JP3215280B2 - Stage positioning control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage positioning control device having a fine movement stage for performing fine positioning on an XY stage for coarse movement, and more particularly to a stage positioning control device having improved positioning characteristics. .

[0002]

2. Description of the Related Art In a semiconductor exposure apparatus represented by a stepper or the like, a passive or active vibration isolator is provided.
An XY stage for coarse movement is mounted, and a fine movement stage for fine positioning is mounted thereon. For example, as shown in FIG. 3, an apparatus configuration is adopted in which an XY stage and a fine movement stage are mounted on a surface plate 8 supported by a passive vibration isolator or an active vibration isolator (not shown). In FIG. 3, 1 is an X stage, 2 is a fine movement stage for finely positioning the silicon wafer 3 mounted on the X stage 1,
4 is a Y stage, 5R and 5L are movers of a linear motor for driving the Y stage 4, 6R and 6L are coils which are stators of the linear motor, 7 is a stage base, and 8 is supported by a vibration isolator (not shown). Shows the surface plate to be used.

Next, the fine movement stage 2 and a device for positioning the fine movement stage 2 will be specifically described. FIG. 4 shows a block diagram of a fine movement stage control device for positioning control of a total of three degrees of freedom, one degree of freedom in the vertical direction and two degrees of rotation in the horizontal plane. The configuration of this fine movement stage control device is proposed in Japanese Patent Application No. 6-132405 filed by the present applicant, and is characterized in that the motion modes of translation and rotation can be controlled without interference. In FIG. 4, reference numeral 9 denotes a flat substrate to be positioned, and reference numerals 10M, 10R, and 10L denote actuators that generate displacement in a vertical direction. For example, this includes a displacement enlarging mechanism using a piezoelectric element (piezo element) as a driving element. Further, a position sensor 1 for measuring the displacement of the substrate 9 in the vertical direction (z-axis) is provided near the driving points of the actuators 10M, 10R, and 10L.
1M, 11R, and 11L, which will be referred to as a drive stage.

Now, position sensors 11M, 11R, 11L
Vertical displacement of the substrate 9 is measured by the displacement amplifier 12M, 12R, the electric signal by 12L z _M, z
_R, is converted to z _L. This electric signal is guided to the motion mode extraction circuit 17 and the motion mode displacement signal (z _g , zθ)
_x , zθ _y ), each of which is a command voltage input terminal 13
M, 13R, is compared to the voltage applied to 13L with motion mode error signal _{(e g, eθ x, eθ} y) becomes. These motion mode deviation signals are input to deviation amplifiers 14M, 14R, 14L in order to obtain a predetermined sensitivity, and are guided to gain compensators 15M, 15R, 15L for adjusting a control loop. The motion mode control signals (c
_g , cθ _x , cθ _y ) and the motion mode distribution circuit 18
Input to and without drive signal to each axis (d _M , d _R , d _L )
Generate Finally, drive signals (d _M , d _R ,
d _L ) excites the power amplifiers 16M, 16R, 16L, and drives the actuators 10M, 10R, 10L up and down to translate the substrate 9 in the vertical direction or to tilt the substrate 9 with respect to the z-axis. These closed loops will be referred to as feedback devices, and here will be referred to as fine movement stage controllers including the fine movement stage and the feedback device. In the above description,
The power amplifiers 16M, 16R, and 16L are of a type that outputs a current in response to a voltage input. At this time, the gain compensators 15M, 15R, and 15L need only be gain adjusters. What is the actuator 10M,
This is because the piezoelectric elements constituting 10R and 10L are capacitors when viewed electrically, and the transfer function including the power amplifiers 16M, 16R and 16L and the piezoelectric elements driven by them has integral characteristics. Therefore, when a closed loop is formed, it becomes a type 1 control system, and according to the teaching of control theory, a steady-state error of zero is guaranteed for a step input.

[0005]

By the way, the positioning mechanism shown in FIG. 3, that is, a passive vibration isolator or an active vibration isolator (not shown), and an X stage 1 which plays a role of coarse movement
The final purpose of the positioning mechanism including the XY stage including the Y stage 4 and the fine movement stage 2 is to position the silicon wafer 3 on the fine movement stage 2 and to expose the silicon wafer 3 to the silicon wafer 3. Therefore, the above-mentioned three types of positioning mechanisms are kineticly moved.

