JP4687911B2 - Positioning device and positioning method - Google Patents

Abstract

An apparatus capable of high accuracy position and motion control is disclosed and utilizes one or more linear commutated motors (54A, 54B, Fig. 5, not shown) to move a guideless stage (14) in one long linear direction and a small rotation in a plane. A carrier/follower (60) holding a single voice coil motor (VCM) (70) is controlled to approximately follow the stage in the direction of the linear motion. The VCM provides an electro-magnetic force to move the stage for small displacements in the plane in a linear direction perpendicular to the direction of the linear motion to ensure proper alignment. One element of the linear commutated motors is mounted on a freely suspended drive assembly frame (22) which is moved in the opposite direction to that of the stage by a reaction force to maintain the center of gravity of the apparatus. <IMAGE>

Description

  The present invention relates to a movable movable body that can move accurately, and more specifically, a stage apparatus that can move in one linear direction and can perform high-precision positioning and high-speed movement. In particular, such a stage apparatus is particularly preferably used in a microlithographic apparatus.

  In a wafer stepper, the alignment of the exposure field with respect to the reticle to be imaged affects the performance of the circuit exposed in that field. In a scanning exposure apparatus, the reticle and wafer move simultaneously during the exposure sequence and are scanned with each other. The present invention discloses an apparatus for performing an accurate scanning motion with respect to such an apparatus.

  In order to obtain high accuracy, the stage must be isolated from mechanical disturbances. This is achieved by positioning and moving the stage using electromagnetic force. Also, a high control bandwidth is required, which requires that the stage is lightweight and that the stage has no moving parts. Also, the stage must be free of excessive heat that can interfere with the measurement of the interferometer or mechanical changes that reduce alignment accuracy.

  Non-rectifying electromagnetic alignment devices, such as those disclosed in U.S. Pat. Nos. 4,506,204, 4,506,205, and 4,507,597, are not economical, for the reason This is because such an electromagnetic alignment apparatus needs to manufacture an assembly of large magnets and coils, which is not commercially available. The weight of the stage and the heat generated also makes it unsuitable to apply such a design to high precision applications.

  An improvement over the non-commutator type device as described above is disclosed in U.S. Pat. No. 4,952,858, which is mechanically guided in the XY direction with a large displacement movement in the plane. Conventional substages are used, which eliminates the need for large magnet and coil assemblies. Electromagnetic means provided on the substage insulates the stage from mechanical disturbances. However, the combined weight of the substage and stage still provides a low control bandwidth and the heat generated by the electromagnetic elements supporting the stage is still significant.

  Although common devices using rectifying electromagnetic means show significant improvements compared to prior art non-commutator means, the low control bandwidth and interferometer interference problems still remain. Remaining. In such an apparatus, the substage is moved in one linear direction using electromagnetic force, while the rectifying electromagnetic means provided in the substage moves the stage in the orthogonal direction. The sub-stage is heavy because it carries a magnetic orbit for moving the stage. Also, heat dissipation on the stage reduces the accuracy of the interferometer.

  It is also known to move a movable member (stage) in a long (for example, longer than 10 cm) linear direction using two parallel linear motors composed of coils and magnets. In this case, the stage is guided by a certain linear guide member, and is driven in a straight line direction by a linear motor provided in parallel to the guide member. When the stage is driven by a very small stroke range, a guideless structure based on a composite of several electromagnetic actuators can be adopted as disclosed in the above-mentioned prior art. However, in order to move the guideless stage for a long distance in a certain linear direction, a specially configured electromagnetic actuator is required as in the prior art, which increases the size of the device, resulting in higher power consumption. The problem of consumption arises.

  An object of the present invention is to provide a lightweight device that can move a movable body in a direction of a long linear motion in a non-contact manner using electromagnetic force, and achieves a small inertia force and a high response. is there.

  It is another object of the present invention to provide a non-contact type movable body using a commercially available normal linear motor as an electromagnetic actuator for causing one linear motion.

  Another object of the present invention is to provide a non-contact type movable body that can actively and accurately perform positioning control over a small displacement without contacting in the direction perpendicular to the direction of the long linear motion. Is to provide.

  Furthermore, an object of the present invention is to provide a movable body (stage body) that can move in one linear direction, and a second body that moves sequentially in the same direction and constantly maintains a certain space between the movable member. By providing a movable member, and providing an electromagnetic force (acting force and reaction force) in a direction perpendicular to the linear direction between the second movable member and the stage body, It is to provide a contact-type movable body.

  Another object of the present invention is to reduce positioning and running accuracy because tensions of various cables (wires) and pipes connected to a non-contact movable body that moves while supporting an object change. It is an object of the present invention to provide a non-contact type movable body that can prevent the above.

In addition, an object of the present invention is to arrange the first movable body and the second movable body in parallel, and to move the first movable body and the second movable body in mutually opposite linear directions. It is to provide a low-contact non-contact type device.
Furthermore, an object of the present invention is to provide an apparatus configured such that the position of the center of gravity of the entire apparatus does not change even when a non-contact type movable body moves in a certain linear direction.

A further object of the present invention is to provide a stage, a carrier / follower, and a linear driving means for driving the stage in a certain linear direction, and a first electromagnetic means for magnetically positioning the stage; A second electromagnetic means provided on the carrier / follower for moving the stage on a predetermined plane in a direction substantially perpendicular to the certain linear direction; And a means for controlling the position of the carrier / follower so as to follow the position of the stage.
Other objects and features of the present invention will become more apparent upon reading the following description with reference to the drawings, wherein like reference numerals designate like elements throughout.
In order to achieve the above object, according to the present invention, in a positioning apparatus including a first movable body movable in a predetermined direction, a second movable body movable on a reference member via a fluid bearing, and the predetermined movable body A first magnetizing member provided on the first movable body and a second magnetizing member provided on the second movable body so as to generate a driving force directed in the direction; First movable means for electromagnetically driving the movable body of the first movable body, and the first movable body and the side surface of the second movable body are opposed to each other so that a side surface of the first movable body faces a side surface of the second movable body. The second movable body is juxtaposed, and the first movable body and the second movable body move in opposite directions in the predetermined direction by excitation of the first driving means.
In the present invention, in the positioning method for positioning the first movable body movable in a predetermined direction, the first movable body is movable on the reference member via the first magnetized member and the fluid bearing provided on the first movable body. A first driving means having a second magnetizing member provided on the second movable body, and applying an acting force to move the first movable body in the predetermined direction, the first movable body And juxtaposing the second movable body, and moving the second movable body in a direction opposite to the direction in which the first movable body moves in accordance with the acting force.

