JPH07307279A - Stage positioning controller - Google Patents

Abstract

PURPOSE:To reduce cost, to improve the setting properties of stage positioning and to miniaturize a device. CONSTITUTION:In equipment constitution, in which a stage 4 is loaded on a surface plate 8, the whole of the stage and surface plate are supported by an active vibration damper and support legs ch1, 3 in the active vibration damper are arranged at the four corners of the surface plate, a plurality of outputs obtained from acceleration sensors mounted on each support leg are introduced to the motion-mode extraction circuit 33 of an acceleration signal detecting the motion attitude of the surface plate. The acceleration signal S1 of the surface plate in the same direction as the direction of movement of the stage is extracted from the motion-mode extraction circuit of the acceleration signal, and the signal is fed back to the pre-stage of a driver 15 driving the stage, thus positioning the stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor exposure apparatus for printing a circuit pattern of a reticle on an IC wafer, a stage positioning control apparatus used for positioning a stage of a liquid crystal substrate manufacturing apparatus, an electron microscope, etc. The present invention relates to improvement of surface plate acceleration feedback for realizing high-speed and high-accuracy positioning by significantly suppressing a response from disturbance applied to an XY stage on an active vibration isolation device in a stage positioning control device.

[0002]

2. Description of the Related Art A semiconductor exposure apparatus represented by an electron microscope using an electron beam or a stepper employs a structure in which an XY stage which is a coarse movement stage is mounted on a vibration isolation device. In this configuration, the vibration isolation device is an air spring,
It has the function of damping vibrations by means of vibration absorbing means such as coil springs and anti-vibration rubber. However, in the passive vibration isolator provided with the above-mentioned vibration absorbing means, although the vibration transmitted from the floor can be damped to some extent, the vibration generated by the XY stage itself mounted on the device cannot be damped effectively. There was a problem. That is, the reaction force generated by the high-speed movement of the XY stage itself causes the vibration isolator to sway, and this vibration significantly impairs the positioning stability of the XY stage. Furthermore, in this passive vibration isolator, a vibration isolation performance is provided between the insulation (vibration isolation) performance of the vibration transmitted from the floor and the vibration suppression (vibration damping) performance generated by the high speed movement of the XY stage itself. When the spring constant and the viscosity constant are changed in an attempt to improve the vibration damping performance, the vibration damping performance is hindered when the vibration damping performance is improved.
There was a so-called trade-off problem.

Therefore, in order to improve the positioning stability of the XY stage, the acceleration of the surface plate supported by the anti-vibration device is detected by using the acceleration sensor installed on the surface plate, and the driver for driving the XY stage is corrected. So-called surface plate acceleration feedback, which is used for feedback, has been adopted. The contents of the platen acceleration feedback will be described below with reference to the drawings.

First, FIG. 5 is a schematic view of an XY stage mounted on a surface plate. Here, 1 is an X stage, 2 is a fine movement stage mounted on the X stage 1 for finely positioning the IC wafer 3, 4 is a Y stage, and 5R and 5L.
Is a moving magnet type mover of a linear motor that drives the Y stage 4, 6R and 6L are coils that are stators of the linear motor, 7 is a stage surface plate, 8 is a surface plate supported by a vibration isolation device (not shown), An acceleration sensor 9 is mounted on the surface plate 8 and detects the acceleration in the positioning direction of the Y stage 4. An acceleration sensor is also mounted on the surface plate 8 for positioning with respect to the X stage 1, but it is omitted in FIG.

Next, the role of the acceleration sensor 9 mounted on the surface plate 8 will be described. For that purpose, a horizontal uniaxial mechanical model of the XY stage is first given in FIG. Here, m ₁ is the Y stage 4, but the following discussion is the same for the X stage 1. Now, using the symbols shown, the equation of motion can be obtained as in equation (1).

