JP2018124464A - Exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure device capable of rapidly attenuating a fine vibration of a stage surface plate.SOLUTION: One aspect of an exposure device includes: a frame; a stage surface plate elevatable to the frame and expanding to a plane direction intersecting with a vertical direction; a movable state mounted on the stage surface plate and movable in the plane direction; an exposure part for exposing by irradiating light to an exposure target mounted on the movable stage; a mover for moving the movable stage in the plane direction to the stage surface plate; an elevator for elevating the stage surface plate on which the movable stage is mounted relative to the frame; and a vibration control damper that is connected to both of the frame and the stage surface plate and suppresses vibration of the stage surface plate to the frame, in which the vibration control damper includes a vessel fastened to one of the frame and the stage surface plate and accommodates the viscous fluid inside thereof and an insertion body that is fastened to the other to the one and a part is inserted in the viscous fluid in the vessel in a state of non-contact with an inner wall of the vessel.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an exposure apparatus, and more particularly to an exposure apparatus that can quickly attenuate the vibration of a stage surface plate that occurs when a movable stage is moved relative to the stage surface plate.

  The exposure apparatus is used for forming a pattern such as a wiring in a manufacturing process of a product called a workpiece such as a printed board or a liquid crystal panel. As a typical configuration example of such an exposure apparatus, mainly, a light irradiation unit, a mask on which a pattern to be exposed (transferred) to a workpiece is formed, a mask stage that holds the mask, and an exposure process are performed. A work stage for holding a work such as a printed circuit board or a liquid crystal panel, and a projection lens for projecting a pattern formed on the mask onto the work are provided.

Patent Document 1 discloses an exposure apparatus having the typical configuration described above. The work stage usually includes a movable stage on which a workpiece can be placed and moved, and a stage surface plate that defines a movable area of the movable stage.
Such a work stage is generally provided in an optical frame (or an optical bench) which is an exoskeleton of the entire exposure apparatus. There is a Z-axis drive mechanism between the stage surface plate and the optical frame. The movable stage can move in the XYZθ directions by combining the movement in the Z direction by such a Z-axis drive mechanism and the planar movement on the stage surface plate.

Japanese Patent No. 5556774

However, the Z-axis drive mechanism is less rigid than the stage surface plate and optical frame, and if the movement of the movable stage becomes faster as the pattern becomes finer, fine vibrations will be generated on the stage surface plate. It has become.
On the other hand, the position accuracy of the movable stage has been refined as the pattern becomes finer, and the exposure apparatus can perform exposure unless it waits until the vibration of the stage surface plate that occurs each time the movable stage moves to a predetermined level. It is gone.
As a result, there is a problem that the tact time is not shortened. This problem is particularly noticeable in step-and-repeat type exposure apparatuses, but is a problem that generally occurs in exposure apparatuses.
In view of the above, an object of the present invention is to provide an exposure apparatus that can quickly attenuate minute vibrations of a stage surface plate.

In order to solve the above-described problems, an aspect of the exposure apparatus according to the present invention includes a frame, a stage surface plate that is movable up and down with respect to the frame and that extends in an in-plane direction intersecting with the up and down direction, and the stage. A movable stage mounted on a surface plate and movable in the in-plane direction, an exposure unit that irradiates and exposes an exposure target placed on the movable stage, and the stage surface plate The frame is connected to both the frame and the stage surface plate, the moving device for moving the movable stage in the in-plane direction, the elevator for moving the stage surface plate mounted with the movable stage relative to the frame, and the frame and the stage surface plate. A vibration damper that suppresses vibration of the stage surface plate with respect to the frame, and the vibration damper is fixed to one of the frame and the stage surface plate and has the viscous flow therein. A housing with a container, fixed to the other with respect to one described above, the viscous fluid partially above the container, comprising inserting a member which is inserted in a non-contact state with the inner wall of the container, the.
According to such an exposure apparatus, minute vibrations of the stage surface plate can be quickly attenuated by the resistance force between the viscous fluid and the insert.

