JP6704658B2 - Stage equipment - Google Patents

Description

The present invention relates to a stage device.

A stage device for positioning an object in a first direction and a second direction orthogonal to the first direction is known. Conventionally, a stage device called a stack type has been proposed in which there is one X-axis direction guide and one Y-axis direction guide (for example, Patent Document 1). This stack type stage device generally includes a first slider, a first guide for guiding the movement of the first slider in a first direction, a second slider for supporting the first guide, and a second slider for moving the second slider in a second direction. A second guide for guiding movement.

JP-A-5-57558

In the stack type stage device as described in Patent Document 1, when the first slider moves, a load change occurs in the first guide, the first guide tilts around the second direction, and the first guide supports the first guide. 2 A moment around the second guide may be generated in the slider. As a result, galling may occur in which the second slider contacts the second guide.

The present invention has been made in view of such a situation, and an object thereof is to provide a stage device capable of suppressing the galling of a slider in contact with a guide.

In order to solve the above problems, a stage device according to an aspect of the present invention includes a first slider, a first guide that guides movement of the first slider in a first direction, and a second slider that supports the first guide. , A second guide that guides the movement of the second slider in the second direction, and at least one posture maintaining member that applies a posture control force for maintaining the posture of the first guide to the first guide.

It should be noted that any combination of the above constituent elements, and those in which the constituent elements and expressions of the present invention are interchanged among devices, methods, systems, etc. are also effective as aspects of the present invention.

According to the present invention, it is possible to suppress the occurrence of galling when the slider contacts the guide.

It is a perspective view showing a stage device concerning an embodiment. It is a figure which shows the cross section of the X-axis guide and the X-axis slider of FIG. It is the sectional view on the AA line of FIG. It is sectional drawing which shows one of the attitude|position maintaining members, and its periphery. It is a block diagram which shows the function and structure of a control part.

Hereinafter, the same or equivalent constituent elements, members, and steps shown in each drawing will be denoted by the same reference numerals, and duplicate description will be appropriately omitted. In addition, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. Further, in each drawing, some of the members that are not important for explaining the embodiment are omitted.

FIG. 1 is a perspective view showing a stage device 100 according to an embodiment. For convenience of explanation, as shown in the drawing, the X-axis guide 12 (described later) has the extending direction as the X-axis direction, and the direction in which the Y-axis guide 16 (described later) extends is Y. An XYZ orthogonal coordinate system in which the Z direction is the axial direction and the direction orthogonal to both is defined. The stage device 100 is called a stack type XY stage, and positions an object in the X-axis direction (first direction) and the Y-axis direction (second direction orthogonal to the first direction).

The stage device 100 includes a base frame 10, an X-axis guide 12, an X-axis slider 14, a Y-axis guide 16, a Y-axis slider 18, a table 20, two side guides 22, and two attitude maintaining members. 26 and a control unit 30 (not shown in FIG. 1).
Hereinafter, the side on which the X-axis guide 12 is provided with respect to the Y-axis guide 16 in the Z-axis direction will be described as the upper side.

The Y-axis guide 16 is a long member and is supported by the base frame 10. The Y-axis slider 18 is guided by the Y-axis guide 16 and moves in the Y-axis direction. The X-axis guide 12 is a long member similar to the Y-axis guide 16, and is supported by the Y-axis slider 18. Therefore, the X-axis guide 12 and thus the X-axis slider 14 move in the Y-axis direction as the Y-axis slider 18 moves in the Y-axis direction. The X-axis slider 14 is guided by the X-axis guide 12 and moves in the X-axis direction.

The table 20 is fixed to the X-axis slider 14. An object to be processed such as a semiconductor wafer is placed on the table 20, for example. By moving the Y-axis slider 18 in the Y-axis direction and moving the X-axis slider 14 in the X-axis direction, the table 20 can be moved in the XY direction and the object can be positioned in the XY direction.