However, in the positioning mechanism shown in FIG. 3, when the positioning performance of the fine movement stage is pursued, the mechanical interference with the XY stage becomes remarkable, so that the overall positioning including the XY stage and the fine movement stage is performed. There was a problem that the performance could not be improved. For example,
It is possible to set the gain in the fine movement stage control device to the maximum within a stable range, so that the fine movement stage itself exhibits the highest positioning performance. However, when the XY stage on which such a fine movement stage is mounted is accelerated / decelerated, a torque disturbance acts on the fine movement stage by step driving in the x-axis and y-axis directions, and the overall movement including the XY stage and the fine movement stage The positioning settability was significantly impaired.

The present invention has been made in view of the above-mentioned problems in the prior art, and has a fine movement stage for controlling a vertical position and an inclination from a vertical axis on a coarse movement stage for positioning in a horizontal plane. An object of the present invention is to improve the positioning performance of a stage positioning control device.

[0008]

In order to solve the above-mentioned problems, in the present invention, an appropriate compensation is applied to a signal for driving the XY stage in a stepwise manner, and this compensation signal is supplied to the fine movement stage control device. The feedforward is configured in consideration of the exercise mode. More specifically, an XY stage for positioning in a horizontal plane mounted on a surface plate, which is a vibration isolator installed on the floor, and a XY stage mounted on the XY stage and having a vertical axis and a vertical axis. a Ru positioning apparatus and a fine movement stage which actuator is arranged to control the tilt, and the XY stage control unit for positioning the XY stage, and a fine movement stage control system for positioning the fine movement stage Means for feeding forward a compensation signal obtained by performing frequency shaping on a step drive signal for positioning the XY stage in accordance with a motion mode to the fine movement stage control device during a step drive period of the XY stage. Features. In a preferred embodiment of the present invention, the means for feeding forward comprises the XY
Switch means for detecting a step drive signal in the stage control device and selecting the drive signal only for the step drive period, and a feedforward compensator for performing appropriate frequency shaping on the signal selected by the switch means The feedforward compensator is configured to feedforward the output signal to the fine movement stage controller only during the step driving of the XY stage in consideration of the motion mode.

[0009]

In the conventional positioning mechanism shown in FIGS. 3 and 4, a passive or active vibration isolator (not shown) is provided.
XY stage that plays the role of coarse movement and fine movement stage 2
Various types of positioning mechanisms will be moved in kinematic coupling to position the silicon wafer 3 on the fine movement stage 2. However, in the conventional positioning mechanism, a control device for an XY stage having a degree of freedom in the horizontal direction and an actuator 10M, 10R, 10
There was no relationship that the control device for the fine movement stage provided with the degree of freedom of driving in the vertical axis direction using L was connected to each other by some kind of control loop. Rather,
No relationship between such control loops was given,
It might be better to say. Since the XY stage whose main purpose is rough positioning in the horizontal direction and the fine movement stage for bringing the surface of the silicon wafer 3 into the best focus state have different degrees of freedom in positioning with each other,
It was very natural that the control devices for both stages were configured independently.

[0010] However, even if the control devices are independent of each other, the XY stage and the fine movement stage have mechanical interference, which hinders improvement of the overall positioning characteristics including both stages. The facts must not be overlooked. That is, it must be noted that the fine movement stage is a vibration load for the positioning of the XY stage.
Disturbance acts on the fine movement stage due to the step driving of the XY stage, and causes vibration.

In the present invention, the XY stage controller and the fine movement stage controller having different degrees of freedom to control each other are controllably associated with each other by a feedforward path from the former controller to the latter. And
It is intended to improve the overall positioning performance including the fine movement stage and the XY stage. Specifically, XY
Since the fine movement stage vibrates due to the step driving of the stage, which causes deterioration of the positioning characteristics including the positioning time and the positioning accuracy, the feedforward compensation signal synchronized with the step driving of the XY stage is used to freely move the stage. In the present invention, input to the fine movement stage control device in consideration of the degree is devised.

