JP2000208402A - Vibration removing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably suppress the inclination of a vibration removing stand, carrying the heavy material such as an X-Y stage, is being moved even when the pressure or the responsiveness of thrust of an air spring is low. SOLUTION: A signal, wherein a proportional gain compensation and a phase leading compensation are worked on the positional information of an X-Y stage, is generated on a feed-forward compensator 10 in this vibration removing device provided with a vibration removing stand 6, displacement sensors 3a and 3b, an acceleration sensor 20, air springs 1a and 1b supporting the vibration removing stand 6, air valves 4a and 4b which control the pressure of the air springs, pressure sensors 5a and 5b which detect the pressure of the air springs, a feed-back compensator which controls the pressure of the air springs by feeding back the detection signal of the displacement sensor, the acceleration sensor and the pressures sensor, and a feed-forward compensator which controls the pressure of the air springs in accordance with the positional information of the X-Y stage placed on the vibration removing stand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air spring type vibration damping device which is used especially in a semiconductor manufacturing apparatus and reduces vibration of a vibration damping table.

[0002]

2. Description of the Related Art As precision instruments such as electron microscopes and semiconductor manufacturing equipment have become more precise, there has been a demand for higher performance of a precision vibration isolator equipped with them. Particularly, in a semiconductor manufacturing apparatus, in order to perform appropriate and quick exposure, a vibration isolator that eliminates vibration transmitted from the outside such as floor vibration of an installation as much as possible is required. This is because, in the semiconductor manufacturing apparatus, when exposing a semiconductor wafer, the XY stage for exposure must be in a completely stopped state. Further, since the exposure XY stage is characterized by an intermittent operation called step and repeat, the repetitive step motion excites the vibration of the vibration isolation table itself. Therefore, the vibration damping device is required to achieve a good balance between the vibration damping performance against external vibration and the vibration damping performance against vibration generated by the operation of the mounted device itself.

In response to such a demand, a so-called active type anti-vibration apparatus has been put into practical use, in which vibration of the anti-vibration table is detected by a vibration sensor and the anti-vibration table is driven by an actuator according to the detection signal. I have. The active anti-vibration device enables balanced implementation of anti-vibration performance and vibration control performance, which is difficult with a passive anti-vibration device including only a support mechanism having a spring and a damper characteristic. In an active type vibration damping device, an air spring is generally used as an actuator. This is because the air spring can easily generate a thrust sufficient to support a heavy object such as the main body of the semiconductor manufacturing apparatus including the vibration isolation table.

[0004]

When a heavy object such as the XY stage moves on the vibration isolation table, the center of gravity of the semiconductor manufacturing apparatus supported by the air spring also moves. The table and the main body are inclined. The vibration isolation device includes a displacement sensor for detecting the displacement of the vibration isolation table and a displacement feedback compensator, and the vibration isolation table supports the floating displacement so as to be constant and the inclination amount thereof to be zero. The tilt of the vibration isolation table due to the movement of the XY stage is also corrected by the feedback of the displacement.

However, in the feedback control, the operation is started after detecting the inclination of the vibration isolation table.
It is impossible to completely suppress the tilt amount to zero during the movement of the Y stage. During the operation of the semiconductor manufacturing apparatus that performs the XY stage movement and the sequential exposure, the tilt of the anti-vibration table cannot be completely suppressed only by the feedback control of the displacement. When the anti-vibration table, which is the base on which the XY stage is mounted, is inclined, gravity acts on the XY stage as a disturbance force. Therefore, the tilt of the vibration isolation table caused by the movement of the XY stage has a disadvantage that the settling time and the settling accuracy of the XY stage are deteriorated, and the exposure accuracy of the semiconductor manufacturing apparatus is deteriorated.

Therefore, by feeding forward a stage target value such as a target position, a target speed or a target acceleration of the XY stage, even if a heavy object such as the XY stage moves, the inclination of the vibration isolating table on which the heavy object moves is moved. The present applicant has previously filed an application for a vibration damping device capable of suitably suppressing the vibration (Japanese Patent Application No. 10-294699). However, in the device of the prior application, the response of the pressure or thrust of the air spring is insufficient due to the increase in the size and the speed of the XY stage, and a sufficient response to suppress the tilt amount of the vibration isolation table is secured. The problem has arisen that they cannot do so.

