JP2001027280A - Active damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress horizontal relative displacement in the vertical position of an equipment caused by vibration, particularly horizontal relative displacement due to the vibration of an equipment body caused by an exiting source in the mounted equipment. SOLUTION: This active damping device is constituted including a base 4 supported by active damping mounts 3 each formed by integrating a passive damping member comprising a cylindrical elastic body 23 and a viscous elastic body 30a, a vertical actuator 32a supported by a height adjusting mechanism 55 disposed in the cylindrical elastic body 23, and a horizontal actuator 32b, an active mass damper 20 provided at an equipment 50 mounted on the base 4, a vibration sensor 17 for detecting the vibration of the base 4 and equipment 50, an equipment controller 9 for driving an exciting source mounted in the equipment 50, and a vibration damping controller 18 for controlling the actuators 32a, 32b, 32c on the basis of the output of the vibration sensor 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration isolator for vibration-insulating precision equipment against floor vibrations.
In particular, the present invention relates to an active vibration isolator suitable for damping vibration of a device main body due to a vibration source of the device itself.

[0002]

2. Description of the Related Art In precision equipment such as a semiconductor manufacturing apparatus such as an electron beam lithography apparatus or a reduced projection exposure apparatus or an electron microscope, a floor is required to improve the precision of the apparatus or to expand the installation in a place having a poor vibration environment. Surface vibrations increasingly affect the precision of precision instruments, and precision instruments have been installed on active vibration isolation devices in order to maintain the precision of those instruments. As a conventional technology of an active vibration isolator,
For example, as described in Japanese Patent Application Laid-Open No. 5-149379, an actuator for driving a mounting table on which precision instruments are mounted in a horizontal direction and an up-down direction is disposed, and vibration detection for detecting the vibration of the mounting table is performed. It is known that a vibration state of a mounting table is suppressed by controlling the actuator by feeding back a vibration state of a substrate to a controller by a container.

[0003] For example, a case where an active vibration isolator is applied to an electron beam drawing apparatus will be described. In an electron beam writing apparatus, a stage for moving a wafer to an arbitrary position is provided in a chamber provided on a substrate, and a lens barrel including an electromagnetic lens for condensing and polarizing an electron beam is provided on the chamber. An electron gun for emitting an electron beam is provided at the top of the lens barrel. Therefore, in the device having such a structure, not only the center of gravity is increased, but also a vibration system is formed by the spring action and the mass of the lens barrel due to the out-of-plane deformation of the upper surface of the chamber supporting the lens barrel.
The above vibration modes exist. In this vibration system, when the stage moves the wafer, the stage is vibrated along with the movement of the stage, and the upper part of the lens barrel provided with the electron gun vibrates with the largest amplitude, and the vibration between the stage and the wafer on the stage. In the related art, a relative displacement in the horizontal direction occurs, so that the moving speed of the stage is limited, and it has been difficult to improve the throughput.

[0004]

According to the above prior art, when the equipment mounted on the mounting base is regarded as a rigid body, a vibration damping effect and a vibration damping effect can be obtained. However,
In precision equipment such as electron beam lithography equipment and reduction projection exposure equipment, X-X is used to move wafers inside the equipment.
While the apparatus itself has a vibration source such as a Y stage and the apparatus body generally has a natural frequency of several hundred Hz, the conventional technique actively generates the frequency component (about 1 to 50 Hz) of the floor vibration. Since the main purpose is to (actively) isolate vibration, the vibration characteristics of the onboard equipment are treated as error factors,
Since the control gain in the high frequency band is reduced so as not to excite the natural frequency of the mounted equipment, a large vibration suppression effect is obtained if the mounted equipment body is directly vibrated by the vibration source inside the mounted equipment. I can't. In such a state, in a semiconductor manufacturing apparatus such as an electron beam lithography apparatus or a reduction projection exposure apparatus, or in a precision instrument such as an electron microscope, the relative position between an object to be drawn or an object to be reduced and projected and an electron gun for emitting an electron beam. Displacement occurs, and a reduction in processing accuracy or fluctuation of the microscope field of view is inevitable.

[0005] Therefore, in order to improve the precision and throughput of precision equipment, a vibration suppression technique for suppressing vibration of the equipment main body in response to a vibrating force inside the equipment will be important in the future.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an active vibration isolator having a high effect of suppressing not only a vibration isolation effect against floor vibration but also a relative displacement of a vibration source in the equipment by vertical vibration of the equipment body. To provide.

[0007]

An object of the present invention is to provide a mounting table (hereinafter referred to as a substrate) having an active anti-vibration mount and devices mounted on the substrate.
This device is a system in which a movable part serving as a vibration source is installed. In such a system, in order to achieve the above object, as a control system, an active vibration isolation mount including an elastic body that is a passive vibration isolation member and an actuator provided in parallel with the elastic body, In addition to the vibration model composed of the substrate to be controlled, the vibration model of the device main body mounted on the substrate is to be controlled. Further, a sensor for detecting vibration is provided not only on the board but also on, for example, the uppermost part of the mounted equipment mounted on the board, and the natural frequency of the main vibration mode of the equipment is set as the control range. In the above-described electron beam lithography apparatus and reduction projection exposure apparatus, it is important to reduce the horizontal relative displacement between members in the height direction of the apparatus, for example, between an electron gun and a wafer or a sample or between a mask and a wafer. Therefore, not only the absolute displacement of the board with six degrees of freedom, but also the absolute displacement of the board, or the board and And a control for suppressing the relative displacement between the vibration detecting means (vibration sensors) provided in the above. By such control, the relative displacement in the horizontal direction between the members at the upper and lower positions of the device mounted on the board can be suppressed in preference to the vibration of the board itself.

