JPH07181276A - Table device - Google Patents

Abstract

PURPOSE:To provide a table device which is compact and small in Z-direction height at a small cost increase, and capable of setting Z direction position and tilt degree of the specimen table independently without complicating the control system and mechanism. CONSTITUTION:A table device is constituted of a base 1, an intermediate part 2 supported movement-free linearly to it, a drive means 10 to displace the intermediate part 2, slanting stages 3 fixed to the intermediate part 2, a table 5 supported movably with a plurality of elastic support means, three roller support mechanisms 6 fixed to the table 5, three rollers 1 contacting the slanting surface of each three slanting stages 3. At least two of the three rollers 7 have center shafts eccentric to the roller center. This eccentric shaft is supported rotation- free with the roller support mechanism 6 and the table device can be positioned at an arbitrary rotational angle with a rotation drive device 9 fixed to the roller support mechanism 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a table device used as an apparatus for manufacturing or inspecting semiconductor devices, an optical device such as a microscope, or a sample stand for a machine tool or the like for highly accurate processing.

[0002]

2. Description of the Related Art Here, a conventional technique of a table device mainly used in a semiconductor device manufacturing apparatus, an inspection apparatus, etc. will be described. Manufacturing of semiconductor devices such as LSI
Generally, it is performed by optically transferring a pattern drawn on a mask, a reticle, or the like onto a silicon wafer or the like and forming a pattern by using a process such as etching. Also, when inspecting the mask pattern used at this time or the pattern formed on the silicon wafer, the surface is observed using an optical microscope or the like.

In order to transfer and observe such a fine pattern, an optical system having a very high resolution is required. However, if the resolution is increased, the depth of focus of the optical system becomes shallow, and a mask or a wafer cannot be obtained. The surface must be accurately positioned at the focal point of the optical system. Therefore, it is important to improve the accuracy of the table device for positioning the mask or wafer at the focal position of the optical system.

Further, in the exposure apparatus for transferring the mask pattern onto the wafer, the exposure area is large, so that the exposure on the wafer is
Not only are the points positioned within the depth of focus. The entire area where the pattern is transferred must be positioned within the depth of focus. Therefore, the table device for mounting a sample such as a wafer in such a device needs not only the function of positioning the table surface in the optical axis direction but also the function of positioning the table perpendicularly to the optical axis.

A table device having such a function is generally called a Z tilt table and is composed of a Z mechanism for moving the table surface in parallel with the optical axis direction and a tilt mechanism for tilting the table surface with respect to the optical axis. .

As the Z mechanism, an autofocus mechanism for focusing in a minute area and a variation in sample thickness,
There is a coarse movement Z table that makes a relatively large displacement of about several mm in order to cope with a change in the type of sample, but here the mechanism of the coarse movement Z table will be mainly described.

As the Z mechanism used for the Z coarse movement table, a mechanism using a tilting table and a roller is widely used. This is because the roller connected to the table is in contact with the tilting platform supported by the linear motion guide on the base, and the linear motion guide is displaced by a driving means such as a ball screw so that the inclined surface of the tilting platform and the roller It is a mechanism that changes the contact point of. When the tilting table is displaced, the height of the contact point with the roller is changed to position the table in the height direction. In addition,
The leaf spring is generally supported by a linear guide so that the table is not displaced in the horizontal direction.

In the case of a table having a small area on which a relatively small sample is placed, the positioning can be performed by one of the Z mechanisms described above. In some cases, if a Z mechanism for positioning at one contact point is used, the end of the table may bend or the table may tilt due to the straightness of the Z-direction guide.

Therefore, in such a large table, the above-described method of constructing the Z mechanism using the tilting table and the three rollers is performed. As a result, the table is supported at three points, and the position and posture of the table are uniquely determined, and if the inclination and displacement of the three tilting stands are the same, the posture of the table does not change and the table is positioned in the Z direction. can do.

Further, the bending of the table can be reduced by devising the position of the tilting table. Next, as the tilt mechanism for adjusting the tilt of the table, the heights of the contact points of the tilt table and the roller are independently determined by independently displacing the three tilt tables of the Z mechanism described above. A mechanism for simultaneously determining the Z-direction position and tilt of the table is also adopted.

Since this method can be realized by making the support guides of the three tilting tables independent and connecting the driving means to each guide, the height of the mechanism does not increase and the Z tilt mechanism can be compactly constructed. There are advantages.