FIG. 2 shows a cross section of the X-axis guide 12 and the X-axis slider 14 taken along a plane orthogonal to the X-axis direction. Although the configurations of the X-axis guide 12 and the X-axis slider 14 will be representatively described, the same description applies to the Y-axis guide 16 and the Y-axis slider 18.

The X-axis guide 12 includes a bottom wall 32, a first side wall 34, and a second side wall 36. The bottom wall 32 is a plate-shaped member that is long in the X-axis direction, and is provided so that the two main surfaces thereof face the Z-axis direction. The first side wall 34 is a standing wall that is long in the X-axis direction, and is provided upright at one end in the Y-axis direction of the upper surface (that is, one main surface) of the bottom wall 32. The second side wall 36 is a standing wall that is long in the X-axis direction, like the first side wall 34, and is erected on the other end of the upper surface of the bottom wall 32 in the Y-axis direction so as to face the first side wall 34 in the Y-axis direction. To do. The first side wall 34 and the second side wall 36 each have a first extending portion 34a and a second extending portion 36a extending toward each other. Therefore, the first side wall 34 and the second side wall 36 have an L-shaped cross-sectional shape.

The X-axis slider 14 is a rectangular parallelepiped member and is housed inside the X-axis guide 12, that is, between the first side wall 34, the second side wall 36, and the bottom wall 32. One or a plurality of air pads 40 are formed on each surface of the X-axis slider 14 facing the X-axis guide 12, that is, the bottom surface 14a, the first side surface 14b, the second side surface 14c, and the upper surface 14d. The air pad 40 ejects a high-pressure gas supplied from an air supply system (not shown) to form a high-pressure gas layer with the X-axis guide 12. As a result, the X-axis slider 14 floats above the X-axis guide 12 with a minute gap maintained.

An air servo chamber 48 for driving the X-axis guide 12 is formed on the first side surface 14b facing the first side wall 34 and the second side surface 14c facing the second side wall 36. That is, in this embodiment, two air servo chambers 48 are formed in the X-axis slider 14. This makes it possible to control the rotation of the X-axis slider 14 around the Z-axis.

Exhaust grooves 42, 44, and 46 for differential exhaust are formed on each surface of the X-axis slider 14 so as to surround the air pad 40. The exhaust groove 42 is open to the atmosphere. The exhaust groove 42 may be connected to an exhaust pump (not shown). The exhaust grooves 44 and 46 are connected to an exhaust pump (not shown) for adjusting the pressure inside the exhaust grooves to a low vacuum pressure level and an intermediate vacuum pressure level, respectively, and to the air pad 40 of the X-axis slider 14 and the air servo chamber. The compressed gas supplied from 48 to the internal space is exhausted to the outside. In this way, by preventing the compressed gas from leaking through the gap between the X-axis guide 12 and the X-axis slider 14, the stage device 100 can be used even in a vacuum environment. When the stage device 100 is used in an atmospheric pressure environment, it is not necessary to provide such exhaust grooves 42, 44, 46.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. The principle by which the X-axis slider 14 moves with respect to the X-axis guide 12 will be described with reference to FIG. Note that the principle of the X-axis slider 14 moving with respect to the X-axis guide 12 will be described as a representative, but the same description applies to the principle of the Y-axis slider 18 moving with respect to the Y-axis guide 16. The stage device 100 further includes a partition wall 56.

In FIG. 3, the gap between the X-axis guide 12 and the X-axis slider 14 and the gap between the partition wall 56 and the air servo chamber 48 are exaggeratedly drawn. In practice, for example, these gaps are on the order of a few microns. The partition wall 56 is fixed to the X-axis guide 12 and divides the air servo chamber 48 of the X-axis slider 14 into two air servo chambers 48A and 48B in the X-axis direction. Air supply systems 50A and 50B for allowing compressed gas to flow in and out are respectively connected to the two air servo chambers 48A and 48B. The air supply systems 50A and 50B include servo valves 52A and 52B and compressed gas supply sources 54A and 54B, respectively.

