XYθ stage device applicable to vacuum vessels

Abstract

The present invention provides an XYθ stage device in which electric motors for driving the X-axis actuator, electric motors for driving the Y-axis actuator, and electric motors for driving the θ-axis actuator are fixedly positioned outside the vacuum processing chamber. [Solution] An XYθ stage device applicable to a vacuum chamber for moving a workpiece placed on a sample stage inside the vacuum chamber, comprising: an X-axis actuator for moving the workpiece in the X-axis direction; a Y-axis actuator for moving the workpiece in the Y-axis direction; and a θ-axis turntable gearhead for rotating the workpiece in the θ-axis direction. An X-axis motor is provided outside the vacuum vessel and drives the X-axis actuator, A Y-axis motor is provided outside the vacuum vessel and drives the Y-axis actuator via a drive force transmission unit 1 that is slidably mounted on a first ball spline, A drive force transmission unit 2 is provided outside the vacuum vessel and is slidably mounted on a second ball spline, and a drive force transmission unit 3 drives the θ-axis turntable gearhead via a drive force transmission unit 3 that is slidably mounted on a third ball spline. A component constituting the drive force transmission unit 1, comprising a first housing fixed to the end of the X-axis actuator, which causes the Y-axis actuator to be driven by the movement of the X-axis actuator in the X-axis direction along a first ball spline axis, A component constituting the drive force transmission unit 2, comprising a second housing fixed to the end of the Y-axis actuator, which causes the Y-axis actuator to be driven by the movement of the X-axis actuator in the X-axis direction along a second ball spline shaft, The drive force transmission unit 3 comprises a third housing fixed to the end of the Y-axis actuator, which causes the θ-axis turntable gearhead to move in the Y-axis direction along a third ball spline shaft.

Description

Technical Field

[0001] The present invention relates to an XYθ stage device for moving a workpiece placed on a table, and more particularly to the structure and function of an XYθ stage device applicable to a vacuum chamber.

Background Art

[0002] Conventionally, in an XYθ stage device for moving a workpiece placed on a table, a ball screw actuator is used as an X-axis actuator and a Y-axis actuator, and a θ-axis actuator is composed of a vacuum motor and a worm gear connected to its rotating shaft. The Y-axis actuator is arranged above the X-axis actuator, and the θ-axis actuator has a stacked structure arranged above the Y-axis actuator.

[0003] When using such an XYθ stage device in a vacuum processing chamber such as an electron beam welding device or a vacuum spraying device, it is desirable to provide a motor for driving an actuator or the like outside the vacuum processing chamber. However, while the motor of the X-axis actuator arranged on the lower side can be installed outside, the motors of the Y-axis actuator and the θ-axis actuator are driven following the movement of the X-axis actuator, so it is difficult to fixedly arrange their motors outside the vacuum processing chamber.

[0004] Therefore, when using the XYθ stage device for vacuum use, as shown in FIG. 1 (plan view of the conventional XYθ stage device), a vacuum motor 40 is used as the motor for driving the Y-axis actuator, and a vacuum motor 70 is used as the motor for driving the θ-axis turntable gear head 5, and these are housed in the vacuum processing chamber.

[0005] However, in a vacuum, there is no convection cooling, and the motor cools only by radiation and conduction. Even with the same torque, heat dissipation is limited in a vacuum, so the temperature tends to rise significantly. In addition, outgassing from coil insulation, adhesives, resin parts, lubricants, etc. can cause deterioration of the vacuum level and process contamination (thin films, surface treatments, etc.).

[0006] Therefore, if the vacuum motor housed in the vacuum processing chamber malfunctions or its performance deteriorates, there is a problem in that the chamber must be opened to the atmosphere, and disassembly, replacement, reassembly, and re-evacuation are required. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Therefore, in view of the above, the object of the present invention is to provide an XYθ stage device applicable to a vacuum vessel, in which an electric motor for driving the X-axis actuator, an electric motor for driving the Y-axis actuator, and an electric motor for driving the θ-axis turntable gearhead are each fixedly located outside the vacuum processing chamber. [Means for solving the problem]