[0006]

[Equation 1] However, the unit and meaning of each symbol are as follows. m ₁ [kg]: Mass of stage m ₂ [kg]: Mass of surface plate k ₁ [N / m]: Spring constant of stage k ₂ [N / m]: Spring constant of surface plate b ₁ [Ns / m] ]: Viscous friction coefficient of stage b ₂ [Ns / m]: Viscous friction coefficient of surface plate x ₁ [m]: Displacement of stage x ₂ [m]: Displacement of surface plate f [N]: Control force 7 shows a block diagram of the position control system. In the figure, a portion 10 surrounded by a broken line is a control target expressed by the equation (1). That is, it is a model of the Y stage 4 including the dynamics of the surface plate 8. In FIG. 7, 1
1 is a position signal converting means, 12 is a PID compensator (P: proportional, I: integral, D: differential), 13 is a driver, 14 is a linear motor composed of movers 5R, 5L and coils 6R, 6L. And the thrust constant is noted. Further, 15 is a platen acceleration feedback circuit for amplifying and filtering the output of the acceleration sensor 9. From the disturbance f _ext to the position (x ₁ −x ₂ ) using the symbols shown.
Ask for a response up to. Equation (2) is obtained from a simple calculation.

[0007]

[Equation 2] However, the unit and meaning of each symbol are as follows. K _p [V / m]: Position gain F _x [V / V]: Proportional gain F _v [Vs / V]: Differential gain F _i [V / Vs]: Integral gain K _i [A / V]: Driver gain T _d [s]: Driver delay time constant K _t [N / A]: Thrust force constant A [Vs ² / m]: Platen acceleration feedback gain T _a [s]: Platen acceleration feedback delay time constant x ₀ [m]: Target position f _ext [N]: Disturbance Now, let's look at the numerator polynomial of Expression (2). As is apparent, when the gain A of the platen acceleration feedback is optimally set as in the equation (3), the influence of the disturbance f _ext on the position (x ₁ −x ₂ ) can be minimized.

[0008]

[Equation 3]

From the disturbance f _ext , the position (x ₁ -x
Let me explain why we focus on the responses up to ₂ ). Normally, when positioning the XY stage by moving it for a long distance, first, the XY stage is moved at a high speed in the mode of the speed control system, and when it is detected that the target position has been reached, the mode of the position control system shown in FIG. 7 is entered. . Immediately before entering the mode of the position control system of FIG. 7, the surface plate 8 is vibrating due to the high speed movement of the XY stage in the speed control system, and the disturbance f _ext is equivalently equivalent to the disturbance f _ext of FIG. 7 in the position control system. It can be regarded as input to the part. Next, the reason why the position (x ₁ -x ₂ ) is the feedback signal in FIG. 7 and the equation (2) is calculated and used as the responsiveness evaluation index will be described. Referring to FIG. 6, the position of the Y stage 4 is measured by a laser interferometer. A measuring head for measurement is mounted on the surface plate 8, and a reflection mirror as a target for the measuring head is mounted on the Y stage 4. To do. Therefore, Y
The signal for positioning the stage is the relative position (x ₁ −
x ₂ ).

By the way, the effect of shortening the positioning time of the XY stage when the platen acceleration feedback having the optimum amplification degree shown in the equation (3) is applied is extremely remarkable.
As an example, FIG. 8 shows a comparison of positioning deviation signals depending on the presence or absence of surface plate acceleration feedback. FIG. 8 is a comparison of positioning deviation signals when the X stage 1 is stepped by 20 mm and position control is applied, with and without the presence of the platen acceleration feedback. In the case where the platen acceleration feedback shown in FIG. 8A is not used, the platen 8 is shaken due to the high speed movement of the X stage 1, and a fluctuation having a natural frequency of the platen is also generated in the positioning deviation signal. As a result, the shortening of the settling time is significantly hindered. On the other hand, when the surface plate acceleration feedback is provided, the X stage 1 is positioned in accordance with the shaking of the surface plate 8, and the shaking of the surface plate 8 is included in the positioning deviation signal as shown in FIG. 8B. It will not mix. Therefore, the settling time can be shortened.

