JP2000154843A - Vibration damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the pressure feedback control of a pneumatic spring. SOLUTION: In a vibration removing device having a displacement compensator 9 which compensates a difference signal between an output signal of a displacement target generator 7 which outputs a target value for the displacement of a vibration removing base 1 and a pneumatic spring 5 and an output signal of a displacement sensor 2 and controls the displacement of the vibration removing base and the pneumatic spring, an acceleration compensator 10 which compensates an output signal of an acceleration sensor 6 to perform negative-feedback of acceleration of the vibration damping table to an input side of the displacement compensator, a pressure command generator 11 which outputs a command for a pressure of the pneumatic spring, and a power amplifier 13 driving an air valve in accordance with an output signal of a pressure compensator 12 which compensates a synthetic signal of output signals of the displacement compensator and the pressure command generator 11 and an output signal of a pressure sensor and controls a pressure of the pneumatic spring, a rigidity compensator 8 which has a low cut filter and a proportional gain element, compensates an output signal of the displacement sensor, to perform negative-feedback to an input side of the pressure compensator 12 is provided to control the rigidity of the pneumatic spring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an IC, an LSI, a C
The present invention relates to an anti-vibration device for reducing transmission of vibration from a device installation base in a precision device such as an exposure device used for manufacturing a semiconductor device such as a CD or a liquid crystal device such as a liquid crystal panel.

[0002]

2. Description of the Related Art With the increase in precision of precision instruments such as electron microscopes and semiconductor manufacturing equipment, there has been a demand for higher performance of 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 to practical use, in which vibration of the anti-vibration table is measured by a vibration sensor and the anti-vibration table is driven by an actuator according to the measurement signal. I have. 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 a semiconductor manufacturing apparatus. FIG. 5 shows the configuration of a typical anti-vibration apparatus found in the prior art.
Shown in

The operation of the vibration isolator according to the prior art shown in FIG. 5 will be described. A vibration isolator 1 on which precision equipment such as an exposure XY stage is mounted is mounted on an
It is supported by floating. The vibration isolation table 1 can be vibration-insulated from the installation floor 100 by floatingly supporting the vibration isolation table 1 with the air spring 5. The pressure of the air spring 5 is adjusted by the air valve 4. As shown in FIG. 6, the air valve 4 is generally of a nozzle flapper type having three ports of an air supply port 61, an exhaust port 62 and an output pressure port 63. The output pressure changes according to the air valve drive amount (flapper opening). FIG. 7 shows the characteristics of the air valve drive amount and the output pressure. FIG.
As shown in the above, the air valve driving amount-output pressure characteristic is nonlinear, has hysteresis, and has strong nonlinearity. In general, an air spring has a slow response and poor localization of pressure. Therefore, when adjusting the pressure of the air spring 5 using the air valve 4, pressure feedback control is performed such that the pressure of the air spring 5 is measured and the air valve driving amount is adjusted according to the measurement signal. Often.

In FIG. 5, a pressure sensor 3 is an air spring 5
Measure the pressure. The pressure target generator 11 includes the air spring 5
Outputs a target value with respect to the pressure in a steady state in which the vibration isolation table 1 is levitated and supported. The pressure compensator 12 performs compensation such that the output signal of the pressure sensor 3 matches the sum of the output signal of the displacement compensator 9 and the acceleration compensator 10 described later and the output signal of the pressure target generator 11. . The power amplifier 13 supplies power to the air valve 4 according to the output of the pressure compensator 11 and drives the air valve 4. Such pressure feedback control controls the pressure of the air spring 5 to a desired value.

[0006] The displacement sensor 2 measures the displacement of the vibration isolation table 1 and the air spring 5. The displacement target generator 7 is a vibration isolation table 1
And a target value for the floating displacement of the air spring 5 is output. The displacement compensator 9 performs compensation so that the difference between the output signal of the displacement target generator 7 and the output signal of the displacement sensor 2 becomes zero. Thus, the floating displacement of the vibration isolation table 1 and the air spring 5 is kept constant. The acceleration sensor 6 measures the vibration of the vibration isolation table 1. The acceleration compensator 10 compensates for the output signal of the acceleration sensor 6 to form a negative feedback system of acceleration. Thereby, the vibration generated in the vibration isolation table 1 is suppressed.