The present invention has been made in view of such circumstances. In other words, the object of the present invention is to provide an XY camera even when the response of the air spring pressure or thrust is low.
An object of the present invention is to provide a vibration damping device that can appropriately suppress the inclination of a vibration damping table on which a heavy object such as a stage moves when it moves.

[0008]

In order to achieve the above object, a vibration isolator according to the present invention comprises: a vibration isolator, a displacement sensor, an acceleration sensor, an air spring supporting the vibration isolator, An air valve for operating the pressure of the air spring; a pressure sensor for detecting the pressure of the air spring; and a feedback for controlling the pressure of the air spring by feeding back detection signals of the displacement sensor, the acceleration sensor, and the pressure sensor. A vibration isolator having a compensator and a feedforward compensator for controlling the pressure of the air spring in accordance with positional information of an XY stage mounted on the vibration isolation table, wherein the feedforward compensator includes the XY stage A signal obtained by applying proportional gain compensation and phase lead compensation to the position information.

In a preferred embodiment of the present invention, the feedforward compensator controls the pressure of the air spring so as to correct the inclination of the vibration isolation table caused by the movement of the XY stage.

In the feedback compensator, a feedback loop is formed for each motion mode such as translation and rotation of the vibration isolation table, and a signal generated by the feedforward compensator is added to a rotation mode signal in the feedback compensator. You.

[0011]

The vibration isolation table on which the XY stage is mounted is floated and supported from the installation floor by an air spring. The air spring generates a thrust in the vertical direction. An air valve for operating pressure and a pressure sensor for detecting pressure are attached to the air spring. The acceleration sensor detects vertical vibration generated in the vibration isolation table. The displacement sensor detects a vertical displacement generated in the vibration isolation table.

The feedback compensator constitutes a pressure feedback loop for controlling the pressure of the air spring, and a feedback loop for each displacement and acceleration motion mode focusing on the motion mode of the vibration isolation table such as translation or rotation. The pressure feedback loop operates to control the pressure of the air spring in response to the signals of the displacement and acceleration feedback loop. By the feedback of the displacement, the vibration isolation table is supported so that the floating displacement is kept constant and the inclination amount is kept at zero. In addition, the vibration is quickly attenuated by applying damping to the vibration isolation table by the acceleration feedback.

When the XY stage moves, the position of the center of gravity of the structure supported by the air spring also moves in the same direction as the XY stage, so that the anti-vibration table tilts. The feedforward compensator performs compensation according to the position information of the XY stage,
The pressure of the air spring is controlled so as to correct the tilt of the vibration isolation table according to the compensation signal. Thus, the tilt of the vibration isolation table due to the movement of the XY stage can be suppressed.

Here, the position information of the XY stage is as follows.
It may be a detection signal of a laser interferometer that detects the position of the XY stage, or a target value of the position of the XY stage.

Since the amount of movement of the center of gravity of the structure supported by the air spring is proportional to the amount of movement of the XY stage, the feedforward compensator that compensates for the position information of the XY stage sets an appropriate gain. It consists of a proportional gain element. Further, in order to secure sufficient responsiveness to suppress the amount of tilt of the vibration isolation table 6, a phase advance compensation element is applied to the position information of the XY stage. by this,
Sufficient air spring pressure responsiveness can be ensured, and the tilt amount of the vibration isolation table can be suitably suppressed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vibration isolator according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration of an anti-vibration apparatus according to one embodiment of the present invention. The anti-vibration table 6 on which precision instruments such as the XY stage 7 are mounted is supported at four corners by floating from the installation floor by four legged air springs 1a, 1b, 1c and 1d. Each of the air springs 1a, 1b, 1c and 1d generates a thrust in the vertical direction. That is, the air springs 1a, 1
b, 1c, and 1d apply a vertical driving force to the vibration isolation table 6. The air springs 1a, 1b, 1c, and 1d are respectively provided with air valves 4a, 4b, 4c, and 4d for operating pressure.
Pressure sensors 5a, 5b, 5c, and 5d for detecting pressure are attached. Note that air springs 1c and 1d, air valves 4c and 4d, and pressure sensors 5c,
5d is not shown. Also, an acceleration sensor 2 described later
c, 2d and the displacement sensors 3c, 3d are also not shown.

