JP2002107479A - Stage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stage device capable of miniaturizing a vacuum chamber by minimizing a driving mechanism-related part in the vacuum chamber. SOLUTION: An X guide mechanism and a Y guide mechanism capable of moving movable rods 1X and 1Y in the X direction and the Y direction are respectively arranged in mutually opposed two pairs of positions on the outside adjacent to the side surface of the vacuum chamber 10. An X actuator and a Y actuator for driving the movable rods in the X axis direction and the Y axis direction are respectively arranged in the X guide mechanism and the Y guide mechanism. The X guide mechanism and the Y guide mechanism respectively house a central part of the movable rods 1X and 1Y in an airtight state, and have vacuum chamber introducing chambers 6X and 6Y communicating with the vacuum chamber 10, and a stage and the movable rods 1X and 1Y are connected by a common X connecting a shaft member at a right angle to the X axis direction and a Y connecting shaft member at a right angle to the Y axis direction via the communicating part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage device, and more particularly, to a stage device driven in at least one axial direction in a vacuum chamber and capable of high-speed, high-precision positioning.

[0002]

2. Description of the Related Art High-speed, high-precision
Higher precision is required. In order to satisfy this requirement, non-contact guides using hydrostatic bearings using air are provided.
A stage device that performs non-contact driving by a linear actuator based on the principle of compressed air pressure or a linear motor has been proposed.

The combination of a non-contact guide mechanism with a static pressure bearing and a compressed air drive mechanism has already been proposed by the present applicant as a fluid pressure actuator (Japanese Patent Application No. 11-225007), an X-ray actuator.
A high-speed, high-precision stage device that can be used in a vacuum non-magnetic environment in a vacuum chamber has been proposed as a Y table (Japanese Patent Application No. 11-224998).

[0004]

By the way, it is desirable to make the vacuum chamber as small as possible in order to increase the rigidity and minimize deformation due to changes in internal pressure (during evacuation) and external pressure (atmospheric pressure). In this case, it is disadvantageous in the device configuration including the driving mechanism in the vacuum chamber, and there is a limit to downsizing.

It is an object of the present invention to reduce the size of a vacuum chamber by minimizing a portion related to a driving mechanism in a vacuum chamber in a stage device for driving and guiding a stage in a vacuum chamber in a non-contact manner. It is to provide a stage device which can be used.

[0006]

According to the present invention, there is provided a stage apparatus in which a stage is movable in at least one axial direction in a vacuum chamber. A first guide mechanism for moving the first moving body in the one axis direction is provided, and at least one of the first guide mechanisms is provided with a first drive for driving the first moving body in the one axis direction. And a first guide mechanism having a first vacuum chamber introduction chamber that accommodates a central portion of the first moving body in an airtight state and communicates with the vacuum chamber.
The stage and the first moving body are connected by a common first connection shaft member perpendicular to the one axial direction through a communication portion between the vacuum chamber introduction chamber and the vacuum chamber.

In this stage apparatus, the second movable body is movable in a direction perpendicular to the uniaxial direction to a position outside and adjacent to a side surface different from the side surface of the vacuum chamber and facing each other. A second driving mechanism for driving the second moving body in a direction perpendicular to the uniaxial direction is provided in at least one of the second guiding mechanisms. Has a second vacuum chamber introduction chamber that accommodates the central portion of the second moving body in an airtight state and communicates with the vacuum chamber. The second vacuum chamber introduction chamber and the vacuum The stage and the second moving body are connected to each other by a common second connecting shaft member parallel to the one axial direction and at a different height from the first connecting shaft member through a communication portion with the chamber. Has been A first cylindrical body is provided on the stage for slidably supporting the first connection shaft member, and a first hydrostatic bearing is provided in the first cylindrical body, whereby the stage is provided. Are slidable in a direction perpendicular to the uniaxial direction, and a second cylindrical body is further provided on the stage to slidably support the second connecting shaft member, and the second cylindrical body By providing the second hydrostatic bearing in the body, the stage can be slid in the uniaxial direction.

In the present stage apparatus, a first fluid exhaust portion for discharging a fluid for a hydrostatic bearing out of a vacuum chamber is provided on both sides of the first and second hydrostatic bearings, respectively. It is desirable to further provide a first exhaust unit for vacuum exhaust at a position outside the fluid exhaust unit.