On the other hand, in this case, three motors for driving the tilting table and three ball screws are required, which causes a problem that the number of parts increases. Further, in order to perform positioning in the Z direction without changing the posture of the table, it is necessary to exactly match the displacements of the three tilting stands, which complicates the control system and the measurement system. The tilt adjustment of the table is less frequent than the adjustment of the position in the Z direction, and once the tilt adjustment of the table is performed, the posture of the table is often constant only by changing the position in the Z direction. Therefore, it cannot be said that this method, which requires control so that the tilt is always changed despite performing only the positioning in the Z direction, is not rational.

Furthermore, since the same tilting table is used for Z-direction positioning and tilt adjustment, Z-direction positioning resolution,
Since the resolution of tilt adjustment cannot be made independent,
The resolution of the drive system must be adjusted to the one with the smaller required resolution.

Generally, the tilt adjustment is minute and the resolution must be small. However, the positioning in the Z direction may not be so small if the autofocus mechanism is additionally provided. Therefore, in this method, the displacement resolution of all three drive systems must be reduced in accordance with the tilt adjustment, which complicates the drive system detection system and increases the cost.

As another tilt mechanism, there is a method of further installing a dedicated tilt mechanism on the Z table having the Z mechanism described above, and providing a table on which a sample such as a wafer is placed.

Specifically, the Z table is provided with the above-described two mechanisms using the tilting table and the roller to adjust the tilt of the sample table, one using two cams, and a piezoelectric element. There is a method of using etc.

In this case, the position and the tilt of the sample table can be positioned with independent positioning resolution, but the Z mechanism and the tilt mechanism are stacked in the optical axis direction, and further the Z direction guide of the Z table is used. In addition, a restraint mechanism such as a leaf spring and a pivot for restraining the translational movement of the tilt table is required. Therefore, at the same time as the height of the table becomes high, the mechanism becomes complicated and the number of parts increases, so that the table device eventually becomes large and the cost increases significantly.

The above is a description of the conventional technique relating to the Z tilt table, but apart from this, the conventional technique of the method of supporting the table on which the sample is placed will be described below. As described above, the sample table on which the sample is placed is often supported by three points in order to determine its position and orientation. The main purpose of this is to uniquely determine the position and orientation of the sample table and not to be affected by the accuracy of the base surface.

Specifically, three supporting members are installed on the base, and the sample table is connected to the supporting members. Since the support member does not transmit the influence of the shape accuracy of the support member to the sample table, a thin portion is provided in the middle part to configure a pivot, or a contact point between the support member and the sample table is used as a ball point. Further, the support member is generally arranged such that there is a portion on the sample table where the deflection becomes extremely large.

This method is a technique common not only to the fixed support member but also to the Z table and the Z tilt table described above. For example, in the Z table described above, the tilting table and the rollers correspond to the supporting member here.
Although a leaf spring or a linear motion guide is used as a constraint in the direction perpendicular to the Z direction, the tilt table and the roller basically determine the position and orientation of the sample table at three points. It is the same that the position and orientation of the sample table are determined.

Even with the sample table supported at three points as described above, if the size of the sample table is small and it is easy to secure the rigidity, there is not much problem, but if the area of the sample table is large or the sample table is When the table has a large inner hole, the rigidity of the sample table is reduced, which causes various problems.

For example, when the sample table is large,
Since the load of the sample table is supported only at three points on the support member, the deflection due to its own weight occurs at points other than the support points of the sample table, which adversely affects the surface accuracy of the sample table. The material of the sample table can be ceramics with a high Young's modulus or the thickness of the sample table can be increased, but the cost and weight increase are significant disadvantages.

Further, when an autofocus mechanism is provided on the sample table, or when the Z mechanism as described above is used for focusing, the vibration mode and the natural frequency of the sample table pose problems.

On a sample table having a large area and low rigidity, if it is supported at three points, the vibration mode in which the support points serve as nodes may be the lowest vibration mode. In this case, if the response frequency of the autofocus mechanism on the sample table is high, the sample table may resonate. In particular, when the closed loop control is performed, resonance occurs and the response frequency of the autofocus mechanism cannot be fully utilized.

In the Z table using the tilting table and the rollers as described above, the weight of the sample table is entirely supported by the contact points between the tilting table and the rollers, and the tilt table is worn. There is also a problem that the life of the tilting platform is shortened due to the influence of.

