JP2002142490A - Coil driver of linear motor, linear motor driver and stage unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small, inexpensive and low power consumption coil driver of linear motor for driving coils constituting a linear motor, and a linear motor driver comprising the coil driver and a stage unit. SOLUTION: The coil driver of a linear motor driving one coil L1 out of a plurality of coils 22a constituting a linear motor comprises MOS-FETs Q1 and Q2 for turning on/off current supply to the coil L1 of the linear motor. A photocoupler PC1 is provided in order to turn on/off the MOS-FETs Q1 and Q2. Two kinds of resistors, i.e., a low resistance resistor R0 and a high resistance resistor R1 are provided in order to drive the photocoupler PC1 and the circuit is arranged to use the resistors selectively depending on the application.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil driving device for driving a coil constituting a linear motor, a linear motor driving device provided with the coil driving device, and a stage device.

[0002]

2. Description of the Related Art A linear motor is used for a stage having a long moving stroke in a wafer stage or a reticle stage of a semiconductor projection exposure apparatus. In recent years, in order to improve the exposure accuracy and the throughput at the time of exposure, a scan type exposure apparatus has been developed, and the thrust of a linear motor has been improved. In order to improve the thrust of the linear motor, the driving voltage and the driving current are increased, and the power consumption is increased. In order to solve this problem, in an MM-type linear motor in which the mover of the linear motor is a magnet, a current is applied to only the coil of the stator coil where the mover exists. An excitation switching type linear motor that switches a coil to be energized in accordance with the movement of a magnet has been proposed. As a result, the coil that does not directly contribute to the thrust of the motor is not energized, and power is saved.

FIG. 10 shows an example of a conventional drive circuit for driving a coil of a linear motor of an excitation switching type. One drive circuit is required for one coil, and a switching circuit for switching excitation is provided.
In FIG. 10, when the control signal SW0 is set to LOW, a current flows through the LED of the photocoupler PC1, and a current flows through the photodiode of the photocoupler PC1. When a current flows through the photodiode of the photocoupler PC1, the gates of the MOS-FETs Q1 and Q2 are driven, the MOS-FETs Q1 and Q2 are turned on, and the drive current can flow to the coil L1 of the linear motor.
Conversely, by setting the control signal SW0 to HIGH, the current to the LED of the photocoupler PC1 does not flow.
OS-FETs Q1 and Q2 are turned off.

In order to turn on the MOS-FETs Q1 and Q2 at a required speed during exposure, it is necessary to supply a current corresponding to the speed to the photodiode of the photocoupler PC1. Therefore, it is necessary to supply a current of about 50 mA to the LED of the photocoupler PC1. Therefore, since the circuit power supply uses 5 VDC, the photocoupler PC1
Assuming that the LED forward voltage drop is 0V for simplicity, about 100Ω is used for resistor R0.

On the other hand, at the start of use of the semiconductor projection exposure apparatus, it is necessary to make initial settings such as magnetic pole alignment.
At the time of the initial setting, it is initially unknown which position the mover of the wafer stage or reticle stage, that is, the linear motor is, so it is necessary to energize all the coils of the stator to move the mover. For this reason, it is necessary to operate all the drive circuits that drive the coils constituting the stator of the linear motor.

[0006]

When a current is supplied to all the coils of the linear motor at the time of initial setting of the semiconductor projection exposure apparatus, for example, three coils having 14 coils per phase are used.
In a phase linear motor, 42 coils must be energized simultaneously. Therefore, only the drive current of the photocoupler PC1 is 50 mA × 42 = 2.1 A, which is 2 A or more. Normally, 5V DC that can be mounted on a board
The maximum supply capacity of the -DC converter is 2.4 A even with a 15 W output. The required current is about 3 A in consideration of power consumption in other parts of the photocoupler PC1 other than the LED.
This causes a problem that the current supply capacity is insufficient. In order to increase the current capacity, a 25 W output DC
-When a DC converter is used, the current can be 4 A,
A problem arises in that the outer shape becomes large, the package cannot be mounted small, and the price becomes expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-power-consumption, small-sized and inexpensive linear motor coil driving device for driving a coil constituting a linear motor, and a linear motor provided with the coil driving device. It is to provide a motor drive device and a stage device.