In the present stage apparatus, the first and second driving mechanisms can each be realized by a linear actuator.

In this stage apparatus, the first and second driving mechanisms can be realized by fluid pressure driving mechanisms.

In particular, when the moving body is a shaft, the guide mechanism has a sealed cylindrical portion on both sides of the vacuum chamber introduction chamber capable of housing both sides of the shaft in a sealed and slidable state. A pressure chamber through which fluid can be taken in and out is formed between the closed cylindrical portion and the end of the shaft body to constitute the fluid pressure driving mechanism, and the vacuum chamber introduction chamber and the pressure chamber A third hydrostatic bearing for slidably supporting the shaft body is provided in the closed cylindrical portion between the bearings.

A second fluid exhaust portion for discharging the fluid for the hydrostatic bearing out of the guide mechanism is provided on both sides of the third hydrostatic bearing, and the second fluid exhaust portion is provided near the vacuum chamber introduction chamber. It is desirable to provide a second exhaust unit for evacuation between the second fluid exhaust unit and the vacuum chamber introduction chamber.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a stage apparatus according to the present invention, a drive mechanism is arranged outside a vacuum chamber in order to reduce the size of the vacuum chamber. A stage device according to the present invention includes an X fluid pressure driving mechanism for driving in the X-axis direction (hereinafter, the fluid pressure driving mechanism is referred to as an actuator) and a Y actuator for driving in the Y-axis direction.

An X guide mechanism (first guide mechanism) having an X actuator will be described with reference to FIGS. 1 and 2. The Y guide mechanism (second guide mechanism) having a Y actuator has exactly the same configuration. It is.

In FIG. 1, an X actuator comprises a movable rod 1 having a shaft, pressure chambers 2a and 2b for pressurizing both end surfaces of the movable rod 1, and a movable rod 1 at a position inside the pressure chambers 2a and 2b. And non-contact static pressure bearings 3a and 3b.

More specifically, the X guide mechanism has a first vacuum chamber introduction chamber 6 which accommodates a central portion of the movable rod 1 in an airtight state and communicates with a vacuum chamber described later. On both sides of the vacuum chamber introduction chamber 6, there are closed cylindrical portions 9a and 9b capable of housing both sides of the movable rod 1 in a sealed and slidable manner.
Pressure chambers 2a and 2b through which compressed air can be taken in and out are formed between the movable rod 1 and the end of the movable rod 1 to constitute an X actuator. A static pressure bearing 3a (third static pressure bearing) for slidably supporting the movable rod 1 in a floating state is provided in the closed cylindrical portion 9a between the vacuum chamber introduction chamber 6 and the pressure chamber 2a. ing.

The sectional shape of the movable rod 1 may be any one of a circle and a polygon, but is preferably a square in consideration of providing a hydrostatic bearing. In this case, the hydrostatic bearings are provided on each surface of the square, that is, at four locations.

Referring also to FIG. 2, on both sides of the hydrostatic bearing 3a, a fluid exhaust portion (second fluid exhaust portion) 5a for discharging the compressed air for the hydrostatic bearing to the outside of the X guide mechanism. An exhaust unit (second exhaust unit) 7a for evacuation is provided between the fluid exhaust unit 5a near the vacuum chamber introduction chamber 6 and the vacuum chamber introduction chamber 6. A fluid exhaust portion (second fluid exhaust portion) 5b for discharging the compressed air for the static pressure bearing to the outside of the X guide mechanism is provided on both sides of the static pressure bearing 3b, and the fluid near the vacuum chamber introduction chamber 6 is provided. An evacuation unit (second evacuation unit) 7b for evacuation is provided between the evacuation unit 5b and the vacuum chamber introduction chamber 6. Fluid exhaust parts 5a, 5b
Is the air leaking from the pressure chambers 2a and 2b and the static pressure bearing 3a,
It is for discharging the compressed air from 3b. On the other hand, the exhaust units 7a and 7b are for minimizing the inflow of air into the vacuum chamber described later, so that the capacity of the vacuum chamber exhaust pump does not exceed the normally required capacity.