Regarding the surface plate acceleration feedback, the journal of Japan Society for Precision Engineering, "Prototype of high-speed air levitation XY stage (JSPE-52-10, '86 -10-1713)".
For the first time, its technical contents were disclosed. Further, in Japanese Patent Laid-Open No. 5-250041 “Positioning device with multiple acceleration feedback” and Japanese Patent Laid-Open No. 5-189050 “Positioning device”, the existence of the optimum value of the acceleration feedback expressed by the equation (3) is quantitatively derived for the first time. In addition, we are expanding the surface plate acceleration feedback technology.
However, in all cases, as shown in FIG. 5, it is necessary to provide an acceleration sensor 9 dedicated to the surface plate acceleration feedback on the surface plate 8.

[0012]

The adoption of the platen acceleration feedback makes a great contribution to the reduction of the positioning settling time of the XY stage as shown in FIG. But,
Adopting the platen acceleration feedback has the following disadvantages. (1) A highly sensitive acceleration sensor is expensive. (2) A servo type acceleration sensor is known as a highly sensitive acceleration sensor. The experimental result of FIG. 8 is also the case where this type of acceleration sensor is used. However, since the servo type acceleration sensor is vulnerable to mechanical shock, it is necessary to pay close attention to the mounting work. (3) The conventional surface plate acceleration feedback is realized by using the output of an acceleration sensor provided at a part of the surface plate for each moving direction of the XY stage. Therefore, in the signal of the acceleration sensor, a signal indicating the surface plate motion, which is unnecessary for positioning the XY stage in each moving direction, is also mixed. Therefore, it hinders the improvement of the positioning performance of the XY stage.

Here, (1) means that the direct cost of the entire apparatus increases, and (2) means that loss cost is likely to occur. In either case, since the total cost of the entire apparatus is significantly increased, there is a problem that the acceleration sensor mounted on the surface plate 8 for removing the surface plate acceleration feedback needs to be removed. Of course, when removing the acceleration sensor, the settling performance of positioning realized by the platen acceleration feedback must be maintained. Regarding (3), it goes without saying that the surface plate vibration due to the movement of the XY stage cannot be represented by the output of a partial acceleration sensor provided on the surface plate in each moving direction of the XY stage. However, in order to meet the recent demand for improving the positioning performance of the XY stage, it is necessary to use the X
There has been a demand for a technique of extracting an acceleration signal of the surface plate, which is significant for the surface plate acceleration feedback to the Y stage, and positively feeding this back to the front stage of each driver of the XY stage.

The present invention has been made to solve the above problems. That is, the first object of the stage positioning control device is to reduce the cost of the entire device. Further, it is a further object to improve the settling property of stage positioning and to enable downsizing of the apparatus.

[0015]

In order to achieve the above object, a stage positioning control device of the present invention comprises a surface plate, a stage mounted on the surface plate, and support legs arranged at four corners of the surface plate. And an active vibration isolation device for supporting the surface plate and the stage, including a control device for the support leg, a position control system for positioning the stage, and a plurality of acceleration sensors mounted on the support legs. A motion mode extraction circuit for an acceleration signal that detects the motion posture of the surface plate by using each output as an input signal, and a movement mode extraction circuit for the surface plate in the same direction as the moving direction of the stage acquired by the motion mode extraction circuit for the acceleration signal. A platen acceleration feedback circuit is provided for giving an optimum amplification degree to the acceleration signal and performing a filtering process. It is characterized in that to perform positioning of the stage in a state of positive feedback in front of the driver for driving the stage. Specifically, XY on the surface plate
In an equipment configuration in which a stage is mounted, the whole of which is supported by an active vibration isolator, and the support legs of the active vibration isolator are arranged at the four corners of the surface plate, an acceleration sensor attached to each support leg From the motion mode extraction circuit for the acceleration signal for detecting the motion posture of the surface plate.
Provided is a stage positioning control device that extracts an acceleration signal of the surface plate in the same direction as the moving direction of the Y stage and positively feeds this signal back to a stage before a driver that drives the XY stage to perform positioning of the XY stage. is doing.