[0008]

FIG. 1 shows an embodiment of the present invention.
The present invention will be described below with reference to FIGS. In order to achieve the above object, the invention according to claim 1 is applied to a coil driving device for a linear motor that drives one coil (L1) of a plurality of coils (22a) constituting a linear motor. Switching means (Q1, Q2) for turning on and off the current to L1), and switching means (Q1, Q2)
Switching control means (R
0, PC1) and first switching control means (R0,
Switching means (Q1, Q2) with lower power than PC1)
Switching control means (R
1, PC1). A second aspect of the present invention is directed to a plurality of coils (2
2a) and a plurality of coil driving devices (1
0) and a control device (12) for controlling the operation of the plurality of coil drive devices (10). Each of the plurality of coil driving devices (10) controls switching means (Q1, Q2) for turning on / off a current to one corresponding coil (L1), and controls on / off of the switching means (Q1, Q2). A first switching control means (R0, PC1) and a second switching control means (R1, PC1) for controlling on / off of the switching means (Q1, Q2) with lower power than the first switching control means (R0, PC1); ) And
When driving a part of the plurality of coils (22a), the control device (12) controls the part of the coil driving device (10) corresponding to the part of the coils to the first switching control means ( R0, PC1), when driving all of the plurality of coils (22a), all the coil driving devices (1) corresponding to all the coils are driven.
0) is operated using the second switching control means (R1, PC1). According to a third aspect of the present invention, in the stage device, a stage (8) on which the moving object (5) is mounted and a linear motor (22) for driving the stage (8) to move the moving object (5).
a and a permanent magnet (not shown), and a plurality of coils (22a, L) constituting a linear motor (22a and a permanent magnet not shown).
A linear motor coil drive device according to claim 1 for driving each of the first and second aspects is provided.

In the section of the means for solving the above-mentioned problems, the description is made in correspondence with the drawings of the embodiments for easy understanding, but the present invention is not limited to the embodiments.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing an embodiment of a coil drive circuit (drive device) for a linear motor according to the present invention,
First, a projection exposure apparatus using the coil drive circuit of the present linear motor and a stage apparatus thereof will be described.

FIG. 1 is a schematic configuration diagram of a projection exposure apparatus.
The projection exposure apparatus mainly includes an illumination optical system 1, a reticle stage device 2, a projection optical system 3, and a wafer stage device 4. FIG. 1 is a view of the projection exposure device as viewed from the front. The projection exposure apparatus employs a slit scan exposure method. The slit scan exposure method is as follows. That is, the reticle 5 is illuminated with the exposure light IL restricted in the form of a slit emitted from the illumination optical system 1, the reticle 5 is driven in one direction, and the reticle 5 is driven in one direction. The exposure light IL scans the entire pattern provided on the reticle 5, and drives the wafer 6 in the opposite direction to the reticle 5 in accordance with this scan. As a result, the entire pattern is projected onto a predetermined area of the wafer 6. Projection exposure is performed via the optical system 3. This is repeated. The slit scan exposure method has a known content (for example, see JP-A-6-140305).

The projection exposure apparatus will be further described with reference to FIGS. In FIG. 1, the direction perpendicular to the paper is X
The axis, the vertical direction is the Z axis, and the horizontal direction is the Y axis.

The reticle stage device 2 includes a reticle base 7, a reticle scanning stage 8, and a reticle fine movement stage 9, and the reticle 5 is mounted on the reticle fine movement stage 9. The reticle scanning stage 8 is also called a reticle coarse movement stage. The reticle scanning stage 8 is driven by a reticle scanning drive device 10, and the reticle fine movement stage 9 is driven by a reticle fine movement drive device 11.
The reticle scanning drive device 10 and the reticle fine movement drive device 11 are connected to and controlled by a control device 12. Control device 1
2 is composed of a microprocessor and peripheral circuits,
Other controls related to the projection exposure apparatus are also performed.

The wafer stage device 4 includes a wafer base 1
3, wafer stage X-axis drive unit 14, wafer stage Y
The wafer 6 is mounted on the wafer stage Y-axis drive unit 15. The wafer stage X-axis driving unit 14 and the wafer stage Y-axis driving unit 15 are driven by a wafer driving device 16, and the wafer driving device 16 is connected to and controlled by the control device 12.

