JP2002112586A - Apparatus-driving method, driver, stage apparatus driving method and stage apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically control an offset value included in a drive output, to a value (almost zero) within the allowable range thereof. SOLUTION: A control signal output circuit 21 outputs an offset command value to a DA converter 313 and inputs this output value to an adder/subtractor 311 via the DA converter 313. The control signal output circuit 21 provides an output to an input amplifier 301, under the condition that a command value of the output current of a power amplifier 30 be maintained at almost zero volt. A current sense resistor 306 detects an offset current outputted from the power amplifier 301. The detected offset current is then inputted to an amplifier controller 2 via a drive current detection amplifier 307 and an offset current monitor amplifier 312. An amplifier controller 2 is determined as to whether the offset current has a value within the allowable range. When the offset current value is out of the allowable range, such offset command value is updated, until the offset value is located within the allowable range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically drives an actuator such as a linear motor by automatically controlling an offset value included in a drive output output from a power amplifier to a value within a permissible range (substantially zero). The present invention relates to a driving method, a driving device, a driving method for a stage device, and a stage device suitable for smoothly moving a stage, etc.

[0002]

2. Description of the Related Art In recent years, high integration of semiconductor elements has progressed, and high-speed and precise movement control of a stage used in various apparatuses such as a semiconductor exposure apparatus has been required. Therefore,
A precise and accurate value is required for a drive output to an actuator for driving the stage. Therefore, the power amplifier that controls the drive output needs to output a drive output having an offset value as close to zero as possible to the actuator.

FIG. 3 is a block diagram schematically showing a conventional stage device. In FIG. 3, the interferometer system 5
Detects the position information of the stage 4 moved by the actuator 10 and transmits it to the host computer 1 and the amplifier control unit 2. The operation of detecting the position information by the interferometer system 5 is well-known, and a description thereof will be omitted. The host computer 1 determines the position of the stage 4
An instruction to move the stage 4 to a predetermined position is output to the amplifier control unit 2.

The amplifier controller 2 receives the command and the position information of the stage 4 from the interferometer system 5 and outputs a command voltage for determining a drive current for moving the actuator 10 to the power amplifier 3.

The power amplifier 3 outputs a drive current according to the command voltage to the actuator 10, and the actuator 10 and the stage 4 move to the target position. FIG. 4 is a diagram illustrating an example in which the power amplifier 3 outputs a three-phase current to drive the actuator 10 and move the stage 4 to a target position in FIG. As shown in FIG.
The power amplifier 3 includes a U-phase power amplifier 31, a V-phase power amplifier 32, and a W-phase power amplifier 33.

As shown in FIG. 5, each power amplifier 31,
The drive currents output from 32 and 33 are three-phase sinusoidal currents. That is, as shown in FIG. 5, the V phase lags the U phase by 120 degrees, and the W phase lags the U phase by 240 degrees. Ideally, the power amplifier 3 drives the actuator 10 and controls the position of the stage 4 by changing the amplitude and frequency while maintaining the phase of the three-phase sine wave current.

However, in practice, the U-phase, V-phase, and W-phase sine wave currents usually have a positive or negative DC offset current. FIG. 6 shows that the three-phase sinusoidal current V
An example is shown in which only the phase has a positive DC offset current. Originally, if the input voltage of the power amplifier 3 from the amplifier control unit 2 is zero volt, each drive current of each U-phase, V-phase, and W-phase becomes zero A. However, as described above, a certain amount of offset current (for example, 10 to 20 mA) usually flows. Also, the offset current fluctuates due to the influence of temperature and changes over time.

Since the drive of the actuator 10 is not smooth due to the influence of the DC offset current, unevenness in the movement of the stage 4 (not moving at a constant speed) occurs, and it is difficult to control the position of the stage 4 accurately. become. Therefore, in the prior art, an offset adjustment circuit (not shown) using a trimmer resistor is provided in the power amplifier 3, and when the stage device shown in FIG. The work to make the offset current zero was performed.

[0009] In the above-mentioned conventional technique, the position of the stage 4 is controlled by an actuator such as a linear motor. Therefore, each power amplifier 31, 32,
The drive output of 33 is input to an actuator such as a linear motor.

[0010]

As described above, in the prior art, in order to make the DC offset value zero, the trimmer resistance in the offset adjustment circuit has been manually adjusted.

