JPH11178311A - Positioning apparatus, driving unit and aligner therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positioning apparatus which is capable of supporting a table having an object to be positioned, such as a wafer, on it so as to be stable with out making-contact, and position the table accurately with out making contact. SOLUTION: A wafer W is held on a wafer table 5 including a magnet plate, and the wafer table 5 is stored in a magnetic circuit consisting of a bottom yoke 10, a top yoke 16,a strut 15A, and so on. At a bottom surface side of the wafer table 5, a number of driving units 11 are arranged two-dimensionally, constituted by mounting X-coils 12A, 12B, Y-coils 13A, 13B, and a Z-coil 14 respectively with respect to a core 20, the floating force of the wafer table 5 is controlled by the Z-coil 14, and thrusts in with respect to X and Y directions are applied to the wafer table 5 by the X-coils 12A, 12B, and the Y-coils 13A, 13B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for non-contact positioning of a flat movable body on which a positioning object such as a semiconductor wafer is placed, and an exposure apparatus having the positioning device.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device, an image pickup device (CC)
D, etc.), in a photolithography process for manufacturing a liquid crystal display element or a thin film magnetic head, etc., a reticle pattern as a mask is projected onto each shot area of a wafer (or a glass plate, etc.) as a substrate via a projection optical system. A projection exposure apparatus such as a stepper for transferring the image onto a substrate is used. In such a projection exposure apparatus, since it is necessary to position the wafer at the exposure position with high precision, the wafer is held on a wafer holder by vacuum suction or the like, and conventionally, the wafer holder is placed on a wafer stage on which the wafer holder can be positioned with high precision. Had been fixed.

On the other hand, recently, wafers can be moved at a higher speed.
In addition, in order to perform high-precision positioning without being affected by the accuracy of a mechanical guide surface, etc., development of a positioning device for floating and positioning a flat table on which a wafer is mounted in a non-contact manner has been advanced. . And, for example, US patents (US
P) In the specification of Japanese Patent No. 5196745, permanent magnets having N poles and S poles on the outside are alternately and two-dimensionally arranged on the upper and lower surfaces of a table on which a wafer is mounted, and the table is stored. There has been proposed a positioning device in which a polyphase coil array corresponding to those permanent magnets is arranged on a fixed body side. In this positioning device, a polyphase coil in a place where the magnetic flux of those permanent magnets is perpendicular to the table generates a horizontal thrust, and a coil in the place where the magnetic flux is horizontal generates a vertical thrust. Using the fact that thrust is generated,
The table is positioned without contact in directions of six degrees of freedom.

[0004]

As described above, in the conventional non-contact positioning device, a plurality of permanent magnets whose polarities are alternately reversed are mounted on the upper and lower surfaces of a table as a movable body. As a result, the table has become larger and heavier. Further, the thrust in the vertical direction by the polyphase coil is very small, and it is substantially difficult to levitate the table having the large weight only by the thrust in the vertical direction.

In addition, the positioning device requires a coil array having a size twice as large as the moving stroke of the table. SUMMARY OF THE INVENTION In view of the above, a first object of the present invention is to provide a positioning device that can stably support a movable body on which a positioning target such as a wafer is mounted, and that can accurately position the movable body. I do.

It is a second object of the present invention to provide a positioning device which can position the movable body in a non-contact manner without making the driving mechanism much larger than the moving stroke of the movable body. Still another object of the present invention is to provide a drive unit that can be used in such a positioning device, and an exposure apparatus that includes such a positioning device and that can manufacture a semiconductor element or the like with high throughput and high accuracy.

[0007]

A first positioning device according to the present invention is a positioning device for positioning a movable body (6) on which a positioning object (W) is placed, the movable body (6) being provided. ), Which generate a magnetic flux directed in one direction perpendicular to the moving surface of the movable body (6) (for example, one or a plurality of flat plates), and a movable body (6). )
And magnetic members (10, 15) arranged so as to sandwich the magnetic body (8) up and down to form a magnetic circuit with the magnetic body (8).
A to 15C, 16), and a drive unit (11) arranged between the magnetic body (8) and the magnetic member to drive the magnetic body (8).

The drive unit (11) has a levitation coil (14) wound so as to generate a variable thrust in a direction perpendicular to the moving surface with respect to the magnet body (8). The movable body is positioned in a non-contact state by the magnetic member and the drive unit (11).

According to the present invention, the movable table (6, 8) comprising the movable body (6) and the magnetizing body (8) can be made thinner and lighter. At this time, the magnetic body (8) is moved to the movable body (6).
May also be used. In the present invention, two magnetic circuits are mainly formed. The first magnetic circuit includes the N of the magnet (8).
This is a magnetic circuit in which the magnetic flux from the pole returns to the S-pole of the magnetic generator (8) via the magnetic member on the top or bottom surface and the magnetic member facing the magnetic member. The second magnetic circuit includes the N of the magnet (8).
This is a magnetic circuit in which the magnetic flux from the pole leaks into the space and returns to the S pole through, for example, a magnetic member on the upper surface.

The first and second magnetic circuits generate an attractive force on the upper and lower magnetic members with respect to the movable table (6, 8), respectively, and magnetically control the attractive force. As a result, a floating force is generated on the movable table, and the weight of the movable table can be supported. Thereby, the floating coil (14) of the drive unit (11) only needs to adjust the repulsive force or the attraction force within a predetermined range, so that the heat generation is minimized. To magnetically control the attraction force, the height of the movable table may be adjusted, the size of the coil of the drive unit (11) may be adjusted, and the permeance of the magnetic member may be adjusted. You may.

For example, by controlling the repulsive force or the attractive force of the levitation coil of three or more drive units (11), the height of the movable table and the inclination angle around the two axes are controlled. it can. That is, positioning in the height direction can be performed accurately. Next, a second positioning device of the present invention is the first positioning device of the present invention, wherein the drive unit (11) includes a core member (20) that allows a magnetic flux to pass through the magnetic circuit; (8) a first thrust generating coil (12A) wound around the core member so as to generate a thrust consisting of Lorentz force in a first direction in the moving plane; ), A second thrust generating coil (13A) wound around the core member so as to generate a thrust consisting of Lorentz force in a second direction intersecting the first direction in the moving plane. And

According to the second positioning device, the thrust generating coil (1) on the bottom surface or the upper surface of the movable table is provided.
2A, 13A) and a reaction force of Lorentz force generated by the magnetic flux of the magnet (8), a two-dimensional thrust is generated on the movable table. Therefore, by providing, for example, three thrust generating coils (two drive units), a large two-dimensional thrust and rotational force can be applied to the movable table. That is, the movable table (6, 8) can be accurately positioned in a two-dimensional plane.

[0013] By combining the first positioning device and the second positioning device, the movable table can be accurately positioned in six degrees of freedom without contact.
At this time, the installation area of the plurality of drive units may be approximately the same as the moving stroke of the movable table, so that the positioning device does not increase in size. Further, since the plurality of drive units are not directly connected magnetically, the inductance of each coil can be reduced, and the response of the current is improved, so that the positioning can be performed at high speed.

Next, a third positioning device according to the present invention is a positioning device for positioning a movable body (6) on which a positioning object (W) is mounted, and is integrated with the movable body. A magnetic body (8) that is incorporated and generates a magnetic flux directed in one direction perpendicular to the moving surface of the movable body, and is arranged so as to sandwich the movable body and the magnetic body up and down to form a magnetic circuit with the magnetic body. Magnetic member (10, 15A-1)
5C, 16) and a drive unit (70X; 7) disposed between the magnet and the magnetic member to drive the magnet.
4X).

Then, the drive unit (70X; 74)
X) includes a core member (71; 75) that allows a magnetic flux to pass through the magnetic circuit, and a core member (71; 75) that generates a thrust of Lorentz force on the magnetic field in a direction along the moving surface. The wound thrust generating coil (73; 7)
3d, 73e)) and a levitation coil (72A, 72B; 76) wound around the core member so as to generate a variable thrust on the magnetized body in a direction perpendicular to the moving surface.
And the movable member is positioned by the magnetic member and the drive unit.