FIG. 2 is a plan view of the reticle stage device 2. The reticle base 7 is formed with two rows of air guides 21a and 21b in the X direction, on which the reticle scanning stage 8 is mounted. A plurality of electromagnets 22a and 22b are embedded outside the air guides 21a and 21b in a row in the X direction, and a permanent magnet (not shown) is embedded on the back surface of the reticle scanning stage 8. The reticle scanning stage 8 includes electromagnets 22a, 22b
And air guides 21a and 21b by permanent magnets (not shown).
Is driven in the X direction along a linear motor system (hereinafter referred to as a linear motor). The driving of the linear motor will be described later.

A reticle fine movement stage 9 is mounted on the reticle scanning stage 8. Further, on the reticle scanning stage 8, actuators 23 and 24 for finely driving the reticle fine movement stage 9 in the X direction, respectively, and Y
An actuator 25 that finely drives in the direction is fixed.
The actuators 23 to 25 are constituted by voice coils, and one end is fixed to the reticle fine movement stage 9. Therefore, the reticle fine movement stage 9 is finely driven in the XY plane with respect to the reticle scanning stage 8 by controlling the current flowing through the voice coil.
It is fixed at a predetermined position on the reticle scanning stage 8.
The reticle fine movement stage 9 includes actuators 23 and 24
Is finely driven also in the rotational direction in the XY plane by adjusting the balance of the control.

Moving mirrors 26, 27 and 28 are fixed to reticle fine movement stage 9 as shown in FIG. Further, laser interferometers 29, 30, 31 are provided to face these movable mirrors 26, 27, 28. The laser interferometers 29, 30, 31 are provided in a fixed relation to the reticle base 7, and the outputs thereof are connected to the controller 12. The combination of the movable mirror 26 and the laser interferometer 29 detects the position of the reticle fine movement stage 9 in the Y direction, and the combination of the movable mirror 27 and the laser interferometer 30 detects the position of the reticle fine movement stage 9 in the X direction. Moving mirror 28
The rotation angle of the reticle fine movement stage 9 in the XY plane is detected by a combination of the laser interferometer 31 and the laser interferometer 31.

FIG. 3 is a plan view of the wafer stage device 4. On the wafer base 13, two rows of air guides 41a and 41b are formed in the X direction, and the wafer stage X-axis drive unit 14 is mounted thereon. A plurality of electromagnets 42a and 42b are embedded in a row in the X direction outside the air guides 41a and 41b, respectively, and a permanent magnet (not shown) is embedded on the back surface of the wafer stage X-axis drive unit 14. The wafer stage X-axis drive section 14 is driven by electromagnets 42a and 42b and permanent magnets (not shown) in the X direction along the air guides 41a and 41b by a linear motor system (hereinafter, referred to as a linear motor). The driving of the linear motor will be described later.

On the wafer stage X-axis drive unit 14, two rows of air guides 43a and 43b are formed in the Y direction, and the wafer stage Y-axis drive unit 15 is mounted thereon. The wafer stage Y-axis driving unit 15 is provided with a stepping motor 44 along the air guides 43a and 43b.
, And is driven in the Y direction via the ball screw 45.

The wafer stage Y-axis drive unit 15 includes
The movable mirrors 46 and 47 are fixed as shown in FIG. Two laser interferometers 48 and 49 are provided facing the moving mirror 46, and a laser interferometer 50 is provided facing the moving mirror 47. The laser interferometers 48, 49, 50 are provided in a fixed relation to the wafer base 13, and the outputs thereof are connected to the controller 12. The combination of the movable mirror 46 and the laser interferometer 48 detects the position of the wafer stage Y-axis drive unit 15 in the Y direction, and the movable mirror 47 and the laser interferometer 5
X of the wafer stage Y-axis drive unit 15 in combination with 0
The position in the direction is detected, and the movable mirror 46 and the laser interferometer 49 are detected.
XY of the wafer stage Y-axis driving unit 15 in combination with
A rotation angle in the plane is detected.

With the reticle stage device 2 and the wafer stage device 4 configured as described above, slit scan exposure can be realized. In the present embodiment, a pattern for one chip is formed on the reticle 5, and one chip is projected and exposed on the wafer 6 by one slit scan exposure. The minute pattern is projected and exposed.

Next, the excitation switching method of the linear motor will be described with reference to the reticle stage device shown in FIG.