[Example]
[Industrial applicability]
Although the present invention is generally applicable to electromagnetic alignment devices, preferred embodiments include the reticle stage scanning device shown in FIGS.
The present invention is configured to have the following features. An apparatus capable of highly accurate position and motion control is disclosed below. This apparatus uses a rectification type linear motor to move the guideless stage in one long linear direction in a certain plane and to perform a small yaw rotation. A carrier / follower holding a single voice coil motor (VCM) is controlled to generally follow the stage in the direction of the long linear motion. The VCM provides an electromagnetic force for moving the stage by a minute distance in the plane in a linear direction orthogonal to the direction of the long linear motion. The follower design eliminates the problem of cable drag on the stage because the cable connected to the stage follows the stage via the carrier / follower. The cable connecting the carrier / follower to the external device will have a certain amount of drag, but the stage will not be subject to such external influences (external factors) because the reason is on the carrier / follower This is because the VCM acts as a buffer by preventing transmission of mechanical disturbances to the stage.

As a special feature of the present invention, rectification type linear motors are provided on both sides of the stage and attached to the drive frame. Each rectifying linear motor includes a coil member and a magnet member. One of these members is attached to one of both sides of the stage, and the other of the members is attached to a drive frame. . Both motors are driven in the same direction. By driving these motors by slightly different distances, a minute yaw rotation of the stage occurs.

  According to another feature of the invention, a movable counterweight is provided, which maintains the position of the center of gravity of the stage apparatus using the momentum conservation law whenever the stage moves. In one embodiment of the invention, a drive frame carrying one member of each linear motor is suspended above the base structure, and the drive assembly moves the stage to one side above the base structure. When applied, the drive frame moves in the opposite direction in response to its reaction force, thereby substantially maintaining the center of gravity of the device. This apparatus substantially eliminates the reaction force between the stage apparatus and the base structure on which the stage apparatus is provided, thereby enabling a large acceleration force and extremely reducing the influence of vibration on the apparatus. To do.

  By limiting the stage movement to three specific degrees of freedom, the device is simplified. By using commercially available electromagnetic components, the design of the apparatus can be easily adapted to changes in the dimensions of the stage. This high-accuracy positioning device is ideal for use as a reticle scanner in a scanning exposure apparatus, and provides a smooth and accurate scanning motion in a certain linear direction, as well as a direction perpendicular to the scanning direction. By controlling a small displacement movement and a small amount of yaw rotation in the plane, accurate alignment is ensured.

  Next, a specific description will be given with reference to FIG. 1 and FIG. The positioning device 10 of the present invention includes a base structure 12 on which a reticle stage 14 is suspended so as to move as desired, a laser interferometer device 15 for tracking the position of the reticle stage, a position sensor 13, and the like. , And a position control device 16 operated by a CPU 16 ′ (see FIG. 8).

An elongated positioning guide 17 is provided on the base 12, and a support bracket 18 (in the illustrated embodiment, two brackets) is movably supported on the guide 17 by, for example, an air bearing 20. . The support bracket 18 is connected to a drive assembly 22 or drive frame in the form of a magnetic track assembly for moving the reticle stage 14 in the X direction and slightly rotating it. The drive frame comprises a pair of magnetic track arms 24, 26 spaced in parallel, which are connected to each other by transverse arms 28, 30 to form an open rectangular body. . In a preferred embodiment, the drive frame 22 is movably supported on the base structure 12, for example by air bearings 32, so that the frame is in the longitudinal direction of the guide 17 on the base structure. It moves freely in the direction along the axis. This direction is the principal axis direction in which the scanning movement of the reticle stage is required. As used herein, “one direction” or “first direction” means that the frame 22 or reticle stage 14 moves forward or backward in the X direction along the longitudinal axis of the guide 17. means.

  1 and FIG. 7, the guide member or guide member 17 elongated in the X direction has front and rear guide surfaces 17A and 17B. These guide surfaces have a base structure. It is substantially orthogonal to the twelve surfaces 12A. The front guide surface 17A faces the rectangular drive frame 22, and guides the air bearing 20 fixed to the inside of the support bracket 18. The support bracket 18 is attached to each end of the upper surface of the arm 24 parallel to the guide member of the drive frame 22. Each support bracket 18 is formed in a hook shape and straddles the guide member 17 in the Y direction, and its free end faces the rear guide surface 17B on the rear side of the guide member 17. The air bearing 20 'is fixed inside the free end of the support bracket 18 and faces the rear guide surface 17B. Accordingly, the movement of each support bracket 18 in the Y direction is restricted by the guide member 17 and the air bearings 20 and 20 ′, and can move only in the X direction.

  Next, according to the first embodiment of the present invention, the air bearing 32 fixed to the bottom surface of the four rectangular parts of the drive frame 22 forms an air layer, and the pad surface and the surface 12A of the base structure 12 are formed. There is a certain gap or gap (1 μm to less than several μm) between the two. The drive frame is levitated from the surface 12A by the air layer and supported in the vertical direction (Z direction). As will be described in detail later, in FIG. 1, the carrier / follower 60 located above the upper portion of the elongated arm 24 is supported by the bracket 62 facing both surfaces 17A and 17B of the guide member 17. The bearings 66A and 66B are supported in the lateral direction (Y direction), and supported in the vertical direction (Z direction) above the surface 12A of the base structure 12. Accordingly, the carrier / follower 60 is supported so as not to contact any part of the drive frame 22. Accordingly, the drive frame 22 is guided from the side by the guide member 17 above the surface 12A of the base and moves linearly only in the X direction.

  Next, a structure including the reticle stage 14 and the drive frame 22 will be described with reference to FIGS. 1 and 2. The reticle stage 14 includes a main body 42, and a reticle 44 is provided above the opening 46 of the main body. The reticle main body 42 includes a pair of opposed side portions 42A and 42B. The reticle main body 42 is placed and suspended above the base structure 12 by, for example, an air bearing 48. A plurality of interferometer mirrors 50 are provided on the main body 42 of the reticle stage 14, and the interferometer mirrors operate together with the position sensing device 15 (see FIG. 8) of the laser interferometer to the position control device 16. The exact position of a given reticle stage is determined, thereby leading to the proper drive signal for moving the reticle stage 14 as desired.

