JPH0844069A - Vibration absorbing device for exposure device and exposure device using the same - Google Patents

Abstract

PURPOSE:To prevent vibration transmitted from a floor and to rapidly attenuate the vibration caused by a movable part. CONSTITUTION:Vibration in an X-axis direction transmitted to a mount top board 6 is rapidly attenuated by viscous resistance by means of viscous fluid between each viscous part fixed plate 14 and each viscous part movable plate 13 exerted on the top board 6 through a parallel leaf spring 11 to which the movable plate 13 is fixed and the repulsive force of respective coil springs 9a and 9b exerted on the top board 6 through a force pin 2. The vibration in a Z-axis direction transmitted to the top board 6 is rapidly attenuated by the viscous resistance by means of the viscous fluid exerted on the top board 6 through the spring 11 and restoring force in proportion to displacement in the Z-axis direction caused in a vertical direction air spring 10. The vibration in a Y-axis direction transmitted to the top board 6 is isolated because the spring 11 is deformed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator for an exposure apparatus used in an exposure apparatus for exposing a substrate such as a wafer, and an exposure apparatus using the same.

[0002]

2. Description of the Related Art With the miniaturization and high integration of semiconductor elements, a sequential movement type projection exposure apparatus (hereinafter referred to as "stepper") has come to be used in the manufacturing process of semiconductor elements.

The stepper has a floor F ₀ , as shown in FIG.
The base surface plate 107 supported by the mount 108 on the
And a positioning stage 106 for supporting and positioning the wafer 105 disposed on the base surface plate 107, and the reticle holding table 1 supported above the positioning stage 106 via a frame 109.
03, and an illumination system 101 for irradiating exposure light through the reticle 102 supported by the reticle holding table 103.
And a reduction projection lens system 104 for focusing the exposure light on a resist formed on the surface of the wafer 105.

In this stepper, the wafer 105 is successively moved by the positioning stage 106 in accordance with a predetermined order to position the portion of the wafer 105 to be exposed next in the image forming area of the reduction projection lens system 104, and then perform exposure. In order to improve resolving power, throughput, alignment accuracy, etc., it is necessary to prevent vibration transmission from the floor F ₀ and damp vibrations generated by the movable parts such as the positioning stage 106. Therefore, a vibration isolator as described below is used for the mount 108.

This vibration isolator, as shown in FIG.
Fixing member 110 fixed on ₀ , and the fixing member 110
And a plate-like movable member 111 immersed in the viscous fluid 113 accommodated in the viscous fluid accommodating portion 110a, and the movable member 111 has a screw portion. It is configured to support the base surface plate 107 via the member 112.

[0006]

SUMMARY OF THE INVENTION In the above conventional technique,
There are conflicting problems as described below.

(1) A high-viscosity viscous fluid is preferably used for short-term convergence of vibrations generated by a movable part such as a positioning stage. However, when a high-viscosity viscous fluid is used, vibration from the floor is generated. The vibration isolation characteristics of transmission are impaired.

(2) Instead of using a highly viscous fluid,
When the gap between the movable member and the fixed member is reduced to increase the viscous resistance value due to the viscous fluid on the wall surface, the viscous resistance value changes sensitively to the change in the size of the gap, and the vibration isolation characteristic becomes unstable. Will be things.

(3) If the area of the movable member is increased to increase the viscous resistance value, the vibration isolation device itself becomes large.

The present invention has been made in view of the above-mentioned problems of the prior art. It is possible to prevent vibration transmission from the floor without using a high-viscosity viscous fluid and to vibrate the movable portion. It is an object of the present invention to realize a vibration isolator for an exposure apparatus capable of rapidly attenuating the exposure light and an exposure apparatus using the same.

[0011]

In order to achieve the above object, a vibration isolator for an exposure apparatus according to the present invention comprises a movable member mounted on a surface plate supporting an exposure apparatus main body and a fixed member fixed on the floor side. And a viscous fluid is interposed in a gap between the viscous part fixing plate and the viscous part movable plate arranged in parallel, and the first viscous fluid is orthogonal to the optical axis direction of the exposure light and a plane orthogonal to the optical axis. A viscous resistance generating member that generates viscous resistance in the direction of the first axis of the second axis and the second axis, and the movable member generates a restoring force proportional to the displacement in the direction of the optical axis. And a first elastic member having a low spring constant in the directions of the first axis and the second axis, and a high spring constant in the direction of the first axis, and the second axis and the optical axis. Through a second elastic member having a low spring constant in the direction of The viscous resistance generating member is supported by a constant member and is deformable in the direction of the second axis, but is elastic in the direction of the optical axis and the first axis via a highly rigid elastic member. And is connected to the viscous part movable plate.