[0026]

As described above,
In a table device having a Z tilt mechanism that determines the position and orientation of the sample table, there was a method of independently displacing the three tilting tables to determine the position and orientation of the sample table at the same time, but the mechanism becomes complicated. , Z without changing the posture
There are problems that the driving means for tilting must be operated even when it is displaced in the direction, the control system becomes complicated, and the positioning resolution in the Z direction and the positioning resolution in tilt cannot be set independently. It was

There has also been a method of independently constructing the Z mechanism and the tilt mechanism, but there are problems that the height of the table is increased, the mechanism is complicated, the number of parts is increased, and the cost is increased. there were.

Therefore, according to the present invention, the position of the sample stage in the Z direction and the tilt amount can be set independently, and the control system and mechanism are not complicated, and especially the height in the Z direction is small and the cost is low. It is an object of the present invention to provide a table device with a small rise in the table.

In addition to this, in a table device in which the sample table is supported by the three supporting means with respect to the base, the surface accuracy of the sample table deteriorates due to the self-weight deflection of the sample table, especially when the sample table is large. Since the natural frequency of the table decreases, resonance may occur when autofocusing is performed, and since the weight is supported at three points, the life of the supporting means decreases.

Therefore, in the present invention, the position and orientation of the sample table are determined by the three supporting means, the surface accuracy of the sample table is not deteriorated by the deflection of the sample table due to its own weight, and the sample table resonates even when autofocusing is performed. It is an object of the present invention to provide a table device that does not reduce the life of the supporting means.

[0031]

In order to achieve the above object, the present invention provides a table device having the following structure. According to the table device of claim 1, a base, an intermediate member movably supported in a uniaxial direction with respect to a base surface of the base, and a drive unit for moving the intermediate member with respect to the base. A table elastically supported so as to be displaceable with respect to the base surface, at least three slanting mounts attached to the intermediate member, and rotating by contacting the slanting faces of these slanting bases, respectively. In a table device comprising at least three possible rollers and at least three roller support mechanisms attached to the table for rotatably supporting the rollers, at least two of the rollers are at the center of each roller. A roller drive means having an eccentric rotation center axis with respect to the eccentric rotation axis and capable of rotationally positioning the roller around the eccentric rotation center axis. It is a symptom.

According to a second aspect of the present invention, the intermediate member is supported by at least three linear guides attached to the base surface, and the at least three rollers and the at least three slanting supports. The virtual lines passing through the respective contact portions and perpendicular to the base surface are configured so as to penetrate the mounting surface of the Leia guide, respectively.

According to the table device of claim 3,
In a table device having a base, a table displaceably supported with respect to the base, and positioning means for displacing the table to adjust the position of the table with respect to the base, the table is pressed against the base. It is characterized by including at least three load generating means for generating a load in the direction. Claim 4
According to the invention described in (1), the load generating means is provided with a load adjusting means for adjusting the load generated by the load generating means.

[0034]

According to the first aspect of the invention, at least two of the rollers contacting the three tilting bases of the same tilt angle fixed to the intermediate member are rotated eccentrically with respect to the center of the rollers. Since the eccentric rotation center axis has a center axis and is rotatably supported by the roller support mechanism and can be positioned at an arbitrary rotation angle by the roller driving means, if the intermediate member is displaced with respect to the base, 3 The contact points between the two rollers and the tilting table move up and down by the same amount, and the Z direction position of the table can be set without changing the posture of the table. Then, by rotating the rollers around the eccentric rotation center axis of the two rollers, the inclination of the table can be changed.

Moreover, not only the position of the table in the Z direction but also the tilt adjustment can be performed only by adding two rotation driving means, so that the mechanism is not complicated and the Z
The height of the direction hardly increases, and the control is performed only by controlling the rotation angle of the rotation driving means, so that the control system is hardly complicated.

In the table device according to the second aspect of the present invention, the intermediate member is supported by three linear guides,
Since the imaginary line passing through the respective contact portions of the three rollers and the three tilting bases is arranged such that the movable part of the linear guide is positioned so as to penetrate the mounting surface of the linear guide, it is added to the tilting base. The table support load is directly transmitted to the linear guide. Therefore, a load is not applied to the intermediate member and the intermediate member is deformed, and the rigidity of the intermediate member is insufficient, so that the supporting rigidity of the table does not decrease.