Even with the third positioning device, the movable body is supported for the most part by the magnetic circuit together with the magnetizing body. Then, the height and tilt angle of the movable body are controlled by the levitation coil, and the position of the movable body in the moving plane is controlled by the thrust generating coil. In this case, as an example, the core member (71) is an arc-shaped member having a convex portion directed toward the magnetizing body, and two ends of the arc-shaped member are magnetically attached to the magnetic member. And the thrust generating coil (73) is wound around an intermediate portion of the arc-shaped member,
The thrust generating coil has an outer area substantially equal to or larger than an area of the core member, and an inner area is formed to be smaller than the outer area.
2A, 72B) are wound around two ends of the arc-shaped member.

In this case, a position measuring system (17X, 17Y, 18) for measuring the position of the movable body in the moving plane.
X, 18Y1, 18Y2). By driving the drive unit (11) based on the position measurement result, the movable body is positioned with high accuracy in a closed loop system. Moreover, you may make it provide the deformation amount measurement system (9A-9D) which measures the deformation amount of the magnetic body (8). For example, an actuator that expands and contracts is provided in the vicinity of these components, and the actuator is driven so as to cancel the detected strain, thereby suppressing the deformation of the magnetic body (8). Instead of using an actuator, a levitation force generated by a plurality of levitation coils (14) may be controlled.

Further, the magnetostrictive member (8) may be provided with a magnetostrictive member that deforms so as to autonomously cancel the deformation of the magnetic body due to magnetism. As the magnetostrictive member, for example, a member formed of a magnetostrictive material such as a ferrite garnet type or a rare earth alloy type can be used. When a magnetostrictive material is used as described above, a magnetostrictive material (CoFe _{2) that} contracts due to a magnetic field is located at a position where the magnetic field is likely to be distorted by a magnetic field.
O ₄ and SmFe _2, etc.) may be deposited to, the distortion easily position the concave its magnetism generation body is by a magnetic field, a magnetostrictive material that expands by the magnetic field (TbFe ₂ and 70 wt% Tb-30 wt
% Fe or the like).

A fourth positioning device according to the present invention provides a movable body (44) on which a positioning object (W) is placed.
And a first and second magnetic field generator (45A) connected to the movable body (44) and generating magnetic fluxes directed in one direction perpendicular to the moving surface of the movable body (44), respectively. , 45B) and the first and second magnets (45A, 45B) are arranged so as to be sandwiched vertically, respectively, and together with the first and second magnets (45A, 45B), respectively. A magnetic member (46) forming a magnetic circuit, a first drive unit (11) disposed between the first magnetic body (45) and the magnetic member (46) for driving the magnetic body, and a second drive unit (11). And a second drive unit (11C) disposed between the magnetic body (45B) and the magnetic member (46) to drive the magnetic body.

Then, the first drive unit (11)
A levitation coil (14) wound in the magnetic circuit so as to generate a variable thrust with respect to the first magnet (45A) in a direction perpendicular to the moving surface, and a second drive The unit (11C) has a levitation coil (14) wound so as to generate a variable thrust with respect to the second magnet in a direction perpendicular to the moving surface in the magnetic circuit, The movable member is positioned in a non-contact state by the magnetic member, the first drive unit, and the second drive unit.

According to the present invention, the movable body (44) on which a positioning object such as a wafer is placed is made of, for example, a long and thin flat non-magnetic material, and is provided at both ends of the movable body (44). The first and second magnetizing members (45A, 45B) are connected, and the first drive unit (11) is disposed on the bottom surface or the upper surface (or both surfaces) of one end of the movable body (44), and the movable body (44) The second drive unit (11C) is arranged on the bottom surface or the upper surface (or both surfaces) of the other end of. Most of the levitation force on the movable body (44) is given by its magnetic circuit (first magnetic circuit) and the second magnetic circuit formed by magnetic flux leaking into the space.

When two directions of the moving surface of the movable body (44) are defined as an X direction and a Y direction, and a direction perpendicular to the moving surface is defined as a Z direction, the movable units (4
4) is accurately positioned without contact in the Z direction. At this time, since the magnetic flux hardly exists at the center of the movable body (44), the positioning device can be applied to, for example, an electron beam transfer device.

In these cases, it is desirable to have a structure in which the reaction force due to the thrust generated when the movable body is positioned is released to the floor. Thereby, generation of vibration is suppressed. In addition, the magnetic body may be either a single pole (when there are a plurality of magnetic bodies, all generate a magnetic flux in the same direction) or a multipole.

Next, an exposure apparatus of the present invention includes the above-described positioning apparatus of the present invention, and transfers a mask pattern onto a substrate (W) positioned by the positioning apparatus. As the exposure device, an electron beam transfer device or the like can be used in addition to the optical projection exposure device. Next, the drive unit according to the present invention is a drive unit (70X; 74X) that is disposed in a magnetic circuit formed by a magnetic body and a magnetic member and generates Lorentz force, and in the magnetic circuit in the first direction. And a coil (73; 73d) wound around the core member in a second direction orthogonal to the first direction. , 73e), and the coil is wound so that the area is large on the side of the magnet and the area is small on the side opposite to the magnet.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In this embodiment, the present invention is applied to a positioning section of a semiconductor wafer in a projection exposure apparatus. FIG. 1 is a schematic configuration diagram showing a projection exposure apparatus of the present embodiment. In FIG. 1, exposure light (bright line such as i-line of a mercury lamp or excimer laser light) IL from an illumination optical system 1 is used. The pattern formed on the lower surface of the reticle R is illuminated with a uniform illuminance distribution, and the pattern of the reticle R is exposed to a predetermined projection magnification β (β is, for example, 1/4, １ ／) and projected onto a predetermined shot area on a semiconductor wafer (hereinafter simply referred to as “wafer”) W. A photoresist is applied to the surface of the wafer W, and the surface substantially matches the image plane of the projection optical system 3. Hereinafter, Z is parallel to the optical axis AX of the projection optical system 3.
The description will be made by taking an axis, an X axis in a plane perpendicular to the optical axis AX, parallel to the plane of FIG. 1, and a Y axis perpendicular to the plane of FIG.

The reticle R is held on a reticle stage 2 that can be finely moved in the X direction, the Y direction, and the rotation direction, and the position of the reticle stage 2 is controlled based on a measurement value of a laser interferometer (not shown). . On the other hand, the thin disk-shaped wafer W of the present example is held on a thin disk-shaped wafer holder 4 (see FIG. 2) by, for example, electrostatic attraction. It is fixed to. The wafer table 5 according to the present embodiment includes a wafer holder 4
In order from the side, a ceramic plate 6 as a non-magnetic material and a uniform magnetic flux 1 directed in the Z direction are generated.
The magnet plate 8 is bonded together, and the magnet plate 8
For example, one permanent magnet has an N pole on the bottom side and an S pole on the top side (the reverse is also possible).

A flat bottom yoke 10 made of a ferromagnetic material is disposed on the bottom side of the wafer table 5 so as to cover the entire movement range of the wafer table 5, and the bottom yoke 10 is placed on a floor (not shown). It is installed directly or via an anti-vibration mechanism such as anti-vibration rubber. A large number of drive units 11 are mounted on the upper surface of the bottom yoke 10, and a drive circuit of each drive unit 11 is incorporated in the wafer table drive system 23. The drive units 11 each include a magnet plate 8
(Thus, the wafer table 5) is given a variable thrust in the X, Y, and Z directions (details will be described later). These drive units 11 are covered by a cover member 21 made of a non-magnetic thin plate and provided with a narrow hollow portion. The cover member 21 also functions as a cooling device for the drive unit 11, and a supply port 21 a is provided in a hollow portion of the cover member 21.
A refrigerant made of a low-temperature liquid is supplied from a refrigerant supply device (not shown) through the, and the refrigerant that flows through the cover member 21 and absorbs heat generated from the large number of drive units 11 is supplied from the outlet 21b. Returned to device. Although the amount of heat generated in each drive unit 11 of this example is small, the amount of heat generated slightly is also carried outside by the refrigerant in the cover member 21, so that the temperature rise of the wafer table 5 is small and positioning is performed with high accuracy. .