[0016]

Originally, the acceleration sensor mounted on the support leg of the active vibration isolator has only the role of providing electrical damping to the mechanism of the support leg. In the present invention, in addition to its role, it serves as a sensor for acquiring a signal for surface plate acceleration feedback, which has a function of suppressing a response from disturbance in positioning control of a stage, for example, an XY stage. is there.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, in the conventional passive vibration isolator supporting the surface plate having the XY stage, there is a trade-off between the vibration isolation performance and the vibration damping performance. Therefore,
In recent years, there is a tendency to introduce an active vibration isolation device that can easily balance vibration isolation and vibration damping performance. In view of such a situation, in the present embodiment, the conventional surface plate is required to use an active vibration isolation device instead of the passive vibration isolation device for horizontally supporting the surface plate 8 on which the XY stage is mounted. Improved acceleration feedback technology.

First, before showing the contents of this embodiment, the structure and control configuration of the active vibration isolator will be described. An active vibration isolator suppresses the floor vibration from being transmitted to the surface plate by driving the actuator in response to the detection signal from the sensor, and further by the vibration of the equipment itself installed on the surface plate. It is a device that has a function to actively suppress the surface plate when it shakes. Generally, an active vibration isolation device is equipped with a voice coil motor or an air spring as an actuator, and either or both of a position sensor and a vibration sensor to detect a state quantity. In many cases, vibration sensors are always equipped. The vibration sensor includes, for example, a known acceleration sensor or speed sensor. The case where an acceleration sensor is used will be described below.

FIG. 9 shows the structure of the support leg and the configuration of the control device in the active vibration isolator using the air spring. In FIG. 9, 16 V (H) is a vertical (horizontal) air spring, 1
7V (H) is vertical (horizontal) acceleration sensor, 18V
(H) is a vertical (horizontal) non-contact position sensor, 19V
(H) is a vertical (horizontal) electro-pneumatic analog valve that controls the flow of working fluid into and out of the air spring 16V (H). Here, as the non-contact position sensor 18V (H),
For example, an eddy current sensor, a differential transformer, an LED, a laser element, etc. are adopted. Also, the electro-pneumatic analog valve 19
As V (H), a servo valve (nozzle flapper), an electro-pneumatic proportional valve (spool valve), an electro-pneumatic regulator (nozzle flapper, etc.) can be used.

Next, the operation of the control device 26 in the horizontal direction will be described. First, the output of the acceleration sensor 17H is negatively fed back to the front stage of the voltage-current converter 21 for opening and closing the electropneumatic analog valve 19H through the filter circuit 20 having an appropriate amplification degree and time constant. This acceleration feedback stabilizes the mechanism. That is, damping is added. Further, the output of the non-contact position sensor 18H is input to the comparison circuit 23 through the displacement amplifier 22.
Here, the output of the comparison circuit 23 becomes the deviation signal e by being compared with the target voltage 24 for placing the surface plate 8 at a predetermined horizontal position. This deviation signal e passes through the PI compensator 25 and activates the voltage-current converter 21. Then, the internal pressure of the air spring 16H is adjusted by opening / closing the electro-pneumatic analog valve 19H, and the surface plate 8 can be held at a predetermined horizontal position without steady deviation. Here, P means proportional and I means integral operation.

Conventionally, when forming the platen acceleration feedback in the positioning of the XY stage, a high-sensitivity acceleration sensor was newly prepared and installed on the platen 8. Considering the effective use of the output of the acceleration sensor 17H that the support leg of the device already has, it is not necessary to mount the acceleration sensor 9 on the surface plate 8 at the site shown in FIG.

This embodiment based on the above idea is shown in FIG.
FIG. 1 is a view of a state in which a surface plate 8 is horizontally supported by support legs ch1 to ch4 of an active vibration isolator, as viewed from the top surface z direction. In the illustrated case, the support legs ch1 and ch3 actively support the horizontal y direction, and ch2 and ch4 actively support the horizontal x direction. The control of these supporting legs is performed by the control device 26 already described in FIG. In FIG. 1, each control device 26 for the support legs ch1 and ch3 is shown, but ch2 and ch4 are omitted.