[0007]

In a vibration isolator using an air spring, the pressure of the air spring is measured by a pressure sensor in order to correct the non-linear characteristics of the air valve and to improve the localization of the pressure of the air spring. A so-called pressure feedback control for measuring and driving the air valve according to the output signal is performed. However, when pressure feedback control is performed on the air spring, there is a problem that the rigidity of the air spring is reduced and the vibration of the vibration isolator increases. The vibration isolation table that the air spring floats and supports is balanced so that the gravity acting on the vibration isolation table and the support force from the air spring coincide. The supporting force from the air spring is determined by multiplying the effective pressure receiving area at the contact portion between the air spring and the vibration isolation table by the pressure of the air spring. In a semiconductor manufacturing apparatus, when vibrations occur in the vibration isolation table due to some disturbance force, such as a driving reaction force of the exposure XY stage mounted on the vibration isolation table, the air spring is originally driven by the displacement of the vibration isolation table. Since the volume changes and the pressure of the air spring changes, a restoring force to the equilibrium state in proportion to the displacement acts on the vibration isolation table, such as returning the vibration isolation table to the equilibrium state. This is the stiffness of the air spring. Since the pressure feedback control functions to keep the pressure of the air spring constant, the pressure of the air spring does not change even when the displacement of the vibration isolation table and the volume change of the air spring occur. That is, the rigidity of the air spring is reduced, and the restoring force to the equilibrium state does not act on the vibration isolation table. Therefore, when pressure feedback control is performed,
When vibration occurs in the vibration isolation table due to a disturbance force or the like, there is a problem that the vibration of the vibration isolation table increases due to a decrease in rigidity of the air spring. In a conventional vibration isolator,
Nothing solves the reduction in the rigidity of the air spring due to the feedback control of the pressure.

The present invention has been made in view of such circumstances. That is, an object of the present invention is to provide a vibration damping device capable of performing feedback control of the pressure of the air spring without lowering the rigidity of the air spring.

[0009]

In order to achieve the above object, a vibration isolator according to the present invention comprises a vibration isolator, an air spring supporting the vibration isolator, and an air adjusting pressure of the air spring. A valve, a pressure sensor for measuring the pressure of the air spring,
A displacement sensor for measuring the displacement of the vibration isolation table and the displacement of the air spring; an acceleration sensor for measuring the vibration of the vibration isolation table; and a negative feedback system of the acceleration by compensating an output signal of the acceleration sensor. An acceleration compensator, a displacement target generator that outputs a target value for the displacement of the vibration isolation table and the air spring, and compensation for a difference signal between an output signal of the displacement target generator and an output signal of the displacement sensor. A displacement compensator for controlling the displacement of the vibration isolation table and the air spring, and a stiffness compensator having a low-cut filter and a proportional gain element, and controlling the stiffness of the air spring by performing compensation on an output signal of the displacement sensor. Stiffness compensator, a pressure target generator that outputs a target value for the pressure of the air spring, the acceleration compensator and the displacement compensator, the stiffness compensator and the pressure A pressure compensator for controlling the pressure of the air spring by compensating for the output signal of the target generator and the output signal of the pressure sensor, and a power amplifier for driving the air valve according to the output signal of the pressure compensator. It is characterized by the following.

[0010] The device manufacturing apparatus according to the present invention comprises:
It is characterized by having the above-mentioned anti-vibration device. As a device manufacturing apparatus, there is a semiconductor manufacturing apparatus for manufacturing a semiconductor chip such as an IC or an LSI.