[0008] To solve the above problems, the present invention provides an XYθ stage device applicable to a vacuum container for moving a workpiece placed on a sample stage inside a vacuum container, An X-axis actuator for moving the workpiece in the X-axis direction, A Y-axis actuator for moving the workpiece in the Y-axis direction, A θ-axis turntable gearhead that rotates the workpiece in the θ-axis direction, An X-axis electric motor is provided outside the vacuum vessel, connected to the screw shaft of the X-axis actuator, and drives the X-axis actuator. A Y-axis electric motor is provided outside the vacuum vessel, connected to the first ball spline shaft, and applies rotational torque to the first ball spline shaft. A θ-axis electric motor is provided outside the vacuum vessel, connected to a second ball spline shaft, and applies rotational torque to the second ball spline shaft. A drive force transmission unit 1 is slidably mounted on the first ball spline shaft and converts the rotational torque transmitted from the first ball spline shaft into rotational torque around the Y axis, and transmits the rotational torque to the screw shaft of the Y axis actuator. A drive force transmission unit 2 is slidably mounted on the second ball spline shaft and converts the rotational torque around the X axis transmitted from the second ball spline shaft into rotational torque around the Y axis, and transmits the rotational torque to the third ball spline shaft. A drive force transmission unit 3 is slidably mounted on the third ball spline shaft and converts the rotational torque around the Y axis transmitted from the third ball spline shaft into rotational torque around the X axis, and applies the rotational torque to the θ axis turntable head. A component constituting the drive force transmission unit 1, comprising a first housing fixed to the end of the X-axis actuator, which causes the Y-axis actuator to be driven by the movement of the X-axis actuator in the X-axis direction along the first ball spline axis, A component constituting the drive force transmission unit 2, comprising a second housing fixed to the end of the Y-axis actuator, which causes the Y-axis actuator to be driven by the movement of the X-axis actuator in the X-axis direction along the second ball spline shaft, The drive force transmission unit 3 comprises a third housing fixed to the end of the Y-axis actuator, which causes the θ-axis turntable gearhead to move in the Y-axis direction along the third ball spline shaft. [Effects of the Invention]

[0009] As described above, the present invention provides an XYθ stage device applicable to a vacuum chamber, in which an electric motor for driving the X-axis actuator, an electric motor for driving the Y-axis actuator, and an electric motor for driving the θ-axis turntable gearhead are fixedly positioned outside the vacuum processing chamber. [Brief explanation of the drawing]

[0010] [Figure 1] This is a plan view of a conventional XYθ stage device. [Figure 2(a)] This is a front view showing the line of sight in the arrow view of an XYθ vacuum processing apparatus, which is an embodiment of the present invention. [Figure 2(b)] This is a view of the XYθ vacuum apparatus, an embodiment of the present invention, as seen from the JJ arrow. [Figure 2(c)] This is a detailed view of the drive force transmission section (section C) to the θ axis, which is an embodiment of the present invention. [Figure 2(d)] This is a detailed view of the drive force transmission section (section d) to the θ axis, which is an embodiment of the present invention. [Figure 3(a)] This is a plan view showing the line of sight for each arrow in the XYθ vacuum apparatus, which is an embodiment of the present invention. [Figure 3(b)] This is a view of the XYθ vacuum apparatus, which is an embodiment of the present invention, as seen by arrow AA. [Figure 3(c)] This is a view of the XYθ vacuum processing apparatus, which is an embodiment of the present invention, as seen from the arrow BB. [Figure 3(d)] This is a view of the XYθ vacuum apparatus, which is an embodiment of the present invention, as seen from the CC arrow. [Figure 3(e)] This is a view of the XYθ vacuum processing apparatus, which is an embodiment of the present invention, as seen from the DD arrow. [Figure 3(f)] This is a view of the XYθ vacuum apparatus, which is an embodiment of the present invention, as seen from the arrow KK. [Figure 4] This is a plan view showing the state in which the sample stage of the XYθ stage apparatus, which is an embodiment of the present invention, is located at coordinates (Xmin, Ymax). [Modes for carrying out the invention]

[0011] Hereinafter, an embodiment of an XYθ stage device applicable to the vacuum vessel of the present invention will be described based on the drawings. Note that the drawings schematically show the constituent members and peripheral members of the XYθ stage device, and the dimensions and dimensional ratios on the drawings do not necessarily match the actual dimensions and dimensional ratios. Also, unless otherwise specified, for the sake of convenience, the directions such as up and down are represented based on the orientation of the XYθ stage device shown in FIG. 2. Redundant explanations will be omitted as appropriate, and the same reference numerals may be assigned to the same members. Also, in this specification, the rotation axis (Z-axis) is taken as the θ-axis, and the rotational torque around the Z-axis is referred to as the θ-axis torque.