In the exposure apparatus, the moving device has a plurality of moving parts that move the movable stage independently of each other in two directional components included in the in-plane direction, and the insert is The portion inserted into the viscous fluid is preferably a plate portion that extends along one of the two directional components.
According to such an exposure apparatus, the plate portion can quickly attenuate the vibration generated in the stage surface plate due to the movement of the movable stage in the one direction component.

Further, in the insert body having the plate portion, it is more preferable that the plate portion extends along both one of the two directional components and the ascending / descending direction. Since the plate portion extends in such a direction, a vibration damper having a sufficient vibration damping capability is easily installed in the gap between the stage surface plate and the frame.
Furthermore, the insertion body having the plate portion includes a plurality of storage tanks in which the container stores the viscous fluid in each of the containers and is arranged along the other of the two directional components with respect to the one. In addition, it is also preferable that the insert has a plurality of the plate portions individually inserted into the plurality of storage tanks. By such a plurality of plate portions, a high vibration damping capacity is realized in a space-saving manner.

Further, in the exposure apparatus, the insertion body may be a plate portion in which a portion inserted into the viscous fluid extends along a direction of vibration of the stage surface plate that is suppressed by the vibration damping damper. . Such a plate portion receives a resistance force from the viscous fluid at a side surface extending along the vibration direction and quickly attenuates the vibration.
In the exposure apparatus, the viscous fluid may have a viscosity of 1000 Pa · s or more. By using such a viscous fluid having a high viscosity, vibration is quickly damped.

  According to the exposure apparatus of the present invention, it is possible to quickly attenuate minute vibrations of the stage surface plate.

FIG. 3 is a structural view of an internal structure in an embodiment of the exposure apparatus of the present invention seen through from the side of the exposure apparatus. It is the top view which looked at the structure around a work stage from the upper part. It is sectional drawing which shows the structure of a damping damper It is a figure which shows the principle of viscous resistance force. It is a graph which shows the vibration attenuation | damping in the comparative example with which the damping damper was removed. It is a graph which shows the vibration attenuation | damping in the Example provided with the damping damper.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a structural view of an internal structure in an embodiment of the exposure apparatus of the present invention as seen through from the side of the exposure apparatus.
In this specification, in order to explain the orientation of the apparatus, a common coordinate system is used for each drawing. The direction perpendicular to the paper surface of FIG. 1 is the X-axis direction of this common coordinate system, the horizontal direction of FIG. 1 is the Y-axis direction, and the vertical direction of FIG. 1 is the Z-axis direction.
An exposure apparatus 1 shown in FIG. 1 is an exposure apparatus that performs a so-called step and repeat process.
The exposure apparatus 1 includes an optical frame 10 that defines the outer shape of the exposure apparatus 1 and supports the entire exposure apparatus 1. The optical frame 10 corresponds to an example of a frame according to the present invention.

The exposure apparatus 1 includes a light source unit 20 above the optical frame 10. The light source unit 20 includes a lamp 21, a mirror 22, and a shutter 23, and the lamp 21 is turned on when power is supplied from a lamp lighting device 24. The light emitted from the lamp 21 is reflected by the mirror 22 downward in FIG. The shutter 23 switches on and off the exposure by switching between transmission and blocking of light downward from the mirror 22.
Inside the optical frame 10, a mask 30 and a projection lens 40 are installed. An exposure pattern is formed on the mask 30, and light from the light source unit 20 is irradiated onto the mask 30. The exposure light that has passed through the mask 30 is projected onto the workpiece W by the projection lens 40.

A combination of the light source unit 20, the mask 30, and the projection lens 40 corresponds to an example of an exposure unit in the present invention.
A work stage 50 that holds the work W and moves it in the XYZθ directions is provided in the optical frame 10.
The exposure apparatus 1 also includes a controller 60 that controls lighting of the lamp 21, on / off of exposure by the shutter 23, and movement of the work stage 50 in the XYZθ directions.
FIG. 2 is a top view of the structure around the work stage 50 as viewed from above.
2 is the Z-axis direction in the common coordinate system described above, the left-right direction in FIG. 2 is the Y-axis direction, and the up-down direction in FIG. 2 is the X-axis direction.