[0011]

The air spring floats and supports a vibration isolation table on which precision equipment such as an exposure XY stage is mounted. The air valve regulates the pressure of the air spring. The pressure sensor measures the pressure of the air spring. The pressure target generator outputs a target value for a steady state pressure at which the air spring floats and supports the vibration isolation table. The pressure compensator calculates the sum of the output signal of the stiffness compensator, the displacement compensator and the acceleration compensator and the output signal of the pressure target generator,
Compensation is performed so that the output signals of the pressure sensors match.
The power amplifier supplies power to the air valve according to the output of the pressure compensator, and drives the air valve.

The displacement sensor measures the displacement of the vibration isolation table and the floating displacement of the air spring. The displacement target generator outputs target values for the displacement of the vibration isolation table and the displacement of the air spring. The displacement compensator performs compensation such that the difference between the output signal of the displacement target generator and the output signal of the displacement sensor becomes zero so that the vibration isolation table is localized at a desired floating position. The acceleration sensor is fixed to the vibration isolation table, and measures vibration generated in the vibration isolation table as an acceleration signal. The acceleration compensator compensates for the output signal of the acceleration sensor to form a negative feedback of the acceleration. This gives damping to the vibration isolation table.

A stiffness compensator having a low-cut filter and a proportional gain element compensates the output signal of the displacement sensor so as to add rigidity to the vibration isolation table and the air spring. The vibration isolation table that the air spring floats and supports is balanced so that the gravity acting on the vibration isolation table and the support force from the air spring coincide. In a semiconductor manufacturing apparatus, when vibrations occur in the vibration isolation table due to some disturbance force such as a driving reaction force of the exposure XY stage mounted on the vibration isolation table, the rigidity compensator removes the vibration via an air spring as an actuator. It functions so that the restoring force to the equilibrium state in proportion to the displacement of the shaking table or the displacement of the air spring acts on the vibration isolating table.

As described above, even if the feedback control of the pressure is performed, the function of the stiffness compensator does not reduce the stiffness of the air spring. The pressure feedback control corrects the non-linear characteristics of the air valve and improves the localization of the pressure of the air spring.
At the same time, since the rigidity of the air spring does not decrease, it is possible to realize an anti-vibration device with good vibration suppression performance.

[0015]

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. In the figure, the vibration isolation table 1 is supported by air springs 5 in a floating manner. The air spring 5 is a supporting leg for supporting the vibration isolation table 1 in a floating manner, and at the same time, an actuator for applying a vibration damping force to the vibration isolation table 1 by a pressure change of the air spring 5 to suppress the vibration of the vibration isolation table 1. .
The pressure of the air spring 5 is adjusted by the air valve 4.

The feedback control of the pressure is realized as follows. The pressure sensor 3 measures the pressure of the air spring 5. The pressure target generator 11 outputs a target value for a pressure in a steady state in which the air spring 5 supports the vibration isolation table 1 in a floating state.
In the pressure compensator 12, the output signal of the pressure sensor 3 matches the sum of the output signal of the rigidity compensator 8, the displacement compensator 9, and the output signal of the pressure target generator 11, which will be described later. Such compensation is performed. Power amplifier 1
Reference numeral 3 supplies power to the air valve 4 according to the output of the pressure compensator 11 to drive the air valve 4. Such pressure feedback control controls the pressure of the air spring 5 to a desired value.

The displacement sensor 2 measures the displacement of the vibration isolation table 1 and the displacement of the air spring 5. Here, the displacement of the air spring 5 refers to the stroke of the air spring 5, and is the same as the displacement of the vibration isolation table 1. The displacement target generator 7 outputs target values for the displacement of the vibration isolation table 1 and the floating displacement of the air spring 5. The displacement compensator 9 performs compensation so that the difference between the output signal of the displacement target generator 7 and the output signal of the displacement sensor 2 becomes zero so that the vibration isolation table 1 is located at a desired floating position. Conventionally, the displacement compensator 9 is designed so that the pressure of the air spring 5 is controlled by integrating the input signal. This is for promptly converging the displacement of the vibration isolation table 1 with respect to the output signal of the displacement target generator 7 without overshooting.