When the compressed gas is supplied to the air pad 40, the X-axis slider 14 slightly floats above the X-axis guide 12 as described above. In this state, for example, when the compressed gas is supplied to the air servo chamber 48A and the compressed gas is discharged from the air servo chamber 48B, the partition wall 56 acts as a piston and the X-axis slider 14 moves leftward in the drawing. In this way, the X-axis slider 14 can be moved to an arbitrary position with respect to the X-axis guide 12 by controlling the opening degrees of the servo valves 52A and 52B.

Returning to FIG. 1, the two side guides 22 are long members. The two side guides are supported by the base frame 10 such that their longitudinal directions coincide with the Y-axis direction and the Y-axis guide 16 is located between them in the X-axis direction.

The sliding surface 22a, which is the upper surface of the side guide 22, is flattened. The sliding surfaces 22a of the two side guides 22 are formed to have the same height, that is, to overlap each other when viewed from the X-axis direction. Further, the two sliding surfaces 22a are formed to be parallel to the Y-axis guide 16 (more specifically, for example, the upper surface of the bottom wall 32 of the Y-axis guide 16) when viewed from the X-axis direction. ..

The two posture maintaining members 26 are fixed to the lower surface 12a of the X-axis guide 12 (that is, the lower surface of the bottom wall 32). In particular, the two posture maintaining members 26 are located on opposite sides of the supported portion of the X-axis guide 12 supported by the Y-axis slider 18 and above the sliding surface 22a of the side guide 22. It is fixed to the lower surface 12a of the X-axis guide 12. In FIG. 1, the two posture maintaining members 26 are fixed to both ends of the lower surface 12a of the X-axis guide 12 in the X-axis direction.

FIG. 4 is a cross-sectional view showing one of the posture maintaining members 26 and its periphery. FIG. 4 shows a cross section taken along a plane orthogonal to the Y-axis direction. The other posture maintaining member 26 has the same structure. The posture maintaining member 26 includes an air pad 70 in the present embodiment, and ejects high-pressure gas supplied from an air supply system (not shown) to the sliding surface 22a. Due to the repulsive force, an upward force acts on the posture maintaining member 26 and thus on the X-axis guide 12. Further, in the posture maintaining member 26, similarly to the X-axis slider 14 and the Y-axis slider 18, exhaust grooves 72, 74, 76 for differential exhaust are formed so as to surround the air pad 70. The exhaust grooves 72, 74, 76 are configured similarly to the exhaust grooves 42, 44, 46, respectively. As described above, by preventing the compressed gas from leaking through the gap between the posture maintaining member 26 and the side guide 22, the stage device 100 can be used even in a vacuum environment. When the stage device 100 is used under an atmospheric pressure environment, it is not necessary to provide such an exhaust groove.

FIG. 5 is a block diagram showing the function and configuration of the control unit 30. Each block shown here can be implemented by an element such as a CPU (central processing unit) of a computer or a mechanical device in terms of hardware, and can be implemented by a computer program or the like in terms of software. It depicts the functional blocks that are realized through these collaborations. Therefore, it is understood by those skilled in the art who have touched the present specification that these functional blocks can be realized in various ways by a combination of hardware and software.

The control unit 30 controls the flow rate of the compressed gas ejected from the air pad 40 to levitate the X-axis slider 14 and the Y-axis slider 18, and the air servo control to move the X-axis slider 14 and the Y-axis slider 18. A movement control unit 64 that controls the flow rate of the compressed gas supplied to the chamber 48, and a posture maintenance control unit 66 that controls the flow rate of the gas ejected from the air pad 70 of the posture maintenance member 26 to maintain the posture of the X-axis guide 12. And, including. As described above, the posture maintaining member 26 ejects a high-pressure gas onto the sliding surface 22a, so that an upward force acts on the posture maintaining member 26 and thus the X-axis guide 12. The posture maintaining control unit 66 uses another way of saying that the upward force can obtain a sufficiently large flying rigidity with respect to a load variation that may occur in the X-axis guide 12 when the X-axis slider 14 moves. Then, the flow rate of the gas ejected from the air pad 70 of the posture maintaining member 26 is controlled so that the sinking of the X-axis guide 12 due to the load variation can be suppressed or prevented.

