JP2001050210A - XY table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-Y table without a motor. SOLUTION: An X-Y table 30 comprises an X actuator 10 including an X guide shaft 11 and an X slider 12 movable along the X guide shaft 11 and a Y actuator 20 including a Y guide shaft 21 and a Y slider 22 movable along the Y guide shaft. In the X actuator 10, a pressure chamber is formed between the circumference of the X guide shaft 11 and the X slider 12, and the X slider 12 is provided with a bulkhead to axially divide the pressure chamber into two cylinder chambers. Compressed air can come into and go out of each of the cylinder chambers through passages provided in the X guide shaft 11. The Y actuator 20 is constituted the same as the X actuator 10. By linking both ends of the Y guide shaft 21 with the X slider 12, the X-Y table 30 attached to the Y slider 22 can be moved along either the X axis or the Y axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an XY table, and more particularly to an XY table suitable for use in a sealed chamber, for example, a sealed chamber such as a vacuum chamber in an electron beam exposure apparatus.

[0002]

2. Description of the Related Art An XY table for an electron beam exposure apparatus is used under a high vacuum, and a material used for an actuator so as not to affect a magnetic field for controlling an electron beam trajectory is non-magnetic. Limited to magnetic materials. Therefore, a table using a non-magnetic material such as alumina ceramics or beryllium copper is generally guided by a roller bearing and driven by friction.

As shown in FIG. 6, an actuator driven by friction sandwiches a slider 62 between a driven wheel (not shown) to which a preload P is applied and a driving wheel 61, and controls the rotational motion of the driving wheel 61 by friction. 62 is a structure for converting the motion into a linear motion. The drive wheels 61 are driven by a servo motor 63. A table 64 is slidably combined with the slider 62 by a roller bearing guide on a guide surface. The amount of movement of the table 64 is detected by the displacement sensor 65 and sent to the controller 66. The controller 66 controls the servomotor 63 such that the table 64 is positioned at a predetermined target position in response to the detected movement amount.

[0006] The actuator shown in FIG. 6 has a configuration for one axis. If this is used as an X-axis actuator, a separate Y-axis actuator is required. The Y-axis actuator has the same configuration as the X-axis actuator, but the X-axis actuator and the table 64 are integrally moved in the Y-axis direction.

[0005]

The above-mentioned actuator is characterized in that it can be driven at a high speed as compared with a ball screw drive mechanism. Can be Further, since the coefficient of friction between the drive wheel 61 and the slider 62 is unknown, the device is often used at a low speed in order to avoid slippage.
It is about 20 sheets / hr. In order to obtain a larger frictional force, a large preload P is required, which poses a problem in terms of reliability, such as abrasion of the material of the actuator, generation of dust, and a reduction in life.

The roller bearing guide is a contact type guide,
Although the guide accuracy is determined by the processing accuracy of the guide surface, the guide rigidity is relatively high, but there is a problem that the guide surface is weak against dust entering the contact surface. In addition, a servo motor 63 is used to rotate the drive wheels 61. Since the servo motor 63 has magnetism, it needs to be installed outside the vacuum chamber.
It is inevitable to adopt a configuration in which the table 64 is driven by the slider 62 from outside the vacuum chamber which does not affect the magnetic field of the electron beam. This is a problem common to both the X-axis and Y-axis actuators. As a result, new problems such as an increase in the occupied area of the actuator and a deterioration in kinetic performance due to a decrease in rigidity due to an increase in the length of the drive shaft occur.

Accordingly, an object of the present invention is to provide an XY table that does not use a motor.

It is another object of the present invention to provide an XY table suitable for use in a vacuum chamber.

[0009]

According to the present invention, there is provided an XY table having an actuator including a guide shaft extending in at least one of the X-axis and the Y-axis and a slider movable along the guide shaft. The actuator forms a pressure chamber between the periphery of the guide shaft and the slider, and a partition partitioning the pressure chamber into two cylinder chambers in the axial direction is provided on one of the slider and the guide shaft. It is characterized in that each of the divided cylinder chambers is configured to allow compressed fluid to enter and exit through a supply / discharge passage provided in the guide shaft.

A discharge portion for discharging a leakage fluid from the bearing and the cylinder chamber is provided between the guide shaft and the slider on both sides of the cylinder chamber in the actuator, respectively. Is provided with a discharge passage from the end to the discharge portion.