[0012] FIG. 1 is a plan view of an XYθ stage device 110 installed in a vacuum vessel of the prior art. In the XYθ stage device 110 shown in FIG. 1, a Y-axis actuator 3 is attached on the slider of an X-axis actuator 2, a θ-axis turntable gear head 5 is attached on the slider of the Y-axis actuator 3, and a sample stage 30 is placed thereon. An X-axis electric motor 29 for moving the X-axis actuator 2 in the X-axis direction is provided outside the housing 1. However, a Y-axis vacuum electric motor 40 for driving the Y-axis actuator 3 is disposed inside the housing 1, and a θ-axis vacuum electric motor 70 for applying torque to the θ-axis to the θ-axis turntable gear head 5 is also disposed inside the housing 1. With such a configuration, the sample stage 20 can move in both the X-axis direction and the Y-axis direction while rotating in the θ-axis direction.

[0013] FIG. 2 is a view showing an embodiment of an XYθ stage device (also referred to as an XYθ vacuum processing device) applicable to the vacuum vessel according to the present invention. FIG. 2(a) is a front view, FIG. 2(b) is a view taken in the direction of arrow J-J (plan view), and FIG. 2(c) is a detailed view of a driving force transmission portion (portion C) to the Y-axis according to an embodiment of the present invention. FIG. 2(d) is a detailed view of a driving force transmission portion (portion d) to the θ-axis according to an embodiment of the present invention.

[0014] Fig. 2(a) is a front view of the XYθ vacuum processing apparatus according to an embodiment of the present invention. As shown in Fig. 2(a), an XYθ stage device 100 according to an embodiment of the present invention includes a housing 1, an X-axis motor 29 that moves an X-axis actuator 2 provided inside the housing 1 in the X-axis direction, a Y-axis motor 39 that moves a Y-axis actuator 3 in the Y-axis direction, and a θ-axis motor 69 that drives a θ-axis drive ball spline shaft 61.

[0015] Fig. 2(b) is a J-J arrow view of the XYθ vacuum processing apparatus according to an embodiment of the present invention. As shown in Fig. 2(b), in this embodiment, a Y-axis actuator 3 is orthogonally mounted on an X-axis linear guide slider 22b. An X-axis support linear guide 4 guides the linear motion of the X-axis actuator 2, stabilizes its posture, and supports the Y-axis actuator 3.

[0016] In an embodiment of the present invention, in order to move the sample stage 30 in the Y-axis direction by rotating a Y-axis ball screw shaft 31a without restricting the movement of the Y-axis actuator 3 in the X-axis direction, a Y-axis drive ball spline shaft 51 is directly connected to a Y-axis motor 39 via a Y-axis rotation introduction seal 37. Also, a Y-axis ball screw drive gear A53 and a Y-axis ball screw drive gear B33 are meshed in an orthogonal arrangement, and a bevel gear structure is used as a driving force transmission unit 1 that converts torque around the X-axis into torque around the Y-axis.

[0017] Further, in an embodiment of the present invention, in order to apply a rotational torque to a θ-axis turntable gear head input shaft 90 without restricting the movement of the θ-axis turntable gear head 5 in the X-axis direction, a second θ-axis drive ball spline shaft 61 is directly connected to a θ-axis motor 69 via a θ-axis rotation introduction seal 67. Then, a driving force transmission unit 2 converts the rotational torque around the X-axis into a rotational torque around the Y-axis. The rotational torque converted into torque around the Y-axis by the driving force transmission unit 2 is again converted into torque around the X-axis by a third driving force transmission unit, and the θ-axis turntable gear head 5 is driven by that torque to rotate the sample stage 60.