Further, the viscous resistance generating member includes a viscous fluid tank which is disposed on the fixed member and which contains the viscous fluid, and a plurality of viscous portions which are disposed in the viscous fluid tank with a gap therebetween. It is effective to provide a fixed plate and a plurality of viscous part movable plates loosely fitted in the gaps.

[0013]

The first elastic member generates a restoring force proportional to the displacement of the exposure light in the optical axis direction, and the viscous resistance generating member generates viscous resistance in the optical axis direction to cause the optical axis direction. Vibrations are rapidly dampened. Further, the second elastic member generates an elastic force in the direction of the first axis of the first axis and the second axis which are orthogonal to each other on the plane orthogonal to the optical axis, and the viscous resistance is generated. Viscous resistance in the direction of the first axis is generated by the member, and vibration in the direction of the first axis is rapidly damped.

[0014]

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

FIG. 1 is a partially cutaway perspective view showing an embodiment of an anti-vibration device for an exposure apparatus according to the present invention.

The vibration isolator for an exposure apparatus of this embodiment comprises a mount top plate 6 which is a movable member attached to a surface plate 20 which supports the main body of the exposure apparatus, and a mount base 1 which is a fixed member fixed to the floor. A vertical air spring air tank 2 fixed to the upper surface of the mount base 1 and a mount bottom plate 3 fixed to the upper surface of the vertical air spring air tank 2
It has.

The mount top plate 6 has a vertical air spring 10 attached to the lower surface thereof, and a columnar laminated structure in which one end side is connected to the vertical air spring 10 and the other end side is fixed to the mount bottom plate 3. It is supported by the rubber 4. Here, the vertical air spring 10 generates a restoring force proportional to the displacement of the exposure light in the direction of the optical axis of the exposure light, that is, the Z-axis direction shown in the drawing, and the first axis and the first axis which are orthogonal to each other on a plane orthogonal to the optical axis The second rubber has a low spring constant in the direction of the second axis, that is, the X-axis direction and the Y-axis direction in the drawing, and the laminated rubber 4 has a high spring constant in the Z-axis direction, but in the X-axis direction and the Y-axis direction. Has a low spring constant. Therefore, the first elastic member including the vertical air spring 10 and the laminated rubber 4 generates a restoring force proportional to the displacement of the exposure light in the optical axis direction, that is, the Z-axis direction, and on a plane orthogonal to the optical axis. It has a low spring constant in the directions of the first axis and the second axis which are orthogonal to each other, that is, in the X-axis direction and the Y-axis direction.

One end of a force pin 7 extending in the X-axis direction is connected to the mount top plate 6 via a connecting member (not shown), and the other end of the force pin 7 is fixed to a force pin mounting plate 8. Has been done. The force pin mounting plate 8 is loosely fitted to the bolts 8a projecting at the four corners of the mounting plate 7a projecting from the mount bottom plate 3, and the mounting plate 7a is fitted in the bolts 8a. The coil springs 9a, between the force pin mounting plate 8 and the force pin mounting plate 8 and the connecting plate 8c fixed to the pair of upper and lower bolts 8a by lock nuts 8b, respectively.
9b is interposed.

Here, the force pin 7 is in the axial direction,
That is, the coil springs 9a and 9b have a high rigidity in the X-axis direction and a low spring constant in the Y-axis direction and the Z-axis direction.
Has a high spring constant in the X-axis direction, but in the Y-axis direction and Z
It has a low spring constant in the axial direction.

Therefore, the second elastic member including the force pin 7, the force pin mounting plate 8 and the coil springs 9a and 9b has a high spring constant in the X-axis direction and a low spring constant in the Y-axis direction and the Z-axis direction. It has a spring constant. That is, in the direction of the optical axis of the exposure light and in the direction of the second axis of the first axis and the second axis orthogonal to each other in the plane orthogonal to the optical axis, the low spring constant and the first axis are provided. It has a high spring constant in the direction of the axis.

Further, a plurality of yokes 11a (only one is shown) projecting from the side edges of the mount top plate 6 in the Y-axis direction at intervals are extended in the X-axis direction in parallel with each other. One end side of the parallel leaf springs 11 is fixed, and viscous part movable plates 13 provided in parallel with each other are fixed to the free end sides of the parallel leaf springs 11, respectively.