For this purpose, the fluid exhaust portions 5a and 5b are provided with grooves in the circumferential direction on the inner walls of the closed cylindrical portions 9a and 9b, respectively, and exhaust passages are formed at one or more of these grooves. And air is exhausted from the passage to the atmosphere through an air pipe. Similarly, the exhaust portions 7a and 7b are provided with grooves in the circumferential direction on the inner walls of the closed cylindrical portions 9a and 9b, and connected to one or more of these grooves by forming an exhaust passage. A pump for evacuation is connected via a pipe.

Servo valves 4 are provided in the pressure chambers 2a and 2b, respectively.
A compressed air supply source is connected via a and 4b. The servo valves 4a and 4b shown in FIG.
2b is cut off.

When compressed air is supplied to the hydrostatic bearings 3a and 3b in the above-described configuration, the movable rod 1 becomes closed cylindrical portions 9a and 9b.
b rises slightly from the inner wall of b. Here, for example, the servo valve 4a is connected to the compressed air supply side (the left side in FIG. 1),
When b is open to the atmosphere (the right side in FIG. 1), the movable rod 1 that has received pressure on the shaft end surface acts as a piston and moves rightward in FIG. The movable rod 1 can be moved to an arbitrary position by controlling the opening of the servo valves 4a and 4b by a control device (not shown) in this manner.

Note that, instead of the actuator using compressed air, an actuator using a fluid such as nitrogen gas may be used, or a driving mechanism such as a linear actuator based on the principle of a linear motor may be used. In the case of a linear actuator, the pressure chamber shown in FIG. 1 is not necessary, and at least one end of the movable rod 1 is exposed from the sealed cylindrical portion in a sealed state, and the exposed portion is driven by the linear actuator. good.

Referring to FIG. 3 and FIG. 4, XY is provided with the X guide mechanism and the Y guide mechanism having the above-described structure, and the stage can be driven in the X axis direction and the Y axis direction in the vacuum chamber.
The stage device will be described.

Vacuum chamber 1 having a square planar shape
An X guide mechanism 11 that makes the movable rod 1X movable in the X-axis direction is provided at an outer position adjacent to the opposing side surface of the O and at positions opposing each other. As described above, each of the X guide mechanisms 11 has a movable rod 1X.
Is provided in the X-axis direction. The X guide mechanism 11 accommodates a central portion of the movable rod 1X in an airtight state and has a vacuum chamber introduction chamber 6X communicating with the vacuum chamber 10. The frame 17 and the two movable rods 1X are connected by a common X connection shaft member (first connection shaft member) perpendicular to the X axis direction through a communication portion between the vacuum chamber introduction chamber 6X and the vacuum chamber 10. The length of this communication part in the X-axis direction is
It is necessary to set a value exceeding the movable range of X.

The X connecting shaft member includes a joint 13X having one end fixed to the center of the movable rod 1X, a movable plate 14X fixed to the other end of the joint 13X,
And two guide rods 15X bridged between the two movable plates 14X. On both sides parallel to the Y-axis direction of the frame 17, a cylindrical body (first cylindrical body) 19Y is provided for slidably supporting the two guide rods 15X of the X connecting shaft member. Shape 19Y
The frame 17 is slidable in the Y-axis direction by providing a hydrostatic bearing (first hydrostatic bearing) 18Y therein.

The movable rod 1Y is movable in the Y-axis direction perpendicular to the X-axis direction at a position outside and adjacent to the side surface of the vacuum chamber 10 opposite to the side surface of the vacuum chamber 10 and facing each other. Y guide mechanism (second guide mechanism) 12 is provided. The Y guide mechanism 12 is provided with a Y actuator that drives the movable rod 1Y in the Y axis direction. The Y guide mechanism 12 includes a movable rod 1Y
And a vacuum chamber introduction chamber 6Y (second vacuum chamber introduction chamber) that accommodates the central portion of the vacuum chamber in an airtight state and communicates with the vacuum chamber 10. The frame 17 and the two movable rods 1Y are in a position parallel to the X-axis direction and at a different height from the above-mentioned X connecting shaft member through the communicating portion between the vacuum chamber introducing chamber 6Y and the vacuum chamber 10 (see FIG. 4). They are connected by a common Y connection shaft member (second connection shaft member). The length of the communicating portion of the vacuum chamber introduction chamber 6Y in the Y-axis direction also needs to be a value exceeding the movable range of the movable rod 1Y.

