces the second scale.   
     
     
         21 . The exposure method according to  claim 19 , wherein
 a pair of the first scales are placed at a predetermined distance on the first plane, with the first direction serving as their longitudinal directions,   the first head group is placed on the second plane of movable body in an arrangement in which at least one each of the first heads can simultaneously face each of the pair of the first scales when the movable body is located in a predetermined effective area, and   in the measurement process, positional information of the movable body in directions of three degrees of freedom within the predetermined plane is computed, based on outputs of two of the first heads that simultaneously face the pair of the first scales respectively, and an output of the second head that faces the second scale.   
     
     
         22 . The exposure method according to  claim 19 , wherein
 a pair of the second scales are placed at a predetermined distance on the first plane, with the second direction serving as their longitudinal directions,   the second head group is placed on the second plane of the movable body in an arrangement in which at least one each of the second heads can simultaneously face each of the pair of the second scales when the movable body is located in the effective area, and   in the measurement process, positional information of the movable body in directions of three degrees of freedom within the predetermined plane is computed, based on outputs of two of the first heads that simultaneously face the pair of the first scales respectively and outputs of two of the second heads that simultaneously face the pair of the second scales respectively.   
     
     
         23 . A device manufacturing method, comprising:
 exposing an object using the exposure method according to  claim 19 ; and   developing the exposed object.   
     
     
         24 . An exposure method of exposing an object held by a movable body that moves substantially along a predetermined plane, with an energy beam, wherein
 a scale, in which a two-dimensional grating whose periodic directions are in a first direction and in a second direction perpendicular to the first direction is formed, is placed with the first direction serving as its longitudinal direction, on a first plane that faces the movable body and is parallel to the predetermined plane;   the method comprises:   a measurement process of computing positional information of the movable body in at least directions of two degrees of freedom within the predetermine plane including the first and second directions based on an output of a two-dimensional head that faces the scale, from among a plurality of the two-dimensional heads that are placed at different positions in the second direction on a second plane of the movable body substantially parallel to the predetermined plane and have their measurement directions in the first and second directions; and   a drive process of driving the movable body along the predetermined plane based on the positional information that has been computed in the measurement process.   
     
     
         25 . The exposure method according to  claim 24 , wherein
 the scale has a width, which three of the two-dimensional heads can simultaneously face, in the second direction, and   in the measurement process, positional information of the movable body in directions of three degrees of freedom within the predetermined plane is computed, based on outputs of at least two of the two-dimensional heads that simultaneously face the scale.   
     
     
         26 . A device manufacturing method, comprising:
 exposing an object using the exposure method according to  claim 24 ; and   developing the exposed object.