A flat top yoke 16 made of a ferromagnetic material is arranged on the upper surface side of the wafer table 5.
The projection optical system 3 is inserted into the opening 16a at the center of the top yoke 16.
The tip of is inserted. The lens barrel of the projection optical system 3 is formed of a ferromagnetic material, and the tip of the projection optical system 3 is also a part of the top yoke 16. And the bottom yoke 10
And the top yoke 16 are pillars 1 made of a ferromagnetic material at four corners.
5A to 15D (only 15A and 15B are shown in FIG. 1), the bottom yoke 10, the magnet plate 8, the top yoke 16, and the columns 15A and 15B form a first closed magnetic circuit. I have. Further, there is also formed a second magnetic circuit in which magnetic flux leaked into the space from the N pole of the magnet plate 8 returns to the S pole of the magnet plate 8 via the top yoke 16,
In this example, the wafer table 5 is mainly formed by the second magnetic circuit.
Has a constant levitation force. Actually, by generating a thrust for attracting the magnet plate 8 to the bottom yoke 10 by the drive unit 11, the magnet plate 8 (wafer table 5) is stably supported in a floating state at a desired position in the Z direction. .

Since the attractive force of the magnet is originally nonlinear and has negative rigidity, it seems that it is difficult to control the position of the wafer table 5 in the Z direction. Analysis showed that the steady levitation force had a negative stiffness, but the degree of nonlinearity was very small.
Therefore, the position in the Z direction can be easily stabilized at a predetermined target value, and the responsiveness is excellent.

At the three positions around the wafer holder 4 on the upper surface of the wafer table 5, cylindrical soft touch-down members 7A to 7C (see FIG. 2) made of synthetic rubber or the like are fixed. Even if sucked to the 16 side, the impact force is reduced by the touch-down members 7A to 7C. An X-axis movable mirror 17X is fixed to an end in the -X direction of the upper surface of the plate 6 of the wafer table 5, and a Y-axis movable mirror 1 is attached to an end in the + Y direction.
7Y is fixed, and the movable mirror 17X is irradiated with a laser beam from the laser interferometer 18X in parallel with the X axis.
Y, two laser interferometers 18Y1,1 arranged in parallel
A laser beam from 8Y2 (see FIG. 2) is irradiated in parallel to the Y axis. Laser interferometers 18X, 18Y1, 18
Y2 measures the displacements of the corresponding movable mirrors 18X and 18Y with a resolution of, for example, about 0.001 μm to 0.01 μm, and outputs the measurement results to the main control system 22 which controls the overall operation of the apparatus in FIG. In this case, for example, the measurement values of the laser interferometer 18X and the laser interferometers 18Y1 and 18Y
The X coordinate and the Y coordinate of the wafer table 5 (wafer W) are respectively obtained from the average value of the measurement values of the two, and the rotation angle of the wafer table 5 is obtained from the difference between the measurement values of the two laser interferometers 18Y1 and 18Y2 on the Y axis. Is required. Main control system 22
By controlling the thrust by a number of drive units 11 arranged on the bottom side of the wafer table 5 through the wafer table drive system 23 based on the measured values,
The wafer table 5 (wafer W) is positioned.

Although not shown, a slit image or the like is projected on the side surface (part of the top yoke 16) of the projection optical system 3 on the surface of the wafer W, and re-combined by reflected light from the wafer W. An oblique incidence type focus position detection system for detecting the defocus amount of the wafer W from the lateral shift amount of the slit image to be formed is also provided. Based on the output of the focus position detection system and the like, the main control system 22 performs an auto focus method. Then, the position and the tilt angle of the wafer W in the Z direction are controlled to adjust the surface of the wafer W to the image plane of the projection optical system 3. And at the time of exposure,
When exposure to a certain shot area on the wafer W is completed,
The wafer W is stepped at a high speed in a non-contact manner through a plurality of drive units 11 to project a next shot area into the projection optical system 3.
, And the operation of projecting and exposing the pattern image of the reticle R to the shot area by the step-and-repeat method is repeated, and the exposure of each shot area of the wafer W is performed.

As described above, the thrusts in the X, Y, and Z directions are applied to the magnet plate 8 of the wafer table 5 of the present embodiment by a large number of drive units 11 disposed on the bottom surface. . In the following, the configuration of the drive unit 11,
And the operation will be described in detail. FIG. 2 is a perspective view in which the top yoke 16 and the cover member 21 of FIG. 1 are partially cut away, and the wafer table 5 (wafer W) moves within the bottom yoke 10 as shown in FIG. A large number (in this example, 7 rows × 7 columns) of drive units 11 having the same configuration at a predetermined pitch in the X direction and the Y direction so as to cover the entire area.
Is incorporated. In this case, the arrangement pitch of the drive units 11 is set so that the drive units 11 are always arranged on the bottom surface of the wafer table 5 in a total of about 3 rows × 3 columns or more. Each drive unit 11 includes a core 20 and an X coil 12 that is a coil for applying a thrust to the magnet plate 8 (wafer table 5) in the X direction.
A and 12B, Y coils 13A and 13B for applying a thrust to the magnet plate 8 (wafer table 5) in the Y direction, and a Z coil for generating a magnetic flux in the Z direction. 14.

In this case, since the plurality of drive units 11 are not directly magnetically connected to each other, the inductance of each coil is reduced, and the responsiveness when switching the drive current is good. FIG. 3A is a plan view showing a core 20 made of a ferromagnetic material for the drive unit 11, and FIG. 3B is a side view of the core 20, as shown in FIGS. 3A and 3B.
The core 20 is provided on the upper side surface of a prism 20a having a square cross section.
Flange portions 20b to 20e which also serve as two rectangular bobbins
Is attached. As a result, the flange portion 20b
Since the magnetic flux BA passing through to 20e is bent and passes through the inside of the prism 20a, the magnetic flux BA passes through the inside of the prism 20a.
There is almost no magnetic flux on the bottom surface of 20e.

FIG. 4 is an exploded perspective view showing the drive unit 11, and when installed on the bottom yoke 10, as shown in FIG. 4, the flange portions 20b and 20c are oriented in the -X direction and the + X direction, respectively. The core 20 is positioned so as to face. Then, the flange portion 2 of the core 20 in the X direction
Winding the X coils 12A and 12B around the axes 0b and 20c, that is, about an axis parallel to the X axis, respectively.
Around the Y-direction flange portions 20d and 20e, that is, around the axis parallel to the Y-axis, respectively.
3B is wound around the prism 20a at the bottom of the core 20,
That is, one drive unit 11 is configured by winding the Z coil 14 around an axis parallel to the Z axis. The other drive units 11 have the same configuration.

In this case, for example, a current IX flowing in the + Y direction (or -Y direction) at the upper portion and flowing in the -Y direction (or + Y direction) at the bottom portion is supplied to the X coil 12A. Since the passing magnetic flux BA does not pass through the bottom due to the action of the core 20, a Lorentz force FXA acts on the X coil 12A as a whole in the X direction. Similarly, the Lorentz force in the X direction acts on the other X coil 12B. On the other hand, for example, -X
Flow in the direction (or + X direction) at the bottom at the + X direction (or -X direction)
The current IY flowing in the direction
Since the magnetic flux BA passing through the top of B does not pass through the bottom,
A Lorentz force FYB acts in the Y direction as a whole on the Y coil 13B, and a Lorentz force acts in the Y direction on the other Y coil 12A as well.