The acceleration sensors 2a, 2b, 2c and 2d are attached to the vibration isolator 6 near the air springs labeled a, b, c and d, respectively. Is detected. In order to detect the vertical vibration of the vibration isolation table 6, usually, only three or more acceleration sensors are required. That is, one of the acceleration sensors 2a, 2b, 2c, and 2d can be omitted.

The displacement sensors 3a, 3b, 3c, 3d are a,
It is attached to the vibration isolation table 6 near the air springs denoted by b, c, and d, and detects the vertical displacement generated on the vibration isolation table 6. In order to detect the vertical displacement of the vibration isolation table 6, three or more displacement sensors are usually sufficient. That is, one of the displacement sensors 2a, 2b, 2c, and 2d can be omitted.

As shown in FIG. 2, the XY stage 7 is mounted on the vibration isolation table 6. The XY stage 7 is movable in the X and Y directions, and the position in each direction is detected by the laser interferometers 20X and 20Y. The laser interferometer 20X detects the position of the XY stage 7 in the X direction, and the laser interferometer 20Y detects the position of the XY stage 7 in the Y direction.

Next, the operation of the feedback compensator 19 shown in FIG. 1 will be described. The vibration isolation table 6 keeps the floating displacement constant,
And it is supported so that the inclination amount may be kept at zero. In addition, damping is applied to the vibration isolating table 6 so that the vibration
The vibration generated in the vibration isolation table 6 due to the movement of the Y stage is promptly attenuated to stabilize the holding operation. The air springs 1a, 1b, 1c, 1d are used to realize these functions.
Is controlled by a feedback compensator 19. The feedback compensator 19 focuses on the motion mode of the vibration isolation table 6, and forms a feedback loop for each motion mode of displacement and acceleration. FIG. 3 shows the vertical motion mode of the vibration isolation table 6. The origin matches the center of gravity of the anti-vibration table 6,
Considering an XYZ coordinate system in which the Z axis is vertically upward,
The anti-vibration table 6 has three motion modes based on this coordinate system: translation in the Z-axis direction, rotation around the X-axis, and rotation around the Y-axis. The feedback compensator 19 keeps the floating displacement of the anti-vibration table 6 in the Z-axis direction constant, and keeps the displacements of the rotation about the X-axis and the Y-axis to zero in order to eliminate the inclination of the anti-vibration table 6. Further, damping is applied to the vibration isolation table 6 so as to quickly attenuate the vibrations generated in these three motion modes.

The structure of the feedback compensator 19 is shown in detail in FIG. The target displacement value generator 11 determines a target displacement value by using a displacement sensor signal when the vibration isolation table 6 floats at a predetermined position. That is, the target displacement value generator generates a displacement target such that the anti-vibration table 6 floats to a predetermined position and the tilt amount becomes zero in response to three detection signals among the displacement sensors 3a, 3b, 3c, and 3d. Generate a value. A deviation signal obtained by comparing and subtracting the detection signal of the displacement sensor from the target value output by the target displacement value generator 11 is input to the displacement motion mode extraction calculator 12. Displacement motion mode extraction device 12
Are motion modes Dz, Dθx,
Dθy is calculated and output. Dz is a motion mode relating to the translational displacement in the Z-axis direction, and represents a deviation between the target floating displacement value and the actual floating displacement of the vibration isolation table 6. Dθx is a motion mode related to displacement around the X axis, and Dθy is a motion mode related to displacement around the Y axis. Dθx is the tilt amount of the vibration isolation table 6 around the X axis, and Dθy is the Y amount of rotation of the vibration isolation table 6. This is the amount of tilt around the axis. Displacement compensators 14z, 14qx, 14q
y generates a drive signal for each motion mode applied to the anti-vibration table 6 so that the motion modes Dz, Dθx, and Dθy relating to displacement become zero. This drive signal is supplied to each air spring 1a, 1b, 1c, 1d by the motion mode distribution calculator 16.
Is converted into a pressure command signal to be generated.

In order to generate a desired pressure on the air springs 1a, 1b, 1c and 1d, pressure feedback control is required. The pressure compensator 17a compares a pressure command signal for the air spring 1a output by the motion mode distribution calculator 16 with a pressure detection signal of the air spring 1a detected by the pressure sensor 5a, and appropriately compares the two. The air valves 4a, 4a
b, 4c and 4d are driven. Thereby, the air spring 1a
The pressure is controlled. The same applies to the air springs 1b, 1c, 1d with the reference numerals b, c, d. The feedback compensator 19 controls the air springs 1 a, 1 b, so that the floating displacement of the vibration isolation table 6 is kept constant and the amount of inclination is kept at zero.
The pressures 1c and 1d are controlled.