[0012] Feedforward is applied to a device for controlling the speed or positioning of two or more driven objects, as long as the driving directions of the driven objects are the same. . For example, JP-A-6-2160
In No. 3, in a mechanism configuration in which a stage is mounted on an anti-vibration table, a technique is disclosed in which a signal from a stage control unit is fed forward to the anti-vibration table control unit to suppress a reaction force of the anti-vibration table caused by driving the stage. Has been made. Japanese Patent Application Laid-Open No. 6-2322021 discloses a second method for applying the same acceleration to the table to the table so that no displacement occurs between the table and the base even if the table is shaken by driving. It has driving means. further,
Japanese Patent Laid-Open No. 6-280930 discloses a technology related to a digital control type active vibration isolator, which uses both ground motion feed forward and feed forward of a driven object. In these patents as well as in commonly used feedforward, for example, when two driving objects are considered, the directions of movement that are moved relative to each other are applied to the same object. That is, when the xy axis is defined in the horizontal plane, x
This technique detects the movement of a first driving object that is driven in the axial direction, feeds it forward, and also drives the second driving object in the x-axis direction.

However, for example, it is possible to detect the movement of the driving object in the x-axis direction and feed forward to the second driving object in the y-axis direction having a different degree of freedom in driving. It has not been. In other words, the present invention is a feed-forward technology for driving objects having different degrees of freedom to control each other, that is, an XY stage and a fine movement stage, and is different from the conventional technology.

The fact that the XY stage and the fine movement stage mechanically interfere with each other and hinder the improvement of the positioning characteristics of the entire positioning mechanism including these stages will be described. Figure 5 is a definitive XY stage when the step driving in the X direction, motion mode deviation signal in the fine movement stage control unit (e _g, eθ _x,
eθ _y ) is an actual measurement result. From the top of the figure,
Vertical translation deviation signal e _g the fine movement stage, x-axis rotational motion deviation signal E.theta _x, y-axis rotational motion deviation signal E.theta _y P and the XY stage controller,
This is the ID compensation signal X-PID. Where P is proportional, I
Denotes integration, and D denotes differential operation. From FIG.
During the acceleration / deceleration period of the Y stage,
It can be seen that brought induce oscillating rotational motion deviation signal E.theta _y of y-axis in response to deflection of the ID compensation signal X-PID. The cause is obvious. That is, the rotational moment about the y-axis acts on the fine movement stage on the XY stage as a torque disturbance due to the rapid acceleration / deceleration of the XY stage in the x-axis direction. Where eθ
If the attenuating property of the swing of _y is good, that is, if the swing of eθ _y occurs only during the step drive period of the XY stage, and it seems that it disappears immediately before the XY stage reaches the target position. This does not deteriorate the overall positioning performance including the XY stage and the fine movement stage. However, if the gain of the fine movement stage control device is increased in order to shorten the positioning time of the fine movement stage itself, the amplitude of eθ _y rampage that occurs during step driving gradually increases, and until it is settled. Takes longer. This state is shown in FIG. 6 by numerical calculation. Since the fluctuation of the deviation signal caused by the application of the torque disturbance about the y-axis is dominated by eθ _y , only this waveform is shown. Here, the magnitude of the torque disturbance is 0.075 [kg
m], and applied for 0.12 [sec] from 0.01 to 0.13 [sec]. Also, in FIG. 6, when the gain of the thick line is normalized as 1 and the thin line is 2,
The dashed line is the response for 2.5. Now, referring to FIG. 6, it can be seen that the amplitude of eθ _y increases with an increase in the gain, and that the time until it settles significantly increases. As described above, the XY stage must be accelerated and decelerated to be positioned at a desired position. Positioning within the desired positioning accuracy is not completed.
That is, there is a problem that it is not possible to shift to the stage of positioning the fine movement stage upon completion of the positioning. The reason is that the fine movement stage is provided with a reflection mirror of a laser interferometer that obtains a position measurement value required for positioning the XY stage. This is because the stage is moved.

In the present invention, an appropriate compensation is applied to the signal for driving the XY stage in a stepwise manner, and the compensation signal is fed forward into the fine movement stage controller in consideration of the motion mode of the fine movement stage. The trembling of the fine movement stage due to the positioning of the XY stage is compensated for, and the positioning characteristics of the fine movement stage and, consequently, the entire stage positioning control device are improved.