Further, an active mass damper for suppressing vibration is mounted on the mounted device in order to effectively suppress the vibration generated in the mounted device with respect to the exciting force caused by the movement of the movable portion of the mounted device. Then, in addition to the control described in the preceding section, the anti-vibration controller receives the output of the vibration sensor that detects the vibration of the substrate and the output of the vibration sensor that detects the vibration of the mounted device as inputs, and controls the active anti-vibration mount. The operation of the actuator or the actuator of the active mass damper is controlled. By controlling in this way, not only the vibration of the equipment and the board caused by the floor vibration, but also the vibration of the equipment due to the vibration source built in the equipment itself and the relative horizontal deformation between the members at the upper and lower positions of the equipment are suppressed. can do.

An active mass damper provided on a mounted device is basically arranged so as to be relatively movable with respect to the mounted device, and a weight member whose own weight is supported by the device and a weight member which is attached to the mounted device relative to the mounted device. And an actuator that vibrates dynamically. For example, when the upper part of the precision equipment has a cylindrical shape, a cylindrical member attached to the cylindrical part, a collar member formed in an annular shape so as to protrude on the lower periphery of the cylindrical member, and an upper part of the mounted equipment. Between the cylindrical member and the ring-shaped weight member, the ring-shaped weight member being arranged so as to surround and be relatively movable with respect to the mounting device, and supported by the collar member via an elastic body. And a plurality of horizontal actuators that are radially arranged to move the weight member relative to the cylindrical member. The side of the horizontal actuator opposite to the side in contact with the weight member is fixed to the cylindrical member, and a reaction force when the weight member is moved acts on the mounted device main body via the cylindrical member. . In order to prevent a shear force from being applied to the actuator due to the weight of the weight, a ring-shaped weight member is supported via an elastic body by a collar member provided below the cylindrical member, and the vibration state of the weight member is measured. Provide multiple vibration sensors. Providing such an active mass damper, detecting the vibration state of the device at the position where the active mass damper is installed, and controlling the drive of the active mass damper by using the detected vibration state as input, the floor vibration and the vibration built in the device are controlled. Horizontal relative deformation between members at the upper and lower positions of the device due to the source can be suppressed.

[0010] Further, a movable part in the mounted device, for example, XY
The movement of the stage or the like and the excitation force due to this can be measured in advance in the magnitude and direction, so by using the feedforward control utilizing the information of the signal controlling the operation of the movable part together, Further, it is possible to more effectively suppress relative deformation in the horizontal direction between members at upper and lower positions of the device due to a vibration source incorporated in the device.

An active anti-vibration mount for supporting a substrate is basically composed of an upper plate and a lower plate which are opposed to each other and which are vertically spaced from each other, and whose axis is vertically set between the upper plate and the lower plate. A cylindrical elastic body such as a coil spring, a vertical actuator provided inside (preferably the center) of the cylindrical elastic body, and a load transmitting member protruded downward from the upper plate. On the other hand, an integrated active anti-vibration mount including a horizontal actuator supported by the lower plate and arranged to apply a force in the horizontal direction. The cylindrical elastic body is provided on a pedestal arranged on the lower plate, and supports loads on the substrate, mounted equipment, and the like via the upper plate. The lower part of the vertical actuator arranged inside the cylindrical elastic body is supported by a height adjusting member capable of changing the height from the lower plate surface of the lower end of the actuator. Further, the horizontal actuator supported by the lower plate is configured to apply a horizontal force to the load transmitting member fixed to the upper plate and projecting downward,
Control horizontal vibration.

At least one horizontal actuator is provided on one active anti-vibration mount, and the active anti-vibration mount having actuators for applying forces in opposite directions is provided. The action lines of both actuators are on the same straight line. And put them together. A pair of horizontal actuators acting in the opposite directions to one active anti-vibration mount are brought into contact with the load transmitting member fixed to the upper plate from opposite sides, and the action lines are aligned. They may be installed side by side. In addition, a pair of horizontal actuators acting in a direction orthogonal to each other are brought into contact with one active vibration isolation mount from different directions with respect to a load transmitting member fixed to the upper plate, and action lines cross each other. It may be installed so that it does. When using an active anti-vibration mount provided with a pair of horizontal actuators acting in directions perpendicular to each other, a similar horizontal actuator (a pair of horizontal actuators acting in directions perpendicular to each other) is used. The active anti-vibration mounts provided are combined and arranged so that the action lines of one of the two horizontal actuators are on the same straight line and act in opposite directions.

For the vertical and horizontal actuators, for example, a laminated piezoelectric actuator or a giant magnetostrictive actuator is used.

When an axially soft member such as a coil spring or rubber is used as a cylindrical elastic body for supporting the weight of the substrate and the mounting equipment, the compression is relatively large due to the weight of the mounting equipment. Tightening between the lower plate and the upper plate or between the pedestal and the upper plate so that the amount of compression that is somewhat smaller than the amount of compression compressed by the mounting weight can be added in advance in consideration of the workability when installing the mounted equipment It is desirable to provide a precompression means such as a rod member or a wire member. Further, when a metal spring such as a coil spring is used as the cylindrical elastic body, surging or the like may occur because a vibration damping effect is hardly obtained. It is desirable to provide a viscoelastic body on the surface.