The acceleration motion mode extraction calculator 13 calculates and outputs motion modes Az, Aθx and Aθy relating to acceleration from three detection signals of the acceleration sensors 2a, 2b, 2c and 2d. Az is a motion mode relating to acceleration in translation in the Z-axis direction, and Aθx and Aθy are motion modes relating to acceleration in rotation around the X-axis and Y-axis, respectively. The acceleration compensators 15z, 15qx, and 15qy provide the motion modes AΖ regarding acceleration so as to suppress the vibration of the vibration isolation table 6.
Appropriate compensation is performed on Aθx and Aθy to generate a drive signal for each motion mode that acts on the vibration isolation table 6. These are sign-inverted and added to the drive signals from the displacement compensators 14z, 14qx, 14qy. As described above, the feedback compensator 19 forms a negative feedback loop of the acceleration, and rapidly attenuates the vibration generated in the vibration isolation table 6.

In addition to the feedback compensator 19 described above, the anti-vibration device according to the present embodiment is a feedforward compensator that controls the pressure of the air springs 1a, 1b, 1c, 1d according to the position information of the XY stage 7. It has ten. When a heavy object such as the XY stage 7 moves, the position of the center of gravity of the structure supported by the air springs 1a, 1b, 1c, and 1d also moves, so that the anti-vibration table 6 is inclined. Although the tilt is corrected by the operation of the feedback compensator 19, the feedback means that the operation is started after detecting that the control amount deviates from the target value. Therefore, the tilt amount is completely reduced to zero during the movement of the XY stage. It is impossible to suppress.
During the movement of the XY stage 7 and the sequential exposure in the semiconductor manufacturing apparatus, the tilt of the anti-vibration table 6 cannot be completely corrected only by the operation of the feedback compensator 19. Therefore, a feedforward compensator 10 that controls the pressure of the empty springs 1a, 1b, 1c, and 1d according to the position information of the XY stage 7 is required.

The configuration and operation of the feedforward compensator 10 will be described. As shown in FIG.
When moved in the axial direction, the air springs 1a, 1b, 1c, 1
Since the position of the center of gravity of the structure supported by d also moves in the same X-axis direction as the XY stage 7, the anti-vibration table 7 is tilted in the rotation θy mode around the Y-axis. Therefore, the XY stage 7 is X
In the case of moving in the axial direction, a self-weight compensation signal of the XY stage in the θy mode corresponding to the position information of the XY stage may be generated, and a moment in the θy mode may be applied to the anti-vibration table 7 to suppress the inclination. The position of the XY stage 7 is detected by the laser interferometer X. When the XY stage 7 moves in the Y-axis direction, the inclination of the vibration isolation table 7 is corrected by applying a moment in the θX mode to the vibration isolation table 7 for the same reason.

In FIG. 1, an XY stage control device 8 controls the position of the XY stage 7. The feedforward compensator 10 includes XY stage weight compensators 9X and 9Y. The XY stage control unit 8 outputs the XY stage weight compensator 9X for the position information in the X axis direction of the XY stage 7 and the XY stage for the position information in the Y axis direction.
The stage self-weight compensator 9Y is operated to perform appropriate compensation. Here, the position information of the XY stage 7 is X
Laser interferometers 20X, 2 for detecting the position of the Y stage 7;
0Y detection signal or XY stage 7
May be a position target value generated by the XY stage control device 8 for controlling the position of.

X generated by the XY stage weight compensator 9X
The Y stage weight compensation signal is fed to the feedback compensator 19.
, The displacement compensator 14qy and the acceleration compensator 15q
y is added to the drive signal in the θy mode generated by y. The motion mode distribution calculator 16 converts the drive signal in the θy mode into a command value of the pressure generated in each of the air springs 1a, 1b, 1c and 1d. Pressure compensators 17a, 17b, 17c, 17
d is a pressure equal to the pressure command value to the air springs 1a, 1b,
The air valves 4a, 4b, 4c,
4d is driven. Thus, when the XY stage 7 moves in the X-axis direction, the air spring 1 is moved according to the position information.
a, 1b, 1c, and 1d are controlled, and θy of the vibration isolation table 6 is controlled.
The mode inclination amount can be suppressed.