Therefore, first, there is a problem that the adjustment of the offset value requires manual operation and a long time is required for the operation. Second, once the offset value is adjusted, if the installation environment of the device changes due to the installation of the device in another place, the offset value fluctuates.
Therefore, there is a problem that it takes a lot of time and labor to adjust the offset value again.

A first object of the present invention is to provide a driving method of a device, a driving device, a driving method of a stage device, and a stage device which can automatically adjust an offset value without manual operation. To provide. Second embodiment of the present invention
The purpose of the device is to adjust the offset value once, and then set the device in another place. If the offset value fluctuates due to, for example, the device, it is possible to automatically reset the offset value. A driving method, a driving device, a driving method of a stage device, and a stage device are provided.

[0013]

According to a first aspect of the present invention, there is provided a method of driving an apparatus, comprising: an amplifier control section for outputting a control signal to a power amplifier; and the power amplifier for outputting a drive output to an actuator based on the control signal. And an actuator driven based on the driving output, wherein the step of monitoring an offset value of the driving output includes: setting an offset command value for making the offset value substantially zero. Steps to find automatically,
Correcting the control signal of the drive output based on the automatically found offset command value.

According to a second aspect of the present invention, there is provided a drive unit for outputting a control signal to a power amplifier, the power amplifier for outputting a drive output to an actuator based on the control signal, and a power amplifier based on the drive output. A drive unit comprising: a drive unit that monitors an offset value of the drive output; an offset command value detection unit that finds an offset command value that makes the offset value substantially zero; A control signal correction unit for correcting the control signal of the drive output based on the found offset command value.

According to a third aspect of the present invention, there is provided a driving method for a stage device, comprising: an amplifier control section for outputting a control signal to a power amplifier; the power amplifier for outputting a driving output to an actuator based on the control signal; A step of monitoring an offset value of the output for driving, wherein the actuator is driven based on an output, and a stage moved by the actuator. Automatically finding the offset command value to be
Correcting the control signal of the drive output based on the automatically found offset command value. .

According to a fourth aspect of the present invention, there is provided a stage device which outputs a control signal to a power amplifier, the power amplifier outputs a drive output to an actuator based on the control signal, and a drive amplifier based on the drive output. And a stage moved by the actuator, the stage device comprising:
A monitoring unit that monitors an offset value of the driving output; an offset command value detecting unit that finds an offset command value that makes the offset value substantially zero; and correcting the control signal of the driving output based on the offset command value. And a control signal correction unit that performs the control.

According to the present invention, the offset value is monitored by monitoring the offset value, finding an offset command value for making the offset value substantially zero, and correcting the drive output control signal. Can be output to the actuator. In addition, Claims 1-4
In the above, "substantially zero" means a value within a range allowed as zero in each method and each device according to claims 1 to 4.

In the first and third aspects, "automatically finding an offset command value for making the offset value substantially zero" means that when an offset command value for changing the offset value is set, the monitored offset value is set. Means that the setting of the offset command value is repeated until is substantially zero.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the attached drawings will be described below.

FIG. 1, FIG. 2, and FIG. 3 are block diagrams showing an embodiment of a stage device driving method and a stage device according to the present invention. The embodiment shown in FIG. 1, FIG. 2, and FIG.
This corresponds to claims 3 and 4 described in the claims. FIG. 1 shows an amplifier control unit 2 of the stage device shown in FIG.
And a part of the power amplifier 3. That is, FIG.
Shows only one phase (power amplifier 30) of the power amplifier 3 (three phases) shown in FIG. The operations of the other two-phase power amplifiers (not shown) are exactly the same as the operations of the power amplifier 30 shown in FIG.

As shown in FIG. 1, the power amplifier 30 comprises:
An input amplifier 301, an integrating amplifier 302, a comparator 303, a triangular wave generator 304, a stage driving sine wave current generating circuit (for one phase) 305, a current sense resistor 306, a driving current detecting amplifier 307, It comprises a current monitor amplifier 308, a pulse detection circuit 309, a photocoupler 310, an adder / subtractor 311, an offset current monitor amplifier 312, and a DA converter 313. The amplifier control unit 2 includes a command signal output circuit 21 and a control circuit 22.

First, the operation during normal operation will be described. The command signal output circuit 21 in the amplifier control unit 2 outputs a sine wave voltage command value to the input amplifier 301 according to an instruction from the control circuit 22 during normal operation of the device. The control circuit 22 includes a CPU, a memory, and the like, and outputs various instructions and performs various determinations.