By energizing the Z coil 14, a variable repulsive force is applied to the magnet plate 8 above the core 20,
Or, a suction force is generated. At this time, the Z coil 14 is disposed below the X coils 12A and 12B and the Y coils 13A and 13B and near the connection between the core 20 and the bottom yoke 10. Since the Z coil 14 surrounds the entire connection portion, a magnetomotive force can be applied to the entire core 20. Therefore, a relatively linear thrust can be applied to the wafer table 5 in the Z direction. If the Z coil 14 is configured to partially apply a magnetomotive force to the core 20, a local magnetic circuit is formed in the core 20, and the force generated by the Z coil 14 becomes very nonlinear. For example, even if the wafer table 5 is lifted, a suction force may act.

Next, the configuration of the drive circuit of the drive unit 11 and the operation of the drive unit 11 will be described with reference to FIG. FIG. 5 is an enlarged view of a part of FIG.
Attention is focused on one drive unit 11 located on the bottom surface of the wafer table 5. In this case, the magnetic plate BA in the wafer table 5 and the bottom yoke 10 and the top yoke 16 in FIG. 2 generate a magnetic flux BA from the magnet plate 8 to the drive unit 11 in the −Z direction, for example. .

A drive circuit 31 is connected to the drive unit 11, and a control unit 35 in the drive circuit 31
Under the control of the main control system 22, the operation of each circuit is supervised. The X-axis driving circuit 3 is provided in the driving circuit 31.
2, a Y-axis drive circuit 33 and a Z-axis drive circuit 34 are provided, and the X-axis drive circuit 32 supplies a current IX flowing in the Y direction on the upper side to the X coils 12A and 12B of the corresponding drive unit 11, The Y-axis drive circuit 33 includes a Y coil 13A,
13B, the current IY flowing in the X direction on the upper side is supplied, and Z
The drive circuit 34 supplies a current IZ to the Z coil 14. As a result, as described with reference to FIG.
The current IX flowing through the X coils 12A and 12B and the magnetic flux BA in the Z direction generate a Lorentz force in the X coils 12A and 12B in the X direction, and a reaction force of the Lorentz force on the magnet plate 8 (wafer table 5). As a result, a thrust FX in the X direction is generated.

Similarly, the current IY flowing through the Y coils 13A and 13B and the magnetic flux BA in the Z direction make the Y coil 13
Lorentz force is generated in A and 13B in the Y direction, and thrust FY in the Y direction is generated in the magnet plate 8 (wafer table 5) as a reaction force of the Lorentz force. Thrust FX, FY
Are proportional to the currents IX and IY, respectively, so that the X-axis drive circuit 32 and the Y-axis drive circuit 33 respectively control the currents IX and IY according to the thrusts instructed by the control unit 35. The directions (± X direction, ± Y direction) of the thrusts FX, FY can be arbitrarily set to any of the directions (signs) of the corresponding currents IX, IY.

The Z-axis drive circuit 34 sends the Z coil 14
, A new variable magnetic flux penetrating the Z coil 14 is generated as described above, and this variable magnetic flux causes the magnet plate 8 to move in the Z direction consisting of the reluctance force. Thrust FZ acts. This thrust FZ can also be set in either the + Z direction (repulsive force) or the −Z direction (attraction force) depending on the direction (sign) of the current supplied to the Z coil. In the Z-axis drive circuit 34, the control unit 35
The current IZ to be supplied to the Z coil 14 is controlled in accordance with the thrust FZ instructed from.

The same drive circuit as the drive circuit 31 of FIG.
Each is connected to each drive unit 11 of FIG.
The wafer table drive system 23 shown in FIG. 1 is constituted by such a large number of drive circuits 31. At this time, the coordinates of the wafer table 5 (wafer W) in the X and Y directions and the rotation angle are obtained from the measured values of the laser interferometers 18X, 18Y1 and 18Y2, and based on the result, the main control system 22 drives each drive. For the control unit 35 in the drive circuit 31 of the unit 11,
An instruction is given as to how much the wafer table 5 is displaced in each part, and in response to the instruction, the control unit 35 generates a predetermined thrust by a corresponding coil. Since the drive units 11 of about 3 rows × 3 columns or more are always arranged on the bottom surface of the wafer table 5 of this example, the drive units 1
By combining thrusts FX, FY, and FZ in the X, Y, and Z directions generated from 1 to the magnet plate 8 (wafer table 5), the wafer table 5 has six degrees of freedom (X direction, Y direction, Displacement in the Z direction, X axis, Y axis,
(Rotation about the Z axis).

Further, strain gauges 9A to 9D are attached to the four corners of the upper surface of the plate 6 of the wafer table 5 of the present embodiment, and the strain gauges 9A to 9D are not connected via flexible lead wires (not shown). The distortion amount of the plate 6 detected by the detection circuit is supplied to the main control system 22. When the distortion of the magnet plate 8 and thus the plate 6 is detected, the main control system 22 controls the thrust in the Z direction by the plurality of drive units 11 on the bottom surface side of the wafer table 5 to correct the distortion.

Instead of actively correcting the distortion as described above, a correction plate made of a magnetostrictive material deformable by a magnetic field is attached to the top or bottom surface of the magnet plate 8, and the magnet plate 8 is autonomously corrected. 8 may be corrected. As the magnetostrictive material, for example, a ferrite garnet type (CoFe ₂ O)
₄ etc.) or rare earth alloys (70wt% Tb-30wt)
% Fe, SmFe ₂ , TbFe ₂ , Tb (CoFe) ₂
Etc.) can be used. When the magnetostrictive material is used in this way, as an example, a position where the magnet plate 8 is easily deformed to be convex by the magnetic field may be covered with a magnetostrictive material that contracts due to the magnetic field. In
What is necessary is just to apply the magnetostrictive material which expands by a magnetic field.

Next, an example of the operation when the wafer table 5 is two-dimensionally displaced will be described with reference to FIG. First, when the wafer table 5 (wafer W) is displaced in the Y direction, as shown in FIG.
A command is issued to the control units 1A, 11B, and 11C to generate a thrust FY1 in the Y direction. In response to this, a thrust FY1 in the Y direction acts on the wafer table 5 from the drive units 11A to 11C, and the wafer table 5 is displaced in the Y direction. Similarly, when displacing the wafer table 5 in the X direction, the plurality of drive units 11D, 11B, 11E at the bottom of the wafer table 5 are used.
, A thrust FX1 in the X direction may be applied to the wafer table 5 from the respective directions.

As shown in FIG. 6B, when a rotation error θ occurs in the wafer table 5 (wafer W), a pair of driving units separated from each other at the bottom of the wafer table 5 in the X direction. A thrust force FY2 in the -Y direction and a thrust force -FY2 in the + Y direction are generated from the units 11A and 11C, respectively.
A pair of drive units 11D and 11E separated in the Y direction generate a thrust FX2 in the −X direction and a thrust −FX2 in the + X direction, respectively, to rotate the wafer table 5 by the rotation error θ.
What is necessary is just to rotate so as to cancel out. At this time, the rotation angle of the wafer table 5 is controlled by the laser interferometers 18Y1, 18Y in FIG.
The rotation angle of the wafer table 5 is accurately corrected in a closed loop based on the monitoring from the measured value of Y2.

As described above, in this embodiment, since the wafer table 5 on which the wafer W is placed is driven in a non-contact manner, the wafer W can be positioned at a high speed. Therefore, the throughput (productivity) of the exposure process is increased. Further, since the drive unit 11 only needs to be arranged over substantially the entire movement range of the wafer table 5, the positioning device does not become large. In FIG. 1, for example, replacement of the wafer W can be performed through a notch (not shown) provided at an end of the top yoke 16.

In this embodiment, the driving unit 11
May be arranged on the upper surface side of the wafer table 5, and the drive units 11 may be arranged on both the upper surface side and the bottom surface side of the wafer table 5. By arranging the drive units 11 on both sides in this manner, a larger thrust can be obtained. Further, in the above embodiment, the oblique incidence type focus position detection system (not shown) for measuring the position of the surface of the wafer W in the Z direction is provided.
A plurality of gap sensors for measuring the distance from the wafer table 5 may be provided on the 0 side. In the above-described embodiment, the present invention is applied to a batch exposure type projection exposure apparatus. However, the present invention relates to a step of performing transfer by scanning a reticle and a wafer in synchronization with a projection optical system. The present invention may be applied to a scanning exposure type projection exposure apparatus such as an AND scan method.