In addition, connecting portions for supplying / discharging the compressed fluid are provided at both ends of the guide shaft, respectively.
A servo valve is provided in a pipe connected to the connection part.

Further, by providing the actuator in the X-axis direction and the Y-axis direction and connecting one guide shaft to the slider of the other guide shaft, the table mounted on the slider of the one guide shaft can be moved in the X-axis direction. XY table is provided, which is movable in the Y-axis direction. In this case, the actuator has two sets of the guide shaft and the slider in a relation to be parallel to each other.

A hydrostatic air bearing is used as the bearing,
An air supply passage extending from the end of the guide shaft to the hydrostatic air bearing is provided in the guide shaft.

The actuator is preferably made of a non-magnetic material.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG.
The driving principle of the -Y table will be described. As will be described later, the XY table according to the present embodiment includes an X actuator for driving in the X-axis direction and a Y actuator for driving in the Y-axis direction. However, since the driving principle as the actuator is the same, Here, the X actuator will be described.

In FIG. 2, the X actuator 10 is
An X guide shaft 11 fixed at both ends by a support and extending in the X axis direction, and an X slider 12 movable along the X guide shaft 11
And The X slider 12 is a cylindrical body that can surround the periphery of the X guide shaft 11.
A space is formed between the outer periphery of the radiator. This space is used as a pressure chamber, and a partition 13 that partitions the pressure chamber into two cylinder chambers 16 a and 16 b in the axial direction is fixed to the inner wall of the X slider 12. The partition 13 is also slidable along the X guide shaft 11 together with the X slider 12. A static pressure air bearing 14 is provided at each end of the X slider 12, and a bearing air supply system 15 is connected to these static pressure air bearings 14. Since the hydrostatic air bearing is well known, a detailed description thereof will be omitted. Both ends of the X slider 12 also have 2
In the cylinder chambers 16a and 16b divided into two,
Cylinder air supply system 17 for allowing compressed air to enter and exit
a and 17b are connected. Cylinder air supply system 17a, 1
7b each comprise a servo valve 18a, 18b, which is connected to a source of compressed air.

With such a configuration, the hydrostatic air bearing 14
When the compressed air is supplied to the X guide shaft 11, the X slider 12 slightly floats with respect to the X guide shaft 11. Here, for example, when the servo valve 18a is on the compressed air supply side and the servo valve 18b is on the atmosphere release side, the partition 13 acts as a piston, and the X slider 12 moves rightward in FIG. Thus, by controlling the opening of the servo valves 18a and 18b, the X slider 12 can be moved to an arbitrary position with respect to the X guide shaft 11. For the position control system,
A method similar to that described with reference to FIG. 6 can be employed. That is, the controller described with reference to FIG. 6 may control the opening of the servo valves 18a and 18b in accordance with the displacement of the X slider 12, and a detailed description thereof will be omitted.

Next, an example of the X actuator 10 utilizing the above-described driving principle will be described with reference to FIG. In this example, a square body having a rectangular cross section is used as the X guide shaft 11, and the X slider 12 also has a rectangular cross section having a rectangular internal space through which the X guide shaft 11 can be inserted. In particular, the inner wall of the X slider 12 and the X guide shaft 11
Is very small. Here, the X guide shaft 11 is made thinner so that a pressure chamber can be formed in a region near the center of the X guide shaft 11. An X guide shaft 1 is provided on the inner wall of the X slider 12 to partition the pressure chamber into two cylinder chambers 16a and 16b.
A partition wall 13 slidable along 1 is fixed.

In the following, the cylinder chamber 1 divided into two sections
The structure on the cylinder chamber 16a side of 6a and 16b will be described. The cylinder chamber 16b side has exactly the same structure.

In order to allow compressed air to enter and exit the cylinder chamber 16a, an air passage 11-1 is provided at the center of the X guide shaft 11 from the end to the center. The air passage 11-1 is branched into a plurality of portions near the cylinder chamber 16a and communicates with the cylinder chamber 16a so that the pressure distribution in the cylinder chamber 16a is uniform.
An air pipe is connected to the air passage 11-1 at the end of the X guide shaft 11, and further provided with the servo valve described with reference to FIG. The maximum stroke of the X slider 12 is determined by the axial dimensions of the cylinder chambers 16a and 16b.