The basic movement of the reticle stage 14 is performed by means in the form of a first electromagnetic drive assembly, ie, separate drive assemblies 52A, 52B provided on each of the opposing sides 42A, 42B. The drive assemblies 52A and 52B include drive coils 54A and 54B fixed to the side portions 42A and 42B of the reticle stage 14, respectively, and these drive coils are magnetic tracks 56A of the magnetic track arms 24 and 26 of the drive frame 22. , 56B. In the preferred embodiment of the present invention, the magnetic coil is attached to the drive frame 22, but the arrangement of such elements of the electromagnetic drive assembly 52 can be reversed.

  Here, the structure of the reticle stage 14 will be described in more detail. As shown in FIG. 1, the stage main body 42 is mounted so as to be movable in the Y direction in a rectangular space in the drive frame 22. The air bearing 48 fixed under each of the four corners of the stage body 42 forms an extremely small air gap between the pad surface and the surface 12A of the base, and the entire stage 14 is levitated from the surface 12A. Support this. The air gap 48 is preferably a preload type having a recess for performing vacuum suction on the surface 12A.

  As shown in FIG. 2, a rectangular opening 46 in the center of the stage main body 42 is provided, so that a projected image of the pattern formed on the reticle 44 can pass through the opening. In the central portion of the base structure 12, another opening is provided so that the projection image can pass through the rectangular opening 46 and through the projection optical device PL (see FIG. 7) provided below the rectangular opening. 12B is provided. The reticle 44 is placed on the surface of the stage main body by the clamp member 42 </ b> C and is adsorbed by the vacuum pressure, and the clamp member is provided to protrude at four points around the rectangular opening 46.

  Next, the interferometer mirror 50Y, which is fixed adjacent to the side portion 42B of the stage main body 42 in the vicinity of the arm 26, has a vertical reflecting surface that is elongated in the X direction, and is the length of the interferometer mirror. Is somewhat longer than the movement stroke of the stage 14 in the X direction, and the laser beam LBY from the Y-axis interferometer is incident perpendicularly to the reflection surface. In FIG. 2, the laser beam LBY is bent at a right angle by a mirror 12 </ b> D fixed to the side of the base structure 12.

  Referring to FIG. 3, which is a partial cross-sectional view taken along line 3-3 in FIG. 2, the laser beam LBY incident on the reflecting surface of the interferometer mirror 50Y is reflected on the bottom surface of the reticle 44 (pattern is attached to the clamp member 42C). Placed in the same plane as the surface to be formed). Also shown in FIG. 3 is an air bearing 20 that acts on the end face of the support bracket 18 facing the guide face 17B of the guide member 17.

  Referring again to FIGS. 1 and 2, the laser beam LBX1 from the X1-axis interferometer is incident and reflected by the interferometer mirror 50X1. Further, the laser beam LBX2 from the X2 axis interferometer is incident and reflected by the interferometer mirror 50X2. These two mirrors 50X1 and 50X2 are configured as corner cube type mirrors, and even when the stage 14 is yaw-rotated, the mirror always has the incident axis and the reflection axis of the laser beam parallel in the XY plane. To maintain. 2 is an optical block such as a prism for directing the laser beams LBX1 and LBX2 to the respective mirrors 50X1 and 50X2, and the optical block is fixed to the components of the base structure 12. The corresponding block for the LBY laser beam is not shown.

  In FIG. 2, the distance BL in the Y direction between the center lines of the two laser beams LBX1 and LBX2 is the length of the reference line used for calculating the amount of yaw rotation, that is, the amount of yaw rotation. . Therefore, the value obtained by dividing the difference between the measured value ΔX1 in the X direction of the X1 axis interferometer and the measured value ΔX2 in the X direction of the X2 axis interferometer by the reference line length BL is the yaw in a very small range. It is roughly equal to the amount of rotation. Further, a half value of the sum of ΔX1 and ΔX2 represents the X coordinate position of the entire stage 14. These calculations are performed by the high-speed digital processor of the position controller 16 shown in FIG.

  Further, the center lines of the laser beams LBX 1 and LBX 2 are set to the same surface as the surface on which the pattern is formed on the reticle 44. The extension line of the line GX shown in FIG. 2 and the extension line of the laser beam LBY shown in FIG. 2 that divides the space between the center lines of the laser beams LBX1 and LBX2 in half are the same surface as the surface on which the pattern is formed. Intersect in. Further, the optical axis AX (see FIGS. 1 and 7) also passes through the intersection as shown in FIG. In FIG. 1, the slit-shaped irradiation field ILS including the optical axis AX is shown on the reticle 44, and the pattern image of the reticle 44 is scanned and exposed to light via the projection optical device PL. The substrate is exposed.

  1 and 2, two rectangular blocks 90A and 90B fixed to the side portion 42A of the stage main body 42 are provided. These blocks 90 </ b> A and 90 </ b> B receive the driving force in the Y direction from the second electromagnetic actuator 70 attached to the carrier / follower 60. Details will be described later.

  The drive coils 54A and 54B fixed on both sides of the stage main body 42 are formed to be flat and parallel to the XY plane, and move in the magnetic flux space of the slot extending without contact in the X direction of the magnetic tracks 56A and 56B. To do. The assembly consisting of the drive coil 54 and the magnetic track 56 used in this embodiment is a general-purpose linear motor that is readily available commercially and may or may not have a commutator. .

Here, considering the actual design, the movement stroke of the reticle stage 14 is roughly the size of the reticle 44 (the amount of movement required when performing scanning for exposure, and the irradiation optics for exchanging the reticle. The amount of movement required when removing the reticle from the apparatus). In this embodiment, when using a 6 inch reticle, the travel stroke is about 30 cm.
As explained above, the drive frame 22 and the stage 14 are levitated independently and supported on the surface 12A of the base, and at the same time, the magnetic action and reaction force are mutually in the X direction only by the linear motor 52. Acted. Thereby, the law of conservation of momentum works between the drive frame 22 and the stage 14.

  Next, assuming that the total weight of the reticle stage 14 is about one fifth of the total weight of the frame 22 including the support bracket 18, a 30 cm forward movement of the stage 14 in the X direction causes the drive frame 22 to move in the X direction. Retract 6 cm. This means that the position of the center of gravity of the device on the base structure 12 is substantially fixed in the X direction. A heavy object does not move in the Y direction. Accordingly, the fluctuation of the position of the center of gravity in the Y direction is relatively small.