The acceleration sensor 5 is fixed to the vibration isolation table 1, and measures a vibration generated in the vibration isolation table 1 as an acceleration signal. The acceleration compensator 10 compensates for the output signal of the acceleration sensor 6 to form a negative feedback of the acceleration. As described above, since the displacement compensator 9 is designed so that the pressure of the air spring 5 is controlled by integrating the input signal, the acceleration compensator 10 generates a compensation value proportional to the output of the acceleration sensor 6. If the compensation value is input to the displacement compensator 9, an integral of the acceleration, that is, a vibration damping force proportional to the velocity can be applied to the vibration damping table 1. Thereby, damping is given to the vibration isolation table 1, and the vibration generated in the vibration isolation table 1 is effectively suppressed.

A stiffness compensator 8 having a low-cut filter 14 and a proportional gain element 15 compensates for the output signal of the displacement sensor 2 so as to provide stiffness to the vibration isolation table 1 and the air spring 5. The anti-vibration table 1 that the air spring 5 floats and supports is
The gravity acting on the vibration isolation table 1 and the support force from the air spring 5 are in equilibrium with each other. In the semiconductor manufacturing apparatus, when vibration occurs in the vibration isolation table 1 due to some disturbance force such as a driving reaction force of the exposure XY stage mounted on the vibration isolation table 1, the stiffness compensator 8 includes the air spring 5 as an actuator. And a restoring force to an equilibrium state in proportion to the displacement of the vibration isolation table 1 or the displacement of the air spring 5 acts on the vibration isolation table 1. Thereby, rigidity is given to the vibration isolation table 1 and the air spring 5, and the vibration generated in the vibration isolation table 1 is effectively suppressed.

Although both the stiffness compensator 8 and the displacement compensator 9 receive the signal of the displacement sensor 2, their functions are completely different as described above. Stiffness compensator 8
Functions to apply a restoring force to an equilibrium state in proportion to the displacement of the vibration isolation table 1 or the displacement of the air spring 5 to the vibration isolation table 1. Thus, it is possible to avoid a decrease in the rigidity of the air spring 5 due to the above-described feedback of the pressure. The displacement compensator 9 integrates the difference between the output signal of the displacement target generator 7 and the output signal of the displacement sensor 2 so that the vibration isolation table 1 is located without overshooting to a desired floating position. It functions so that a force acts. Therefore, rigidity cannot be given to the air spring 5 by the function of the displacement compensator 9. This is because rigidity is a restoring force to an equilibrium state in proportion to the displacement.

Hereinafter, the operation of the rigidity compensator 8 will be described in more detail. FIG. 2 shows an anti-vibration table 1, an air valve 4 and an air spring 5.
2 shows a dynamic model of a portion consisting of. Vibration isolation table 1 has massΜ
Can be modeled as the mass element of The displacement is x, the disturbance force acting on the vibration isolation table 1 is f, and the vibration isolation table 1 is an air spring 5.
Let A be the effective pressure receiving area of the portion receiving the force from. The air valve 4 adjusts the inflow / outflow flow rate of air and the pressure p of the air spring 5 according to the air valve drive amount u. Assuming that the pressure p is a fluctuation amount from the equilibrium state, the equation (1) is obtained from FIG. The expression (2) holds for the pressure of the air spring 5.

[0022]

(Equation 1)

In the equation (2), the coefficient ω applied to the pressure p on the left side is a physical quantity determined from the mechanical parameters of the air spring 5. Also, a coefficient G that affects the air valve drive amount u on the right side
_q is the pressure gain of the air valve 4. Similarly the term including displacement x of the anti-vibration table 1 on the right side represents the changing pressure p of the air spring 5 by a displacement x, G _v is its influence coefficients. By Laplace transforming the equations (1) and (2), a block diagram of FIG. 3 that mathematically shows the dynamic model of FIG. 2 is obtained. In FIG. 3, the symbol s represents the Laplace operator. From FIG. 3, the input is the air valve drive amount u.
The input / output equation in which the disturbance force f and the output are the displacement x of the vibration isolation table 1 is as shown in equation (3). (3) In the formula, the left side of the _{AG v s / (s + ω} ) represents the stiffness of the air spring 5.