According to the table apparatus of the third aspect, in addition to the table positioning means, at least three load generating means are connected between the table and the base, so that the weight of the table is at least. It will be supported by 6 points. Therefore, by connecting the load generating means to the place where the deflection of the table due to its own weight is large, the deflection can be reduced, and at the same time, the vibration mode of the table can be increased and the natural frequency can be increased. Further, since the load applied to the positioning means is reduced, the life of the positioning means can be extended.

In the table device according to claim 4,
Since the load generated by the load generating means can be adjusted respectively, the correction amount of the deflection of the table can be arbitrarily adjusted. Therefore, the surface accuracy of the table can be adjusted to be the highest.

Further, by making the load generated by the load generating means substantially constant irrespective of the position of the table with respect to the base, the Z mechanism and the tilt mechanism are incorporated in the table, and even when the table position is variable, it is always possible. It is possible to correct the deflection of the table and keep the natural frequency of the table high.

[0040]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of the table device according to the present invention. The table device shown in the present embodiment mainly includes a base 1, an intermediate member 2, and a table 5.

Guides 8a, 8b, 8c that support the intermediate member 2 so as to be linearly movable in the Y-axis 29 direction are installed on the base 1, and the respective movable parts are connected to the intermediate member 2.
As the guides 8a, 8b, 8c, various guide means such as those using rolling bearings, those using sliding bearings, non-contact bearings such as air bearings can be used.

On the base 1, the intermediate member 2 is attached to the Y-axis 29.
A drive means 10 for displacing in the direction is installed, and the movable portion is connected to the intermediate member 2. On the intermediate member 2, tilting platforms 3a, 3b, 3c having slopes having the same tilt angle are installed so that the directions of the respective tilting planes are the same.

The table 5 on which the sample is mounted is fixed on the base 1 by the fixed portions 11a, 11b, 11c, 1 and 1.
Elastic guide means 4a, 4b, 4 such as leaf springs for 1d
They are connected by c, 4d, 4e, 4f, 4g and 4h. As a result, the translational movement in the X-axis 27 direction, the translational movement in the Y-axis 29 direction, and the rotational movement about the Z-axis 28 are restrained in the table 5, and the translational movement in the Z-axis 28 direction, the X-axis 27 and the Y-axis 29 rotational movement. Rotational movement is possible.

On the back surface of the table 5, three roller support mechanisms 6a, 6b and 6c are provided. The roller 7a is inclined to the slope 3a, the roller 7b is inclined to the slope 3b and the roller 7c is inclined. It is installed so as to contact the slope of the table 3c.

However, the rollers 7a and 7b supported by the roller support mechanisms 6a and 6b have an eccentric shaft, and the eccentric shaft is connected to driving means 9a and 9b such as a motor. Details of the configuration for this will be described later.

The other roller support mechanism 6c merely supports the roller 7c and has no drive means. Here, the roller support mechanism 6a and the roller 7 described above are used.
The detailed structure near a will be described.

FIG. 2 is an exploded perspective view showing details of the vicinity of the support mechanism 6a of the table device shown in FIG. Roller 7a
Has an outer ring 13a that is rotatably supported by a rolling guide or the like with respect to the central portion 12a. The outer ring 13a contacts the slope of the tilting table 3a and rolls on the slope.

The central portion 12a of the roller 7a is connected to a rotary shaft 14 having a central shaft 20a that is eccentric with respect to the central shaft 21a of the outer ring 13a. The rotary shaft 14 is rotatably supported by the roller support mechanism 6a. , Roller support mechanism 6a
It can be positioned at an arbitrary rotation angle by the rotation driving means 9a fixed to.

The rotation driving means 9a outputs the rotation of the motor using a speed reducer, and an output shaft (not shown) is connected to the rotation shaft 14. As a result, the size of the motor can be reduced, the rigidity of the rotating shaft 14 in the rotating direction is increased, and the rotation angle of the rotating shaft 14 can be easily maintained even when the motor is de-energized. The same applies to the roller support mechanism 6b and the roller 7b of the table device shown in FIG.