  As described above, the stage 14 can move in the X direction, but the moving coils (54A, 54B) and the stator of the linear motor 52 can be moved in the Y direction when there is no actuator in the X direction. Interfere with each other. Therefore, the carrier / follower 60 and the second electromagnetic actuator 70, which are characteristic components of the present invention, are provided to control the stage 14 in the Y direction.

Next, the structure will be described with reference to FIG. 1, FIG. 2, FIG. 3 and FIG.
As shown in FIG. 1, the carrier / follower 60 is attached to be movable in the Y direction by a hook-shaped support bracket 62 straddling the guide member 17. As is clear from FIG. 2, the carrier / follower 60 is provided above the arm 24 and maintains a certain space between the stage 14 (main body 42) and the arm 24. One end portion 60 </ b> E of the carrier / follower 60 protrudes substantially inwardly (above the stage body 42) above the arm 24. In this end part, a drive coil 68 (same shape as the coil 54) that enters the slot space of the magnetic track 56A is fixed.

  An air bearing 66A (see FIGS. 2, 3, 4 and 7) supported by the bracket 62 and facing the guide surface 17A of the guide member 17 is provided with the guide member and arm of the carrier / follower 60. It is fixed in the space between 24. Also shown in FIG. 3 is an air bearing 66 that levitates the carrier / follower 60 and supports the carrier / follower on the base surface 12A.

  The air bearing 66B in contact with the guide surface 17B of the guide member 17 is also fixed to the free end of the support bracket 62 provided on the side of the hook opposite to the air bearing 66A, and between the air bearings 66A and 66B. In addition, the guide member 17 is located.

  Next, as is apparent from FIG. 7, the carrier / follower 60 is arranged so as to maintain a certain space in the Y direction and the Z direction with respect to the magnetic track 56A and the stage main body 42, respectively. FIG. 7 shows the projection optical device PL and a column rod CB for supporting the base structure 12 above the projection optical device PL. Such a structure is common for projection aligners, where unnecessary movement of the center of gravity of the structure above the base structure 12 causes lateral displacement between the column rod CB and the projection optics PL. Therefore, during exposure, the image on the photosensitive substrate is distorted. Thus, the advantage of an apparatus such as this embodiment in which the movement of the stage 14 does not move the center of gravity above the base structure 12 is significant.

  The structure of the carrier / follower will be described with reference to FIG. In FIG. 4, the carrier / follower 60 is broken down into two parts 60A, 60B for ease of understanding. As is clear from FIG. 4, the drive coil 68 that moves the carrier / follower 60 itself in the X direction is fixed to a lower portion of the end portion 60 </ b> E of the carrier / follower 60. Further, the air bearing 66C faces the base structure 12A on the bottom surface of the end portion 60E, and plays a role of floating the carrier / follower 60.

  Accordingly, the carrier / follower 60 is supported in the Z direction by the three points of the two air bearings 66 and the one air bearing 66C, and the movement in the Y direction is restricted by the air bearings 66A and 66B. It can move in the X direction. The important point in this structure is that the second magnetic trajectory arm 70 is arranged in a back-to-back relationship with the support bracket 62. Therefore, when the actuator generates a driving force in the Y direction, the stage 14 and the carrier / The reaction force in the Y direction with the follower 60 positively acts on the air bearings 66 </ b> A and 66 </ b> B fixed in the support bracket 62. In other words, by providing the actuator 70 and the air bearings 66A, 66B on a line parallel to the Y axis of the XY plane, the carrier / follower 60 is mechanically moved when the actuator 70 'is operating. To prevent undesired stresses that may be deformed. Conversely, this means that the weight of the carrier / follower 60 can be reduced.

  As is apparent from FIGS. 2, 4 and 6 described above, the magnetic trajectory 56A in the arm 24 in the form of the drive frame 22 provides magnetic flux to the drive coil 54A on the stage body 42 side. At the same time, magnetic flux is provided to the drive coil 68 for the carrier / follower 60. As for the air bearings 66A, 66B, 66C, a vacuum preload type is preferable because the carrier / follower 60 becomes light. A magnetic preload type can be used instead of a vacuum preload type.

  Next, the second actuator provided in the carrier / follower 60 will be described with reference to FIGS. 3, 5, and 7. A second electromagnetic drive assembly in the form of a voice coil motor 70 comprises a voice coil 74 attached to the main body 42 of the reticle stage 14 and a magnet 72 attached to the carrier / follower 60, the magnet Moves the stage 14 in the X direction by a small distance on a motion plane orthogonal to the long linear movement of the stage 14 in the X direction caused by the drive assembly 22. The positions of the coil 74 and the magnet 72 can be reversed. A schematic structure of a voice coil motor (VCM) 70 is shown in FIGS. 3 and 7, and a detailed structure thereof is shown in FIG. FIG. 5 shows a cross-sectional view of the VCM cut along a horizontal plane indicated by an arrow 5 in FIG. In FIG. 5, the magnet 72 of the VCM 70 is fixed on the carrier / follower 60 side. The coil of the VCM 70 includes a coil main body 74A and a support component 74B, and the support component 74B is a connection plate (XY) that extends firmly between the two rectangular blocks 90A and 90B. A plate perpendicular to the plane) 92 is fixed. The center line KX of the VCM 70 indicates the direction of the driving force of the coil 74. When a current flows through the coil body 74, the coil 74 performs a positive motion or a negative motion in the Y direction according to the direction of the current. And a force corresponding to the magnitude of the current is generated. In a commonly used VCM, a ring-shaped damper or bellows is generally provided between the coil and the magnet, thereby maintaining a gap between the coil and the magnet. For example, the gap is maintained by the following movement of the carrier / follower 60, and thus a support element as described above such as a damper or bellows is not necessary.

  In this embodiment, as shown in FIG. 5, capacitive gap sensors 13A and 13A are provided as positioning sensors 13 (see FIG. 8). In FIG. 5, electrodes for capacitive sensors are provided to detect changes in the gap in the X direction between the side surfaces of the rectangular blocks 90A and 90B facing each other in the X direction and the side surface of the case 70 ′ of the VCM 70. . Such a positioning sensor 13 can be placed anywhere as long as it can sense a change in the gap in the Y direction between the carrier / follower 60 and the stage 14 (or body 42). . Further, the sensor type can be any non-contact type, such as an optoelectronic, dielectric, ultrasonic, or air micro device.