X generated by the XY stage weight compensator 9Y
The Y stage weight compensation signal is fed to the feedback compensator 19.
, The displacement compensator 14qx and the acceleration compensator 15q
x is added to the drive signal in the θx mode generated by x. The motion mode distribution calculator 16 converts the drive signal in the θx mode into a command value of the pressure generated in each of the air springs 1a, 1b, 1c and 1d. Pressure compensators 17a, 17b, 17c, 17
d is a pressure equal to the pressure command value to the air springs 1a, 1b,
The air valves 4a, 4b, 4c,
4d is driven. Thus, when the XY stage 7 moves in the Y-axis direction, the air spring 1 is moved according to the position information.
a, 1b, 1c, and 1d are controlled, and θx
The mode inclination amount can be suppressed.

Since the amount of movement of the center of gravity of the structure supported by the air springs 1a, 1b, 1c, and 1d is proportional to the amount of movement of the XY stage 7, the position information of the XY stage generated by the XY stage controller 8 is used. The feedforward compensator 10 that performs compensation on the compensation is constituted by a proportional gain element in which an appropriate proportional gain is set. FIG. 5 shows the configuration of the feedforward compensator 10 using the proportional gain element. The XY stage dead weight compensator 9X is represented by a proportional gain element Gx, and the XY stage dead weight compensator 9Y is represented by a proportional gain element Gy. However, in the feedforward compensator 10 of FIG. 5 using only the proportional gain element, when the response of the pressure or thrust of the air spring is insufficient, it is necessary to ensure sufficient response to suppress the inclination amount of the vibration isolation table. Can not.

Therefore, in this embodiment, phase lead compensation is further applied to the position information of the XY stage.
That is, as shown in FIG. 6, with the Laplace operator set to s, the XY stage weight compensator 9X outputs the proportional gain element Gx
And the product of the phase lead compensation element (1 + sT) / (1 + sT ′), and the XY stage weight compensator 9Y has a proportional gain element Gy
And the phase lead compensation element (1 + sT) / (1 + sT ′). However, in FIG. 6, T> T ′> 0.
The phase advance compensating element (1 + sT) / (1 + sT ′) acts on the position information of the XY stage 7, and the air spring 1 is moved in accordance with the signal that advances the phase of the position information of the XY stage 7.
By controlling the pressures of the air springs 1a, 1b, 1c, and 1d, the responsiveness of the air springs 1a, 1b, 1c, and 1d or the thrust force is low. Responsiveness can be ensured.

FIG. 7 shows the response of the air spring pressure and the effect of the phase lead compensation element (1 + sT) / (1 + sT ') by frequency characteristics. It is assumed that the response of the air spring pressure is represented by 1 / (1 + sT) where s is a Laplace operator. If the response of the air spring pressure is insufficient to suppress the tilt amount of the vibration isolation table 6 due to the large time constant T, the phase advance compensating element (1 + s) is provided in the feedforward compensator 10.
By constructing (T) / (1 + sT ′), the cascade connection between the two becomes as shown in equation (1).

[0032]

(Equation 1) Since the time constant T> T ′ in the equation (1), the response of the air spring pressure is improved from the time constant T to a time constant T ′ (T> T ′). Therefore, sufficient responsiveness of the air spring pressure can be secured, and the amount of inclination of the vibration isolation table 6 can be suitably suppressed.

Although the vibration isolator 6 and the four-legged air springs 1a, 1b, 1c and 1d supporting the vibration isolator 6 have been disclosed as preferred embodiments of the vibration isolator according to the present invention, the present invention is not limited thereto. It is not limited to the embodiment. The essence of the present invention of controlling the pressure of the air spring in the vertical direction according to the position information of the XY stage can be suitably implemented irrespective of the shape of the vibration isolation table and the number of air springs. Further, the semiconductor manufacturing apparatus having the vibration damping device according to the present invention can be suitably implemented in various types of semiconductor manufacturing apparatuses regardless of an exposure system such as a sequential exposure system or a scanning exposure system.