Now, by the step driving of the XY stage in the x-axis (y-axis) direction, the fine movement stage is rotated around the y-axis (x
A torque disturbance around the axis acts, and the torque disturbance causes a rotational motion deviation signal eθ _y (eθ _x ) around the y-axis (around the x-axis) in the fine motion stage controller. That is, it is assumed that the positioning mechanism including the XY stage and the fine movement stage is configured to cause such a phenomenon. Here, a feedforward compensation signal in which the drive signal of the XY stage is subjected to appropriate frequency shaping is generated, and this compensation signal is added into the fine movement stage control device in consideration of the motion mode of the fine movement stage.
Then, it works so as to synchronously suppress the fluctuation of the deviation signal in the fine movement stage control device which occurs in synchronization with the step driving of the XY stage.

[0017]

FIG. 1 is a block diagram of a stage positioning control device according to an embodiment of the present invention. Horizontal x for simplicity
5 shows a case where the fine movement stage shown in FIG. 5 is mounted on the coarse movement stage 19 which is step-driven in the axial direction. Therefore, coarse movement stage 19 corresponds to X stage 1 in FIG.

The apparatus shown in FIG.
0, the output beam 22 from the laser interferometer 21 is applied to the bar mirror 20, and the position of the coarse movement stage 19 in the x-axis direction is measured. This measured value is converted into an electric signal by the position measuring means 23 and compared with a value applied to the control command terminal 24. This comparison output signal passes through the speed compensator 25 or the position compensator 26 and is input to the power amplifier 27. Then, the power amplifier 27 supplies a current to the actuator 28 that drives the coarse movement stage 19. here,
Reference numeral 29 denotes a first switch means which outputs the output of the speed compensator 25 when the coarse movement stage 19 is in a step drive state for moving the coarse movement stage 19 to a position near a desired position at a high speed. The outputs of the amplifiers 26 are selected and input to the power amplifier 27.

As described above with reference to the conventional example shown in FIG. 4, a torque disturbance about the y-axis acts on the substrate 9 by the step driving of the coarse movement stage 19. Therefore rotational movement deviation signal E.theta _y around the y-axis is mainly violently in the fine movement stage control device, it has to disturb the positioning settling performance of the substrate 9 of the fine movement stage. In addition, since the bar mirror 20 for obtaining the position information of the coarse movement stage 19 is provided on the substrate 9, if the substrate 9 vibrates, the positioning stabilization of the coarse movement stage 19 also deteriorates. Therefore, in the apparatus shown in FIG. 1, the signal applied to the command terminal 24 to step-drive the coarse movement stage 19 is switched only in the speed mode in which the coarse movement stage 19 is rapidly accelerated / decelerated, that is, only during the step drive period. Turns on second
Is input to the feed-forward compensator 31 around the y-axis through the switch means 30 of FIG. Then, the output of the feedforward compensator 31 around the y-axis is added to the output signal of the compensator 15L at a stage preceding the motion mode distribution circuit 18 in the fine movement stage controller 100. Therefore, it is possible to synchronously suppress the fluctuation of the motion mode deviation signal generated in the fine movement stage control device in synchronization with the step drive.

Similarly, when the fine movement stage including the substrate 9 is a coarse movement stage (not shown) in the Y direction, that is, the Y stage is step-driven in the y axis direction, a torque disturbance about the x axis acts on the substrate 9 substantially. The rotational motion deviation signal eθ _x about the x axis in the fine movement stage controller is oscillated. At this time, the drive signal to the Y stage is guided to the signal line 32 only at the time of the step drive, and is subsequently input to the feedforward compensator 33 around the x-axis.
3 is output to the compensator 15R in the fine movement stage controller.
May be added to the output signal. Note that X
A closed loop composed of position measuring means 21, 23, a speed compensator 25, a position compensator 26, and a power amplifier 27 provided for stepwise driving and finally positioning the stage at a desired position is the same as that for the Y stage. Is referred to as an XY stage control device.