Hereinafter, the structure of the work stage 50 will be described with reference to both FIG. 1 and FIG.
In the present embodiment, a so-called H-type stage is employed as the work stage 50. The work stage 50 includes a stage surface plate 51 that extends along the XY plane, a Z-axis drive mechanism 52 that supports the stage surface plate 51 on the optical frame 10, and moves on the stage surface plate 51 in the XYθ direction. A possible movable stage 53 is provided. The Z-axis drive mechanism 52 drives (lifts) the stage surface plate 51 in the Z-axis direction and supports it at an arbitrary height. The workpiece W held on the workpiece stage 50 is moved and held by the Z-axis drive mechanism 52 to a position where the exposure pattern is focused by the projection lens 40.

The stage surface plate 51 corresponds to an example of a stage surface plate according to the present invention, the movable stage 53 corresponds to an example of a movable stage according to the present invention, and the Z-axis drive mechanism 52 is an example of an elevator according to the present invention. It corresponds to.
Two fixed guides 54 extending in the Y-axis direction are fixed to the upper surface of the stage surface plate 51. A moving guide 55 is stretched between the two fixed guides 54, and the movable stage 53 is placed on the moving guide 55.

The movement guide 55 is driven on the fixed guide 54 by the Y-axis drive mechanism 54a which is an actuator by a linear motor, for example, and moves in the Y-axis direction. Further, the movable stage 53 is driven on the movement guide 55 by the X-axis drive mechanism 55a which is an actuator by a linear motor, for example, and moves in the X-axis direction. Thereby, the movement of the movable stage 53 and the workpiece | work W in an XY in-plane direction is implement | achieved.
A combination of the fixed guide 54, the Y-axis drive mechanism 54a, the movement guide 55, and the X-axis drive mechanism 55a corresponds to an example of a mobile device according to the present invention, and the Y-axis drive mechanism 54a and the X-axis drive mechanism 55a are included. This corresponds to an example of a plurality of moving units according to the present invention.

The two Y-axis drive mechanisms 54a provided on the two fixed guides 54 can be driven in opposite directions, and the movement guide 55 rotates in the XY plane by such drive. The rotation in the XY plane realizes the rotation of the movable stage 53 and the workpiece W in the θ direction.
A bar mirror 53 a is fixed to the side surface of the movable stage 53, and the laser length measuring device 11 is installed on the inner wall of the optical frame 10. The position of the movable stage 53 is precisely measured by the laser light emitted from the laser length measuring device 11 and reflected by the bar mirror 53a. As the positional accuracy of the movable stage 53 and the workpiece W, higher accuracy has been required in recent years with the miniaturization of the exposure pattern.

By the way, when the movable stage 53 moves in the XY plane direction (direction along the surface of the workpiece W) in the configuration described above, a reaction force is generated to push the stage surface plate 51.
Since the stage surface plate 51 itself needs to be moved up and down to focus the exposure pattern, it is not directly fixed to the optical frame 10 but supported by the Z-axis drive mechanism 52. For this reason, the rigidity is slightly inferior to that of other members fixed directly to the optical frame 10, and the reaction force against the driving of the movable stage 53 causes the stage surface plate 51 to vibrate in the XY plane direction.

This vibration eventually attenuates, but at the time of vibration, this vibration becomes an adverse effect of exposure with high positional accuracy. Therefore, when the exposure apparatus 1 of the present embodiment forms a pattern in each exposure region by the step & repeat method, a certain amount of vibration is settled after the movable stage 53 is moved from one region to the next region. You will have to wait.
Since such a waiting time results in a loss of task time, in this embodiment, a vibration damper 70 that suppresses the vibration of the stage surface plate 51 with respect to the optical frame 10 is provided, so that the vibration is quickly attenuated. The vibration damper 70 corresponds to an example of a vibration damper according to the present invention.