[0034]

[Embodiment of Device Production Method] Next, an embodiment of a device production method using an exposure apparatus having the above-described vibration isolator will be described. FIG. 8 shows a flow of manufacturing micro devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). In step 1 (circuit design), a device pattern is designed. Step 2 is a process for making a mask on the basis of the designed pattern. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon or glass. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer prepared in step 4, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). including. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 9 shows a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. Step 15
In (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern on the mask is printed and exposed on the wafer by the exposure apparatus having the above-described vibration isolator. Step 17 (development) develops the exposed wafer. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. By using the production method of this embodiment, it is possible to manufacture a highly integrated device, which was conventionally difficult to manufacture, at low cost.

[0036]

As described above, according to the present invention,
It is possible to preferably suppress the inclination of the vibration isolation table due to the movement of the XY stage and the movement of the center of gravity of the structure supported by the air spring. Therefore, it is possible to avoid the inconvenience that the anti-vibration table, which is the basis of the installation of the XY stage, is tilted, the settling time and the settling accuracy of the XY stage are deteriorated, and the exposure accuracy of the semiconductor manufacturing apparatus is deteriorated. That is, it is possible to provide an anti-vibration apparatus capable of suitably suppressing the inclination of the anti-vibration table and a highly accurate semiconductor manufacturing apparatus having the same.

[Brief description of the drawings]

FIG. 1 is a drawing suitably showing an embodiment of a vibration damping device according to an example of the present invention.

FIG. 2 is a drawing showing a schematic structure of an anti-vibration table, an XY stage, and a laser interferometer.

FIG. 3 is a view showing a motion mode of a vibration isolation table.

FIG. 4 is a diagram illustrating a moving direction of an XY stage and an operation of a feedforward compensator.

FIG. 5 is a diagram illustrating a mathematical model of a feedforward compensator including a proportional gain element.

FIG. 6 is a diagram illustrating a mathematical model of a feedforward compensator including a proportional gain element and a phase lead compensation element.

FIG. 7 is a diagram illustrating an effect of a phase lead compensation element.

FIG. 8 is a diagram showing a flow of manufacturing a micro device.

FIG. 9 is a diagram showing a detailed flow of a wafer process in FIG. 8;

[Explanation of symbols]

1a, 1b, 1c, 1d: air spring, 2a, 2b, 2
c, 2d: acceleration sensor, 3a, 3b, 3c, 3d: displacement sensor, 4a, 4b, 4c, 4d: air valve, 5a, 5
b, 5c, 5d: pressure sensor, 6: anti-vibration table, 7: XY stage, 8: XY stage controller, 9X, 9Y: XY
Stage weight compensator, 10: feed forward compensator, 11: displacement target value generator, 12: displacement motion mode extraction calculator, 13: acceleration motion mode extraction calculator, 14
z, 14qx, 14qy: displacement compensator, 15z, 15q
x, 15qy: acceleration compensator, 16: motion mode distribution calculator, 17a, 17b, 17c, 17d: pressure compensator,
18a, 18b, 18c, 18d: power amplifier, 1
9: feedback compensator, 20X, 20Y: laser interferometer.

Claims (5)

[Claims] 1. An anti-vibration table, a displacement sensor, an acceleration sensor, an air spring that supports the anti-vibration table, an air valve that operates the pressure of the air spring, and a pressure that detects the pressure of the air spring. A feedback compensator that controls the pressure of the air spring by feeding back detection signals of the sensor, the displacement sensor, the acceleration sensor and the pressure sensor, and the feedback compensator according to position information of an XY stage mounted on the vibration isolation table. A vibration isolator having a feedforward compensator for controlling the pressure of an air spring, wherein the feedforward compensator generates a signal obtained by applying proportional gain compensation and phase lead compensation to position information of the XY stage. And a vibration isolator. 2. The method according to claim 1, wherein the feedforward compensator controls the pressure of the air spring so as to correct the inclination of the vibration isolation table caused by the movement of the XY stage in accordance with the position information of the XY stage. The anti-vibration device according to claim 1, wherein: 3. A feedback loop is formed in the feedback compensator for each motion mode such as translation or rotation of the vibration isolation table, and a signal generated by the feedforward compensator is added to a rotation mode signal in the feedback compensator. The anti-vibration device according to claim 1 or 2, wherein: 4. A device manufacturing apparatus having the vibration isolator according to claim 1. 5. A device manufacturing apparatus for manufacturing a device using the manufacturing apparatus according to claim 4.