  The case 70 ′ in FIG. 5 is integrated with the carrier / follower 60 and is provided so as not to contact any member on the reticle stage 14 side (spatial). Regarding the gap in the X direction (scanning direction) between the case 70 ′ and the rectangular blocks 90 </ b> A and 90 </ b> B, the gap on the sensor 13 </ b> B side decreases as the gap on the sensor 13 </ b> A side increases. Accordingly, the difference between the gap value measured by the sensor 13A and the gap value measured by the sensor 13B is obtained by digital calculation or analog calculation, and controls the drive current of the drive coil 68 for the carrier / follower 60. The direct servo (feedback) controller is designed with a servo drive circuit that zeros this gap difference so that the carrier / follower 60 automatically follows the X-direction tracking movement. Run and always maintain some space for the stage body 42. In addition, the indirect servo controller, which controls the flow of current to the drive coil 68 by the operation of the position controller 16 of FIG. 8, has a measured gap value obtained from only one of the sensors and the X-axis interference. It is possible to design without using the two gap sensors 13A and 13B differentially by using the X coordinate position of the stage 14 measured from the meter.

  In the VCM 70 shown in FIG. 5, the gap in the X direction (non-excitation direction) between the coil body 74A and the magnet 72 is actually about 2-3 mm. Accordingly, the accuracy of tracking of the carrier / follower 60 with respect to the stage main body 42 can be about ± 0.5-1 mm. This accuracy depends on how much the yaw rotation amount of the stage main body is allowed, and also depends on the length of the line in the KX direction (excitation direction) of the coil main body 74A of the VCM 70. In addition, the degree of accuracy is the accurate positioning accuracy (± 0.03 μm) of the stage main body 42 when using an interferometer (for example, assuming that the resolution of the interferometer is 0.01 μm). Is much lower. This means that the servo device for the follower can be designed fairly easily, and the cost of installing the follower control device is reduced. 5 is set so as to pass through the center of gravity of the entire stage 14 on the XY plane, and the center of gravity of each of the pair of air bearings 66A and 66B provided inside the support bracket 62 shown in the drawing. Is also located on the line KX in the XY plane.

  FIG. 6 shows a cross-sectional view of a part including the guide member 17, the carrier / follower 60, and the magnetic track 56 </ b> A cut from the direction of the arrow 6 in FIG. 2. The arm 24 that houses the magnetic track 56A is levitated and supported on the base surface 12A by the air bearing 32, and the carrier / follower 60 is levitated on the base surface 12A by the air bearing 66. And is supported. At this time, the height of the air bearing 48 on the bottom surface of the stage main body 42 (FIG. 3 or FIG. 7) and the height of the air bearing 32 are determined by the drive coil 54A on the stage main body 42 side of the slot of the magnetic track 56A. In space, it is determined to maintain a gap of 2-3 mm in the Z direction.

  The Z and Y spaces between the carrier / follower 60 and the arm 24 rarely change because both the carrier / follower and the arm have a common guide member 17 and This is because it is guided by the surface 12A of the base. Also, on the surface 12A of the base on which the air bearing 32 on the bottom surface of the drive frame 22 (arm 24) is guided and on the surface 12A of the base on which the air bearing 48 on the bottom surface of the stage body is guided. Even if there is a difference in height in the Z direction between the parts, as long as such a difference is strictly constant within the range of the movement stroke, the Z between the magnetic trajectory 56A and the drive coil 54A. The direction gap is also kept constant.

  Further, since the drive coil 68 for the carrier / follower 60 is originally fixed to the carrier / follower 60, a 2-3 mm gap is maintained above and below in the slot space of the magnetic track 56A. It is made like that. The drive coil 68 rarely shifts in the Y direction with respect to the magnetic orbit 56A.

  Cables 82 (see FIG. 2) for sending signals are provided to the drive coils 54A and 54B on the stage 14, the coil 74 of the voice coil motor, and the carrier / follower drive coil 68, and these cables 82 are provided. Is provided on the carrier / follower 60 and the guide 17, and thus removes the pulling force applied to the reticle stage 14. The voice coil motor 70 acts as a buffer by preventing transmission of mechanical disturbance force to the stage 14.

  Therefore, the output of the cable will be described in detail with reference to FIGS. As shown in FIG. 2, a connector 80 is provided on one end of the guide member 17 on the base structure 12 to connect the electric wire of the electric device and the pipe of the pneumatic and vacuum device (hereinafter referred to as a cable). It has been. The connector 80 connects a cable 81 from an external control device (including a control device for pneumatic and vacuum devices in addition to the electrical system control device shown in FIG. 8) to the flexible cable 82. The cable 82 is also connected to the end piece 60E of the carrier / follower 60, and the system wires and the pneumatic and vacuum equipment tubes required for the stage body 42 are distributed as a cable 83.

  As described above, the VCM 70 acts to eliminate the effects of cable pulling force or tension, but sometimes the effect is an unexpected moment between the carrier / follower 60 and the stage body 42. May appear as In other words, the tension of the cable 82 applies a force for rotating the guide surface of the guide member 17 or the surface 12A of the base to the carrier / follower 60, and the tension of the cable 83 depends on the carrier / follower 60 and the stage. A force to rotate these relative to the main body is given.

  One such moment, ie, the component that shifts or moves the carrier / follower 60 is not a problem, but the moment that shifts the stage body in the X, Y and θ directions (yaw rotation direction) is , Alignment or overlay accuracy may be affected. For the X and θ directions, the shift can be corrected by a series of drives by two linear motors (54A, 56A, 54B, 56B), and for the Y direction, the shift is corrected by the VCM 70. be able to. In this embodiment, the total weight of the stage 14 can be significantly reduced, and the response of the VCM 70 in the Y direction of the stage 14 and the response by the linear motors in the X and θ directions are completely non-contacting. Combined with the guideless structure, it is extremely expensive. Further, even when micron vibration (micron unit vibration) is generated in the carrier / follower 60 and such micron vibration is transmitted to the stage 14 via the cable 83, such vibration (several Hz to several Hz) is generated. (Up to 10 Hz) can be sufficiently eliminated by the high response described above.