Next, a second embodiment of the present invention will be described with reference to FIGS. In this example, a drive unit different from that of the first embodiment is used.
In FIG. 9, portions corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 7 is a cross-sectional view showing a main part on the wafer stage side of the projection exposure apparatus of the present example. In FIG.
The top yoke 16 is fixed via C, 15D and the like, and a number of drive units 60 are arranged on the bottom yoke 10 at predetermined pitches in the X direction and the Y direction so as to cover the entire moving surface of the wafer table 5, The wafer table 5 (bottom portion is a magnet plate 8) is arranged on many drive units 60.

Also in this embodiment, the first yoke circuit, the first magnetic circuit including the magnet plate 8, the top yoke 16, the columns 15C, 15D, etc. in the wafer table 5, and the leak from the bottom surface of the magnet plate 8 into the space. The magnetic flux that flows is the top yoke 1
A second magnetic circuit that returns to the magnet plate 8 through 6 is formed, and a lifting force toward the top yoke 16 acts on the wafer table 5 mainly by the second magnetic circuit. A drive unit 60 of about 3 rows × 3 columns is always arranged on the bottom surface of the wafer table 5. Then, the driving unit 60
Also provided are X coils 27A and 27B for giving a thrust in the X direction to the magnet plate 8, Y coils 28A and 28B for giving a thrust in the Y direction, and a Z coil 29 for giving a thrust in the Z direction. .

FIG. 8 shows one drive unit 60 in FIG.
In FIG. 8, the inverted U-shaped cores 25A and 2 parallel to the X direction are provided on the bottom yoke 10 in FIG.
5B are installed diagonally, and inverted U-shaped cores 26A and 26B parallel to the Y direction are installed so as to cross these cores. Then, as shown by the two-dot chain line, the core 25
A, an X coil 2 around an axis parallel to the X axis at the top of 25B
7A and 27B, and Y is wound on the cores 26A and 26B.
The drive unit 60 is configured by winding the Y coils 28A and 28B around an axis parallel to the axis, and winding the Z coil 29 around an axis parallel to the Z axis so as to surround them as shown by a solid line. Have been.

In the present embodiment, for example, the magnetic flux BA entering from the upper part of the core 25A passes through the bottom yoke 1 through an inverted U-shaped path.
Since it goes to zero, there is almost no magnetic flux at the bottom of the X coil 27A. Therefore, when a current IX heading in the Y direction is supplied to the upper part of the X coil 27A, a Lorentz force FXA heading in the X direction acts on the X coil 27A by the current IX and the magnetic flux BA. The same applies to the other X coil 27B. On the other hand, a Lorentz force acting in the Y direction acts on the Y coils 28A and 28B by supplying a current flowing in the X direction. Furthermore, in this example, for example, in the core 25A, the magnetic flux generated by the X coil 27A forms a closed magnetic circuit composed of the core 25A and the bottom yoke 10 as shown by a path 30, and the other cores 25B, 26A, 26B
Is not affected, so that the thrust control accuracy in the X direction and the Y direction is improved.

Next, the operation of the drive unit 60 of this embodiment will be described with reference to FIG. 9. In FIG. 9, the drive circuit of the drive unit 60 is the same as that of the first embodiment shown in FIG.
Can be used. Then, the X coil 27
The current IX flowing through the A and 27B and the magnetic flux BA in the Z direction generate a Lorentz force in the X direction, and the magnet plate 8 (wafer table 5) has a thrust F in the X direction as a reaction force.
X occurs. Similarly, a Lorentz force is generated in the Y direction by the current IY flowing through the Y coils 28A and 28B and the magnetic flux BA in the Z direction.
A thrust FY is generated in the direction. Further, by controlling the value of the current IZ supplied to the Z coil 29, a new variable magnetic flux penetrating through the Z coil 29 is generated.
A thrust FZ (repulsive force or suction force) acts in the direction.
Therefore, by using a plurality of drive units 60 in combination, the wafer table 5 can be used similarly to the first embodiment.
Can be driven with six degrees of freedom.

Next, a third embodiment of the present invention and its modification will be described with reference to FIGS. This example also uses a drive unit different from that of the above-described embodiment. In FIGS. 14 to 17, parts corresponding to FIGS. 7 to 9 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 14 is a cross-sectional view showing a main part on the wafer stage side of the projection exposure apparatus of this embodiment. In FIG. 14, a magnetic circuit between the bottom yoke 10 and a top yoke 16 (not shown) (see FIG. 7) is shown. The two types of drive units 70X are alternately arranged at predetermined pitches in the X direction and the Y direction on the upper surface of the bottom yoke 10 so as to cover the entire surface of the moving surface of the wafer table 5. , 70Y
Is arranged. The X-axis drive unit 70X applies a variable thrust to the magnet plate 8 in the wafer table 5 in the Z direction and the X direction, and the Y-axis drive unit 70Y is arranged by rotating the drive unit 70X by 90 °. Thus, a variable thrust in the Z direction and the Y direction is applied to the magnet plate 8 (therefore, the wafer table 5). The drive units 70X and 70Y of about 3 rows × 3 columns are always arranged on the bottom surface of the wafer table 5, so that the wafer table 5 (magnet plate 8) is given a variable thrust with six degrees of freedom as a whole.

One drive unit 70X has a core made of an arc-shaped, that is, an inverted U-shaped ferromagnetic material having two legs fixed on the bottom yoke 10 and convex with respect to the magnet plate 8. 71 and a horizontal coil 73 wound around an axis substantially parallel to the X-axis on the upper part of the core 71 as a bobbin.
And two Z coils 72 </ b> A and 72 </ b> B wound around an axis parallel to the Z axis and formed by two legs of the core 71. The horizontal coil 73 of the drive unit 70X is an X coil, and the horizontal coil 73 of the drive unit 70Y is a Y coil.
It corresponds to a coil.

FIG. 15 shows a state in which the horizontal coils 73 are separated from the drive units 70X and 70Y, respectively.
Is formed by winding a coil around an opening 73c through which an upper portion 71a above the dotted line of the core 71 is inserted. The upper part 73a of the horizontal coil 73 is substantially flat,
1 has a larger area than the upper part 71a, and the lower part 73b
The coil is narrowed down, and the lower portion 73b is
Is configured to be able to pass between the legs 71b and 71c.

In this case, as an example, the leg portions 71b and 71c and the upper portion 71a constituting the core 71 are formed of three separate plate members, and the horizontal coil 73 is a plate member having the same sectional area as the upper portion 71a. And wound using a horizontal coil 7
After the upper portion 71a is inserted through the opening 73c of the third unit 71, the leg units 71c and 71b, around which the Z coils 72A and 72B are wound, are screwed from both sides of the upper portion 71a. Can be assembled. Alternatively, an L-shaped ferromagnetic thin plate is
The drive unit 70X can also be assembled by alternately inserting the I-shaped ferromagnetic thin plates into the left and right gaps after alternately inserting the I / F into the left and right openings 73c.
The same applies to the other drive unit 70Y.

In FIG. 15, the legs 71b of the core 71,
Each of the legs 71c is directly magnetically connected to the bottom yoke 10, but the legs 71b and 71c are not directly magnetically connected to each other. This is for each coil 72A, 72B,
This is for improving the thrust responsiveness by reducing the inductance of 73. In FIG. 14, on the upper surface of the horizontal coil 73 (X coil) of the drive unit 70X, the magnetic flux BA in the magnetic circuit including the magnet plate 8, the core 71, and the bottom yoke 10 is in the Z direction (− in FIG. 14). Z direction)
When a current IX in the + Y direction is applied to the horizontal coil 73, a Lorentz force in the −X direction is generated in the horizontal coil 73, and the wafer table 5 (magnet plate 8) acts in the + X direction as a reaction. Thrust FX is generated. Its current I
By controlling the direction and magnitude of X, the direction and magnitude of thrust FX on wafer table 5 can be controlled. Similarly, by controlling the current IY in the X direction supplied to the horizontal coil 73 (Y coil) of the drive unit 70Y,
A variable thrust FY can be generated for the wafer table 5 in the Y direction. Since the magnetic flux density is small except for the upper portion 73a of the horizontal coil 73, for example, the lower portion 73b of the horizontal coil 73
(See FIG. 15), the Lorentz force in the reverse direction hardly occurs. This is because the magnetic flux from the magnet plate 8 flows to the bottom yoke 10 via the core 71 which is a ferromagnetic material.