[0018] To explain the operation overview in Figure 2(b), the X-axis motor 29 rotates the X-axis ball screw shaft 21a of the X-axis actuator 2. This rotation guides the X-axis ball screw nut 21b to the X-axis linear guide stator 22a, causing it to move in the X-axis direction. The X-axis linear guide slider 22b is attached to the X-axis ball screw nut 21b via a coupling, and the Y-axis actuator 3 is mounted on top of it in a direction perpendicular to the X-axis actuator 2. As the X-axis actuator 2 operates, the Y-axis actuator 3 moves in the X-axis direction along the Y-axis drive ball spline shaft 51.

[0019] The θ-axis turntable gearhead 5 is mounted on the Y-axis linear guide slider 32b of the Y-axis actuator 3 and moves in the Y-axis direction along the third θ-axis drive ball spline shaft 71 by the rotation of the Y-axis ball screw shaft 31a. The θ-axis turntable gearhead 5 rotates the sample stage 60 in the θ-axis direction by the rotational torque of the drive force transmission unit 3 described above.

[0020] Figure 2(c) is a detailed view of the drive force transmission unit (c) shown in Figure 2(b). The drive force transmission unit (c) consists of a drive force transmission unit 1 that converts the rotational torque around the X axis to the rotational torque around the Y axis using a Y-axis motor 39, thereby rotating the Y-axis ball screw shaft 31a, and a drive force transmission unit 2 that converts the rotational torque around the X axis of a second θ-axis drive ball spline shaft 61, which is rotated by a θ-axis drive motor 69, to the rotational torque around the Y axis, thereby rotating the θ-axis drive ball spline shaft 71.

[0021] As shown in Figure 2(c), the drive force transmission unit 1 has a bevel gear consisting of a Y-axis ball screw drive gear A53 attached to a Y-axis drive ball spline nut 52 that rotates due to the rotation of the Y-axis drive ball spline shaft 51, and a Y-axis ball screw drive gear B33 whose rotation axes are perpendicular to each other. The bevel gear rotates together with the nut, causing the Y-axis ball screw shaft 31a to rotate. As a result, the sample stage 30 moves in the Y-axis direction.

[0022] The housing 55 contains a support bearing 54 for the ball spline nut 52, which is positioned on the outer circumference of the ball spline nut 52 for Y-axis drive. This configuration ensures that the ball spline nut 52 for Y-axis drive is stably supported. The housing 55 is fixed to one end (end) of the Y-axis actuator 3, so that when the X-axis actuator 2 moves in the X-axis direction, the Y-axis actuator 3 follows along the groove of the ball spline shaft 51 for Y-axis drive in the X-axis direction. The bevel gear, consisting of the Y-axis ball screw drive gear A53 and the Y-axis ball screw drive gear B33, also moves in the X-axis direction without any gaps in the gear meshing.

[0023] As shown in Figure 2(c), the drive force transmission unit 2 is equipped with a bevel gear consisting of a θ-axis drive gear A63 attached to a θ-axis drive ball spline nut 62 that rotates due to the rotation of the θ-axis drive ball spline shaft 61, and a θ-axis drive gear B73 whose rotation axes are perpendicular to each other. The bevel gear rotates together with the nut, causing the θ-axis drive ball spline shaft 71 to rotate.

[0024] Figure 2(d) is a detailed view of part (d) shown in Figure 2 of the drive force transmission unit to the θ axis, which is an embodiment of the present invention. As shown in Figure 2(d), the drive force transmission unit 3 is composed of a bevel gear consisting of a θ axis drive gear A79 attached to a θ axis drive ball spline nut 72 that rotates by a θ axis drive ball spline shaft 71, and a θ axis drive gear B83 whose rotation axes are perpendicular to each other. The bevel gear rotates together with the nut, and the θ axis turntable gear head 5 rotates by the θ axis turntable gear head input shaft 90.

[0025] Figure 3 shows the views of the XYθ stage device 100 from various viewpoints. Figure 3(a) is a plan view indicating the line of sight for each view. Figure 3(b) is the AA view, Figure 3(c) is the BB view, Figure 3(d) is the CC view, Figure 3(e) is the DD view, Figure 3(f) is the KK view, and Figure 3(g) is the L-L view. Each view will be explained below.