Referring also to FIG. 3, a static pressure air bearing 14 is provided around the X guide shaft 11 near the cylinder chamber 16a.
19-2 are provided. Since the cross-sectional shape of the X guide shaft 11 is rectangular, the static pressure air bearings 14 are provided on four surfaces thereof. The exhaust portions 19-1 and 19-2 are for exhausting air leaking from the cylinder chamber 16a and air from the static pressure air bearing 14, and X is used to facilitate exhaust.
A groove is formed around the guide shaft 11, and exhaust is performed through this groove. The X guide shaft 11 is further provided with a vacuum exhaust unit 19-3 at a position outside the hydrostatic air bearing 14 in the axial direction. The reason why the vacuum exhaust unit 19-3 is provided in consideration of use in a vacuum chamber is that the vacuum exhaust unit 19-3 is also provided with a groove around the X guide shaft 11 to facilitate the exhaust. Is formed, and vacuum evacuation is performed through this groove.

In order to supply compressed air to the static pressure air bearing 14, the static pressure air bearing 1 is inserted into the X guide shaft 11 from the end thereof.
4 are provided. The X guide shaft 11 also has exhaust portions 19-1 and 1-1 from its ends.
A plurality of exhaust passages 11-3 reaching the groove 9-2 are provided. The X guide shaft 11 is further provided with an exhaust passage 11-4 extending from its end to the groove of the vacuum exhaust unit 19-3.
The exhaust passage 11-4 is provided in a groove of the vacuum exhaust unit 19-3.
It is preferable that holes are provided for each of the four surfaces of the X guide shaft 11 so as to communicate with each of the holes. In FIG. 3, for convenience, a plurality of types of passages provided in the X guide shaft 11 are all indicated by solid lines, but these passages are provided at different positions in the X guide shaft 11 in the circumferential direction. Needless to say.

An air pipe is connected to a plurality of air passages 11-2 at the end of the X guide shaft 11, and a compressed air supply source is further provided. Similarly, an air pipe is connected to the plurality of exhaust passages 11-3 at the end of the X guide shaft 11,
Further, an exhaust pump is provided. An air pipe is connected to the exhaust passage 11-4 at the end of the X guide shaft 11,
Further, a pump for evacuation is provided.

As shown in FIG. 1, both ends of the X guide shaft 11 pass through the side wall of the vacuum chamber 1 so as to be supported by the side wall. Therefore, the connection of the air pipes at both ends of the X guide shaft 11 is performed outside the vacuum chamber 1.

Although the X actuator 10 has been described above, the Y actuator has exactly the same structure.

Next, an example of an XY table using the above X actuator 10 and Y actuator will be described with reference to FIG. In this example, the X actuator 10 has two sets of the X guide shaft 11 and the X slider 12 in such a relationship that they are parallel to each other, and the Y actuator 20 also has the Y guide shaft 21 and the Y slider 22.
And two combinations in parallel with each other. Particularly, both ends of two sets of Y guide shafts 21 are connected to two sets of X guides.
It is connected to the slider 12. As a result, the two sets of Y guide shafts 21 can move in the X-axis direction together with the two sets of X sliders 12. Further, a table 30 is provided between the two sets of Y sliders 22. In this way, by combining the movement of the X slider 12 in the X axis direction and the movement of the Y slider 22 in the Y axis direction, the table 30 can be moved in both the X axis direction and the Y axis direction. . In the case of such an XY table, both ends of the X guide shaft 11 are fixed to the side wall of the vacuum chamber as described with reference to FIG.

When the XY table is used under a high vacuum such as a vacuum chamber in an electron beam exposure apparatus, each of the components is set so as not to affect the magnetic field for controlling the electron beam trajectory. As a material of the element, a non-magnetic material such as alumina ceramics or beryllium copper is used.

FIG. 5 shows another example of the X actuator. In this example, the X guide shaft 11 'has the same cross-sectional shape in the axial direction. On the other hand, the X slider 12 'is connected to the two members 12-1, 12- through which the X guide shaft 11' is inserted.
2 and a cylindrical body 12-3 which connects these two members 12-1 and 12-2 while covering them, thereby forming a pressure chamber around the center of the X guide shaft 11 '. Has formed. Furthermore, the pressure chamber is divided into two cylinder chambers 16a and 16b by fixing the partition 13 'to the X guide shaft 11' in the pressure chamber. Two members 12
-1, 12-2 are movable along the X guide shaft 11 'together with the cylindrical body 12-3, and the inner wall of the cylindrical body 12-3 forming the pressure chamber is the outer periphery of the partition wall 13'. Can slide on top. The structure for allowing compressed air to enter and exit the cylinder chambers 16a and 16b, the static pressure air bearing 14, the exhaust units 19-1, 19-2, the vacuum exhaust unit 19-3, and the surrounding structure are the same as those described above. Same is good.