Now, control of the Y stage 4 mounted on the stage surface plate 7 on the surface plate 8 will be described. for that reason,
First, the symbols are explained. In FIG. 1, 27 is a measurement head of a laser interferometer installed on the surface plate 8, and 28 and 29 are y for displacement measurement installed on the fine movement stage 2.
Axial and x-axis reflective mirrors. In the illustrated case, the laser beam 30 emitted from the measuring head 27 of the laser interferometer is y
The displacement of the Y stage 4 in the y-axis direction is measured by being applied to the reflection mirror 28 for the axis. This measured value is compared with the target position x ₀ and then guided to the position signal converting means 11. Further, the output signal of the position signal converting means 11 is the PID compensator 1
2, the Y stage 4 is positioned and driven by energizing the driver 13 with this signal. However, P means proportional, I means integral, and D means differential operation. Here, in the conventional technique shown in FIG. 9, the output of the acceleration sensor 9 installed on the surface plate 8 is guided to the surface plate acceleration feedback circuit 15 by a signal line 32 shown by a broken line, and this output is directly fed to the front stage of the driver 13. I was returning.
However, the vibration of the surface plate 8 in the y-axis direction should have already been captured by the acceleration sensor built in the support legs ch1 and ch3 of the active vibration isolator without newly installing the acceleration sensor 9. Is. Therefore, in the device of the present embodiment shown in FIG. 1, the outputs of the acceleration sensors (not shown in FIG. 1) built in the support legs ch1 and ch3 are guided to the motion mode extraction circuit 33 for the acceleration signal, With surface plate 8
The translational acceleration signal S _t representing the translational movement in the y-axis direction and the rotational acceleration signal S _r representing the rotational movement around the z-axis are acquired, and only the translational acceleration signal S _t is input to the platen acceleration feedback circuit 15. This output signal is positively fed back to the front stage of the driver 13 as in the conventional case. Therefore, according to the present invention, the acceleration sensor 9 which is conventionally installed on the surface plate 8 to realize the surface plate acceleration feedback can be eliminated. Of course, the configuration of the platen acceleration feedback for the X stage 1 is similar to that for the Y stage 4. That is, the output of the acceleration sensor (not shown) incorporated in the support legs ch2 and ch4 of the active vibration isolation device is guided to the motion mode extraction circuit (33) for the x-axis direction, and the acceleration signal indicating the translation in the x-axis direction. Is obtained, and this may be fed back positively in the preceding stage of the driver that drives the X stage.

Therefore, in positioning control of the XY stage, conventionally, it was necessary to install two acceleration sensors, one for each of the X stage and the Y stage, on the surface plate 8 according to the present invention. The acceleration sensor is not required, and as a result, it greatly contributes to cost reduction.

Next, experimental results showing the effectiveness of this embodiment will be shown. FIG. 2 shows how the acceleration of the surface plate 8 is detected. Figure 2
(A) is an output waveform of the acceleration sensor 9 when the conventional surface plate acceleration feedback is adopted and the Y stage is stepped by 20 mm in the y direction. On the other hand, FIG.
(B) is a waveform according to the present embodiment when the acceleration of the translational component in the y direction is calculated based on the output of each acceleration sensor mounted on the support leg of the active vibration isolator. Comparing the two, in each case, the natural vibration of the surface plate 8 in the low frequency region is well detected, and both are in agreement with respect to this vibration component. That is, when the platen acceleration feedback is applied to the positioning control of the XY stage, an acceleration sensor for detecting a horizontal acceleration signal of the platen 8 is not specially prepared near the XY stage and on the platen 8. I understand that it is okay. In other words, the horizontal translational acceleration signal of the surface plate 8 can be detected with sufficient accuracy even by calculation using the output of the acceleration sensor incorporated in each support leg in the horizontal active vibration isolator. Moreover, since the acceleration sensor 9 installed on the surface plate 8 has high sensitivity, it also detects a high-frequency local vibration component as shown in FIG. On the other hand, FIG. 2B shows a waveform obtained by amplifying the output of the low-sensitivity acceleration sensor incorporated in each support leg, but there is no detection of the vibration component unnecessary for the platen acceleration feedback, which is preferable. You are getting signal quality.