Further, the vertical vibration actuator and the horizontal vibration actuator of the active vibration isolation mount, and the vibration isolation controller for controlling the horizontal vibration actuator of the active mass damper are provided on the board, the mounting equipment, and the weight member. One or both of an input from a sensor, a signal for controlling the movement of the movable unit from a device controller for driving the movable unit built in the mounted device, that is, an input relating to a vibration force caused by the movement of the movable unit. Based on the above, the absolute acceleration or the relative displacement of the substrate and the relative acceleration or the relative displacement between the upper and lower members of the mounting equipment or between the member of the mounting equipment and the substrate are reduced.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

First, FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIGS. 2, 3, 4, 5, and 6. FIG. FIG.
Is an example of an embodiment in which the active vibration isolation mount 3 of the present invention is applied to an electron beam writing apparatus. The electron beam lithography apparatus according to the embodiment shown in FIG. 5 includes a pedestal 2 which is a rectangular flat plate installed on a floor 1 and an active filter fixedly installed on each of four corners of the pedestal 2. A vibration mount 3, a square substrate 4 mounted and fixed on the four active vibration isolation mounts 3, a stage 7 provided at the center of the upper surface of the substrate 4 for moving a wafer, and a stage 7. A box-shaped chamber 5 provided on a substrate 4, a lens barrel 6 having an electron gun 10 supported by a top plate of the chamber 5 and positioned above a stage 7, and provided in a cylindrical portion of the lens barrel 6. Electromagnetic lens (not shown in the figure)
An active mass damper 20 provided to surround the upper peripheral edge of the lens barrel 6, a motor 8 connected to the stage 7 via a ball screw or the like and provided outside the chamber 5 to move the stage 7, A device controller 9 for controlling the electron gun 10 and the motor 8; a plurality of vibration sensors 17 for detecting and outputting vibrations of the substrate 4, the top of the lens barrel 6, and the active mass damper 20; An anti-vibration controller 18 that controls the four active anti-vibration mounts 3 and the active mass damper 20 using the outputs of the sensor 17 and the device controller 9 as inputs.
And is configured.

An anti-vibration controller 18 includes a low-pass filter 11 connected to the plurality of vibration sensors 17 and an A / D converter 12 connected to the low-pass filter 11.
A DSP (digital signal processor) 13 connected to the A / D converter 12 and the device controller 9; a personal computer 14 and a D / A converter 15 connected to the DSP 13; Converter 1
5 and an amplifier 16 connected to the low-pass filter 11. The outputs of the amplifiers 16 are the actuators of the four active vibration isolation mounts 3 and the active mass dampers 20. Is to be transmitted.

In the present embodiment, as shown in FIG. 6 which is a plan view of FIG. 5, an active mass damper 20 is provided so as to surround the upper part of the lens barrel 6, and the active mass damper 20 is connected to the weight member. It comprises a plurality of actuators for moving the weight member in the horizontal direction.

In the electron beam writing apparatus, the motor 8 is driven by the command of the equipment controller 9 to move the stage 7 on which the wafer is mounted, and the electron gun 10 moves the wafer on the stage from the electron gun 10 in accordance with the movement. The beam is irradiated.

FIG. 6 shows an arrangement example of the active anti-vibration mount 3 and the vibration sensors 17. The signals from these vibration sensors 17 are supplied to the low-pass filter 11, the A / D
The signal is input to a DSP (Digital Signal Processor) 13 through a converter 12. The DSP 13 controls the actuators of the active anti-vibration mount 3 and the active mass damper 20 so that the relative displacement (or relative acceleration) of the substrate 4 and the upper part of the lens barrel 6 is reduced by using the output of each vibration sensor 17 as an input. An execution program to be executed is written, and the anti-vibration controller 18
The signal calculated at high speed in 3 is sent to each actuator via the D / A converter 15, the low-pass filter 11 and the amplifier 16, and the operation of those actuators is controlled.
The execution program further includes a command signal that is input to the DSP 13 from the device controller 9 that controls the stage 7 and the electron gun 10 of the electron beam drawing apparatus and that indicates the operation state and operation speed of the stage 7, The control of the actuator suitable for each state can be carried out in a feed-forward manner based on the information on the irradiation state.

FIGS. 1 and 2 show a longitudinal sectional view and a transverse sectional view of the active anti-vibration mount 3 shown in FIG. As shown in FIG. 1, the active anti-vibration mount 3 is basically a lower plate 21 which is a substantially rectangular flat plate fixedly arranged on the gantry 2.
And a lower plate 2 having the same shape as the lower plate 21 and above the lower plate 21.
1, an upper plate 29, a lower plate 21, and an upper plate 29.
A cylindrical elastic body 23, such as a coil spring, whose axis is vertically arranged between the lower plate 21 and a vertical actuator 32 a provided at the center of the inside of the cylindrical elastic body 23; A load transmitting member 39a attached to the plate 29 so as to protrude downward, and a pair of horizontal members provided on the lower plate 21 so as to be opposed to each other so that the load transmitting member 39a is sandwiched by the operation end and the axes are aligned. And a direction actuator 32b. A cylindrical stopper member 3 with a bottom is provided at the upper end of the cylindrical elastic body 23.
5 is covered with the bottom up, and the bottom of the stopper member 35 is located between the upper end of the tubular elastic body 23 and the upper plate 29. The cylindrical elastic body 23 supports the lower surface of the upper plate 29 via the bottom of the stopper member 35, and the vertical actuator 32 a acts on the upper plate 29 via the bottom of the stopper member 35.