According to the stage device 100 according to the embodiment described above, the two posture maintaining members 26 are fixed to the lower surface 12a of the X-axis guide 12, and the gas is jetted from the posture maintaining member 26 to the sliding surface 22a. As a result, an upward force acts on the posture maintaining member 26, and thus on the X-axis guide 12. Here, when the X-axis slider 14 moves along the X-axis guide 12 in the X-axis direction, a load variation occurs in the X-axis guide 12, the X-axis guide 12 tilts around the Y-axis direction, and the X-axis guide 12 is supported. A moment around the Y-axis guide 16 may be generated in the Y-axis slider 18 that operates. As a result, galling may occur in which the Y-axis slider 18 contacts the Y-axis guide 16. In particular, in the present embodiment, the Y-axis slider 18 is levitated by the pressure of gas, and therefore, when a moment about the Y-axis guide 16 is generated in the Y-axis slider 18, galling is likely to occur. On the other hand, in the present embodiment, as described above, the two posture maintaining members 26 suppress the upward force on the X-axis guide 12, for example, the sinking of the X-axis guide 12 due to the load fluctuation generated in the X-axis guide 12. The upward force that can be done works. This prevents the X-axis slider 14 from tilting around the Y-axis direction even if the X-axis slider 14 moves, and causes a moment around the Y-axis guide 16 in the Y-axis slider 18 that supports the X-axis slider 14. Is suppressed, and as a result, it is possible to prevent the galling of the Y-axis slider 18 in contact with the Y-axis guide 16. Further, since the X-axis guide 12 is prevented from tilting around the Y-axis direction, the posture accuracy of the table 20 is improved.

Further, according to the stage device 100 according to the embodiment, the slider includes the exhaust grooves 42, 44, 46 for exhausting the compressed gas supplied from the air pad 40 and the air servo chamber 48 to the outside. Similarly, the posture maintaining member 26 includes exhaust grooves 72, 74, 76 for exhausting the compressed gas supplied from the air pad 70 to the outside. By thus preventing the compressed gas from leaking out, the stage device 100 can be used in a vacuum environment.

The stage device according to the embodiment has been described above. It should be understood by those skilled in the art that this embodiment is an exemplification, and that various modifications can be made to the combination of each constituent element, and such modifications are also within the scope of the present invention. Further, the embodiments can be combined with each other.

(Modification 1)
Although not particularly mentioned in the embodiment, when the X-axis slider 14 moves to one side of the X-axis guide 12 with respect to the supported portion of the X-axis guide 12, the posture maintenance control unit 66 controls the one side of the X-axis guide 12. The flow rate of the gas ejected from the air pad 70 of the posture maintaining member 26 may be increased, the flow rate of the gas ejected from the air pad 70 of the attitude maintaining member 26 on the other side may be reduced, or the ejection of the gas may be stopped. You may use together. The same applies when the X-axis slider 14 moves to the other side of the X-axis guide 12 with respect to the supported portion of the X-axis guide 12. Further, the posture maintenance control unit 66 ejects the air pads 70 of the two posture maintenance control units 66 according to the speed at which the X-axis guide 12 moves, that is, according to the magnitude of the load fluctuation that occurs in the X-axis slider 14. The flow rate of gas may be adjusted.

(Modification 2)
In the embodiment, the case where the two posture maintaining members 26 are fixed to the X-axis guide 12 so as to be positioned on the opposite sides of the supported portion of the X-axis guide 12 has been described, but the present invention is not limited to this.

The stage device 100 may include only one posture maintaining member 26. In this case, the posture maintaining member 26 is naturally fixed only to one side of the supported portion of the X-axis guide 12. In this case, when the X-axis slider 14 moves to the side where the posture maintaining member 26 is fixed with respect to the supported portion of the X-axis guide 12, the posture maintaining member 26 increases the flow rate of the gas ejected, which is the opposite. When the X-axis slider 14 moves to the side, the flow rate of the gas jetted by the posture maintaining member 26 may be reduced or the jetting of the gas may be stopped.