The sine wave voltage command value is determined by the power amplifier 3
0 indicates to the stage 4 how much sine wave current to output as the drive current. Here, the output of the input amplifier 301 corresponds to the “drive output control signal” described in claims 1 to 4. At the time of the offset current setting operation, the command signal output circuit 21 outputs zero V to the input amplifier 301.

The input amplifier 301 includes a command signal output circuit 2
The reference potential of the sine wave voltage command value output from 1 is accurately adjusted to the ground potential, and functions such as removing noise are performed. The sine wave voltage command value (control signal) with the ground potential as the reference potential is added or subtracted. Output to the unit 311. Adder / subtractor 3
11, a sine wave voltage command value output from the input amplifier 301 is input. The output voltage of the drive current detection amplifier 307 is input to the adder / subtractor 311. The drive current detection amplifier 307 detects the voltage across the current sense resistor 306, amplifies the detected voltage, and outputs the amplified voltage. The DA converter 313 is an adder / subtractor 311
The signal to be output to is described later.

The adder / subtractor 311 detects an error by taking the difference between the sine wave voltage command value and the voltage indicating the sine wave current value (feedback control), and outputs the error to the integration amplifier 302. The integrating amplifier amplifies the error and outputs it to the comparator 303. The triangular wave generator 304 outputs a triangular wave voltage to the comparator 303. Comparator 30
3 compares the triangular wave voltage with the output voltage of the integrating amplifier 302. For example, only when the triangular wave voltage is higher than the output voltage of the integrating amplifier 302, the pulse width with respect to the photodiode of the photocoupler 310 is A pulse corresponding to the period is output. As a result, the photodiode of the photocoupler 310 emits light.

The phototransistor of the photocoupler 310 turns on only during the light emitting period of the photodiode,
The current is supplied to the stage driving sine wave current generation circuit 305. The stage driving sine wave current generation circuit 305 generates a sine wave current based on ON / OFF of the photocoupler 310 and outputs the current to an actuator (not shown). That is, the stage driving sine wave current generation circuit 305
Based on the result of feedback control of the sine wave voltage command value input from the input amplifier 301, a sine wave current is formed and output.

Next, the feedback control will be described. The stage driving sine wave current generation circuit 305
Is detected as a potential difference generated between both ends of the current sense resistor 306. The detected potential difference is amplified by the drive current detection amplifier 307 and fed back to the adder / subtractor 311. Therefore, the sine wave current output from the stage driving sine wave current generation circuit 305 becomes a value corresponding to the sine wave command value by the feedback loop.

The reason why the photocoupler 310 is used is that the reference voltage of the stage driving sine wave current generating circuit 305 is different from that of the other circuit portions. The output of the drive current detection amplifier 307 is input to the amplifier control unit 2 via the drive current monitor amplifier 308. The amplifier control unit 2 receives the output of the drive current monitor amplifier 308, and when the output current of the stage drive sine wave current generation circuit 305 detects an abnormality, stops the subsequent operation.

The pulse detection circuit 309 composed of a low-pass filter detects, as an abnormal state, a state in which the pulse output from the comparator 303 continuously outputs H or L for a predetermined time or more. When detecting the abnormal state, the pulse detection circuit 309 notifies the amplifier control unit 2 of a circuit abnormality. In this case, the amplifier control unit 2 stops the subsequent operation.

Next, an outline of the operation when the offset current is made substantially zero will be described. At the time of the offset current adjusting operation, the control circuit 22 in the amplifier control unit 2 instructs the command signal output circuit 21 to output zero V as the sine wave voltage command value. Command signal output circuit 21
Receives the command and outputs zero V to the input amplifier 301 as a sine wave voltage command value. Therefore, at this time, the current output from the power amplifier 30 to the stage 4 is originally zero A. However, actually, a slight offset current flows as described above.

In this state, the control circuit 22 in the amplifier control unit 2 instructs the command signal output circuit 21 to output an offset command value (initial value). The command signal output circuit 21 receives the command,
The command signal output circuit 21 outputs an offset command value (digital value) to the A converter 313. The initial value of the offset command value is determined by estimating in advance how much an offset current flows from the design of the apparatus shown in FIG. 1 and stored in a memory (not shown).