  Next, FIG. 4 shows how each cable is distributed by the carrier / follower 60. The drive signals 54A and 54B for the stage main body 42 and the drive signals to the drive coil 74 of the VCM 70 and the sensing signals from the position sensor 13 (gap sensors 13A and 13B) enter the system electric wire 82A from the connector 80. Pressure gas and vacuum to each air bearing 48, 66 enters the pneumatic system tube 82B from the connector 80. On the other hand, the drive signals to the drive coils 54A and 54B enter the electric wire 83A connected to the stage main body 42, and the pressure gas for the air bearing 48 and the vacuum for the clamp member 42C are supplied to the air system. Enter the hose 83B.

  In addition to the line shown in FIG. 2, it is preferable to provide another line for the pneumatic system for the air bearings 20, 20 ′, 32 of the drive frame 22. Further, as shown in FIG. 4, when the tension or vibration of the cable 83 cannot be prevented, the moment caused by the tension or vibration received by the stage main body 42 is arranged so as to be limited only in the Y direction as much as possible. good. In this case, the moment can only be resolved by a VCM having a very high response.

  1, 2, and 8, the positioning of the reticle stage 14 is performed by first knowing its current position using the laser interferometer device 15. A drive signal is sent to the drive coils 54A and 54B of the reticle stage to drive the stage 14 in the X direction. In driving, when a differential force is applied to both side portions 42A and 42B of the reticle stage 14, the reticle stage 14 generates a minute yaw rotation. An appropriate drive signal to the voice coil 72 of the voice coil motor 70 causes a minute displacement or movement of the reticle stage 14 in the Y direction. As the position of the reticle stage 14 changes, a drive signal is sent to the carrier / follower coil 68 so that the carrier / follower 60 follows the reticle stage 14. The resulting reaction force against the applied drive force moves the magnetic track assembly or drive frame 22 in a direction opposite to the movement of the reticle stage 14, thereby substantially maintaining the position of the center of gravity of the device. It will be appreciated that a counterweight or reaction of the magnetic track assembly 22 need not be included in the device, in which case the magnetic track assembly 22 can be fixedly provided on the base 12.

  As described above, the control device shown in FIG. 8 is provided to control the stage device of this embodiment. This control device of FIG. 8 will be described in detail below. The reticle stage 14 is provided with an X1 drive coil and an X2 drive coil configured as drive coils 54A and 54B of the two linear motors, and a Y drive coil configured as a drive coil 72 of the VCM 70, respectively. The drive coil 68 is provided on the carrier / follower 60. Each of these drive coils is driven by the position control device 16 in accordance with the drive signals SX1, SX2, SY1, SΔX. The laser interferometer apparatus for measuring the coordinate position of the stage 14 includes an X1-axis interferometer that transmits / receives a beam, that is, a light beam LBY, and an X2-axis interferometer that transmits / receives a beam LBX2. Information IFY, IFX1, IFX2 regarding each direction of each axis is transmitted to the position control device 16. The position control device 16 transmits the two drive signals SX1, SX2 to the drive coils 54A, 54B, whereby the difference between the position information IFX1, IFX2 in the X direction becomes a set value. In other words, the yaw rotation amount of reticle stage 14 is maintained at the set value. Therefore, of course, once the reticle 44 is aligned on the stage main body 42 during the exposure, the beams LBX1, LBX2, the X1-axis interferometer and the X2-axis interferometer, the position control device 16, and the drive signals SX1, SX2 are used. The positioning of the yaw rotation (in the θ direction) is always performed.

  Further, the control device 16 that has obtained the current coordinate position of the stage 14 in the X direction from the total average value of the position information IFX1 and IFX2 in the X direction receives various commands from the host CPU 16 ′ and information on each parameter. Based on the CD, drive signals SX1, SX2 are transmitted to the drive coils 54A, 54B, respectively. In particular, when scanning exposure is operating, it is necessary to linearly move the stage 14 in the X direction while correcting the yaw rotation amount, and the control device 16 applies the same or slightly different force as necessary. The two drive coils 54A and 54B are controlled.

  The position information IFY from the Y-axis interferometer is also transmitted to the control device 16, and the control device 16 transmits an optimal drive signal SΔX to the drive coil 68 of the carrier / follower 60. At this point, the control device 16 receives the sensing signal Spd from the position sensor 13 that measures the space in the X direction between the reticle stage 14 and the carrier / follower 60, and transmits the necessary signal SΔX, The signal Spd is set to the above set value. The tracking accuracy of the carrier / follower 60 is not so strict, and the sensing signal Spd of the control device 16 does not need to be determined strictly. For example, when the motion is controlled by reading the position information IFY, IFX1, IF2 from each interferometer every 1 millisecond, the high speed processor (arithmetic unit) of the control device 16 detects the sensing signal each time. The current of Spd is sampled, and it is determined whether the value is larger or smaller than the reference value. If the deviation exceeds a certain point, a signal SΔX proportional to the deviation can be transmitted to the drive coil 68. Further, as described above, it is possible to provide a control device 95 that directly servo-controls the drive coil 68 and directly controls the follow-up motion of the carrier / follower 60 without going through the position control device 16.

  The illustrated movable stage apparatus does not have any attachments that constrain the movable stage apparatus in the X direction, so small effects can cause such stage apparatus to drift or fluctuate in the positive or negative X direction. Sometimes. This can cause certain parts to collide with each other when such imbalance becomes excessive. Such effects include cable forces, inaccurate leveling of the base reference surface 12A, ie, levelness, or friction between components. One simple method is to use a weak bumper (not shown) to prevent excessive movement of the drive assembly 22. Another simple method is to shut off the supply of air to one or more air bearings (32, 20) used to guide the drive assembly 22 when the drive assembly reaches near the end of the stroke. It is to be. Such an air bearing can be activated when driving in the opposite direction begins.

  A more accurate method involves monitoring the position of the drive assembly by means of measurement (not shown) and providing a driving force to restore and maintain the correct position. The accuracy of such measuring means does not need to be exact, but accuracy of about 0.1 to 1.0 mm is required. The drive force can be provided using another linear motor (not shown) attached to the drive assembly 22 or another motor connected to the drive assembly.

  Finally, the one or more air bearings (66, 66A, 66B) of the carrier / follower 60 can be deactivated to act as a brake during the idle period of the stage 42. When the carrier / follower 60 coil 68 is energized and the carrier / follower 60 is braked, the drive assembly is driven and accelerated. Accordingly, the position controller 16 monitors the position of the drive assembly 22. As the drive assembly drifts out of position, the drive assembly is repositioned with sufficient accuracy using the carrier / follower 60 coil 68 intermittently.