Now, the guide 8a for supporting the intermediate member 2 so as to be displaceable in the Y-axis 29 direction with respect to the base 1 is the roller 7
The straight line 24 in the Z-axis 28 direction passing through the contact point 22 between the a and the tilting table 3a indicates the mounting surface of the movable portion 15a of the guide, for example, the point 2
It is installed at a position where it passes through 3 and penetrates. With this arrangement, the load applied to the tilting table 3a in the Z-axis 28 direction is directly transmitted to the movable portion 15a of the guide, and unnecessary bending moment or the like is not generated in the intermediate member 2.

Therefore, the intermediate member 2 is not bent by the load, and an error is not caused in the displacement in the Z-axis 28 direction. Moreover, since the rigidity of the intermediate member 2 has almost no influence on the displacement rigidity in the Z-axis 28 direction, the thickness of the intermediate member 2 can be reduced, and the size and weight can be reduced. The guides 8b and 8c are also installed in the same manner.

The driving of the intermediate member 2 is carried out by the driving means 10. Specifically, the ball screw 18 is connected to the rotation driving means 19 such as a motor fixed on the base 1, and the movable portion 17 having the nut is intermediately moved. It is connected to the member 2.

In the present embodiment, the driving means 10 uses a motor and a ball screw / nut, but any kind of mechanism such as a sliding screw, a motor, and other linear actuators can be used as long as it is a mechanism for generating a linear displacement. It doesn't matter.

The structure of the table device shown in FIG. 1 has been described above. Next, the operation of this table device will be described. First, the operation when performing translational movement in the Z-axis 28 direction will be described with reference to FIG.

In order to translate the table 5 in the Z-axis 28 direction, the driving means 10 displaces the intermediate member 2 in the Y-axis 29 direction. The intermediate member 2 is provided with the tilting stands 3a, 3b, 3c having the same tilt angle, so that the rollers 7a, 7b, 7c are in contact with each other. The table 5 is moved by the guide means 4a to 4h to the X-axis 27 and the Y-axis 29.
The rollers 7a, 7b, 7c are constrained in the direction.
Respectively roll the slopes of the tilting stands 3a, 3b, 3c to change the height of the contact point. Three tilting stands 3a, 3b, 3c
If the inclination angle and the direction of the inclined surface are equal, the position of each contact point in the Z-axis 28 direction changes by the same amount. The position / posture of the table 5 is determined by the positions of the three contact points, but if the amounts of change at the three points are the same, the table 5 moves in parallel in the Z-axis 28 direction.

Next, the operation for changing the attitude of the table 5 will be described. When changing the posture of the table 5, the rotation driving means 9a and 9b fixed to the roller supporting mechanisms 6a and 6b in FIG. 1 are rotated. As a result, the eccentric shafts of the rollers 7a and 7b are rotated to change the contact state between the rollers 7a and 7b and the tilting supports 3a and 3b.

Details of the operation will be described with reference to FIG. FIG. 3 is a diagram showing a contact state between the roller 7a and the tilting table 3a. The roller 7a is in contact with the tilting base 3a by the outer ring 13a. The outer ring 13a is rotatably supported with respect to the center portion 12a, and can roll on the slope of the tilting platform 3a without slipping even when the center portion 12a rotates. Here, since the central portion 12a has a rotating shaft 20a that is eccentric by e from the central axis 21a of the outer ring 13a, the central portion 12a
When is rotated around the central axis 20a, the position of the contact point 22a changes and the distance in the Z-axis 28 direction from the contact point 22a to the central axis 20a changes.

At this time, if the intermediate member 2 is not displaced, the roller 7a which determines the position and orientation of the table 5 in FIG.
The position of one of the contact points between the tilting table 3a, the roller 7b and the tilting table 3b, and the contact point between the roller 7c and the tilting table 3c changes, so that the posture of the table 5 changes.

If the same operation is performed on the roller 7b, the table 5 can be rotated about the X-axis 27 and the Y-axis 29 to change the posture. Next, a modified example of the table device of the present invention will be described.

FIG. 4 is an exploded perspective view showing a first modification of the table device of the present invention. The parts without numbers are the same as those shown in FIG. In this table device, the base 41, the intermediate member 42, the table 4
Each has a through hole. In the table device of the present invention, since the means for determining the position and orientation of the table 45 can be arranged in the peripheral portion of the table 45, it is particularly easy to have such a configuration.

Therefore, by disposing an optical system or the like at the center of the table device, it becomes easy to observe the sample with transmitted light while adjusting the focus and inclination of the optical system on the sample on the table. Since the operation is exactly the same as that of the table device shown in FIG. 1, description thereof will be omitted.