Next, the effectiveness of the present invention will be shown by numerical calculations. In the conventional fine movement stage control device 100 shown in FIG. 4, a motion mode deviation signal (eg, e _g ) when a torque disturbance around the y-axis acts on the substrate 9 constituting the fine movement stage.
When eθ _x and eθ _y ) are simulated based on the control model, the results shown in FIG. 7 are obtained. The calculation conditions are the same as in FIG. From the upper part of FIG. 7, the translational motion deviation signal e _g , the rotational motion deviation signals eθ _x and y around the x-axis
9 shows a rotational motion deviation signal eθ _y about an axis. It can be seen that a response waveform similar to the experimental result shown in FIG. 5 is obtained qualitatively. Next, the XY with the fine movement stage
Since the step drive signal to the stage is known, the drive signal is compensated and fed forward to the fine movement stage controller. FIG. 8 shows the results. The broken line in the drawing indicates the response without feedforward, and the solid line indicates the response with feedforward. Obviously, it can be confirmed that when feedforward is performed, the flapping of eθ _y is well suppressed. Therefore, the disturbance response around the y-axis generated on the fine movement stage by the step driving of the X stage could be suppressed. Similarly, a step response in the y-axis direction of the Y stage causes a disturbance response around the x-axis in the fine movement stage. This response is based on a feedforward compensation signal received from the step drive signal of the Y stage in the fine movement stage controller. in front of the motion mode distributing circuit 18 can be suppressed by adding to the x-axis of the control signal C theta _x.

Next, a configuration example of a specific compensator for performing feedforward will be described. Here, for simplicity, an example of how to perform feedforward will be described based on a block diagram when a position control system is configured for a fine movement positioning mechanism having one degree of freedom. FIG. 9 is a control block diagram for explaining feedforward to the fine movement stage control device. Where m is the mass, d is the coefficient of viscous friction,
k is a spring constant, k _i is an integrator gain, k _loop is a loop gain, k _s is a position sensor conversion constant, V _com is a command value, V
_s position sensor output voltage, x is the displacement, F _F feedforward input, d _d represents a disturbance input. Using symbols in Fig. 9, to obtain _{V s, V com, F F} , when determining the relationship between the d _d by simple calculation of the equation (1).

[0023]

(Equation 1) Since the effect of input disturbance d _d is on the position sensor output V _s may be input to the thus suppression of the feedforward F _F, it is sufficient to configure the feedforward F _F satisfying the expression (2) Relationship I understand. That is, a transfer function having pseudo-differential characteristics may be realized.

[0024]

(Equation 2) In realizing the expression (2), it is necessary to identify the values of d and k. However, the shape of the transfer function showing the relationship between ultimately d _d and F _F is

[0025]

(Equation 3) It is sufficient to design the mounting so that the gain k _ff and the time constant T _ff can be adjusted together. That is, even when k and d cannot be accurately identified, there is no difficulty in realizing a feedforward compensator and adjusting it to secure desired performance. The transfer function of the feedforward compensator 31 around the y-axis which is designed based on the above idea and used for obtaining the numerical calculation of FIG. 8 is as follows.

[0026]

(Equation 4)

The transfer function of the equation (2) having the pseudo-differential characteristic is derived when it is assumed that a step-like disturbance is applied. However, the gist of the present invention is to perform appropriate frequency shaping on the drive signal of the XY stage and feed forward the output signal to the fine movement stage controller in consideration of the motion mode. In the case described above, this frequency shaping is merely a pseudo-differential characteristic as shown in equation (3). Therefore, the feedforward compensation is not limited to the pseudo-differential characteristic, but may be any as long as appropriate frequency shaping is performed according to the pattern and the signal quality of the step drive signal acquired from the XY stage controller.

[0028]

Other Embodiment In the embodiment shown in FIG. 1, a signal to be fed forward into the fine movement stage controller is received from the command terminal 24. However, the signal for feedforward is not limited to the signal of the command terminal 24 unless it departs from the gist of the present invention. For the signal for feedforward, for example, (1) a vibration sensor for detecting the state of step drive in the x-axis direction, for example, an acceleration sensor is mounted on the coarse movement stage 19 or the fine movement stage substrate 9, and this output signal is appropriately or adding after frequency shaping control signal C theta _y in the fine movement stage control device, or, (2) any of the closed loop positioning control coarse movement stage 19 an input signal or an output signal to the power amplifier 27 signal is detected and may be added to the control signal C theta _y only selectively fine movement stage controller within the period of the step driving also performed the appropriate frequency shaping.