In the present embodiment, four damping dampers 70 are provided as an example. In the case of the present embodiment, the vibration in the Y-axis direction is suppressed by a suppression mechanism having a counter mass (not shown). It is to suppress.
Hereinafter, the details of the structure of the vibration damper 70 will be described.
FIG. 3 is a cross-sectional view showing the structure of the vibration damper.
3 is the X-axis direction of the common coordinate system described above, the left-right direction in FIG. 3 is the Y-axis direction, and the up-down direction in FIG. 3 is the Z-axis direction.
The vibration damper 70 includes a container 71 and an insert 72. As an example, the container 71 is fixed to the optical frame 10, and the insert 72 is fixed to the stage surface plate 51. The container 71 corresponds to an example of the container according to the present invention, and the insert 72 corresponds to an example of the insert according to the present invention. The container 71 is provided with a storage tank 73 that is open on the upper surface side and has a bottom on the lower surface side and extends in the X-axis direction. The internal space of the storage tank 73 is filled (accommodated) with a viscous fluid 74. Yes.

A part of the insert 72 is a plate portion 75 extending in the X-axis direction. The plate portion 75 is inserted into the viscous fluid 74 from the opening on the upper surface side of the storage tank 73 and is held in a state of being separated from the inner wall of the storage tank 73. The plate portion 75 corresponds to an example of a plurality of plate portions referred to in the present invention.
Since the plate portion 75 is separated from the inner wall of the storage tank 73, the damping damper 70 does not support the Z direction of the stage surface plate 51, but is purely the workpiece surface direction (actually the X axis). Direction)).

The viscous fluid 74 has a high viscosity of, for example, 6000 Pa · s (Pascal second) at room temperature, and generates a high resistance force between the insert 72 and the container 71.
Thus, the vibration damper 70 having a structure in which the storage tank 73 and the plate portion 75 extend in the X-axis direction is provided along the stage surface plate 51 in a limited space between the optical frame 10 and the stage surface plate 51. It can be installed and contributes to downsizing of the device.

FIG. 4 is a diagram showing the principle of viscous resistance force.
It is assumed that there is a gap h between the container wall 101 and the moving object 102 and the gap is filled with a viscous fluid 103 having a viscosity μ. The moving object 102 is mainly in contact with the viscous fluid 103 on a lower surface 102a in the figure, and this surface 102a is hereinafter referred to as a resistance surface 102a. When the moving object 102 moves parallel to the wall 101, the viscous fluid 103 filled in the gap between the moving object 102 and the wall 101 generates a viscous resistance opposite to the moving direction of the moving object 102. When the area of the resistance surface 102a is A and the speed of the moving object 102 is V, the resistance force F of the viscous resistance generated on the resistance surface 102a is obtained by F = μAv / h.

  Since the vibration generated in the stage surface plate 51 of the exposure apparatus 1 hinders the task time from being reduced even in the sub-millisecond decay time, faster decay is desirable. In order to realize such a quick damping, a higher viscous resistance is required, so an increase in area A and a decrease in interval h are desired. Further, it is desirable that the resistance surface 102a and the moving body 102 extend along the direction of vibration to be suppressed (X-axis direction in the example of FIG. 3) so that the viscous resistance efficiently works to attenuate the vibration. However, there is a limit to the increase in the area A and the decrease in the interval h due to securing rigidity in the vibration damping damper 70 itself and limiting the installation space.