The DA converter 313 converts the offset command value into an analog signal and outputs the analog signal to the adder / subtractor 311. The adder / subtractor 311 receives and adds the offset command value, the sine wave voltage command value output from the input amplifier 301, and the output voltage of the drive current detection amplifier 307, and performs addition and subtraction. Thereby, the offset current is adjusted. FIG.
As shown in (2), the output of the drive current detection amplifier 307 is input to the amplifier control unit 2 via the offset current monitor amplifier 312. The amplifier control unit 2 receives an offset current (analog signal) output from the offset current monitor amplifier 312 and converts it into a digital value by an AD converter (not shown). Then, the amplifier control unit 2
The control circuit 22 determines whether the offset current converted into a digital value is within a permissible range. As described above, the control circuit 22 controls the CP
U, a memory, and the like.

If the control circuit 22 determines that the value is not within the allowable range, the control circuit 22 outputs the updated offset command value (digital value) to the DA converter 313. When the control circuit 22 determines that the value is within the allowable range, the control circuit 22 stores the offset command value (digital value) output to the DA converter 313 in a memory (not shown), and stores the offset stored in the memory. Continue outputting the command value. Thus, during operation of the device, the offset current is maintained at a value within the allowable range.

Next, the operation of setting the offset current value to a current value within an allowable range will be described in more detail with reference to the flowchart shown in FIG. In step S1, an operation of starting up the stage device shown in FIG. 1 is performed.
At this time, as described above, the command signal output circuit 21 of the amplifier control unit 2 receives the command from the control circuit 22 and outputs zero V as a sine wave voltage command value to the input amplifier 301.

In step S2, the command signal output circuit 21 receives the command from the control circuit 22, and outputs the initial value of the offset command value to the DA converter 313. As a result, the DA converter 313 converts the offset command value from a digital value to an analog value, and outputs it to the adder / subtractor 311. Thereby, the offset current of the output current of the power amplifier 30 changes according to the offset command value.

In step S3, the control circuit 22 receives the output of the offset current monitor amplifier 312 and converts the offset current from an analog value to a digital value (AD conversion). In step S4, the control circuit 22 determines whether or not the AD-converted offset current is smaller than an allowable lower limit. If it is determined in step S4 that the value is smaller than the allowable lower limit, the process proceeds to step S6.

In step S6, the control circuit 22 updates the offset command value by adding a predetermined value to the offset command value output in step S2, and returns to step S2. If it is determined in step S4 that the value is larger than the allowable lower limit, the process proceeds to step S5.

In step S5, the control circuit 22 determines whether or not the AD-converted offset current is larger than an allowable upper limit. If it is determined in step S5 that the value is larger than the allowable upper limit value,
Proceed to step S7. In step S7, the control circuit 22 updates the offset command value by subtracting a predetermined value from the offset command value output in step S2, and returns to step S2.

If it is determined in step S5 that the offset current is smaller than the allowable upper limit, it is confirmed that the offset current is within the allowable range, and the process is terminated. In the embodiment described above, the stage device (method) has been described as an example. However, the present invention is not limited to this, and the offset may be applied to other movable devices other than the stage device. It can be widely applied as a technique for setting a value within an allowable range.

In this case, the embodiments shown in FIGS. 1, 2 and 3 correspond to the first and second aspects of the present invention. Here, the steps of monitoring described in claims 1 and 3 correspond to operations of the current sense resistor 306, the drive current detection amplifier 307, the offset monitor detection amplifier 312, and the like. Steps S2 to S7 shown in FIG. Claims 1 and 3
The step of correcting the drive output control signal based on the offset command value described in (1) corresponds to the operation of the adder / subtractor 311 shown in FIG.

In FIG. 1, the correspondence with the inventions described in claims 2 and 4 is as follows. The monitor section described in claims 2 and 4 corresponds to the current sense resistor 306, the drive current detection amplifier 307, the offset monitor detection amplifier 312, and the like. The offset command value detecting section according to claim 2 or 4 is a control circuit for controlling the offset value shown in FIG.
Corresponds to the function of performing steps S2 to S7. The control signal correction unit according to claims 2 and 4 corresponds to the adder / subtractor 311 shown in FIG.