The Z coils 72A and 72B are arranged below the horizontal coil 73 and near the connection between the core 71 and the bottom yoke 10. Since the Z coils 72A and 72B substantially surround the entire connection portion, a magnetomotive force is applied to the entire core 73 by flowing a current IZ1 around the Z axis to the Z coils 72A and 72B of the drive unit 70X. be able to. Therefore, a relatively linear Z-direction thrust FZ1 can be applied to wafer table 5 (magnet plate 8). Further, by controlling the current IZ2 flowing through the Z coils 72A and 72B of the other drive unit 70Y to control the thrust FZ2 on the wafer table 5 in the Z direction, the wafer table 5 can be leveled.

In this example, for example, the driving unit 70X
When a current IX is caused to flow through the horizontal coil 73, an electromotive force that causes a current to flow in the reverse direction, that is, a magnetic flux penetrating through a closed magnetic circuit formed by the core 71 and the bottom yoke 10, is generated. 5 may be reduced. In order to prevent such a decrease in thrust FX, currents are applied to Z coils 72A and 72B in directions opposite to each other so as to be superimposed on current IZ1 and generate a magnetic flux for canceling the magnetic flux. You can make it flow. As a result, the thrust FX on the wafer table 5 in the X direction (the same applies to FY) can be controlled to a desired value.

Here, a modification of the drive unit according to the third embodiment for reducing the electromotive force for causing a current to flow in the reverse direction to the horizontal coil 73 will be described with reference to FIG.
6, and will be described with reference to FIG. FIG. 16 shows an exploded state of one X-axis drive unit 74X of this modification. In FIG. 16, a core 75 made of a rectangular thick flat ferromagnetic material is fixed on the bottom yoke 10, A pair of horizontal coils 73d and 73e wound around respective axes (openings 73c) parallel to the X axis so as to sandwich the upper portion of the core 75 in the X direction are mounted. The horizontal coils 73d and 73e are equivalent to half coils in the −X direction and the + X direction when the horizontal coil 73 of FIG. 14 is symmetrically bisected in a plane parallel to the ZY plane. And
Around the core 75 and the horizontal coils 73d and 73e,
The drive unit 74X is configured by mounting a Z coil 76 wound in a rectangular frame shape around the Z axis.

FIG. 17 is a sectional view taken along the line AA showing a state where the wafer table 5 is located on the drive unit 74X in FIG. 16. In FIG. 17, the magnet plate 8, the core 75, The horizontal coil 73d on the upper surface of the core 75 is
The magnetic flux BA passes through 73e in the Z direction. Therefore, by supplying the current IX1 to the horizontal coils 73d and 73e in the Y direction (see FIG. 16), the magnet plate 8 (wafer table 5) is moved in the X direction as a reaction of the Lorentz force generated in the horizontal coils 73d and 73e. Generates a variable thrust FX. Further, by passing a current IZ around the axis parallel to the Z axis to the Z coil 76, the magnetic flux penetrating the entire core 75 changes, and changes substantially linearly with respect to the magnet plate 8 (wafer table 5). A variable thrust FZ in the Z direction is generated.

In this modification, the horizontal coils 73d, 73d
e when the current IX1 is supplied to the core 75
Since no electromotive force (magnetic flux) in the direction of canceling X1 is generated, only the current corresponding to the thrust FZ in the Z direction needs to be supplied to the Z coil 76. Further, the core 76 does not saturate. Next, a fourth embodiment of the present invention will be described with reference to FIGS. For example, in the embodiment shown in FIG. 1 and FIG. 2, since the wafer W moves in the magnetic flux, the positioning device is an exposure device that transfers a mask pattern using a charged particle beam, such as an electron beam transfer device. Tends to be difficult to apply. Therefore, in this embodiment, an example of a positioning device that can be used in an electron beam transfer device or the like without a wafer passing through a magnetic flux is shown.

FIG. 10 shows a main part of the projection exposure apparatus of this embodiment. In FIG. 10, a mask pattern (not shown) is transferred onto the wafer W via the projection optical system 41. As the projection optical system 41, in addition to an optical projection optical system that projects a pattern image under ultraviolet light such as excimer laser light, an electron that transfers a reduced image of a mask pattern or the like under an electron beam is used. An optical system or the like can also be used. Hereinafter, the Z-axis is set in the optical axis direction of the projection optical system 41, and an orthogonal coordinate system in a plane perpendicular to the Z-axis is described as an X-axis and a Y-axis.

At this time, the wafer W is placed in the wafer holder 42
The wafer holder 42 is held on the sample table 43 by suction, and the sample table 43 is fixed to the center of a movable plate 44 made of a non-magnetic material that is elongated along substantially the X-axis. Then, rectangular plate-like magnet plates 45A and 45B that generate uniform magnetic fluxes directed in the Z direction are fixed to the bottom surfaces of the + X direction end 44a and the −X direction end 44b of the movable plate 44, respectively. Have been. Each of the magnet plates 45A and 45B is, for example, a single permanent magnet having an N pole on the bottom surface and an S pole on the top surface. A yoke plate 46 made of a ferromagnetic material is arranged on the bottom side of the movable plate 44. Both ends 46a and 46b of the yoke plate 46 vertically sandwich the magnet plates 45A and 45B at both ends of the movable plate 44, respectively. As shown in FIG.

A large number of drive units 1 are arranged between the magnet plate 45A on the + X direction side and the yoke plate 46 at a predetermined pitch in the X and Y directions so as to cover the moving range of the magnet plate 45A.
1, the magnet plate 45B and the yoke plate 4 on the −X direction side.
A large number of drive units 11Y are arranged at predetermined pitches in the X and Y directions so as to cover the movement range of the magnet plate 45B. The drive unit 11 on the + X direction side has the same configuration as the drive unit 11 of the first embodiment shown in FIG. 5, and in FIG. 10, the magnet plate 45A on the + X direction side
, A floating force is applied in the yoke plate 46, and the thrust fX1 in the X direction, the thrust fY1 in the Y direction, and the thrust fZ1 in the Z direction are applied to the magnet plate 45A from the plurality of drive units 11. Is working. By controlling these thrusts, the end portion 44a of the movable plate 44 on the + X direction side can be moved in the X direction, the Y direction, and the Z direction.
It is positioned without contact in the direction.

On the other hand, the drive unit 11Y on the −X direction side
Is different from the drive unit 11 of the first embodiment,
The drive unit generates only thrusts in the Y direction and the Z direction. FIG. 11 shows the magnet plate 45 on the −X direction side in FIG.
B shows the state of the bottom surface. In FIG.
A drive unit 11Y of, for example, about 3 rows × 3 columns is always accommodated on the bottom side of 5B. Then, one drive unit 11Y is connected to the core 20 shown in FIG.
A pair of flange portions (the flange portions 20d and 2d in FIG. 4)
0e), the Y coils 13A and 13B are wound, and the Z coil 14 is wound so as to surround the bottom of the core 20. For example, when a current IY is supplied to the Y coil 13B in the X direction, the magnetic flux BA which enters from the upper surface of the core 20 and bends inward at the flange portion causes the Y coil 13B
, A Lorentz force FYB acts in the Y direction. Similarly, a Lorentz force acts in the Y direction on the other Y coil 13A, and a thrust in the Y direction is generated on the upper magnet plate 45B as a reaction. I do. Further, by supplying a current to the Z coil 14, a thrust in the Z direction is generated in the magnet plate 45B above the Z coil 14. As a result, the drive unit 11Y
Can apply variable thrusts in the Y and Z directions without contacting the magnet plate 45B thereon.