The Y connecting shaft member includes a joint 13Y having one end fixed to a central portion of the movable rod 1Y, a movable plate 14Y fixed to the other end of the joint 13Y,
And two guide rods 15Y bridged between the two movable plates 14Y. On both sides of the frame 17 parallel to the X-axis direction, a cylindrical body (second cylindrical body) 19X is provided for slidably supporting the two guide rods 15Y of the Y connecting shaft member. 19X
By providing a hydrostatic bearing (second hydrostatic bearing) 18X therein, the frame 17 can be slid in the X-axis direction.

As shown in FIG. 4, on both sides of the static pressure bearing 18X, a fluid exhaust portion (first fluid exhaust portion) 21a for exhausting the compressed air for the static pressure bearing out of the vacuum chamber 10 is provided. And the fluid exhaust unit 21a and the vacuum chamber 1
Exhaust section for vacuum exhaust (first exhaust section)
22a is provided. Although not shown, a fluid exhaust portion (first fluid exhaust portion) for discharging compressed air for the static pressure bearing out of the vacuum chamber 10 is provided on both sides of the static pressure bearing 18Y, respectively. An evacuation unit (first evacuation unit) for evacuation is provided between the evacuation unit and the inside of the vacuum chamber 10. The structure and the purpose of use of the fluid exhaust unit and the exhaust unit for vacuum exhaust are the same as those of the fluid exhaust units 5a and 5b described above.
This is the same as the exhaust units 7a and 7b. The above-described static pressure bearing, the fluid exhaust portion, and the exhaust portion around the frame 17 are connected to piping outside the vacuum chamber 10 via flexible piping. Further, the wafer table 16 is fixed on the frame 17 to form a stage.

In the above configuration, when compressed air is supplied to the hydrostatic bearings 18X and 18Y for supporting and guiding the frame 17, the frame 17 also slightly floats. Here, for example, X
When the movable rod 1X of the actuator is moved, the frame 17 on which the wafer table 16 is mounted is pushed in the X-axis direction by the X guide rod 15X, and moves along the Y guide rod 15Y. On the other hand, when the movable rod 1Y of the Y actuator is moved, the frame 17 is pushed by the Y guide rod 15Y and the X guide rod 15Y is moved.
Move along X.

In the above embodiment, the stage device movable in the X-axis direction and the Y-axis direction has been described. However, the present invention is also applied to a stage device movable in one of the X-axis direction and the Y-axis direction. In this case, there is no need for a hydrostatic bearing in the vacuum chamber. Further, two sets of the same actuator are used in one direction, but one set may be configured with only a guide without an actuator.

[0031]

In the stage device according to the present invention, since the movable part is guided in a non-contact manner and the actuator can also adopt a non-contact type, problems caused by friction between them, material abrasion, dust generation, Problems such as shortened life can be solved,
Since there is no frictional resistance, high-speed, high-precision positioning can be performed.

Further, the amount of air leaking into the vacuum chamber introduction chamber and the amount of air leaking from the hydrostatic bearing guide in the vacuum chamber can be limited to a range not exceeding the exhaust capacity of the vacuum pump for the vacuum chamber.

Further, since the inside of the vacuum chamber is only the guide portion, the size of the vacuum chamber can be reduced. As a result, the amount of chamber deformation during assembly adjustment (atmospheric pressure in the vacuum chamber) and during operation (vacuum in the vacuum chamber) can be reduced, and errors in the table position measuring instrument can be reduced. Further, the deformation of the chamber due to a change in the atmospheric pressure is reduced, and the accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a configuration of an X guide mechanism including an X actuator used in the present invention.

FIG. 2 is a diagram for explaining the relationship between the hydrostatic bearing shown in FIG. 1, a fluid exhaust unit installed adjacent thereto, and an exhaust unit.

FIG. 3 is a diagram showing an embodiment of a stage device according to the present invention including the X guide mechanism of FIG. 1 and a Y guide mechanism having the same configuration.

FIG. 4 is a sectional view of the stage device of FIG. 3 taken along line AA.