The offset value in claims 1, 2, 3, and 4 corresponds to an offset current. In FIG. 1, the input amplifier 301, the DA converter 313, and the adder / subtractor 311 may be provided in the amplifier control unit 2 instead of in the power amplifier 30. Further, the adder / subtractor 311 may be provided in the integration amplifier 302. Further, although the drive current output from the power amplifier 30 is a sine wave current for one phase of the three-phase AC current, the present invention is not limited to this, and a single-phase AC current may be used. And so on.

As is clear from the above description, according to the above embodiment, the adjustment of the offset current can be performed automatically only by starting up the apparatus without manual operation. In addition, once the offset current is adjusted, if the offset current fluctuates due to, for example, installing the device in another location, resetting the offset current automatically is performed only by starting the device. Becomes possible.

In addition, since the offset current is appropriately set to substantially zero, the actuator and therefore the stage can be moved smoothly. It should be noted that the correction for the control signal according to the present invention may be performed at any part of the apparatus. Further, the correction of the control signal is not limited to addition, but may be performed by subtraction, multiplication, division, or the like.

[0045]

According to the first to fourth aspects of the present invention, a method of driving a device, a driving device, and a stage device capable of automatically adjusting an offset value without manual operation. A driving method and a stage device can be provided. Also, a method of driving a device capable of automatically executing readjustment of an offset value when the offset value fluctuates due to, for example, installing the device in another place after adjusting the offset value once. , A driving device, a driving method of a stage device, and a stage device.

Further, since the offset value is appropriately set, it is possible to provide a method of driving a device, a driving device, a method of driving a stage device, and a stage device capable of smoothly moving an actuator or a stage.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a part of a power amplifier and an amplifier control unit according to an embodiment of a stage device of the present invention.

FIG. 2 is a flowchart showing an operation of setting an offset current value to substantially zero (a current value within an allowable range) in the embodiment shown in FIG.

FIG. 3 is a block diagram schematically showing a stage device of the present invention and a conventional stage device.

FIG. 4 is a block diagram showing an example in which a power amplifier outputs a three-phase current and moves a stage in FIG. 3;

FIG. 5 is a diagram showing a three-phase sine wave current output from each power amplifier shown in FIG.

FIG. 6 is a diagram showing an example in which only a V-phase has a DC offset current among three-phase sine-wave currents.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host computer 2 Amplifier control part 3, 30, 31, 32, 33 Power amplifier 4 Stage 5 Interferometer system 10 Actuator 21 Command signal output circuit 301 Input amplifier 302 Integrating amplifier 303 Comparator 304 Triangular wave generator 305 Sine wave current for stage drive Generation circuit 306 Current sense resistor 307 Drive current detection amplifier 308 Drive current monitor amplifier 309 Pulse detection circuit 310 Photocoupler 311 Adder / subtractor 312 Offset current monitor amplifier 313 DA converter (DAC)

Claims (4)

[Claims] An amplifier control unit that outputs a control signal to a power amplifier; the power amplifier that outputs a drive output to an actuator based on the control signal; and the actuator that is driven based on the drive output. Monitoring the offset value of the drive output; automatically finding an offset command value that makes the offset value substantially zero; and automatically detecting the offset command value. Correcting the control signal of the driving output based on the value. 2. An amplifier control unit that outputs a control signal to a power amplifier, the power amplifier that outputs a drive output to an actuator based on the control signal, and the actuator that is driven based on the drive output. A drive unit that monitors an offset value of the driving output, an offset command value detection unit that finds an offset command value that makes the offset value substantially zero, and a drive unit that detects an offset command value based on the found offset command value. And a control signal correction unit for correcting the control signal of the drive output. 3. An amplifier control unit that outputs a control signal to a power amplifier, the power amplifier that outputs a drive output to an actuator based on the control signal, and the actuator that is driven based on the drive output. A method of driving a stage device comprising: a stage moved by the actuator; a step of monitoring an offset value of the driving output; and a step of automatically finding an offset command value that makes the offset value substantially zero. And correcting the drive output control signal based on the automatically found offset command value;
Driving method of a stage device comprising: 4. An amplifier controller that outputs a control signal to a power amplifier, the power amplifier that outputs a drive output to an actuator based on the control signal, and the actuator that is driven based on the drive output. A stage moved by the actuator, and a stage device comprising: a monitoring unit that monitors an offset value of the driving output; and an offset command value detection unit that finds an offset command value that makes the offset value substantially zero. And a control signal correction unit for correcting the control signal of the driving output based on the offset command value.