Further, the stage device 100 may include three or more posture maintaining members 26. In this case, even if all the posture maintaining members 26 are fixed to only one side of the supported portion of the X-axis guide 12, a part of the posture maintaining member 26 is fixed to one side of the supported portion of the X-axis guide 12. The rest may be fixed to the other side of the supported portion.

(Modification 3)
In the embodiment, the case where the posture maintaining member 26 includes the air pad 70 that ejects gas has been described, but the present invention is not limited to this.

For example, the posture maintaining member 26 may be an air pad that sucks gas. In this case, for example, the load fluctuation that may occur in the X-axis guide 12 due to the movement of the X-axis slider 14 and the floating rigidity of the air pad of the posture maintaining member 26 on the side opposite to the side on which the X-axis slider 14 has moved. By controlling the above, the amount of suction that the posture maintaining member 26 sucks is controlled so that the downward force acting on the posture maintaining member 26 and thus the X-axis guide 12 becomes substantially equal. In other words, the suction amount of the posture maintaining member 26 is controlled so that the sinking of the X-axis guide 12 due to load fluctuation can be suppressed or prevented.

Further, for example, the posture maintaining member 26 may be an air pad capable of simultaneously ejecting gas and sucking gas. For example, the posture maintaining member 26 may have a gas ejection portion in the center thereof and a gas suction portion around the gas ejection portion. In this case, by controlling the amount of suction and the amount of ejection of gas by the posture maintaining member 26 to control the levitation rigidity of the posture maintaining member 26, the sinking of the X-axis guide 12 due to load fluctuation is suppressed or prevented.

(Modification 4)
In the embodiment, the case where the posture maintaining member 26 is fixed to the X-axis guide 12 has been described, but the present invention is not limited to this. The posture maintaining member 26 may be fixed to the upper surface of the side guide 22. In this case, the posture maintaining member 26 may be spread all over the upper surface of the side guide 22 in the Y-axis direction.

(Modification 5)
In the embodiment and the above-described modified example, the case where the posture maintaining member 26 includes the air pad 70 has been described, but the present invention is not limited to this. The attitude maintaining member 26 can apply a force (that is, an attitude control force) for maintaining the attitude of the X-axis guide 12 to the X-axis guide 12 without contacting the base frame 10 (side guide 22) or the X-axis guide 12. Anything will do. Therefore, for example, the posture maintaining member 26 may be one that can apply a magnetic force or an electromagnetic force as a posture control force.

Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. The new embodiment produced by the combination has the effects of the combined embodiment and the modified examples. It is also understood by those skilled in the art that the functions to be fulfilled by the constituent elements described in the claims are realized by the individual constituent elements shown in the embodiment and the modified examples or by the cooperation thereof. ..

10 base frame, 12 X-axis guide, 14 X-axis slider, 16 Y-axis guide, 18 Y-axis slider, 22 side guide, 22a sliding surface, 26 attitude maintaining member, 30 control unit, 40 air pad, 70 air pad, 100 stage device ..

Claims (5)

A first slider,
A first guide for guiding the movement of the first slider in a first direction;
A second slider that supports the first guide;
A second guide for guiding the movement of the second slider in the second direction;
At least one posture maintaining member that applies a posture control force for maintaining the posture of the first guide, to the first guide. The stage device includes two posture maintaining members,
2. The two attitude maintaining members are provided so as to apply attitude control forces to opposite sides of a supported portion of the first guide supported by the second slider. The stage device described in. The stage apparatus according to claim 1, wherein the posture maintaining member includes an air pad that ejects a compressed gas. The stage apparatus according to claim 3, wherein the posture maintaining member is fixed to the first guide and slides on a sliding surface that runs substantially parallel to the second guide. 5. The posture maintaining force by the posture maintaining member is controlled according to a change in a load generated on the first guide as the first slider is guided and moved by the first guide. The stage device according to any one of 1.

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