Hereinafter, the structure of the active anti-vibration mount 3 will be described in more detail. The cylindrical elastic body 23 (which is a metal coil spring in the present embodiment) is mounted on a cylindrical base 22 with a flange disposed on the lower plate 21 with the axis thereof extending vertically. 22 and concentric with the mounting device (in this embodiment, an electron beam writing apparatus)
50 and the substrate 4 are supported. The pedestal 22 is provided with a collar portion which is annularly protruded from the outer periphery of the cylindrical portion to the outer diameter side at the upper portion of the cylindrical portion, and the horizontal actuator 32b is installed on the collar portion. On the inner peripheral side of the cylindrical portion of the pedestal 22, the inner diameter is large at the upper portion and smaller at the lower portion, and has a stepped shape. The lower end of the cylindrical elastic body 23 is supported at a portion corresponding to the stepped bent surface. ing. The vertical actuator 32 arranged at the center of the cylindrical elastic body 23
The lower portion of “a” is supported by a height adjusting member 55 whose height from the lower plate 21 can be adjusted. This height adjusting member 55
A vertical support member 24 provided in the vicinity of the center on the lower plate 21 and having a U-shaped vertical cross section, and a screw hole formed in an upper horizontal portion of the vertical support member 24 and vertically penetrating therethrough. Screw member 26, a bevel gear 25 having a rectangular cross-section inserted into a rectangular cross-section hole formed in the center of the lower end of the screw member 26, and a bevel gear 25 meshing with the bevel gear 25. 27, a bevel gear 25A provided by penetrating the vertical portion of the support member 24 and the pedestal 22, a rotary knob member 28 attached to the end of the shaft 27, and an upper end of the screw member 26 with the axis line up and down. A circular hole provided, a block member 31 which is disposed by inserting a cylindrical portion provided below the hole into the hole and supports a lower end of the vertical actuator 32 via a low friction material; Is it fixed on the upper surface of the support member 24? Wherein is a block and stopping member 34 provided in contact with a surface on a part of the formed flat on the side surface of the member 31, it contains.

The height adjusting member 55 operates as follows.
That is, when the rotation knob member 28 is rotated, the bevel gear 2
The screw member 26 is rotated by 5A and 25. Since the hole of the rectangular cross section provided at the center of the lower end of the screw member 26 with respect to the axis of the bevel gear 25 can be slid in the vertical direction, the screw member 26 rotates and the vertical supporting member is rotated. It moves vertically with respect to the 24 screw holes. Further, a circular hole is provided at the upper end of the screw member 26, and a cylindrical portion provided at the lower portion of the block member 31 that supports the lower end of the vertical actuator 32 via a low friction material in this hole. The screw member 26 is rotated by the bevel gear 25, so that a part of the side surface of the block member 31 is in contact with the detent member 34 provided on the vertical support member 24. When it moves in the direction, the vertical actuator member 32a also moves up and down without rotating. Therefore, by adjusting the height position of the vertical actuator 32a,
The upper end of the vertical actuator 32a can be pressed against the stopper member 35 (that is, against the upper plate 29). A shear elastic member 33 that allows shear deformation is provided at the upper end of the vertical actuator 32a.

Further, a bolt-nut type compression member 36 for fastening the upper plate 29 and the flange of the pedestal 22 is provided, and the compression member 36 allows the tubular elastic body 23 to mount the weight of the mounting device 50 including the substrate 4. Thus, a compression displacement (preliminary compression displacement) can be added in advance by a displacement substantially equal to the compression displacement due to the above. An elastic holding member 37 is provided between the compression member 36 and the brim portion side of the pedestal 22 so as not to restrain the relative displacement between the lower plate 21 and the upper plate 29, and the substrate 4 and the When the mounted device 50 is mounted,
Preliminary compression displacement is adjusted so that the cylindrical elastic body 23 is further slightly compressed.

Further, in the present embodiment, as described above, a cylindrical stopper member 35 with a bottom is placed on the upper end of the cylindrical elastic body 23 with the bottom facing upward.
The bottom of the stopper member 35 is located between the upper end and the upper plate 29. The lower end of the cylindrical portion of the stopper member 35 is located between the cylindrical elastic member 23 and the inner peripheral surface of the portion of the pedestal 22 having a large inner diameter, and a certain gap is maintained between them. The stopper member 35 prevents the active anti-vibration mount 3 from being damaged when an earthquake occurs, especially against a horizontal seismic force. A bar member having rigidity in the compression direction as a compression member (for example, the upper plate 2
9, the active anti-vibration mount 3 can be prevented from being damaged. When the compression member 36 is not used as the vertical stopper member, a wire may be used as a compression member for preliminary compression.

On the flange of the pedestal 22, a pair of horizontal support members 38 each having a groove whose one end is open,
The axis of the groove is aligned with each other, and the open end is fixed to the collar portion with the load transmitting member 39a interposed therebetween, and the horizontal actuator 32b has an operating end with an open end of the groove. Is installed in this groove.
On the wall surface at the other end of the groove of the horizontal support member 38, a screw hole is formed so that the axis thereof is aligned with the axis of the mounted horizontal actuator 32b. Outside (with the tip inside the groove). The front end of the bolt member 42 abuts on the rear end (the end opposite to the working end) of the horizontal actuator 32b via the pressing member 40a inserted in the groove so as to be movable in the groove axis direction, and 42, the horizontal actuator 32b is connected to the load transmitting member 39.
It can be pressed against the a side. The pressing member 40a is in surface contact with the wall surface of the groove, and the pressing member 40a does not rotate even if the bolt member 42 rotates. The upper plate 2 is located between the working ends of the two horizontal actuators 32b.
9, the lower ends of the load transmitting members 39a attached to the load transmitting members 39a, and the operating ends of the two horizontal actuators 32b are moved by the rotation of the bolt members 42.
Can be sandwiched. In this embodiment, a shear member 33 is provided between the operating ends of the two horizontal actuators 32b and the load transmitting member 39a.