Further, in the above-described embodiment, as shown in FIG.
In the coordinate system, the actuator 10M is positioned on the positive side on the y-axis.
FIG. 1 shows an XY stage on which an actuator 10R is arranged on the x-axis positive side and on the y-axis negative side, and an actuator 10L is arranged on the x-axis negative side and on the y-axis negative side. An example in which step driving is performed in the x-axis or y-axis direction of the xy coordinate system shown in FIG. Therefore, in the step driving in the x-axis direction, the torque disturbance around the y-axis, and in the step driving in the y-axis direction, the torque disturbance around the x-axis mainly acts on the fine movement stage. The motion mode deviation signal is also eθ _{y in} the step drive in the x-axis direction.
However, in the step driving in the y-axis direction, eθ _x mainly oscillates. However, the present invention does not rely on the particularity of such an actuator arrangement. Furthermore, in the above description, the fine movement stage control device employs a decoupling control system configuration based on the motion mode, but the present invention does not depend on such a special structure of the control system. FIG.
FIG. 1 shows a block diagram in a case where the present invention is applied to a fine movement stage control device having a normal independent control system structure. 2, components having substantially the same functions and functions as those of FIG. 1 are denoted by the same reference numerals and description thereof will be omitted. In FIG. 2, the motion mode extraction circuit 17 and the motion mode distribution circuit 18 are removed from the fine motion stage control device shown in FIG. 1, and the position sensors 11M, 11R, 11L near the actuators 10M, 10R, 10L are removed. A control loop independent of each axis is configured by the feedback from the signal. Therefore, the command voltage input terminals 13'M, 13 '
R, the 13'L are applied position target value for each axis, the deviation signal _{(e M, e R, e} L) and the control signal _{(c M, c R, c} L
) Are for each axis. Here, the coarse movement stage 19
Is step-driven in the x-axis direction, a torque disturbance around the y-axis acts on the substrate 9 of the fine movement stage. However, the signal of the command terminal 24 is fed-forward compensated around the y-axis only during the step driving. To a feeder 31, and further outputs the output signal to a feedforward signal distribution operation circuit 34.
And added to the previous stage of the power amplifiers 16M, 16R, 16L of each axis. The operation of the feedforward signal distribution operation circuit 34 receives the output of the feedforward compensator 31 around the y axis, distributes this signal, and finally generates displacement in the actuators 10R and 10L to resist torque disturbance. That is. Similarly, when the Y-direction coarse movement stage (not shown) is step-driven in the y-axis direction, the signal of the feedforward compensator 33 around the x-axis is guided to the feedforward signal distribution calculation circuit 34,
Actuator 1 to resist torque disturbance around axis
An output signal of the feedforward signal distribution operation circuit 34 is added to a stage preceding the power amplifiers 16M, 16R, 16L so as to generate displacements in 0M, 10R, 10L.

Further, according to FIG. 2, even when the arrangement of the actuators 10M, 10R, 10L of the fine movement stage is other than that of FIG.
It can be seen that a design change can be made to the calculation content of No. 4 to cope with the problem. That is, in the xyz coordinate system of FIG. 10, the actuator 10 is added to a new coordinate system rotated around the z-axis.
Even when M, 10R, and 10L are rearranged and the XY stage, which is a coarse movement stage, is step-driven in the x-axis and y-axis directions in the old coordinate system, the XY stage is fed so as to resist torque disturbance during step driving. The operation content of the forward signal distribution operation circuit 34 can be configured.

In the embodiments shown in FIGS. 1 and 2, the control device is realized by an analog operation circuit, but a part or all of the control device may be replaced by a digital operation device such as an electronic computer.

[0032]

Conventionally, the XY stage controller and the fine movement stage controller have not been associated with each other in the control loop. Therefore, when the positioning performance of the fine movement stage is pursued, the mechanical interference between the control device and the XY stage becomes remarkable even if the control devices are independent of each other, so that the overall positioning performance including the XY stage and the fine movement stage cannot be improved. I was In the stage positioning control device of the present invention, since the control loop between the XY stage control device and the fine movement stage control device is related, the gain in the fine movement stage control device is set to the maximum within a stable range. Even in this case, disturbance of the stabilization of the fine movement stage control device caused by the step driving of the XY stage can be suppressed in synchronization with the step driving. Therefore, there is an effect that the quality of the overall positioning performance can be improved.

Conventionally, the parameter adjustment as a closed loop system for the XY stage control device and the fine movement stage control device did not become independent as a result although the control devices were independent. According to this, there is an effect that so-called orthogonal adjustment is possible. That is, since the parameter adjustment for each control device can be performed independently, the work time required for the parameter adjustment can be reduced, which greatly contributes to the reduction in the startup time of the device.