[Explanation of symbols]

 1, 1X Movable rod 2a, 2b Pressure chamber 3a, 3b, 18X, 18Y Static pressure bearing 4a, 4b Servo valve 5a, 5b, 21a Fluid exhaust part 6, 6X, 6Y Vacuum chamber introduction chamber 7a, 7b, 22a Exhaust part 9a , 9b Sealed cylindrical part 13X, 13Y Joint 14X, 14Y Movable plate 15X, 15Y Guide rod 16 Table 17 Frame 19X, 19Y cylindrical part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F078 CA08 CB09 CB16 CC11 3J102 AA02 BA05 BA13 CA19 EA02 EA06 EA22 GA01 GA19 GA20 5F046 CC01 CC02 CC03 CC18

Claims (7)

[Claims] 1. A stage apparatus in which a stage is movable in at least one axial direction within a vacuum chamber, wherein the first movement is performed in the uniaxial direction at a position outside and adjacent to a side surface of the vacuum chamber and facing each other. A first guide mechanism for moving the body is provided, and at least one of the first guide mechanisms is provided with the first guide mechanism;
A first driving mechanism for driving the moving body in the uniaxial direction, wherein the first guide mechanism accommodates a central portion of the first moving body in an airtight state and communicates with the vacuum chamber. A first vacuum chamber introduction chamber, wherein the stage and the first moving body are connected to each other through a communication portion between the first vacuum chamber introduction chamber and the vacuum chamber. A stage device connected by a shaft member. 2. The stage apparatus according to claim 1, wherein the second side of the vacuum chamber is located at a position outside and adjacent to the side surface different from the side surface and facing each other in a direction perpendicular to the uniaxial direction. A second guide mechanism that makes the moving body movable; and at least one of the second guide mechanisms has the second guide mechanism.
A second driving mechanism for driving the moving body in a direction perpendicular to the uniaxial direction, wherein the second guide mechanism accommodates a central portion of the second moving body in an airtight state and the vacuum chamber. A second vacuum chamber introduction chamber communicating with the second vacuum chamber introduction chamber and the vacuum chamber, and the stage and the second moving body are parallel to the uniaxial direction through a communication portion between the second vacuum chamber introduction chamber and the vacuum chamber. The first connection shaft member is connected to the first connection shaft member by a common second connection shaft member at a position different in height, and the first connection shaft member is slidably supported on the stage by the first connection shaft member. And the first cylindrical body is provided.
By providing a first hydrostatic bearing in the cylindrical body of (1), the stage can be slid in a direction perpendicular to the uniaxial direction, and the stage further supports the second connecting shaft member so as to be slidable. By providing a second cylindrical body for this purpose, and by providing a second hydrostatic bearing in the second cylindrical body,
A stage apparatus wherein the stage is slidable in the uniaxial direction. 3. The stage device according to claim 2, wherein
On both sides of the first and second hydrostatic bearings, a first fluid exhaust portion for exhausting a fluid for the static pressure bearing out of the vacuum chamber is provided, and a first fluid exhaust portion is provided at a position outside the fluid exhaust portion. A stage device further comprising a first exhaust unit for evacuation. 4. The stage device according to claim 3, wherein
A stage device, wherein each of the first and second driving mechanisms includes a linear actuator as a driving source. 5. The stage device according to claim 3, wherein
A stage apparatus, wherein each of the first and second drive mechanisms includes a fluid pressure drive mechanism as a drive source. 6. The stage apparatus according to claim 5, wherein
The moving body is a shaft, and the guide mechanism has a sealed cylindrical portion on both sides of the vacuum chamber introduction chamber capable of housing both sides of the shaft in a sealed and slidable state. A pressure chamber capable of taking in and out of a fluid is formed between the end portion of the shaft and the end of the shaft body to constitute the fluid pressure driving mechanism, and the hermetic seal between the vacuum chamber introduction chamber and the pressure chamber is provided. A stage device, wherein a third hydrostatic bearing for slidably supporting the shaft body is provided on the cylindrical portion. 7. The stage apparatus according to claim 6, wherein
On both sides of the third hydrostatic bearing, a second fluid exhaust portion for exhausting fluid for the hydrostatic bearing out of the guide mechanism is provided, and the second fluid exhaust near the vacuum chamber introduction chamber is provided. A stage device, wherein a second exhaust unit for evacuation is provided between the unit and the vacuum chamber introduction chamber.