In contrast, the viscosity μ of the viscous fluid 103 has no particular upper limit, and it is desirable to use the viscous fluid 103 having a high viscosity μ. The viscosity μ at which a sufficiently large resistance can be obtained even with a practical apparatus size is more preferably 5000 Pa · s or more at room temperature. In addition, if the installation space can be secured, a viscous fluid of 1000 Pa · s or more is also preferably used. Such a suitable viscous fluid is specifically high viscosity silicone oil, for example.
Returning to FIG. 3, the description will be continued.
The plate portion 75 of the insertion body 72 extends in the X-axis direction and also in the Z-axis direction, and the resistance surface 75a on which the plate portion 75 mainly receives viscous resistance from the viscous fluid 74 is in the XZ plane direction. Will spread. Further, both the front and back surfaces of the plate portion 75 are resistance surfaces 75a, and the surface of the maximum area among the surfaces of the plate portion 75 is the resistance surface 75a.

The vibration generated in the stage surface plate 51 by the reaction force of the movable stage 53 driven by the X-axis drive mechanism 55a is the vibration in the X-axis direction. The viscous resistance due to the plate portion 75 extending in the X-axis direction effectively attenuates the vibration in the X-axis direction. Further, the plate portion 75 and the resistance surface 75a move in the X-axis direction at a sufficiently high speed with respect to the viscous fluid 74 and the storage tank 73 in accordance with the vibration generated in the stage surface plate 51 by the reaction force of the drive, and the high viscous resistance. Occurs. The vibration in the X-axis direction is quickly damped by such a high viscous resistance.
The structure in which the plate portion 75 extends in the XZ in-plane direction is a structure in which a large resistance surface 75a can be obtained in a space-saving manner and has a large rigidity with respect to movement in the X-axis direction. For this reason, even if a large resistance force is generated, the vibration of the stage surface plate 51 is reliably transmitted to the resistance surface 75a and is surely attenuated by the viscous resistance.

  On the other hand, the driving of the stage surface plate 51 by the Z-axis drive mechanism 52 is sufficiently smaller than the vibration of the stage surface plate 51 and therefore has a low viscous resistance. Unimpeded. Further, since the plate portion 75 extends also in the Z-axis direction, even if the stage surface plate 51 is driven in the Z-axis direction, the distance between the resistance surface 75a and the inner wall of the storage tank 73 does not change, and the damping damper 70 The basic performance of is maintained. Since the storage tank 73 has a certain depth and the filled viscous fluid 74 has a certain volume, even if the plate part 75 moves up and down as the stage surface plate 51 moves up and down, the storage tank 73 and The plate portion 75 never leaves the viscous fluid 74.

  Furthermore, in the present embodiment, the container 71 of the vibration damper 70 is provided with a plurality (for example, two) of storage tanks 73. The plurality of storage tanks 73 are arranged in a space-saving structure because they are arranged in a direction intersecting the resistance surface 75a (Y-axis direction as an example). These storage tanks 73 correspond to an example of a plurality of storage tanks referred to in the present invention. In addition, a plurality of plate portions 75 are individually inserted into the plurality of storage tanks 73. This increases the number of resistance surfaces 75a, increases the total area, and increases the resistance.

Next, experimental results for verifying the performance of the vibration damper 70 will be described.
FIG. 5 is a graph showing vibration damping in a comparative example in which the damping damper is removed.
FIG. 6 is a graph showing vibration attenuation in an embodiment provided with a vibration damper.
5 and 6, the vertical axis represents vibration displacement in arbitrary units, and the horizontal axis represents time. Further, thin line graphs G1 and G2 shown in FIG. 5 and FIG. 6 represent actual measurement values of vibration, and thick line graphs G3 and G4 represent three-point moving average values. Further, FIGS. 5 and 6 show attenuation curves T1 and T2 obtained by fitting the envelopes to the graphs G3 and G4 of the three-point moving average values. The attenuation state is shown.