[Brief description of the drawings]

FIG. 1 is a block diagram of a stage positioning control device according to one embodiment of the present invention.

FIG. 2 is a block diagram of a stage positioning control device according to another embodiment of the present invention.

FIG. 3 is a schematic diagram of an XY stage mounted on a surface plate.

FIG. 4 is a block diagram of a fine movement stage control device.

FIG. 5 is a motion mode deviation signal in the fine movement stage control device at the time of XY stage X step driving.

FIG. 6 shows a motion mode deviation signal eθ _y when a loop gain is changed when a torque disturbance around the y-axis acts on the fine movement stage.

FIG. 7 shows a motion mode deviation signal when a torque disturbance around the y-axis acts on the fine movement stage.

FIG. 8 is a motion mode deviation signal based on the presence or absence of feedforward compensation when a torque disturbance around the y-axis acts on the fine movement stage.

FIG. 9 is a control block diagram for explaining feedforward compensation to a fine movement stage control device.

FIG. 10 is a layout diagram of actuators 10M, 10R, and 10L.

[Explanation of symbols]

1: X stage, 2: fine movement stage, 3: silicon wafer, 4: Y stage, 5R, 5L: linear motor mover, 6R, 6L: coil, 7: stage base, 8: base, 9: substrate , 10M, 10R, 10L: actuator, 11M, 11R, 11L: position sensor, 12M, 1
2R, 12L: displacement amplifier, 13M, 13R, 13L:
Command voltage input terminals, 14M, 14R, 14L: deviation amplifier, 15M, 15R, 15L: gain compensator, 16M,
16R, 16L: power amplifier, 17: motion mode extraction circuit, 18: motion mode distribution circuit, 19: coarse motion stage,
20: Bar mirror, 21: Laser interferometer, 22: Outgoing beam, 23: Position measuring means, 24: Command terminal, 25:
Speed compensator, 26: position compensator, 27: power amplifier, 2
8: actuator, 29: first switch means, 3
0: second switch means, 31: feed forward compensator around y axis, 32: signal line, 33: feed forward compensator around x axis, 34: feed forward signal distribution operation circuit.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/027 G03F 9/00 G05D 3/12 305

Claims (4)

(57) [Claims] 1. An XY stage mounted on a surface plate which is a vibration isolator installed on a floor surface for positioning in a horizontal plane, and a vertical axis position and an inclination from the vertical axis mounted on the XY stage. a fine motion stage actuator is arranged to control the, the XY stage control device for positioning the XY stage, the stage positioning control device Ru and a fine movement stage control system for positioning the fine movement stage, A means for feeding forward a compensation signal obtained by subjecting a step drive signal for positioning the XY stage to frequency shaping according to a motion mode to the fine movement stage control device only for a step drive period of the XY stage is provided. Stage positioning control device. 2. The feed-forward means, wherein
Switch means for detecting a step drive signal in the Y stage control device and selecting the drive signal only for the step drive period, and feedforward compensation for performing appropriate frequency shaping on the signal selected by the switch means vessels and, claims, characterized in Rukoto a feedforward circuit for feedforward considering only motion mode to the fine stage controller periods step driving of the XY stage output signal of the feedforward compensator 2. The stage positioning control device according to 1. 3. The fine movement stage control device is a control device having a decoupling structure based on a motion mode.
The step drive signal in the Y-stage control device is a signal applied to a command terminal, the feedforward compensator has a pseudo-differential characteristic, and the feedforward circuit has a feed-forward compensator having the pseudo-differential characteristic. 3. The output of the motion mode distribution circuit in the fine motion stage control device having a decoupling structure based on the motion mode is added to the output of the motion mode distribution circuit.
A stage positioning control device as described in the above. 4. The fine movement stage control device is a control device in which a drive axis is constituted by a control loop independent of each axis, and a step drive signal in the XY stage control device is a signal applied to a command terminal. The feed-forward compensator has a pseudo-differential characteristic, and the feed-forward circuit outputs the output of the feed-forward compensator having the pseudo-differential characteristic to each of the fine-movement stage controllers configured by a control loop independent of each axis. 3. The stage positioning control device according to claim 2, further comprising a feedforward signal distribution operation circuit for distributing the signal to a stage preceding the power amplifier of the shaft.