In this embodiment, the pair of horizontal actuators 32b of each active anti-vibration mount 3 have the same axial direction (the direction in which the axial lines are on the same straight line).
It is arranged to become. In this case, the active anti-vibration mount 3 is mounted on the gantry 2 such that the axes of the horizontal actuators of the active anti-vibration mount 3 are parallel to each other as shown in FIG. The axis of the horizontal actuator of the active anti-vibration mount 3 and the axis of the horizontal actuator of the active anti-vibration mount 3 on the other diagonal are arranged to be orthogonal to each other. In addition, it is desirable to use a laminated piezoelectric actuator or a giant magnetostrictive actuator having high responsiveness and high resolution for these vertical and horizontal actuators. Further, a viscoelastic member 30a is provided in a gap between the coil springs in order to prevent surging of the coil spring which is a cylindrical elastic body. Further, as the cylindrical elastic body 23, a hollow vibration-proof rubber may be used in addition to the coil spring. The major reason for providing the vertical actuator at the center of the cylindrical elastic body is to make the active anti-vibration mount compact,
When the cylindrical elastic body is not used because the mounting load is small, the normal elastic body and the vertical actuator may be adjacently arranged in parallel.

Each actuator of the active anti-vibration mount is configured to operate within the active anti-vibration mount, and is not connected to a structure outside the active anti-vibration mount such as the board 4 or the gantry 2 even after installation. Therefore, the actuator can be adjusted by the active anti-vibration mount alone, and the adjustment work after installation can be reduced.

Next, details of the active mass damper 20 provided so as to surround the upper part of the lens barrel 5 will be described with reference to FIGS. The active mass damper 20 includes a mounting member 44 having a ring-shaped cross section and a vertical side fixed to the upper outer peripheral surface of the lens barrel 5 and a horizontal side (collar portion) of the mounting member 44. A ring-shaped weight member 45 mounted on the upper side of the lens barrel 5 via the shear elastic member 33c, and an outer peripheral surface of a vertical side of the mounting member 44 and an inner peripheral surface of the weight member 45, A plurality of (four in this embodiment, four evenly distributed in two orthogonal horizontal axes) radially arranged and supported by the vertical sides of the mounting member 44; and a weight member 45 is screwed with its head to the outside in a screw hole formed at a position corresponding to the axis of the horizontal actuator 32c, and the distal end side is contacted with the horizontal actuator 32c via the pressing member 40a and the shearing member 33. And a bolt member 42 in contact therewith. In it is configured. A plurality of vibration sensors 17 for measuring the vibration state are mounted on the upper surface of the weight member 45. The end of the horizontal actuator 32c on the attachment member 44 side is:
It is screwed into a screw hole of the mounting member 44 and fixed.

According to this configuration, the ring-shaped weight member 45 is supported by the collar portion provided below the mounting member 44 via the shear elastic member 33c, so that the weight member 45 is added to the horizontal actuator 32c by its own weight. The bolt member 42 which is prevented from shearing and is screwed into the weight member 45
As a result, a compressive load is applied to the horizontal actuator 32c via the pressing member 40a and the shear member 33. The horizontal actuator 32c used here
Is preferably a laminated piezoelectric actuator or a giant magnetostrictive actuator.

Now, the natural frequency of the vibration mode caused by out-of-plane deformation of the lens barrel 6 and the top plate of the chamber 5 supporting the lens barrel is several hundred Hz. It is necessary to take a long stroke. Therefore, suppose that this natural frequency is set to 100 Hz and the weight member 45
Is required to be moved at an acceleration of 500 cm / s _2, a trial calculation of the stroke of the horizontal actuator 32c used here indicates that a stroke of the horizontal actuator 32c of 25 μm is sufficient. Therefore, it is possible to use a laminated piezoelectric actuator. The active mass damper 20 is configured to provide a mass damper effect in two horizontal directions. However, by using a common ring-shaped weight member 45, the mass ratio with respect to the lens barrel 6 of the main mass system is reduced. Can be increased, and a large mass damper effect can be obtained.

Next, the operation of this embodiment will be described with reference to FIGS. When the substrate 4 and the lens barrel 6 of the electron beam writing apparatus are vibrated by floor vibration, movement of a movable member such as the stage 7 or other vibration sources on the substrate, the anti-vibration controller 18 And lens barrel 6
The actuators 32a and 32b of the active anti-vibration mount 3 and the actuator 32c of the active mass damper 20 are based on the signal of the vibration sensor 17 provided on the
Is controlled so as to suppress the absolute acceleration or the absolute displacement of the substrate 4 and the relative displacement or the relative acceleration between the members of the electron beam writing apparatus main body or between the member and the substrate. In particular, the difference in output indicating the horizontal vibration (displacement) of the vibration sensor 17 provided on the substrate 4 and the lens barrel 6, etc., that is, the difference between the substrate 4 and the lens barrel 6
Is controlled so as to reduce the horizontal relative displacement, and the horizontal relative displacement between the members (electron gun and wafer) or between the member (electron gun) and the substrate of the electron beam writing apparatus main body is preferentially suppressed.