As described above, reticle scanning stage 8
Are electromagnets 22a, 22 provided on the reticle base 7.
It is driven by two linear motors on the left and right constituted by b and a permanent magnet provided on the reticle scanning stage 8.
In the linear motor on the left side of FIG. 2, a stator is constituted by the electromagnet 22a, and a permanent magnet provided on the reticle scanning stage 8 corresponding to the electromagnet 22a constitutes a mover. The linear motor on the right side of FIG. 2 forms a stator with the electromagnet 22b,
A permanent magnet provided on the reticle scanning stage 8 corresponding to the electromagnet 22b forms a mover. These linear motors are moving magnet type (MM) linear motors.

Hereinafter, the linear motor on the left side (the electromagnet 22a side) in FIG. 2 will be described. The electromagnet 22a has three phases (U-phase, V-phase, and W-phase). In the present embodiment, 14 electromagnets 22a are provided in the X direction. Therefore, U phase, V
Phase and W-phase coils are alternately overlapped for 14 sets (14 sets).
(× 3 phases = 42 coils) provided at predetermined intervals. Although only seven sets are clearly shown in FIG. Actually, 14 sets are provided. A plurality of permanent magnets provided on the reticle scanning stage 8 side are provided in a predetermined range corresponding to seven electromagnets 22a. In the present embodiment, since the excitation switching method is adopted during slit scan exposure, energization of the electromagnet 22a is energized only in a range corresponding to the permanent magnet of the reticle scanning stage 8.
That is, power is supplied to seven electromagnets 22 a selected according to the position of the reticle scanning stage 8, and power supply to each coil is switched as the reticle scanning stage 8 moves.

According to this method, since no power is supplied to the electromagnet which does not contribute to driving the mover, a low power consumption linear motor is realized. 2 (electromagnet 22b
The same applies to the linear motor on the side.

On the other hand, as described in the section of the prior art, when the use of the semiconductor projection exposure apparatus is started, it is necessary to perform initial settings such as magnetic pole alignment. During this initial setup,
At first, since it is unknown where the reticle scanning stage 8 is located, it is necessary to energize all the coils of the electromagnets 22a and 22b to move the reticle scanning stage 8. In this case, all coils of the electromagnets 22a and 22b are energized without using the excitation switching method.

Next, the coil drive circuit of the linear motor according to the present embodiment will be described. Hereinafter, the electromagnet 22a of FIG.
The linear motor on the side of the electromagnet 22b will be described, but the same applies to the linear motor on the side of the electromagnet 22b.

FIG. 4 shows a coil drive circuit of the linear motor according to the present embodiment. One circuit is provided for each coil of the electromagnet 22a. Therefore, 14 × 3 phases = 4
Two circuits are provided in the reticle scanning drive device 10 of FIG. The circuit of FIG. 4 corresponds to the circuit of FIG. 10 of the prior art, and the same components are denoted by the same reference numerals. The difference from the circuit of FIG. 10 is that a resistor R1 is provided in FIG.
An input terminal for the control signal SW0A is provided.

In FIG. 4, when the control signal SW0A or the control signal SW0B is set to LOW, a current flows through the LED of the photocoupler PC1 and the photocoupler PC1 is turned on.
Current flows through the photodiode. Photo coupler PC
When a current flows through one photodiode, MOS-FE
The gates of the transistors TQ1 and Q2 are driven via the resistors R5 and R6, the MOS-FETs Q1 and Q2 are turned on, and the drive current can flow through the coil L1 of the linear motor. Conversely, both control signals SW0A and SW0B are set to H
By setting it to IGH, the LED of the photocoupler PC1
Current stops flowing, and the MOS-FETs Q1 and Q2 are turned off.

The resistor R0 uses 100Ω as in FIG. 10, and the resistor R1 uses 220Ω. Circuit power supply is 5V
Since it is DC, when the control signal SW0B is set to LOW, a current of about 50 mA flows to the photocoupler PC1 and is consumed as described in the related art. On the other hand, the control signal SW
When 0A is set to LOW, a current of about 22 mA flows to the photocoupler PC1 and is consumed.