[0024]

(Equation 2)

FIG. 4 is a block diagram mathematically showing the operation of the vibration damping device according to this embodiment. FIG. 4 shows the rigidity compensator 8.
Only elements necessary and sufficient to explain the operation of FIG. 1 are shown, and other components such as the displacement compensator 9 and the acceleration compensator 10 are omitted. In FIG. 4, the pressure compensator 12 is a proportional calculator, and its gain is represented by G. The transfer function of the stiffness compensator 8 is G _k . The input / output equation in FIG. 4 where the input is the disturbance force f and the output is the displacement x of the vibration isolation table 1 is as shown in equation (4).

[0026]

(Equation 3)

If G _k = 0 without the stiffness compensator 8, the input / output equation of the equation (4) becomes the equation (5). In this case, the stiffness term which represents the stiffness of the air spring 5 is (5) the left side than the AG _v s / of formula (s + omega + G _q G), the gain G of the pressure compensator 12 is in the denominator of the rigid section, the gain As G increases, the rigidity term decreases. That is, it can be seen from equation (5) that the rigidity of the air spring 5 decreases as the gain G of the pressure feedback loop increases.

[0028]

(Equation 4)

The stiffness compensator 8 functions to avoid a decrease in the stiffness of the air spring 5 due to pressure feedback control. (4) As can be seen from the equation, by the operation of the rigid compensator 8, the stiffness term of the air spring 5 _{AG v s / (s + ω} + G
_{q G) + AG v / (} s + ω + G q G) xG q GG k / G
_v . That is, the transfer function G of the rigidity compensator 8
_{Since the} rigidity term increases as _k increases, the rigidity required for the air spring 5 can be secured. The transfer function G _k is
Specifically, it may be designed as follows. First, when no feedback control of the pressure, stiffness term of the air spring 5 is (3) / left side of equation than _{AG v s (s + ω)} .
The transfer function G _k is designed so that the rigidity term of the equation (4), which is the input / output equation of the vibration damping device according to the present invention, matches this equation.
Comparing Equations (3) and (4), the transfer function G _k of the stiffness compensator 8 is determined as in Equation (6).

[0030]

(Equation 5)

By substituting the transfer function G _k determined by the expression (6) into the input / output expression (4) of the vibration isolator according to the present embodiment, the expression (7) is obtained. Equation (7) is an input / output equation when the feedback control of the pressure is not performed on the left side of the equation (3).
The left side of the equation is exactly the same. It can be seen that the operation of the stiffness compensator 8 can ensure exactly the same stiffness of the air spring 5 as when pressure feedback control is not performed. The transfer function G _k of the stiffness compensator 8 represented by the equation (6) is formed by a series connection of a transfer function s / (s + ω) representing a low cut filter and a proportional gain G _v (ω + G _q G) / G _q G. Have been. The vibration isolator according to the present embodiment is characterized in that the stiffness compensator 8 has a low cut filter 14 and a proportional gain element 15.

[0032]

(Equation 6)

As described above, since the rigidity of the air spring 5 can be prevented from being reduced by the operation of the rigidity compensator 8, the vibration isolator according to the present embodiment realizes a suitable vibration suppression performance. Note that the vibration isolation device according to the present invention is not limited to the embodiment shown in FIG. The essence of the present invention, which is an anti-vibration device capable of performing feedback control of the pressure of the air spring without lowering the rigidity of the air spring, includes the shape of the anti-vibration table and the number and arrangement of the air springs supporting the same. It can be implemented regardless of. Further, the semiconductor manufacturing apparatus having the anti-vibration device according to the present invention can be realized by any of a sequential driving type and a scanning type.