The vibration isolation controller 18 includes, as a control system, a cylindrical elastic body 23 which is a passive vibration isolation member, and a vertical actuator 32a and a horizontal actuator 32b provided in parallel with the elastic body. Not only the vibration model composed of the active anti-vibration mount 3 and the substrate 4 supported by the active vibration isolation mount 3 but also the vibration model of the device main body mounted on the substrate 4 is controlled, and the natural vibration of the main vibration mode of the device is controlled. The number is also the control range.

By using a laminated piezoelectric actuator as an actuator of the active mass damper 20, the vibration isolation controller 18 can also control a vibration mode of a high frequency of several hundred Hz. For example, the lens barrel 6 and the chamber 5 can be controlled. The vibration of the lens barrel 6 can also be suppressed by grasping the vibration state of the lens barrel 6 with the vibration sensor 17 installed above the lens barrel 6 for the vibration system composed of the top plate. In particular, since the relative displacement between the stage 7 and the electron gun 10 caused by the vibration of the lens barrel 6 by the vibration source in the apparatus is suppressed, even if the stage 7 moves at a high speed, the drawing displacement is reduced. It becomes possible to suppress.
Further, since a large vibration damping force can be directly applied to the lens barrel 6 by the active mass damper 20, the lens barrel 6 can be protected against a shocking vibration force generated by acceleration / deceleration of the stage 7 with a large acceleration. Vibration can be suppressed.

The active state of the movable member such as the stage 7 is fetched from the equipment controller 9 in advance as information such as the moving direction, the moving speed, and the timing into the anti-vibration controller 18 so that the active mass damper 20 is obtained.
Can be controlled in a feed-forward manner, and a vibration-suppressing effect can be exerted from an initial response to a shocking excitation force. If the active mass damper 20 cannot be provided on the mounted device, it may be provided on the substrate 4. Even if a large earthquake occurs while the active anti-vibration device is operating, the magnitude of the earthquake is judged by the vibration sensor 17 and the control is stopped. The compressive member 36 exerts a stopper function on the seismic force in the direction, thereby preventing the active vibration isolator from being damaged.

As described above, according to the above-described embodiment, signals from the vibration sensors provided on the substrate and the apparatus main body are input to the vibration isolation controller, and the vibration model including the substrate and the active vibration isolation mount supporting the substrate is provided. Control signal and feedforward control signal that take into account the vibration model (including not only the frequency range of the floor vibration but also the natural frequency range of the main vibration modes of the device) By controlling the vertical and horizontal actuators provided on the active anti-vibration mount, the vibrations of the substrate and the main body of the precision equipment with respect to the floor vibration and the excitation force in the precision equipment can be quickly suppressed. Furthermore, even if there is a vibration source (vibration source) that generates an impact force in the device, the vibration damping force is generated by the active mass damper provided in the device body,
Effective vibration suppression can be achieved even for vibrations such as impulses. Moreover, a signal (for example, a signal for controlling the operation of the stage) for notifying the timing of generating the impulse disturbance from the device controller for controlling the vibration characteristics of the generated external force and the operation of the precision device is obtained in advance by the vibration isolation controller. Accurate feedforward control becomes possible.

FIGS. 7 and 8 are a longitudinal sectional view and a transverse sectional view, respectively, of a second embodiment of the present invention. The difference between this embodiment and the embodiment shown in FIGS. 1 and 2 lies in the arrangement of the horizontal actuators of the active anti-vibration mount 3. In the present embodiment, the horizontal actuators 32b are orthogonal to each other. This is a point that is arranged in two axial directions, one by one in the axial direction. Attachment of these horizontal actuators 32b and load transmitting members 39b
For example, the active anti-vibration mount 3 is arranged as shown in FIG. 10, and the operation is performed simultaneously on two horizontal actuators 32b whose axes (action lines) are aligned. By doing so, the position of the substrate 4 does not need to be changed during the initial setting of the active anti-vibration mount 3.

The details of the embodiment shown in FIGS. 7 and 8 will be described below. Only the points different from the embodiment shown in FIGS. 1 and 2 will be described, and the description of the same parts will be omitted.
On the brim portion of the pedestal 22, a pair of horizontal support members 38 having an L-shaped cross section are provided so that the extended surfaces of the vertical sides thereof are orthogonal to each other, and the lower plate 21 has a substantially square surface. Are fixed to the upper surface of the brim portion so that the lateral sides of the L-shaped cross section are opposed to one of the corner portions. The load transmitting member 39b is fixed in a state of projecting downward from the upper plate 29 so as to face the surface of the vertical side of the horizontal support member 38 opposite to the surface facing the corner. That is, in the present embodiment, the load transmitting member 39b is arranged for each horizontal actuator 32b. Horizontal support member 3 of load transmitting member 39b
8, a hole (square hole) having a square cross section with an axis perpendicular to the vertical side is formed on the side opposite to the vertical side, and the square hole has a rectangular cross section. The member 40b is inserted. A shearing member 33 is attached to an end of the pressing member 40b on the horizontal support member 38 side. A round hole having the same axis as the square hole and a smaller diameter than the square hole is penetrated through a portion of the load transmitting member 39b which is the bottom of the square hole.