When the control signal SW0B is set to LOW and when the control signal SW0A is set to LOW, the current flowing through the LED of the photocoupler PC1 is different, and appears as a difference in electromotive force in the photodiode of the photocoupler PC1. Both when the control signal SW0B is set to LOW and when the control signal SW0A is set to LOW, the MOS-FET Q1,
Q2 are both turned on, but the difference between the electromotive forces in the photodiodes of the photocoupler PC1 is
It appears as a difference between the switching speeds of Q1 and Q2. That is, when the control signal SW0B is set to LOW, the MOS-
The switching speed of the FETs Q1 and Q2 is high, and the MOS-FETs Q1 and Q2 when the control signal SW0A is LOW.
2, the switching speed is slow.

In the excitation switching method at the time of the slit scan exposure, the excitation switching of the coil needs to be performed accurately and at a fast timing. Therefore, the excitation switching is performed using the control signal SW0B. On the other hand, when all the coils are driven at the time of the above-mentioned initial setting, the switching speed of the MOS-FETs Q1 and Q2 may be low because the excitation switching is not required. Therefore, the MOS-FETs Q1 and Q2 are turned on using the control signal SW0A.

Thus, in the case of the excitation switching, FIG.
On the side of the electromagnet 22a, 7 electromagnets 22a are energized, so that 5 VDC of the drive circuit is 7 × 3 phase × 50 m
It requires a current of A = 1050 mA. On the other hand, when all the coils are energized, 1
A current of 4 × 3 phases × 22 mA = 924 mA is required. When all coils are energized, 14 circuits × 3 phases × 50 mA = 2100 mA are required in the circuit of FIG. 10 of the related art, but in the present embodiment, the capacity of the 5 VDC power supply can be reduced to about half.

As a result, it is possible to realize a small and inexpensive linear motor driving device with low power consumption including a power supply. Also,
Heat generation in the switching circuit is reduced, reliability is improved, and the influence of temperature fluctuation on the surroundings can be prevented.

FIG. 5 is an overall connection diagram of the coils of the 14 electromagnets 22a, the coil drive circuit, and the drive power supply on the electromagnet 22a side in FIG. The coil of the 14 electromagnets 22a has one drive current source for each of the U-phase, V-phase, and W-phase, and the U-phase drive current Iu, the V-phase drive current Iv,
The W-phase drive current Iw is supplied. Each drive current is 120
They are supplied out of phase by degrees. U phase coil is L1
U, L2U..L13U, L14U, and the V-phase coil is represented by L1V, L2V..L13V, L14V, and W
The phase coils are represented by L1W, L2W... L13W, L14W. 42 switches SW1U to SW14W
Are respectively realized by the coil drive circuit of FIG. FIG.
The same applies to the linear motor on the electromagnet 22b side.

In the example of FIG. 5, the switches SW13U, SW13
14U, SW13V, SW14V, SW13W, SW1
An example in which 4W is ON is shown. For example, when the reticle scanning stage 8 is moved from the upper part to the lower part in FIG. 2 by sequentially switching the seven electromagnets 22a, the following control is performed. In this case, it is assumed that the 14 electromagnets 22a are arranged in the order of 1 to 14 from the upper part to the lower part in FIG. 2, and the coils of each electromagnet are arranged in the order of U phase, V phase, and W phase.

First, switches SW1U to SW7U, switches SW1V to SW7V, switches SW1W to SW7W
Only the 21 switches are kept ON. That is, the switches SW1U to SW7U and the switch SW1V
SW7V and switches SW1W to SW7W other than the 21 switches are turned off. Next, the U-phase drive current Iu,
The V-phase drive current Iv and the W-phase drive current Iw are supplied, and the reticle scanning stage 8 starts moving. When the reticle scanning stage 8 starts to move, the position of the reticle scanning stage 8 in the X direction is acquired by a signal from the interferometer 30, and at a predetermined timing, the switch SW1U is turned off and the switch S
W8U is turned ON. At the next predetermined timing, the switch SW1V is turned off and the switch SW8V is turned on. These are sequentially repeated with the movement of the reticle scanning stage 8, and the excitation of the coil of the electromagnet 22a is switched.

FIG. 6 shows a control signal S for each switch for switching the excitation of the coil, that is, for each coil drive circuit.
4 shows a timing chart of WOB. Control signal SW0B
Is low, the switches SW1U and the like are turned on. At this time, the control signals SW0A of all the coil drive circuits are H
It is IGH.