FIG. 5 is an exploded perspective view showing a second modification of the table device of the present invention. The parts without numbers are the same as those shown in FIG. In this table device, guide means 54a, 54 of the table 55 are provided.
b, 54c, and the fixed portion 56 are arranged in the central portion of the table device.

The intermediate member 52 and the table 55 have a through hole in the center, and a fixing portion 56 fixed to the base 51 is installed at the center of the hole. The table 55 is moved by a guide means 54a, 54b, 54c such as a leaf spring to the X-axis.
Translation in the directions of the shaft 27 and the Y-axis 29 and rotation around the Z-axis 28 are restricted. The operation and the like are the same as those of the table device shown in FIG. 1, but with such a configuration,
Since the guide means can be arranged inside the table without arranging the guide means at the peripheral portion, a more compact table device can be obtained.

In the above description, as shown in FIG. 1, two rollers out of the three rollers are provided with an eccentric shaft and driven by a motor or the like, and the position of the table in the Z direction is changed without changing the posture. Although it can be done, the Z direction position changes when the posture is changed. Therefore, in order not to change the height of a certain point on the table in the Z direction even if the posture is changed, the roller 7c in FIG. 1 has an eccentric rotation shaft similar to 7a and 7b, and a rotation drive for rotating this rotation shaft. Means are provided. By doing so, the heights of the three contact points can be arbitrarily set, so that the posture of the table can be changed without changing the height in the Z direction at a specific place on the table, and at the same time, only the intermediate member can be changed. By displacing, the Z-direction position of the table can be changed without changing the posture of the table.

The embodiment of the table device according to the first invention of the present application has been described above. An embodiment of the table device according to the second invention of the present application will be described below. FIG. 6 is an exploded perspective view showing an embodiment of the table device according to the present invention.

Three position determining means 64 are provided on the base 61.
a, 64b, 64c are installed and connected to the three support points 63a, 63b, 63c of the table 65, respectively. As the position determining means, here, a fixing member in which a pivot is formed by a thin portion is used, but the type and configuration thereof are not limited as long as they are means for determining the position and orientation of the table 65 at three points.

The table 65 has three load generating means 6
6a, 66b, 66c are fixed and contact at three points 69a, 69b, 69c on the base 61, respectively, to generate a load between the base 61 and the table 65. A compression spring, a constant force spring, a solenoid, an air cylinder, or the like can be used as the load generating means, but an embodiment using an air cylinder is shown here.

Load generating means 66 using an air cylinder
a, 66b, 66c are installed in a portion of the table 65 having a large deflection, that is, a portion away from the support points 63a, 63b, 63c, and compressed air is supplied from the pipes 67a, 67b, 67c to the movable portions 68a. ,
68b and 68c extend and contact the contact points 69a, 69b and 69c on the base 61, respectively, and generate a load on the table 65.

FIG. 7 is an exploded perspective view showing a further embodiment of the table device of the present invention. In this embodiment, four load generating means 77a, 77b, 77c, 77d are installed on the table 75. In FIG. 7, the piping of the air cylinder, which is the load generating means, is not shown and is omitted.
Other parts are the same as those of the table device shown in FIG. 6, and the load generating means 77a, 77b, 77c, 77.
The operation of d is the same as that of the load generating means shown in FIG.

In the above embodiment, the load generating means is fixed to the table side and is operated to generate a load by contacting the base. However, the load generating means is fixed to the base side and operated. As a result, the same effect can be obtained even with a configuration in which a load is generated by contacting the table. This also applies to the following description.

Now, the operation of the present invention will be described in detail below with reference to schematic diagrams. FIG. 8 is a schematic diagram showing an example of a modification of the table when the table is supported by three position determining means. When the table 85 is considered as a rigid body, its position and orientation are uniquely determined as indicated by the broken line in the figure. However, in reality, the table is an elastic body, and when the area is large, the deformation of the table 85 due to its own weight causes a deformation as shown by the solid line at the portions apart from the supporting points 83a, 83b, and 83c. It becomes a big problem when you want to keep high.

FIG. 9 is a schematic view showing an example of a vibration mode when the table is supported by three position determining means. Considering the vibration of the table 95, in addition to the deformation mode shown in FIG. 8, a vibration mode causing deformation as shown in FIG. 9 can be considered. In this vibration mode, the support points 93a, 93
A vibration mode having nodes b and 93c may appear as a low-order mode. Since such a mode has a low natural frequency, when a vibration source such as an autofocus mechanism is present on the table 95, it may have an adverse effect such as resonance.