On the side of the pressing member 40b facing the round hole, a screw hole is formed so that the axis is aligned with the round hole, and the screw hole is inserted through the round hole. The screw shaft of the rotating member 54 having the screw shaft and the rotary knob is screwed. A constricted portion is formed in the screw shaft portion of the rotating member 54 at a position close to the rotating knob portion.
The half-split member 53 fitted in the constricted portion and fixed around the round hole of the load transmitting member 39b restrains the load transmitting member 39b from moving in the axial direction. The horizontal actuator 32 b has one end supported by the vertical side of the horizontal support member 38, and the other end connected to the axial end of the pressure member 40 b in the axial direction of the horizontal support member 38 via a shear member 33. Abut.

Therefore, when the rotary knob of the rotary member 54 is turned, the constricted portion of the shaft is supported by the half-split member 53 and the axial movement is restrained.
Cannot move in the axial direction, but the pressing member 40b can be moved in the axial direction by rotation of the screw shaft portion screwed into the screw hole of the pressing member 40b. Moreover, the pressing member 40b
Has a rectangular cross section, the pressing member 40b does not rotate within the load transmitting member 39b, and does not apply a rotating force to the horizontal actuator 32b. Can be applied to the horizontal support member 38.

FIG. 10 shows an example of the arrangement of the active vibration isolation mount on the gantry 2 when the active vibration isolation mount shown in FIGS. 7 and 8 is used. As shown, an active anti-vibration mount with a similar horizontal actuator is combined, and the axis (action line) of each horizontal actuator is one of the horizontal actuators of any other active anti-vibration mount. They are arranged so as to be on the same straight line as the action line and to act in opposite directions.

In this embodiment, the viscoelastic member 30
Is provided between the upper plate 29 and the holder member 51 disposed on the horizontal plate above the vertical support member 24 in parallel with the vertical actuator 32a. The operation of the viscoelastic member 30 is the same as that of the embodiment shown in FIGS. The detachment preventing member 52 mounted on the lower surface of the upper plate 29 corresponds to the stopper member 35 shown in FIG. 1 and prevents the tubular elastic body 23 from coming off in response to a horizontal earthquake motion.

FIG. 11 shows an example in which the present invention is applied to an electron microscope 56. In the case of an electron microscope, since the portion extending below the chamber 5 is long, the gantry 2A is
The active anti-vibration mount 3 similar to that shown in FIGS. 1 and 2 is provided by providing a support base at the frame-shaped rising portion. As in the embodiment shown in FIG. 5, the substrate 4 is supported by the active anti-vibration mount 3, the chamber 5 is installed on the substrate 4, and the lens barrel 6 stands on the chamber 5. A sample stage 7A is installed in the chamber 5, and the sample is irradiated by an electron gun 10 installed above the lens barrel 6. In the case of an electron microscope, the vibration caused by the operation of the movable part inside the apparatus is not enough to be controlled, but in order to prevent the microscope field from swaying due to the vibration of the lens barrel 6, an active mass damper is provided on the outer periphery of the upper part of the lens barrel 6. 20 are installed. The configuration of the active mass damper 20 is the same as that shown in FIGS. 3 and 4, and based on the vibration information output from the vibration sensor 17 provided on the upper part of the lens barrel 6 and the active mass damper 20, The horizontal actuator 32C is driven so as to prevent the displacement of No. 6 from occurring. The prevention of the vibration of the substrate 4 due to the vibration input from the floor is the same as that described for the electron beam writing apparatus, and the description is omitted here.

With the same configuration, the relative displacement of the reduction projection exposure apparatus based on the vibration of the light source for projection and the light receiving surface of projection can be prevented.

Note that the active anti-vibration mount in each of the above embodiments may be the one described in FIGS.
Similar effects can be obtained with the ones shown in FIGS.

In each of the above embodiments, the active mass damper 20 is mounted on the upper part of the lens barrel 6, and the anti-vibration controller 18 controls both the active anti-vibration mount 3 and the active mass damper 20 to perform vibration isolation of the device. However, even when the active mass damper 20 is not mounted, a vibration sensor is mounted at a position where relative displacement with respect to a substrate of a device mounted on the substrate 4 is to be suppressed, and the vibration sensor and the substrate are mounted. The input of the output of the vibration sensor that detects the vibration of the device, and the provision of an anti-vibration controller that controls the operation of each actuator of the active anti-vibration mount 3 with the frequency range of the device also as the control target range, enables the To reduce the horizontal relative displacement of vertically separated devices, improve the accuracy of the devices, and improve the throughput. It is possible. When the device mounted on the substrate has a built-in excitation source like the electron beam writing apparatus, it is further activated in a feedforward manner by using a control signal of a device controller for driving and controlling the excitation source. By controlling the operation of each actuator of the anti-vibration mount 3, it is possible to effectively reduce vibration and relative displacement.

That is, the active anti-vibration mount is used in combination with the active mass damper mounted on the main body of the device and the vibration data of the substrate supported by the active anti-vibration device and the vibration data of the device mounted on the substrate are input. By controlling the actuator of the active mass damper installed in the equipment main body, the floor vibration input and the vibration due to the excitation force acting inside the equipment are reduced, and the floor vibration input and the substrate due to the excitation force acting inside the equipment are reduced. And the relative displacement between the members of the device are reduced, and the effect of improving the accuracy of the device and the throughput is obtained.