In this experiment, similarly to the structure of the above-described embodiment, there are four vibration dampers 70 around the stage surface plate 51, and each vibration damper 70 has two storage tanks 73 and a plate portion 75. A device was used. The area of the resistance surface is about several hundreds square cm for each vibration damper 70, and the gap between the storage tank 73 and the plate portion 75 is 1 cm or less.
When the stage surface plate 51 was vibrated by applying an impact force, the stage surface plate 51 vibrated at about 70 Hz. This vibration was attenuated at a damping rate of ζ = 0.03 in the comparative example, whereas it was attenuated at a damping rate of ζ = 0.065 in the example. For example, the vibration wave became almost zero after 200 ms. .
In addition, although the example provided with what is called an H-type stage is shown in the said embodiment, the stage surface plate and movable stage said to this invention may comprise what is called a plane stage. In the case of an H-type stage, the stage surface plate according to the present invention does not need to have a flat upper surface, and may have a framework structure having a spread in the plane direction to the extent that the fixing guide can be fixed. Good.

In the above embodiment, an example in which the container 71 is fixed to the optical frame 10 and the insert 72 is fixed to the stage surface plate 51 is shown. However, the insert and container referred to in the present invention are the inserts. The container may be fixed to the stage surface plate 51 while being fixed to the optical frame 10.
Moreover, in the said embodiment, although the damping damper which attenuates a vibration with viscous resistance is illustrated, the damping damper said to this invention may attenuate a vibration with a pressure resistance.
Moreover, in the said embodiment, although the damping damper 70 which suppresses the vibration of a X-axis direction is illustrated, the damping damper said to this invention may suppress the vibration of a Y-axis direction. The vibration in the direction intersecting both the X-axis direction and the Y-axis direction may be suppressed. Furthermore, the exposure apparatus of the present invention may include a plurality of vibration dampers having different directions for suppressing vibration.

DESCRIPTION OF SYMBOLS 1 ... Exposure apparatus, 10 ... Optical frame, 20 ... Light source part, 30 ... Mask, 40 ... Projection lens,
50 ... Work stage, 60 ... Control unit, 51 ... Stage platen, 52 ... Z-axis drive mechanism,
53 ... movable stage, 54 ... fixed guide, 55 ... moving guide, 54a ... Y-axis drive mechanism,
55a ... X-axis drive mechanism, 70 ... damping damper, 71 ... container, 72 ... insert, 73 ... storage tank,
74: viscous fluid, 75: plate

Claims (6)

Frame,
A stage surface plate which is movable up and down with respect to the frame and which spreads in an in-plane direction intersecting the up and down direction;
A movable stage mounted on the stage surface plate and movable in the in-plane direction;
An exposure unit that irradiates and exposes an exposure target placed on the movable stage; and
A moving machine for moving the movable stage in the in-plane direction with respect to the stage surface plate;
An elevator that raises and lowers the stage surface plate mounted with the movable stage with respect to the frame;
A vibration damper that is connected to both the frame and the stage surface plate and suppresses vibration of the stage surface plate with respect to the frame; and
The damping damper is
A container that is fixed to one of the frame and the stage surface plate and contains a viscous fluid therein;
An insert that is fixed to the other of the one and partially inserted into the viscous fluid in a non-contact state with the inner wall of the container;
An exposure apparatus comprising: The moving machine has a plurality of moving units that move the movable stage independently of each other for each of two directional components that intersect each other included in the in-plane direction,
2. The exposure apparatus according to claim 1, wherein a portion of the insertion body inserted into the viscous fluid is a plate portion extending along one of the two directional components.   3. The exposure apparatus according to claim 2, wherein in the insert, the plate portion extends along both one of the two directional components and the up-and-down direction. The container contains the viscous fluid in each of them, and has a plurality of storage tanks arranged along the other of the two directional components with respect to the one;
The exposure apparatus according to claim 2, wherein the insert has a plurality of the plate portions individually inserted into the plurality of storage tanks.   5. The insert body is a plate portion that extends along a direction of vibration of the stage surface plate that is suppressed by the vibration damper, wherein the portion inserted into the viscous fluid is a portion of the insert body. The exposure apparatus according to any one of the above.   The exposure apparatus according to claim 1, wherein the viscous fluid has a viscosity of 1000 Pa · s or more.

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