FIG. 3 shows the outputs S _t and S _r of the motion mode extraction circuit 33 when the Y stage is stepped in the y direction by 20 mm. Here, S _t represents a translational acceleration signal and S _r represents a rotational acceleration signal. Comparing S _t and S _r based on the fact that the detection sensitivities of both signals are the same, it can be seen that the signal S _r indicating the rotation of the surface plate 8 around the z axis also appears significantly. However, the effective signal for the platen acceleration feedback to the XY stage is
It is an acceleration component of the surface plate 8 that moves in the same direction as the movement of the XY stage. In the case of FIG. 3, S _t is an effective signal for the surface plate acceleration feedback of the Y stage 4, and S _r is Y
Positive feedback to the driver 13 that drives the stage 4 is not preferable. From this point of view, in the present invention, the motion mode extraction circuit 33 of the acceleration signal extracts only the acceleration component for which the surface plate acceleration feedback effectively functions, and positively feeds this back to the driver that drives the XY stage. You can On the other hand, in the conventional surface plate acceleration feedback, referring to FIG. 1, the acceleration sensor 9 is installed in the center of the movable range of the X stage 1 near the Y stage 4. Therefore, the average acceleration signal in the y-axis direction of the surface plate 8 due to the movement of the Y stage 4 can be detected, but the surface plate 8 is included in the detection signal from the acceleration sensor 9.
That is, a signal component other than the translational component in the y-axis direction, which is unnecessary for the platen acceleration feedback, was also mixed. Therefore, as a result of the unnecessary signal component exciting the driver 13, the positioning performance of the Y stage 4 is impaired.

Finally, FIG. 4 shows a positioning waveform of the Y stage 4 in the apparatus configuration of FIG. In the case of FIG. 4A in which the output of the platen acceleration feedback circuit 15 is cut off, Y
The fluctuation of the natural frequency of the surface plate 8 is mixed in the position deviation signal of the stage 4, and the settling time is remarkably lengthened. On the other hand, the outputs of the acceleration sensors built in the support legs ch1 and ch3 of the active vibration isolator are guided to the motion mode extraction circuit 33 of the acceleration signal and further positively fed back to the front stage of the driver 13 via the platen acceleration feedback circuit 15. Figure 4
In the case of (b), the fluctuation of the natural frequency of the surface plate 8 is suppressed and the positioning time is shortened. Therefore, it can be concluded that the conventional surface plate acceleration feedback device configuration can be replaced by the device configuration of the present invention.

[0028]

Other Embodiments In the case of FIG. 1, the acceleration signal for the platen acceleration feedback to the Y stage 4 was obtained from the acceleration sensors built in the support legs ch1 and ch3 of the active vibration isolator. This is ch1 to ch4
This is because the control directions of the support legs up to are the y, x, y, and x axes, respectively. In other words, it is nothing but how to extract the acceleration signal depending on the special arrangement of the support legs in the active vibration isolator. Of course, an acceleration signal motion mode extraction circuit (33) is provided for calculating and extracting an acceleration signal effective for the platen acceleration feedback to the XY stage by using a plurality of acceleration signals obtained from each supporting leg in the active vibration isolator. A stage positioning device in which this signal is positively fed back to the front stage of the driver 13 via the platen acceleration feedback circuit 15 is also included in the scope of the present invention.

Although the active vibration isolation system shown in FIG. 1 uses an air spring as an actuator, it goes without saying that the active vibration isolation system using a voice coil motor as an actuator can also be used to control the active vibration isolation system. For this reason, since the acceleration sensor is equipped as standard, an acceleration signal for feedback of the platen acceleration in the positioning control of the XY stage may be acquired from here.

Further, in the active vibration isolator shown in FIG. 1, each support leg is provided with an independent control device 26 to position the surface plate 8 in the horizontal plane. However, x on the surface plate 8
Focusing on the motion modes of the translational motion of the axes and the y-axis and the rotational motion around the z-axis, there is also a control device for an active vibration isolator that decouples the acceleration signal in addition to the position. In this case, an arithmetic circuit such as a motion mode extraction circuit 33 for the acceleration signal is included in the control loop of the control device of the active vibration isolation device itself. Therefore, the signal for the platen acceleration feedback to the XY stage can be directly obtained from here. Such a stage positioning control device is also included in the scope of the present invention.