FIG. 7 is a diagram for explaining control by a control signal SW0A and a control signal SW0B in a drive circuit of one coil. FIG. 7A shows a case of control for exciting all coils at the time of initial setting or the like. Control signal SW
By setting 0A to LOW, the coil is excited. The control signal SW0B is kept HIGH. All other coils are similarly excited since the other coils are similarly controlled.

FIG. 7B shows the case of controlling the excitation switching at the time of slit scanning. In FIG. 7B, the coil is energized when the control signal SW0B is set to LOW at a predetermined timing, and the coil is energized when the control signal SW0B is set to HIGH at a predetermined timing.
FF is performed. During this time, the control signal SW0A is kept HIGH. The other coils are also controlled by the control signal SW0B at the timing of each coil, and the excitation switching control is performed.

The control device 12 shown in FIG. 1 is different from the interferometer 30 shown in FIG.
, The position of reticle fine movement stage 9 in the X direction is acquired, and control signals SW0A and SW0 to each drive circuit are obtained.
Generate B. In this embodiment, it is assumed that reticle fine movement stage 9 and reticle scanning stage 8 have a fixed positional relationship for convenience of explanation. That is, it is assumed that acquiring the position of the reticle fine movement stage 9 also acquires the position of the reticle scanning stage 8.

FIG. 8 is a flowchart showing the control performed by the control device 12 when all the coils are turned on at the time of initial setting or the like. In step S1, it is determined whether or not the mode is for turning on all the coils. If the mode is for turning on, the process proceeds to step S2. A predetermined flag is checked to determine whether or not the mode is set to turn on all the coils. If the mode is not the ON mode, the process ends. In step S2, the control signals SW0A of all the coil drive circuits that drive the coils of the electromagnet 22a are set to LOW.
And the control signal SW0B is maintained at HIGH. Thereby, all the coils on the electromagnet 22a side in FIG. 2 are energized.

FIG. 9 is a diagram showing a flowchart of control in the control device 12 when the excitation switching method is adopted. As described above, the excitation switching method is executed at the time of slit scanning or the like. The processing in FIG.
A state of the control of the excitation switching in a state where the coils of the seven electromagnets 22a are already energized and the mover is moving is shown.

In step S11, a signal from the interferometer 30 is obtained. In step S12, the position of the reticle scanning stage 8 in the X direction is calculated based on the signal of the interferometer 30. In step S13, based on the position of the reticle scanning stage 8 calculated in step S12, it is determined whether or not it is at the position where the excitation is switched to the adjacent coil. If it is determined that the excitation switching position has been reached, the process proceeds to step S14. In step S14, the control signal SW0B of the drive circuit of the last coil of the seven electromagnets 22a, which is the last coil of the seven electromagnets 22a considering the U-phase, V-phase, and W-phase, is set to HIGH. . Step S1
5, the control signal S of the drive circuit of the next coil in the traveling direction
Set W0B to LOW. Thereafter, the process returns to step S11 to repeat the processing.

On the other hand, if it is determined in step S13 that the position of the excitation switching has not been reached yet, step S1
Return to 1. During the control of the excitation switching method of FIG. 9, the control device 12 controls the control signal SW0A of the drive circuit of each coil.
Are all HIGH.

It is to be noted that the reticle scanning stage 8 can be used regardless of whether all coils are energized or the excitation switching method is employed.
That is, acceleration, deceleration, stop, and the like of the mover of the linear motor are controlled by the drive current flowing through the coil L1 in FIG. When the drive current is increased, a large acceleration acts, and when driving in a predetermined direction, when a reverse current flows, a deceleration acts. If the drive current is kept at zero at a predetermined position, the stop state is maintained at that position.

In the above embodiment, only the linear motor on the electromagnet 22a side may be described in some cases, but the description can be similarly applied to the linear motor on the electromagnet 22b side.

Although the above embodiment has been described with reference to the example of the reticle stage device 2, the present invention can be similarly applied to the wafer stage device 4. That is, the above contents are shown in FIG.
Electromagnets 42a and 42b and wafer stage X-axis drive unit 1
4 can be similarly applied to a linear motor constituted by a permanent magnet (not shown) provided on the back surface of the motor.

In the above embodiment, the example has been described in which the number of electromagnets of the linear motor is 14 and the number of electromagnets to be energized by switching the excitation is 7, but the present invention is not limited to this. The number of electromagnets of the linear motor may be more than 14 or less than 14. The number of electromagnets to be energized in the excitation switching method may be more than seven or less than seven.