Returning to FIG. 10, the magnet plate 45B on the −X direction side
Is provided with a levitation force in the yoke plate 46, and a plurality of drive units 11Y to Y are attached to the magnet plate 45B.
The thrust fY2 in the direction and the thrust fZ2 in the Z direction are acting. By controlling these thrusts, the magnet plate 45 </ b> B, and thus the end 44 b on the −X direction side of the movable plate 44, are positioned in a non-contact manner in the Y and Z directions. Displacing the end 44b in the Y direction in this way means rotating the movable plate 44 around an axis parallel to the Z axis. Furthermore, by controlling the thrust in the Z direction by the three or more drive units 11 and 11Y on the bottom surfaces of the magnet plates 45A and 45B, the position of the movable plate 44 in the Z direction, the inclination angle around the X axis, and The tilt angle around the Y axis can be controlled, and as a result, the wafer W on the sample table 43 fixed to the movable plate 44 can be positioned with six degrees of freedom.

In this case, since the yoke plate 46 of this embodiment has a structure in which the left and right U-shaped yoke plates are connected, the leakage of the magnetic flux to the central portion of the movable plate 44, that is, the wafer W side is extremely small. Has become. Therefore, the positioning section of this example can be used also as a wafer stage of an electron beam transfer device or the like. Note that, also in this example, the drive units 11 and 11
Y may be arranged on the upper surfaces of the magnet plates 45A and 45B, respectively, and the drive units 11 and 11Y may be arranged on both sides of the upper and lower surfaces of the magnet plates 45A and 45B. In the present embodiment, the drive unit 11 is provided with a core, an X coil, a Y coil, and a Z coil.
1Y is provided with a core, a Y coil, and a Z coil. In addition, for example, four drive units are provided, two of which are only Z coils, and one drive unit is a core, an X coil, and a Y coil. Only the coil and the other one may include only the core and the Y coil.

Next, a fifth embodiment of the present invention will be described with reference to FIG. This example is also an example of a positioning device that can be applied to a charged particle beam transfer device without applying a magnetic flux to a wafer W as a positioning target. In FIG. 12, portions corresponding to FIG. The detailed description is omitted. FIG. 12 shows a main part of the projection exposure apparatus of this embodiment. In FIG. 12, a mask pattern (not shown) is transferred onto the wafer W via the projection optical system 41. The wafer W is suction-held on a wafer holder 42, and the wafer holder 42 is fixed on an end portion 47b in the −X direction of a movable plate 47 made of a non-magnetic material that is elongated along substantially the X axis. On a bottom surface of the end 47b on which the wafer W is mounted, bases 51 on which the end 47b can be mounted as needed are arranged at predetermined intervals.

A rectangular plate-like magnet plate 45 for generating a uniform magnetic flux in the Z direction is fixed to the bottom surface of the end 47a in the + X direction of the movable plate 47. Magnet plate 4
Reference numeral 5 denotes a single permanent magnet having, for example, a bottom N pole and a top S pole. Also, the bottom yoke 50 and the four pillars 49A to 49D at the four corners so as to vertically sandwich the magnet plate 45 at the end of the movable plate 47 and cover the entire moving range of the magnet plate 45.
(Only 49A to 49C are shown in FIG. 12), and a yoke member connecting the top yoke 48 is arranged. At the bottom of the magnet plate 45, a number of drive units 11 are arranged on the upper surface of the bottom yoke 50 at predetermined pitches in the X and Y directions. The drive unit 11 has the same configuration as the drive unit 11 of the first embodiment shown in FIG. 5, and in FIG. 12, the magnet plate 45 is provided with a levitation force in a yoke member, The plate 45 has a thrust fX in the X direction, a thrust fY in the Y direction, a thrust fZ in the Z direction, a torque in the θ direction around the Z axis, a torque around the X axis, and a torque around the X axis. A torque around the Y axis can be applied. By controlling these thrusts and torques, the magnet plate 45 and, consequently, the movable plate 47 are controlled.
Is positioned with six degrees of freedom in a cantilever manner.

Also in this embodiment, only the end 47a in the + X direction of the movable plate 47 is in the magnetic flux, and almost no magnetic flux acts on the wafer W. Can also be used on stage. In the above embodiment, the magnet plate 8 has a single-pole structure, but the table can be similarly positioned even with a multi-pole structure.

FIG. 13 is a plan view of an example of a multi-pole magnet plate 8A. In FIG. 13, a plurality of drive units are arranged at predetermined pitches in the X direction and the Y direction as indicated by dotted lines on the bottom side of the magnet plate 8A. 11 (same as shown in FIG. 2). The magnet plate 8A is formed by arranging small rectangular plate-shaped magnet plates in 4 rows × 4 columns, and the polarities of these small magnet plates are alternately reversed in both the X and Y directions. In addition, one driving unit 11 has a magnet plate 8A.
And 2 rows × 2 columns (4 pieces) of small magnet plates (polarities on the same diagonal line are the same, and polarities on diagonal lines that cross each other are different) are arranged, and the X coil When a magnet plate having an N-pole (or S-pole) bottom surface faces 12, a magnet plate having an S-pole (or N-pole) bottom surface faces the Y coil 13. Therefore, the X coil 12 or Y
Only by reversing the polarity of the current flowing through the coil 13, the magnet plate 8A can be driven as in the above-described embodiment.

In FIG. 13, a part of the X coil 12 and a part of the Y coil 13 are placed on magnet plates having different polarities.
Since this portion is a portion where the coil is bent in the Z direction, it does not contribute much to the thrust in the X direction and the Y direction. When using the multi-pole magnet plate 8A as described above,
Since it is necessary to determine to which coil the current flows according to the position of the magnet plate 8A, the control tends to be complicated.

Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

[0075]

According to the first positioning device of the present invention,
The movable table including the movable body and the magnetizable body can be thin and light. Also, for example, most of the weight of the movable table is supported by a magnetic circuit composed of a magnetic member and a magnet, and the levitation force of the magnet is controlled by a levitation coil. There is an advantage that the placed movable body can be stably supported without contact, and the movable body can be accurately positioned in the height direction with a large thrust.

Further, since a large thrust is obtained in the height direction, a large gap can be formed between the movable table and the drive unit, and there is an advantage that a cooling mechanism or the like can be easily arranged in the space of the gap. Similarly, according to the second or third positioning device of the present invention, most of the weight of the movable table including the movable body and the magnetizing body is supported by the magnetic circuit, and the thrust generating coil (or drive unit) Since a two-dimensional thrust is generated on the magnetized body within the moving surface of the movable body, the movable body on which the positioning target such as a wafer is placed can be stably supported in a non-contact manner, and a large There is an advantage that the movable body can be accurately and two-dimensionally positioned by thrust.

Further, for example, since a plurality of drive units may be arranged so as to cover almost the entire moving range of the movable body (magnetizing body), the drive mechanism is made much larger than the moving stroke of the movable body. The movable body can be positioned in a non-contact manner without performing. In addition, when a position measurement system that measures the position of the movable body in the moving plane is provided, the positioning accuracy is improved. When a deformation amount measurement system that measures the amount of deformation of the magnetizable body is provided, the position measurement system is actively activated. The deformation of the magnetic body can be corrected.

Further, when a magnetostrictive member which deforms so as to cancel the deformation of the magnetic body by magnetism is attached to the magnetic body, the flatness of the magnetic body can be maintained with high accuracy. Next, according to the fourth positioning device of the present invention, similarly to the first or second positioning device, the movable body on which the positioning object is placed can be stably supported in a non-contact manner and with a large thrust. There is an advantage that the movable body can be accurately positioned. Furthermore, since the magnetic flux hardly acts on the positioning object by placing the positioning object between, for example, two magnets, there is an advantage that the positioning object can be applied to a positioning device such as a charged particle beam transfer device.