In the embodiment of the present invention shown in FIG. 1, most of the control system is realized by an analog arithmetic circuit, but some or all of this may be replaced by a digital arithmetic unit such as an electronic computer. I don't care.

[0032]

As described above, according to the present invention, it is possible to eliminate the acceleration sensor conventionally installed on the surface plate due to the adoption of the surface plate acceleration feedback when positioning the stage such as the XY stage. Of course, this does not impair the positioning settling property of the stage for which the conventional surface plate acceleration feedback is realized. Therefore, there is a significant contribution in reducing the direct cost of the overall device. In addition, since it is not necessary to install an acceleration sensor on the surface plate, the space on the identification plate can be effectively used for other purposes, and it is possible to redesign the surface plate and reduce the overall size of the device. The effect is that it will be possible. Further, since there is no complicated work of installing the acceleration sensor on the surface plate, there is an effect that the device manufacturing becomes simple.

Furthermore, the positioning performance of the stage, which has been realized by the conventional surface plate acceleration feedback, can be exceeded.
There is an effect. This is because, as described in the above embodiment, in the present invention, only the acceleration component of the surface plate that performs an effective function for the surface plate acceleration feedback for the stage is extracted, and this is directly added to the front stage of the driver that drives the stage. This is because the configuration for returning is adopted.

[Brief description of drawings]

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

FIG. 2 is an acceleration waveform of a surface plate when the Y stage is stepped by 20 mm.

FIG. 3 shows a translational acceleration signal S _t and a rotational acceleration signal S _r .

FIG. 4 is a positioning waveform of the Y stage showing the effect of the present invention.

FIG. 5 is a schematic view of an XY stage mounted on a surface plate.

FIG. 6 is a horizontal uniaxial mechanical model of the XY stage.

FIG. 7 is a block diagram of a position control system.

FIG. 8 is a comparison of position deviation signals with and without surface plate acceleration feedback.

FIG. 9 is a structure of a support leg and a configuration of a control device in an active vibration isolation device using an air spring.

[Explanation of symbols]

1: X stage, 2: Fine movement stage, 3: IC wafer,
4: Y stage, 5R, 5L: moving magnet type mover, 6R, 6L: coil, 7: stage surface plate, 8:
Surface plate, 9: acceleration sensor, 10: controlled object, 11: position signal conversion means, 12: PID compensator, 13: driver,
14: linear motor, 15: surface plate acceleration feedback circuit, 16V (H): vertical (horizontal) direction air spring, 1
7V (H): Vertical (horizontal) acceleration sensor, 18V
(H): Vertical (horizontal) non-contact position sensor, 19V
(H): Vertical (horizontal) electro-pneumatic analog valve, 2
0: filter circuit, 21: voltage-current converter, 22: displacement amplifier, 23: comparison circuit, 24: target voltage, 25: PI
Compensator, 26: Horizontal control device, 27: Laser interferometer measuring head, 28, 29: y-axis and x-axis reflecting mirrors, 30: laser light, 32: signal line, 33: motion mode of acceleration signal Extraction circuit, e: deviation signal, _St : translational acceleration signal, _Sr : rotational acceleration signal.

Claims (1)

[Claims] 1. A surface plate, a stage mounted on the surface plate, support legs arranged at four corners of the surface plate, and a control device for the support legs, and an active plate supporting the surface plate and the stage. Anti-vibration device, position control system for positioning the stage, motion mode of an acceleration signal for detecting the motion posture of the surface plate using a plurality of outputs obtained from acceleration sensors mounted on the support legs as input signals An extraction circuit and a constant for giving an optimum amplification degree and performing a filtering process to the acceleration signal of the surface plate in the same direction as the moving direction of the stage acquired by the motion mode extraction circuit of the acceleration signal. A plate acceleration feedback circuit is provided, and the output of the surface plate acceleration feedback circuit is positively fed back to the stage preceding the driver that drives the stage. Stage positioning control device, characterized in that to perform determined.