  In the first embodiment of the present invention, the drive frame 22 functioning as a counterweight is provided so as not to move the position of the center of gravity of the entire apparatus, and is moved in a direction opposite to the stage main body 42. However, when the structure of FIGS. 1 to 7 is applied to an apparatus in which the movement or shift of the center of gravity is not a big problem, the drive frame 22 can be fixed together with the base structure 12. In such a case, some effects and functions can be obtained without making any changes to the apparatus except for the problem concerning the center of gravity.

  The present invention provides a stage that can be used to provide precise position and motion control with three degrees of freedom in a plane. Its features are (1) long linear motion, (2) short linear motion orthogonal to such long linear motion, and (3) small amount of yaw rotation. This stage is insulated from the mechanical adverse effects of surrounding structures by using electromagnetic force as a stage driver (stage driving device). By using the structure for the guideless stage, a high control bandwidth can be obtained. These two key points contribute to achieving a smooth and accurate operation of the stage.

  With the description of the embodiment shown in FIGS. 1-8 in mind, referring to FIGS. 9 and 10, a preferred embodiment of the present invention is shown, with the last two digits of the reference number of each component of this embodiment. Generally corresponds to the two-digit reference number of each component in FIGS.

  9 and 10, unlike the first embodiment described above, the drive frame functioning as a counterweight is removed, and the magnetic tracks 156A and 156B of the two linear motors are firmly attached to the base structure 112. It is attached. The stage body 142 that moves linearly in the X direction is provided between the two magnetic tracks 156A and 156B. As shown in FIG. 10, an opening 112B is formed in the base structure 112, and the stage main body 142 is disposed so as to straddle the opening portion 112B in the Y direction. At both ends of the stage body 142 in the Y direction, four preload type air bearings 148 are fixed to the bottom surface, and the air bearings float the stage body 142 and support the surface 112A of the base. Yes.

  Further, according to the present embodiment, the reticle 144 is sandwiched and supported on a reticle holding plate, that is, a reticle chuck plate 143 provided separately on the stage main body 142. A reticle chuck plate 143 is provided with a linear mirror 150Y for the Y-axis laser interferometer and two corner mirrors 150X1 and 150X2 for the X-axis laser interferometer. The driving coils 154A and 154B are fixed to the magnetic tracks 156A and 156B at both ends in the Y direction of the stage main body 142, and move the stage main body 142 linearly in the X direction by the control subsystem described above. Rotate the yaw by a very small amount.

  As is clear from FIG. 10, the magnetic track 156B on the right side of the linear motor and the magnetic track 156A on the left side of the linear motor are arranged so that the heights in the Z direction between these tracks are different. In other words, the bottom surfaces of both ends in the direction of the long axis of the left magnetic track 156 are arranged at a certain height above the surface 112A of the base using the block member 155, as shown in FIG. ing. The carrier / follower 160 to which the VCM is fixed is provided in the space below the magnetic track 156A above.

  The carrier / follower 160 is levitated and supported by a preloaded air bearing 166 (two points) on the base surface 112A 'of the base structure 112 at a lower level. Further, two preload type air bearings 164 provided on the base structure 112 and facing the vertical guide surface 117A of the linear guide member 117 are fixed to the side surface of the carrier / follower 160. This carrier / follower 160 is different from that shown in FIG. 4 for the above-described embodiment, and the drive coil 168 (FIG. 9) for the carrier / follower 160 is perpendicular to the bottom of the carrier / follower 160. It is fixed horizontally to the elongating part and is provided without contact in the magnetic flux slot of the magnetic track 156A. The carrier / follower 160 is disposed so as not to contact any part of the magnetic track 156A within the range of the movement stroke, and includes a VCM 170 that accurately positions the stage main body 142 in the Y direction.

  In FIG. 9, an air bearing 166 that floats and supports the carrier / follower 160 is provided under the VCM 170. The following movement of the carrier / follower 160 with respect to the stage main body 142 is also performed based on the sensing signal from the position sensor 13 as in the above-described embodiment.

  In the second embodiment configured as described above, since there is substantially no member functioning as a counterweight, the center of gravity of the entire apparatus moves or shifts in accordance with the shift of the stage body 142 in the X direction. There is an inconvenience. However, by using the carrier / follower 160 to follow the stage main body 142 without contact, the stage main body 142 can be accurately positioned in the Y direction by the non-contact electromagnetic force generated by the VCM 170. is there. Further, since the two linear motors are arranged so that there is a difference in the height direction Z, the vector sum of force moments generated by the respective linear motors is extremely small at the center of gravity of the entire reticle stage. The reason is that the force moments of the respective linear motors substantially cancel each other.

  Further, since the action axis in the longitudinal direction of the VCM 170 (line KX in FIG. 5) passes through the center of gravity of the entire structure of the stage not only on the XY plane but also in the Z direction, the driving force of the VCM 170 causes an unnecessary moment. Is more difficult to apply to the stage main body 142. Further, since the method of connecting the cables 82 and 83 via the carrier / follower 160 can be applied in the same manner as the first embodiment, there is a problem with the completely non-contact type guideless stage. Improved.

  The same guideless principle can be employed in other embodiments. For example, in FIGS. 11 and 12, the stage 242 supported on the base 212 is driven in the longitudinal X direction by a single moving coil 254 moving in a single magnetic track 256. The magnetic track is firmly attached to the base 212. The center of gravity of the coil is located near the center of gravity of the stage 242. In order to move the stage in the Y direction, a pair of VCMs (274A, 274B, 272A, 272B) are activated and an acceleration force in the Y direction is applied. To control yaw rotation or yawing, the coils 274A, 274B are activated differentially under the control of the electronic subsystem. VCM magnets (272A, 272B) are attached to the carrier / follower stage 260. The carrier / follower stage is guided and driven as in the first embodiment described above. This alternative embodiment can be used for a wafer stage. When used in a reticle stage, a reticle can be provided on one side of the coil 254 and track 256, and the center of gravity of the stage 242 needs to be maintained through the coil 254 and track 256. Can be provided with a compensation opening on the side of the coil 254 and the track 256 opposite to the reticle to keep the stage 242 balanced.

  The advantages obtained from each of the above embodiments can be roughly summarized as follows. To maintain accuracy, the carrier / follower design eliminates the problem of cable tension for the stage because the cable connected to the stage follows the stage via the carrier / follower. The cable connecting the carrier / follower to the external device has a certain amount of tension, but the stage is not affected by this, because it transmits mechanical disturbances to the stage. By blocking, the stage is not directly connected to the carrier / follower acting as a buffer.