The viscous part movable plates 13 are provided in parallel with the viscous fluid tank 12 on the mount bottom plate 3 facing the movable viscous part plates 13 with a gap therebetween. The viscous part fixing plate 14 is loosely fitted in each gap, and the viscous fluid tank 12 stores a sufficient amount of viscous fluid to fill each gap.

The operation of this embodiment will be described.

When vibration in the X-axis direction is transmitted to the mount top plate 6 which is a movable member, the viscous part movable plate 13 vibrates in the X-axis direction, but each viscous part fixing plate 14 and each viscous part movable plate 13 is vibrated. The viscous resistance of the viscous fluid between the mount top plate 6
Is generated in the direction opposite to the moving direction of the mount top plate 6, and at the same time, the elastic force of each coil spring 9a, 9b acts in the direction opposite to the moving direction of the mount top plate 6 via the force pin 7. Vibrations are rapidly dampened.

When vibration in the Z-axis direction is transmitted to the mount top plate 6, the viscous part movable plate 13 vibrates in the Z-axis direction, but the viscosity between each viscous part fixed plate 14 and each viscous part movable plate 13 is increased. The viscous resistance due to the fluid is generated in the direction opposite to the moving direction of the mount top plate 6, and at the same time, the restoring force proportional to the displacement in the Z-axis direction of the vertical air spring 10 is opposite to the moving direction of the mount top plate 6. Since the vibration occurs in the direction, the vibration in the Z-axis direction is rapidly damped.

With respect to the vibration transmitted from the floor F to the fixed member represented by the mount base 1, the vibration transmitted from the floor F via the mount base 1 is rapidly generated by the same principle as the above. Is attenuated to.

Vibration in the Y-axis direction with respect to the mount top plate 6 is insulated.

That is, since each viscous part movable plate 13 is connected to the mount top plate 6 via the parallel plate spring 11 which is deformable around the X axis, each parallel plate spring 11 is X-shaped.
The viscous resistance is not generated by viscous fluid between each viscous part fixed plate 14 and each viscous part movable plate 13 due to deformation around the axis.
In addition, since the laminated rubber 4, the vertical air spring 10 and the force pin 7 have a low spring constant in the Y-axis direction, no elastic force is generated in the Y-axis direction.

As is clear from the above description, the vibration isolator for the exposure apparatus of the present embodiment is capable of rapidly damping vibrations in the X-axis direction and Z-axis direction and insulating against vibrations in the Y-axis direction. Has been done. Accordingly, the vibration isolator for the exposure apparatus of the present embodiment is one for damping the vibration of the surface plate 20 shown in FIG. 1 in the X-axis direction, and the surface plate rotated 90 degrees about the Z-axis to this. When the surface plate 20 is supported in combination with those having a direction for damping the vibration of the Y-axis direction of the surface plate 20,
It is possible to realize an exposure apparatus that can rapidly damp vibrations in the axial direction, the Y-axis direction, and the Z-axis direction.

FIG. 2 is an explanatory view showing an embodiment of an exposure apparatus using the vibration isolation apparatus for the exposure apparatus shown in FIG.

As shown in FIG. 2, in the exposure apparatus of this embodiment, the surface plate 20 supporting the main body of the exposure apparatus controls the vibration isolator E-1 for one exposure apparatus to vibrate the surface plate 20 in the X-axis direction. The vibration isolator E-2 for the exposure apparatus is rotated in the Y-axis direction by rotating the exposure apparatus anti-vibration apparatus E-2 by 90 degrees around the Z-axis while the vibration isolator E-2 is arranged in the direction of damping. Is supported by at least one set disposed in a direction that attenuates. Like the conventional stepper shown in FIG. 3, the exposure apparatus main body includes a positioning stage 21 for supporting and positioning the wafer W as a substrate, a frame 23, and a reticle holding base for supporting a reticle R as an original plate. 24
And an illumination system 25.

Next, the operation of the exposure apparatus of this embodiment will be described.

The wafer W is transferred by a transfer unit (not shown), placed on the positioning stage 21, and held.

After the above steps, the positioning stage 2
Step 1 is moved to the exposure start position to position the exposure start portion of the wafer W at the image formation position of the reduction projection lens system 22.

After the first exposure is performed after the above steps, the positioning stage 21 is step-moved in the X-axis direction and the Y-axis direction, and the portion of the wafer W to be exposed next is imaged by the reduction projection lens system 22. To position
Perform exposure.

The entire surface of the wafer W is exposed by sequentially repeating the above steps.

Since a large acceleration is applied at the start and end of the step movement of the positioning stage 21, the entire exposure apparatus vibrates, but this vibration is rapidly attenuated by the principle described below.