[0049]

As described above, according to the present invention, it is possible to suppress the relative displacement between the upper and lower portions of the device main body due to the device vibration caused by the vibration input from the floor. Further, it is possible to suppress relative displacement between the upper and lower portions of the device main body due to the movement of the movable portion inside the device main body.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of an active vibration isolation mount of the present invention.

FIG. 2 is a cross-sectional view of the embodiment shown in FIG.

FIG. 3 is a longitudinal sectional view of one embodiment of the active mass damper of the present invention.

FIG. 4 is a cross-sectional view of the embodiment shown in FIG.

FIG. 5 is a longitudinal sectional view of an embodiment in which the active vibration isolator of the present invention is applied to an electron beam writing apparatus.

FIG. 6 is a plan view of the embodiment shown in FIG.

FIG. 7 is a longitudinal sectional view of another embodiment of the active vibration isolation mount of the present invention.

8 is a cross-sectional view of the embodiment shown in FIG.

FIG. 9 is a cross-sectional view showing an example of the arrangement of the embodiment shown in FIGS. 1 and 2;

FIG. 10 is a cross-sectional view showing an example of the arrangement of the embodiment shown in FIGS. 7 and 8;

FIG. 11 is a longitudinal sectional view of an embodiment in which the active vibration isolation device of the present invention is applied to an electron microscope.

[Explanation of symbols]

Reference Signs List 1 floor 2, 2A gantry 3 active anti-vibration mount 4 substrate 5 chamber 6 lens barrel 7 stage 7A sample table 8 motor 9 device controller 10 electron gun 11 low-pass filter 12 A / D converter 13 DSP 14 personal computer 15 D / A Converter 16 Amplifier 17 Vibration sensor 18 Vibration isolation controller 20 Active mass damper 21 Lower plate 22 Pedestal 23 Cylindrical elastic body 24 Vertical support member 25, 25A Bevel gear 26 Screw member 27 Shaft member 28 Rotary knob member 29 Upper plate 30 Viscoelastic member 31 Block member 32a Vertical actuator 32b Horizontal actuator 32c Horizontal actuator of active mass damper 33 Shear elastic member 34 Detent member 35 Stopper member 36 Compression member 37 Elastic holding member 38 Horizontal support member 39 Load transmitting member 40 Pressing member 42 Bolt member 44 Mounting member 45 Weight member 50 Mounted device 51 Holder member 52 Detachment prevention member 53 Half-break member 54 Rotating member 55 Height adjusting member 56 Electron microscope

Continued on the front page (72) Inventor Ikuji Otake 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Takao Konno 603, Kanda-cho, Tsuchiura-shi, Ibaraki Pref. (72) Inventor Tomio Nakamura 603, Kandamachi, Tsuchiura-shi, Ibaraki F-term in Tsuchiura Works, Hitachi, Ltd.

Claims (5)

[Claims] 1. A horizontal actuator for applying a horizontal force to a substrate on which a device is mounted, a vertical actuator for applying a vertical force to the substrate, a vibration sensor for detecting vibration of the substrate, An anti-vibration controller configured to control an operation of the horizontal and vertical actuators by using an output of the vibration sensor as an input, and an active vibration isolator configured to suppress vibration of the device; A vibration sensor for detecting vibration is provided, and the controller for vibration isolation receives the output of the vibration sensor for detecting the vibration of the substrate and the output of the vibration sensor for detecting the vibration of the device as inputs, and controls the operation of the horizontal actuator. An active vibration isolator characterized by being controlled. 2. A horizontal actuator for applying a horizontal force to a substrate on which equipment is mounted, a vertical actuator for applying a vertical force to the substrate, a vibration sensor for detecting vibration of the substrate, An anti-vibration controller configured to control an operation of the horizontal and vertical actuators by using an output of the vibration sensor as an input, and an active vibration isolator configured to suppress vibration of the device, wherein the device or An active mass damper comprising: a weight member movably arranged in the horizontal direction with respect to the substrate and having its own weight supported by the device or the substrate; and an actuator for horizontally moving the weight member with respect to the device or the substrate. And a vibration sensor for detecting vibration of the device and a vibration sensor for detecting vibration of the weight member. The controller receives the outputs of the vibration sensor that detects the vibration of the device and the vibration sensor that detects the vibration of the weight member as inputs, and horizontally moves the horizontal actuator and the weight member that apply a horizontal force to the substrate. An active vibration isolator, which is configured to control an operation of a horizontal actuator to be moved. 3. The active vibration isolation device according to claim 1, wherein the vibration isolation controller inputs an output of a vibration sensor for detecting vibration of the device and an output of a vibration sensor for detecting vibration of the substrate. As a feature, a difference between outputs representing both horizontal displacements is detected, and an operation of a horizontal actuator for applying a horizontal force to the substrate is controlled so as to reduce the difference. Active anti-vibration device. 4. The active vibration isolator according to claim 2, wherein said weight member is formed in an integral ring shape so as to surround a part of said apparatus, and said horizontal actuator moves said weight member in a horizontal direction. An active vibration isolator, wherein an annular member disposed between the device and the weight member and supporting the weight of the weight member is provided in the device. 5. The active vibration isolator according to claim 2, wherein the device mounted on the substrate includes a movable unit serving as a vibration source and a device controller for controlling and driving the movable unit. The anti-vibration controller receives, in addition to the outputs of the vibration sensors, a signal indicating the operation state of the movable unit output from the device controller as an input, and applies a force to the substrate in the horizontal direction and the weight member. An active vibration isolator, which is configured to control the operation of a horizontal actuator that moves the actuator horizontally.