  The counterweight design also maintains the position of the center of gravity of the stage device during stage movement in the long stroke direction using the law of conservation of momentum. This device substantially eliminates the reaction force between the stage device and the base structure to which the stage device is mounted, thereby enabling large accelerations while minimizing the effects of vibration on the device.

  Also, since the stage is designed to perform limited motion with three degrees of freedom, as described above, such a stage performs full range of motion in all three degrees of freedom. Compared to a stage that is designed to be very simple. Also, unlike the non-commutator type device, the present invention uses commercially available electromagnetic elements. Since the present invention does not require custom-made electromagnetic elements that become increasingly difficult to manufacture as the stage dimensions and stroke increase, the present invention facilitates changing the stage dimensions or stroke. It is.

In the embodiment using a single linear motor, it is not necessary to use the other linear motor, and the yaw angle can be corrected by using two VCMs.
Although the invention has been described in terms of a preferred embodiment, the invention can take various alternative forms and should be limited only by the scope of the claims.

It is a schematic perspective view of the apparatus of this invention. It is a top view of the apparatus shown in FIG. FIG. 3 is an elevational view showing the structure shown in FIG. 2 as viewed in the direction of the arrow along line 3-3. FIG. 2 is an enlarged perspective view showing the structure of the carrier / follower of FIG. 1 partially disassembled in a state disassembled from a positioning guide. FIG. 8 is an enlarged horizontal sectional view showing a part of the structure shown in FIG. 7 as viewed along the line 5 in the direction of the arrow. FIG. 3 is an enlarged vertical sectional view showing a part of the structure shown in FIG. 2 when the voice coil motor is removed and viewed along the line 6 in the direction of the arrow. FIG. 7 is a vertical sectional view showing a part of the structure shown in FIG. 2 as viewed in the direction of the arrow along line 7-7. 2 is a block diagram schematically illustrating a sensing / control device for controlling the position of a stage. FIG. 3 is a plan view similar to FIG. 2 showing a preferred embodiment of the present invention. FIG. 10 is a vertical sectional view showing the structure shown in FIG. 9 as viewed in the direction of the arrow along line 10-10. FIG. 10 is a plan view similar to FIG. 9 showing another embodiment of the present invention in a highly simplified manner. FIG. 11 is an elevational view similar to FIG. 10, showing yet another embodiment of the present invention in a highly simplified manner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Positioning device 12 Base structure 14 Reticle stage 16 Position control device 16 'CPU
17A, 17B Guide surface 17 Positioning guide 18 Support bracket 20 Air bearing 22 Drive assembly (drive frame)
24, 26 Magnetic track arm 32 Air bearing 42 Main body 52 Electromagnetic drive assemblies 54A, 54B Drive coils 56A, 56B Magnetic track 60 Carrier / follower

Claims (18)

A first movable body movable in a predetermined direction;
A second movable body movable on the base via a fluid bearing;
A first magnetizing member provided on the first movable body and a second magnetizing member provided on the second movable body so as to generate a driving force directed in the predetermined direction; A positioning device comprising: first driving means for electromagnetically driving the first movable body,
The first movable body and the second movable body are arranged such that a side surface of the first movable body and a side surface of the second movable body are opposed to each other.
The positioning device according to claim 1, wherein the first driving means is excited so that the first movable body and the second movable body move in opposite directions in the predetermined direction. The positioning device according to claim 1,
The positioning device, wherein the weight of the second movable body is larger than the weight of the first movable body. In the positioning device according to any one of claims 1 and 2,
One of the first magnetizing member and the second magnetizing member is a coil, and the other of the first magnetizing member and the second magnetizing member is a magnet. In the positioning device according to any one of claims 1 to 3,
The positioning apparatus according to claim 1, wherein the first movable body is movable with respect to the base via a fluid bearing. In the positioning device according to any one of claims 1 to 4,
The positioning apparatus characterized in that the second movable body has a rectangular shape. In the positioning device according to any one of claims 1 to 5,
The positioning device characterized in that the first driving means is capable of rotating the first movable body. In the positioning device according to any one of claims 1 to 6,
A positioning apparatus comprising: a second driving unit that moves the first movable body in a direction intersecting the predetermined direction. The positioning device according to claim 7 ,
The positioning device according to claim 1, wherein the second driving means includes a coil and a magnet, and a driving force generated by the second driving means acts on the center of gravity of the first movable body . In the positioning device according to any one of claims 1 to 8,
A positioning apparatus comprising: a linear motor that is provided separately from the first driving means and the second driving means and adjusts the position of the second movable body. In the positioning device according to any one of claims 1 to 9,
The positioning device according to claim 1, wherein the second movable body is movable in the predetermined direction along a guide via a fluid bearing. In a positioning method for positioning a first movable body movable in a predetermined direction,
Arranging a second movable body movable on a base via a fluid bearing so that a side surface of the second movable body and a side surface of the first movable body face each other;
By means of a first driving means having a first magnetizing member provided on the first movable body and a second magnetized member provided on the second movable body, the first movable body is Giving an acting force to move in a predetermined direction;
A positioning method comprising: moving the second movable body in a direction opposite to a direction in which the first movable body moves in accordance with the acting force. The positioning method according to claim 11,
One of the first magnetizing member and the second magnetizing member is a coil, and the other of the first magnetizing member and the second magnetizing member is a magnet. In the positioning method as described in any one of Claim 11 or Claim 12,
The positioning method, wherein the first movable body is movable with respect to the base via a fluid bearing. In the positioning method according to any one of claims 11 to 13,
The positioning method, wherein the second movable body has a rectangular shape. The positioning method according to any one of claims 11 to 14,
The positioning method, wherein the first driving means is capable of rotating the first movable body. The positioning method according to any one of claims 11 to 15, wherein the second movable body includes a second driving unit having a coil and a magnet,
The positioning method includes moving the first movable body in a direction crossing the predetermined direction by the second driving means . The positioning method according to claim 16, wherein
The method includes the step of exciting the second driving means so that the driving force generated by the second driving means acts on the center of gravity of the first movable body . The positioning method according to any one of claims 11 to 17,
By a linear motor provided separately from the first driving means and the second driving means,
A positioning method comprising adjusting a position of the second movable body.

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