When the compressed air is introduced into the cylinder chamber 16a, for example, the X actuator 12 '
5 differs from the example of FIG. 1 in that it moves to the left in FIG. 5, but the operation principle is exactly the same.

In the above description, the XY table in which both the X slider and the Y slider are driven by the pneumatic actuator, which is a feature of the present invention, has been described. However, only one slider is driven by the pneumatic actuator. May be. Further, not only the compressed air but also a fluid such as another gas such as nitrogen gas or a liquid such as water may be used.

[0031]

As described above, the XY table according to the present invention has a structure in which the slider is guided in a non-contact manner with respect to the guide shaft. That is, problems such as material abrasion, dust generation, and shortened life can be solved. The components shown in FIG. 4 except for the compressed air supply source and the pump for evacuation can be arranged in the vacuum chamber, and the area occupied in the vacuum chamber can be reduced. X according to the invention
The -Y table is particularly suitable for use in a vacuum chamber such as an electron beam exposure apparatus by constituting each component with a non-magnetic material.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a structure of an X actuator for forming an XY table according to the present invention.

FIG. 2 is a diagram for explaining the operation principle of the X actuator shown in FIG.

3 is an enlarged sectional view showing a static pressure air bearing, an exhaust unit, a vacuum exhaust unit, and a passage provided on an X guide shaft for connecting them to an air pipe in FIG. 1;

FIG. 4 is a perspective view showing an XY table configured by combining the X actuator and the Y actuator shown in FIG. 1;

FIG. 5 is a sectional view showing another example of the X actuator.

FIG. 6 is a diagram showing an example of a conventional actuator driven by friction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 10 X actuator 11 X guide shaft 12 X slider 13 Partition wall 14 Static pressure air bearing 16a, 16b Cylinder chamber 18a, 18b Servo valve 19-1, 19-2 Exhaust part 19-3 Vacuum exhaust part 20 Y actuator 21Y Slider 30 table

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takashi Shibukawa 63-30 Yuyugaoka, Hiratsuka-shi, Kanagawa F-term in Hiratsuka Works of Sumitomo Heavy Industries, Ltd. (Reference) 3H081 AA04 BB03 CC29 DD26 DD27 EE20 EE23 FF26 HH04 5C001 AA03 CC06 5F056 CB21 EA14 EA16

Claims (7)

[Claims] 1. An XY table having an actuator including a guide shaft extending in at least one of the X-axis and the Y-axis and a slider movable along the guide shaft, wherein the actuator is provided around the guide shaft. A pressure chamber is formed between the slider and the slider, and a partition partitioning the pressure chamber into two cylinder chambers in the axial direction is provided on one of the slider and the guide shaft. An XY table, wherein each of the XY tables is configured by allowing compressed fluid to enter and exit through a supply / discharge passage provided in the guide shaft. 2. The XY table according to claim 1, wherein leakage fluid from the bearing and the cylinder chamber is discharged between the guide shaft and the slider on both sides of the cylinder chamber in the actuator. And a discharge passage extending from the end of the guide shaft to the discharge portion is provided in the guide shaft.
Y table. 3. The XY table according to claim 1, wherein connecting portions for supplying / discharging the compressed fluid are provided at both ends of the guide shaft, and a pipe connected to the connecting portion is provided. X characterized by having a servo valve
-Y table. 4. The XY according to claim 1, wherein
In the table, the actuator is provided in the X-axis direction and the Y-axis direction, and one of the guide shafts is connected to the slider of the other guide shaft. An XY table, which is movable in an axial direction. 5. The XY table according to claim 4, wherein the actuator has two sets of the guide shaft and the slider, which are parallel to each other. 6. The XY table according to claim 2, wherein a static pressure air bearing is used as said bearing, and an air supply passage extending from an end of said guide shaft to said static pressure air bearing is provided in said guide shaft. An XY table characterized by the following. 7. XY according to claim 1, wherein
An XY table, wherein the actuator is made of a non-magnetic material.