When the positioning stage 21 is stepwise moved in the X-axis direction, the vibration in the X-axis direction is damped by one of the exposure apparatus vibration isolation devices E-1. That is, the vibration in the X-axis direction is sequentially transmitted to the coil springs 9a and 9b via the mount top plate 6 and the force pin 7, and is sequentially transmitted through the mount top plate 6 and the parallel plate spring 11 to a plurality of viscosities. It is transmitted to the movable plate 13.

Here, the viscous resistance due to the viscous fluid filling the gap formed by the viscous part movable plate 13 and the viscous part fixed plate 14 is the viscous part movable plate 13 and the viscous part fixed plate 1.
4 and is inversely proportional to the size of the gap between the viscous part movable plate 13 and the viscous part fixed plate 14, and this viscous resistance rapidly damps the vibration in the X-axis direction.

On the other hand, the vibration in the Y-axis direction generated when the positioning stage 21 is step-moved in the Y-axis direction is damped by the other vibration isolator E-2 for exposure apparatus described above. The vibration isolator E-2 for the exposure apparatus need only read the X-axis and the Y-axis in the above description in reverse, so the description thereof will be omitted.

In the present invention, the viscosity of the viscous fluid is changed by increasing or decreasing the number of combinations of the viscous part movable plate and the viscous part fixed plate or by increasing or decreasing the gap distance between the viscous part movable plate and the viscous part fixed plate. It is possible to adjust the viscous resistance value without doing so.

[0042]

Since the present invention is configured as described above, it has the following effects.

The vibration transmitted to the movable member can be attenuated in a short time, and the viscous resistance value can be increased without using a highly viscous viscous fluid, so that stable vibration isolation characteristics can be obtained. As a result, an exposure apparatus with high accuracy and high throughput can be realized.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of an anti-vibration device for an exposure apparatus of the present invention.

FIG. 2 is an explanatory diagram showing an embodiment of an exposure apparatus using the exposure apparatus vibration isolation apparatus shown in FIG.

FIG. 3 is an explanatory view showing a conventional sequential movement type projection exposure apparatus.

FIG. 4 is a schematic cross-sectional view of an essential part showing an example of a conventional vibration isolator for an exposure apparatus.

[Explanation of symbols]

 1 Mount Base 2 Air Tank for Vertical Air Spring 3 Mount Bottom Plate 4 Laminated Rubber 5 Mounting Member 6 Mount Top Plate 7 Force Pin 7a Mounting Plate 8a Bolt 8b Lock Nut 8c Connecting Plate 9a, 9b Coil Spring 10 Vertical Air Spring 11 Parallel Plate Spring 12 Tank for viscous fluid 13 Viscous part movable plate 14 Viscous part fixed plate 20 Surface plate 21 Positioning stage 22 Reduction projection lens system 23 Frame 24 Reticle holding table 25 Illumination system

Claims (3)

[Claims] 1. A viscous fluid is provided in a gap between a movable member attached to a surface plate supporting an exposure apparatus main body, a fixed member fixed to a floor side, a viscous portion fixing plate and a viscous portion movable plate arranged in parallel. Viscous resistance is generated in the direction of the first axis of the first axis and the second axis which are interposed and are orthogonal to each other on a plane orthogonal to the optical axis of the exposure light and the optical axis. A viscous resistance generating member, wherein the movable member generates a restoring force proportional to the displacement in the direction of the optical axis and has a low spring constant in the directions of the first axis and the second axis. Elastic member and the first
Is supported by the fixing member via a second elastic member having a high spring constant in the direction of the axis and a low spring constant in the direction of the optical axis, and
Although it is deformable in the direction of the second axis, it is coupled to the viscous part movable plate of the viscous resistance generating member via an elastic member having high rigidity in the directions of the optical axis and the first axis. An anti-vibration device for an exposure apparatus. 2. The viscous resistance generating member includes a viscous fluid tank which is disposed on a fixed member and which stores the viscous fluid, and a plurality of viscous portions which are disposed in the viscous fluid tank with a gap therebetween. The vibration isolator for an exposure apparatus according to claim 1, further comprising a fixed plate and a plurality of viscous part movable plates loosely fitted in the respective gaps. 3. An anti-vibration device for an exposure apparatus according to claim 1 or 2, wherein a viscous resistance is generated in a direction of a first axis and a direction of an optical axis of exposure light and a direction of a second axis. Direction and the direction of the optical axis of the exposure light, the surface plate supporting the exposure apparatus main body is supported by at least one set arranged so as to generate viscous resistance, and the exposure apparatus main body supports and positions the substrate. And an exposure device for exposing the substrate through an original plate.