In the present invention, by applying a load to the table by at least three load generating means, the deformation of the table is reduced and the natural frequency of the table is increased.

FIG. 10 is a schematic diagram showing the table device shown in FIG. The table 105 is supported by three position determining means 104a, 104b, 104c, and the load generating means 106a, 106b, 106c are connected to the portions apart from the supporting points 103a, 103b, 103c. This position is a portion where the deflection of the table is large as shown in FIG. Base 10 on this part
By applying a load from 1, the deflection of the table 105 is improved. Further, since the number of supporting points that share the load of the table 105 increases, the load generating means 106a, 1
When the load shared by 06b and 106c is sufficiently large, the number of vibration mode nodes of the table 105 increases, so that the natural frequency of the table 105 increases.

FIG. 11 is a schematic diagram showing the table device shown in FIG. The table 115 is supported by the three position determining means 104a, 104b, 104c, but the load generating means 116 is provided near the four corners of the table 115.
a, 116b, 116c, 116d are connected.

In this case, the load generating means is not necessarily connected to a place where the flexural deformation is large,
The effect of correcting the deformation is great. Further, since the number of supporting points is further increased as compared with the table device shown in FIG. 10, the natural frequency of the table 115 can be further increased. Further, when the table 115 is rectangular, it can be connected to the four corners, so that the load of the table 115 can be supported in a well-balanced manner.

The above effects can be obtained by dispersing the table load supporting points by using the load generating means. However, in order to further improve the accuracy of the table surface, the generating force of each load generating means can be varied. And

For example, in FIG. 10, the load generating means 10
Even if the generated loads of 6a, 106b and 106c are equal, the deflection correction effect of the table 105 can be obtained, but in order to optimize the deflection correction amount, the generated load of each load generating means is changed so that the deformation of the table 105 is minimized. Adjust so that Specifically, the load generating means using an air cylinder corrects the deformation of the table by adjusting the pressure supplied to each air cylinder. Further, the load generation means using a solenoid or the like adjusts the energizing current. Further, in a compression spring or the like, the above effect can be obtained by adjusting the amount of compression.

The table device in which the table is supported by the fixed position determining means having three points has been described above.
The present invention can obtain the same effect when the table is supported by the variable position determining means.

Hereinafter, an embodiment in which the table device according to the second invention of the present application is applied to the table device according to the first invention of the present application shown in FIG. 1 will be described. FIG. 12 is an exploded perspective view showing an embodiment in which the table device shown in FIG. 7 is applied to the table device shown in FIG.

In this table device, four load generating means 1 using air cylinders are provided near the four corners of the table 125.
36a, 136b, 136c, 136d are installed, and the pipes 138a, 138b, 138c, 13 are respectively installed.
High pressure air is supplied by 8d. The other parts have exactly the same configuration as the table device shown in FIG. The operation is also the same as the operation described for the table device shown in FIG. Therefore, here, the operation of the load generating means will be described.

The table 125 includes rollers 127a and 12a.
7b, 127c and tilting stands 123a, 123b, 123c
Its contact point determines its position and orientation. Therefore, here, the roller 127a and the tilt table 123a, the roller 127b and the tilt table 123b, and the roller 127c and the tilt table 123c function as position determining means.

Now, the load generating means 136a, 136b,
When the 136c and 136d are not operating, the table 125 supports the weight of the table 125 only at three contact points of the rollers 127a, 127b and 127c and the tilting supports 123a, 123b and 123c. Therefore, the table 125 is flexibly deformed due to its own weight, and the cost is reduced. Further, a low-frequency vibration mode having three contact points as nodes occurs, and resonance may occur when a vibration source such as an autofocus mechanism is mounted on the table 125. Further, when the weight of the table 125 is large, the contact stress at the contact point between the roller and the tilting base becomes high, the life of the slope of the tilting base is shortened, and the driving means 130 for driving the intermediate member 122 is large. Thrust is required and the motor becomes larger.