Further, when a reaction force due to a thrust generated when the movable body is positioned is released to the floor, generation of vibration is suppressed. Also, the magnetizing body is
If it is unipolar, the structure is simplified. Next, according to the exposure apparatus of the present invention, since the positioning apparatus of the present invention is provided, a semiconductor element or the like can be manufactured with high throughput and high accuracy. Further, the drive unit of the present invention can be used, for example, as a drive unit of the third positioning device of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a projection exposure apparatus according to a first embodiment of the present invention.

FIG. 2 shows a top yoke 16 to a bottom yoke 10 of FIG.
FIG. 2 is a partially cutaway perspective view showing the configuration up to FIG.

FIG. 3A shows a core 2 of a drive unit 11 in FIG.
0 is a plan view, and (b) is a side view thereof.

FIG. 4 is an exploded perspective view showing the drive unit 11 in FIG.

FIG. 5 is a diagram for explaining a drive circuit of the drive unit 11 and an operation of the drive unit 11 in FIG. 2;

FIG. 6 is a plan view when the wafer table 5 is driven and rotated in the X and Y directions using a plurality of drive units 11 in FIG.

FIG. 7 is a sectional view showing a main part of a projection exposure apparatus according to a second embodiment of the present invention.

8 is an exploded perspective view showing the drive unit 60 in FIG.

FIG. 9 is a diagram provided for explaining an operation of a drive unit 60 in FIG. 7;

FIG. 10 is a perspective view showing a main part of a projection exposure apparatus according to a fourth embodiment of the present invention.

11 is a plan view showing a drive unit 11Y on the bottom surface side of the magnet plate 45B of FIG.

FIG. 12 is a perspective view showing a main part of a projection exposure apparatus according to a fifth embodiment of the present invention.

FIG. 13 is a plan view showing a case where a multi-pole magnet plate is used in the embodiment of the present invention.

FIG. 14 is a perspective view illustrating a main part of a wafer stage according to a third embodiment of the present invention.

FIG. 15 is an exploded perspective view showing a state where some coils are removed from the drive units 70X and 70Y of FIG.

FIG. 16 is an exploded perspective view showing a state where some coils are removed from a drive unit according to a modified example of the third embodiment.

FIG. 17 is a sectional view taken along the line AA in FIG. 16, showing a state in which a drive unit according to a modification of the third embodiment is assembled.

[Explanation of symbols]

R reticle, 3 projection optical system, W wafer, 5 wafer table, 6 plate, 8, 45, 45A, 45B
Magnet plate, 10 bottom yoke, 11, 11Y, 60, 7
0X, 70Y, 74X drive unit, 12A, 12B
X coil, 13A, 13B Y coil, 14Z coil, 15A, 15B support, 16 top yoke, 17
X, 17Y moving mirror, 18X, 18Y1, 18Y2 laser interferometer, 20, 71, 75 core, 21 cover member, 22 main control system, 23 wafer table drive system, 3
1 drive circuit, 44, 47 movable plate, 46 yoke plate, 72A, 72B, 76 Z coil, 73, 73
d, 73e Horizontal coil

Claims (12)

[Claims] 1. A positioning device for positioning a movable body on which a positioning object is mounted, wherein the magnetic flux is integrated with the movable body and is directed in one direction perpendicular to a moving surface of the movable body. A magnetic member that is generated; a magnetic member that is arranged so as to sandwich the movable body and the magnetic member up and down to form a magnetic circuit with the magnetic member; and a magnetic member that is arranged between the magnetic member and the magnetic member. A drive unit for driving the magnetic field, wherein the drive unit has a levitation coil wound to generate a variable thrust in a direction perpendicular to the moving surface with respect to the magnet, and A positioning device, wherein the movable body is positioned by a member and the drive unit. 2. A positioning device for positioning a movable body on which a positioning object is mounted, wherein the magnetic flux is integrated with the movable body and is directed in one direction perpendicular to a moving surface of the movable body. A magnetic member that is generated; a magnetic member that is arranged so as to sandwich the movable body and the magnetic member up and down to form a magnetic circuit with the magnetic member; and a magnetic member that is arranged between the magnetic member and the magnetic member. A driving unit that drives a magnetic field, wherein the driving unit is configured to transmit a magnetic flux in the magnetic circuit; A first thrust generating coil wound around the core member so as to generate the thrust, the thrust comprising a Lorentz force in a second direction intersecting the first direction in the moving plane with respect to the magnet; Will cause A second thrust generating coil wound around the core member, and the movable member is positioned by the magnetic member and the drive unit. 3. A positioning device for positioning a movable body on which an object to be positioned is mounted, wherein the magnetic flux is integrated into the movable body and is directed in one direction perpendicular to a moving surface of the movable body. A magnetic member that is generated; a magnetic member that is arranged so as to sandwich the movable body and the magnetic member up and down to form a magnetic circuit with the magnetic member; and a magnetic member that is arranged between the magnetic member and the magnetic member. A drive unit for driving the magnetic circuit. A thrust generating coil wound around the core member, and a levitation coil wound around the core member so as to generate a variable thrust in a direction perpendicular to the moving surface relative to the magnet. , With And a positioning device for positioning the movable body by the magnetic member and the drive unit. 4. The positioning device according to claim 3, wherein the core member is an arc-shaped member having a convex portion directed toward the magnet body, and two ends of the arc-shaped member are connected to each other. The thrust generating coil is magnetically connected to the magnetic member, the thrust generating coil is wound around an intermediate portion of the arc-shaped member, and the thrust generating coil has an outer area substantially equal to or larger than the area of the core member. And a levitation coil is wound around two ends of the arc-shaped member, the inner area being formed smaller than the outer area. 5. The positioning device according to claim 1, further comprising: a position measuring system for measuring a position of the movable body in the moving surface. . 6. The positioning device according to claim 1, further comprising a deformation amount measuring system for measuring an amount of deformation of the magnetized body. 7. The positioning device according to claim 1, wherein a magnetostrictive member that deforms so as to autonomously cancel the magnetic deformation of the magnetic body is attached to the magnetic body. A positioning device, characterized in that: 8. A positioning device for positioning a movable body on which a positioning target is placed, wherein the positioning apparatus is connected to the movable body and generates a magnetic flux directed in one direction perpendicular to a moving surface of the movable body. The first and second magnets are arranged in a state where the first and second magnets are connected to vertically sandwich the first and second magnets, respectively.
A magnetic member forming a magnetic circuit together with the magnetic body of the first, a first drive unit disposed between the first magnetic body and the magnetic member to drive the magnetic body, and a second magnetic body. A second drive unit disposed between the magnetic member and the magnetic member, wherein the first drive unit includes the first drive unit in the magnetic circuit.
A levitation coil wound so as to generate a variable thrust in a direction perpendicular to the moving surface with respect to the magnetized body, wherein the second drive unit includes the second drive unit in the magnetic circuit.
A floating coil wound so as to generate a variable thrust in a direction perpendicular to the moving surface with respect to the magnetizing member, wherein the magnetic member, the first drive unit, and the second
A positioning unit for positioning the movable body in a non-contact state by the drive unit of (1). 9. The positioning device according to claim 1, wherein a reaction force generated by a thrust generated when the movable body is positioned is released to a floor. Positioning device. 10. The positioning device according to claim 1, wherein the magnetic body is a single pole or a multipole. 11. An exposure apparatus, comprising: the positioning device according to claim 1; and transferring a mask pattern onto a substrate positioned by the positioning device. 12. A drive unit disposed in a magnetic circuit formed by a magnet and a magnetic member to generate a Lorentz force, wherein a magnetic flux passes in a first direction in the magnetic circuit.
A core member magnetically connected to the magnetic member; and a coil wound around the core member in a second direction orthogonal to the first direction. A drive unit characterized by being wound so as to be large and to have a small area on the side of the repulsive magnetic body.