The mathematical symbols used so far are summarized below. M: mass of the vibration isolation table 1 A: effective pressure receiving area of the air spring 5 x: displacement of the vibration isolation table 1 p: pressure of the air spring 5 u: driving amount of the air valve f: disturbance force acting on the vibration isolation table 1 : Physical quantity determined from mechanical parameters of the air spring 5 G _q : Pressure gain of the air valve 4 G _v : Influence coefficient of the displacement x of the vibration isolation table 1 to the pressure p of the air spring 5 G: The pressure compensator 12 performs a proportional operation G _k when the device is a compensator: Transfer function of the stiffness compensator 8

[0035]

[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.

[0037]

As described above, according to the present invention,
It is possible to provide a vibration damping device capable of performing feedback control of the pressure of the air spring without reducing the rigidity of the air spring. In the vibration damping device according to the present invention, the feedback control of the pressure corrects the non-linear characteristic of the air valve,
Improves the localization of air spring pressure. At the same time, a reduction in the rigidity of the air spring, which has been a problem in the prior art, does not occur, so that suitable vibration suppression performance can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vibration isolation device according to an embodiment of the present invention.

FIG. 2 is a drawing showing a dynamic model of a vibration isolation table and an air spring.

FIG. 3 is a drawing mathematically showing a dynamic model of a vibration isolation table and an air spring.

FIG. 4 is a view mathematically illustrating an operation of the vibration damping device according to the present invention.

FIG. 5 is a view illustrating a vibration isolator according to the related art.

FIG. 6 is a drawing showing a structure of an air valve.

FIG. 7 is a drawing showing characteristics of an air valve.

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]

1: vibration isolation table, 2: displacement sensor, 3: pressure sensor, 4: air valve, 5: air spring, 6: acceleration sensor, 7: displacement target generator, 8: rigidity compensator, 9: displacement compensator, 10: acceleration compensator, 11: pressure target generator, 12: pressure compensator,
13: power amplifier, 14: low cut filter, 1
5: proportional gain element.

Continued on the front page F-term (reference) 3J048 AB08 AB11 AB20 AD02 BE02 CB13 EA13 3J069 AA21 AA32 AA52 EE01 5F046 AA23 DA27 DA30 DB14 5H004 GA09 GB15 HA07 HB03 HB07 HB09 JA03 JB15 KB21 KB33 KB39 LA05 LA13 LA20 MA11 MA13

Claims (3)

[Claims] An anti-vibration table, an air spring supporting the anti-vibration table, an air valve for adjusting a pressure of the air spring, a displacement sensor for measuring a displacement of the anti-vibration table and the air spring, A displacement target generator that outputs a target value with respect to the displacement of the vibration isolation table and the air spring, and performs compensation on a difference signal between an output signal of the displacement target generator and an output signal of the displacement sensor. A displacement compensator for controlling the displacement of the air spring, an acceleration sensor for measuring the vibration of the vibration isolation table, and a compensation for the output signal of the acceleration sensor to provide an input side of the vibration compensation table with the vibration isolation table. An acceleration compensator that negatively feeds back acceleration, a pressure sensor that measures the pressure of the air spring, a pressure target generator that outputs a target value for the pressure of the air spring, and a displacement compensator and the pressure target generator. output A pressure compensator that controls the pressure of the air spring by compensating a combined signal of the output signal of the pressure sensor and the output signal of the pressure sensor; a power amplifier that drives the air valve according to the output signal of the pressure compensator; A stiffness compensator having a filter and a proportional gain element, and having a stiffness compensator for compensating an output signal of the displacement sensor and negatively feedback to an input side of the pressure compensator to control the stiffness of the air spring. A vibration isolator characterized by the above-mentioned. 2. A device manufacturing apparatus comprising the vibration isolator according to claim 1. 3. A device manufacturing method, comprising manufacturing a device using the device manufacturing apparatus according to claim 2.