Therefore, the piping 138a, 138b, 138
c, 138d to supply high pressure air, and load generating means 1
When 36a, 136b, 136c, and 136d are operated, the table 125 is supported at four points in addition to the three contact points that determine the position and orientation, and the contact stress at the contact points of the roller and the tilting table is large. And the life of the tilting platform is increased, and at the same time, the driving means 13 for the intermediate member 122 is reduced.
The motor load of 0 is greatly reduced and heat generation is reduced.

Further, since the number of supporting points of the table 125 is increased, the flexural deformation of the table 125 is reduced, the surface accuracy of the table 125 is easily improved, and the low frequency vibration mode is eliminated, so that the natural frequency is significantly increased.

Here, the load generating means 136a, 136b,
By making the generated loads of 136c and 136d variable, the deformation of the table 125 can be further appropriately corrected.
Now, in the table device shown in FIG. 12, the intermediate member 122
When the table is driven, the table 125 is displaced in the Z-axis 28 direction. If the load generating means uses a spring or the like, the generated load changes with the displacement of the table 125, and the amount of deformation of the table 125 changes. Therefore, by using the load generating means such as the air cylinder or the solenoid that generates a substantially constant load regardless of the displacement of the movable portion as shown in FIG. 12, a sufficient effect can be obtained even when the table 125 is displaced. .

Although the embodiment in which the table device according to the second invention of the present application is applied to the table device according to the first invention of the present application has been described above, the table device according to the second invention of the present application is a table at three locations. The present invention can be applied to a table device whose position or orientation is determined, and is effective regardless of the presence or absence of displacement of the table, the direction of displacement, and the presence or absence of orientation change.

[0088]

As described above, according to the present invention,
The table device that can set the Z direction position and tilt amount of the table, which is the sample table, independently, does not complicate the control system and mechanism, and is particularly small in Z direction height, compact, and less costly. Will be realized.

Further, while determining the position and orientation of the table by the three supporting means, the surface accuracy of the table is not deteriorated by the deflection of the table due to its own weight, and the table does not resonate even when autofocusing is performed. A table device that does not shorten the life is realized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a table device according to the present invention.

FIG. 2 is an exploded perspective view showing details of the vicinity of a roller support mechanism of the table device shown in FIG.

FIG. 3 is a diagram showing a contact state between a roller and a tilting table.

FIG. 4 is an exploded perspective view showing a first modification of the table device of the present invention.

FIG. 5 is an exploded perspective view showing a second modification of the table device of the present invention.

FIG. 6 is an exploded perspective view showing an embodiment of a second table device of the present invention.

FIG. 7 is an exploded perspective view showing a further embodiment of the second table device of the present invention.

FIG. 8 is a schematic diagram showing an example of table deformation when the table is supported by three position determining means.

FIG. 9 is a schematic diagram showing an example of a vibration mode when the table is supported by three position determining means.

10 is a schematic diagram showing the table device shown in FIG.

FIG. 11 is a schematic diagram showing the table device shown in FIG. 7.

12 is an exploded perspective view showing an embodiment in which the table device shown in FIG. 7 is applied to the table device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Intermediate member 3 Inclined table 4 Elastic guide means 5 Table 6 Roller support mechanism 7 Roller 9 Rotation drive means 10 Drive means 11 Fixed part 12 Center part 20 Center axis

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 21/68 K

Claims (4)

[Claims] 1. A base, an intermediate member movably supported in a uniaxial direction with respect to a base surface of the base, a driving means for moving the intermediate member with respect to the base, and a base surface with respect to the base surface. A table which is elastically supported so as to be displaceable, at least three tilting mounts attached to the intermediate member, and at least three rollers which are rotatable by contacting the tilting faces of these tilting mounts. A table device comprising at least three roller supporting mechanisms attached to the table and rotatably supporting the rollers, wherein at least two of the rollers have a rotation center axis eccentric to the center of each roller. And a roller drive means capable of rotationally positioning the roller around the eccentric center axis of rotation. 2. The base member is supported by at least three linear guides mounted on the base surface, and passes through respective contact portions of the at least three rollers and the at least three tilting bases. 2. The table device according to claim 1, wherein imaginary lines perpendicular to the surface are configured to penetrate through the mounting surface of the Leia guide. 3. A table apparatus having a base, a table displaceably supported with respect to the base, and positioning means for displacing the table to adjust the position of the table with respect to the base. A table device comprising at least three load generating means for generating a load in a direction of pressing the table. 4. The table device according to claim 3, further comprising a load adjusting means for adjusting a load generated by the load generating means.