In the above embodiment, the example of the linear motor used for the stage of the projection exposure apparatus has been described. However, the present invention is not limited to this. It can be applied to anything using a linear motor.

In the above embodiment, an example in which two types of resistors are used has been described with reference to FIG. 4, but the present invention is not limited to this. For example, two photocouplers PC1 may be provided for switching.

In the above embodiment, a photocoupler is used as a coupling element, and M is used as a switching element.
Although the description has been made using the example in which the OS-FET is used, the present invention is not limited to this example. Another coupling element may be used, or a circuit may be configured without using a coupling element. Further, a bipolar transistor or another switching element may be used as the switching element.

[0053]

Since the present invention is configured as described above, it has the following effects. According to the first and second aspects of the present invention, in the coil drive device for a linear motor, a first switching control means for controlling on / off of the switching means and a second switching control means for controlling on / off of the switching means with lower power than the first switching control means Since two switching control means are provided, the first switching control means and the second switching control means can be selectively used as necessary, realizing a small and inexpensive linear motor driving device with low power consumption. It is possible to do. According to the third aspect of the present invention, the same effect as described above can be obtained in the stage device.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a projection exposure apparatus.

FIG. 2 is a plan view of the reticle stage device as viewed from above.

FIG. 3 is a plan view of the wafer stage device as viewed from above.

FIG. 4 is a coil drive circuit of the linear motor according to the embodiment.

FIG. 5 is an overall connection diagram of a coil of an electromagnet, a coil drive circuit, and a drive power supply.

FIG. 6 shows a control signal SW0 for switching the excitation of the coil.
4B is a timing chart.

FIG. 7 shows a control signal SW in a driving circuit for one coil.
The figure explaining control by 0A and SW0B.

FIG. 8 is a diagram showing a flowchart of control when all coils are turned on.

FIG. 9 is a view showing a flowchart of control when the excitation switching method is adopted.

FIG. 10 shows a conventional coil drive circuit.

[Explanation of symbols]

Reference Signs List 1 illumination optical system 2 reticle stage device 3 projection optical system 4 wafer stage device 5 reticle 6 wafer 7 reticle base 8 reticle scanning stage 9 reticle fine movement stage 10 reticle scanning drive device 11 reticle fine movement drive device 12 control device 13 wafer base 14 wafer stage X-axis drive unit 15 Wafer stage Y-axis drive unit 16 Wafer drive device 21a, 21b, 41a, 41b, 43a, 43b Air guide 22a, 22b, 42a, 42b Electromagnet 23 to 25 Actuator 26 to 28, 46, 47 Moving mirror 29 ~ 31, 48 ~ 50 Laser interferometer 44 Stepping motor 45 Ball screw SW0A, SW0B Control signal PC1 Photocoupler PC1 R0-R6 Resistance Q1, Q2 MOS-FET

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F031 CA02 CA07 HA53 JA02 JA06 JA32 KA06 KA08 LA03 LA08 MA27 5F046 CC01 CC02 CC13 CC17 5H540 AA10 BA03 BA05 BB03 BB06 BB09 EE02 FA14

Claims (3)

[Claims] 1. A linear motor coil driving device for driving one of a plurality of coils constituting a linear motor, comprising: switching means for turning on / off a current to the one coil; and controlling on / off of the switching means. A linear motor coil driving device comprising: a first switching control unit; and a second switching control unit that controls on / off of the switching unit with lower power than the first switching control unit. 2. A linear motor driving device comprising: a plurality of coil driving devices for respectively driving a plurality of coils constituting a stator of a linear motor; and a control device for controlling the operation of the plurality of coil driving devices. Each of the plurality of coil driving devices, switching means for turning on and off the current to a corresponding one coil,
A first switching control unit that controls on / off of the switching unit; and a second switching control unit that controls on / off of the switching unit with lower power than the first switching control unit. When driving a part of the plurality of coils, a part of the coil driving device corresponding to the part of the plurality of coils is operated using the first switching control means, and the plurality of coils are driven. When driving all of the coils, all of the coil driving devices corresponding to all of the coils are operated using the second switching control means. 3. A stage on which a moving object is mounted, a linear motor for driving the stage for moving the moving object, and a plurality of coils respectively driving a plurality of coils constituting the linear motor. And a linear motor coil driving device.