[0026] The arrow-view in Figure 3(b) shows the X-axis motor 29, Y-axis motor 39, and θ-axis motor 69 located on the side of the housing 1. The X-axis motor 29 is connected to an X-axis ball screw 21a via an X-axis coupling 28 and an X-axis rotation introduction seal 28. The Y-axis motor 39 is connected to a Y-axis drive ball spline shaft 51 via a Y-axis coupling 38 and a Y-axis rotation introduction seal 37. The θ-axis motor 69 is connected to a θ-axis drive ball spline shaft 61 via a θ-axis coupling 68 and a θ-axis rotation introduction seal 67.

[0027] The arrow-view in Figure 3(c) shows the X-axis actuator 2 and X-axis support linear guide 4 positioned on the bottom surface of the housing 1, with the Y-axis actuator 3 mounted on top of them by a mounting plate. A Y-axis stage 30 is mounted on the upper surface of a Y-axis ball screw nut 31b, which moves in the Y-axis direction guided by a Y-axis linear guide stator 32a. A θ-axis turntable gearhead 5 is mounted on the Y-axis stage 30, and a sample stage 60 is shown on top of it. The X-axis ball screw nut 21b and X-axis linear guide slider 22b, which constitute the X-axis actuator 2, are also shown.

[0028] The arrow-view in Figure 3(d) shows the X-axis actuator 2, the Y-axis actuator 3 mounted on top of it by a mounting plate, the Y-axis stage 30 to which the Y-axis ball screw nut 31b is attached, and the θ-axis turntable gearhead 5 mounted on top of the Y-axis 30.

[0029] Also shown are a support bearing housing 55 for a Y-axis drive ball spline nut, which is slidably mounted on the Y-axis drive ball spline shaft 51 and fixed to the end of the X-axis actuator 2, and a Y-axis ball screw shaft 31a driven by a drive force transmission unit 1 that converts the orientation of the rotation axis of the Y-axis drive ball spline shaft 51 from around the X axis to around the Y axis. Furthermore, a θ-axis drive ball spline shaft 71 that transmits driving force to the θ-axis turntable gearhead 5 is also shown.

[0030] The arrow-view in Figure 3(e) shows the X-axis actuator 2 and the X-axis support linear guide 4 mounted on the bottom surface of the housing 1, with the Y-axis actuator 3 mounted on top of them by a mounting plate on the X-axis actuator 2. The θ-axis turntable gearhead 5 is mounted on the upper surface of the Y-axis ball screw nut 31b, which moves in the Y-axis direction due to the rotation of the Y-axis ball screw shaft 31a of the Y-axis actuator 3, and the sample stage 60 is placed on top of it. Due to the difference in line of sight, the Y-axis and θ-axis ball spline shaft holder B57, the θ-axis drive ball spline shaft holder A77 and θ-axis drive ball spline shaft holder B78 which hold the θ-axis drive ball spline shaft 71 are shown, and the support bearing housing 75 for the ball spline nut fixed to one end (end) of the θ-axis turntable gearhead 5 is also shown.

[0031] The arrow-view in Figure 3(f) shows the X-axis linear guide slider 22b of the X-axis actuator 2, which is operated by the X-axis electric motor 29, the Y-axis actuator 3 connected to its upper surface, the Y-axis drive ball spline shaft 51, the ball spline shaft holder A56 and ball spline shaft holder B57 that support it, the Y-axis drive ball spline shaft 51, and the support bearing housing 65 for the θ-axis drive ball spline nut. The θ-axis turntable gearhead 5 is shown mounted on top of the Y-axis actuator 3, and the sample stage 60 is shown placed on top of the θ-axis turntable gearhead 5.

[0032] Figure 4 is a plan view showing the state in which the sample stage of the XYθ stage apparatus, an embodiment of the present invention, is located at coordinates (Xmin, Ymax). In the XYθ axis stage apparatus of the present invention, the X-axis motor, Y-axis motor, and θ-axis motor are fixedly positioned outside the vacuum processing chamber, and the X-axis actuator 2 moves the sample stage 60 in the X-axis direction, the Y-axis actuator 3 moves the sample stage 60 in the Y-axis direction, and the θ-axis turntable gearhead 5 rotates the sample stage 60 around the θ axis. The θ-axis ball spline shaft 71 is used as the rotating shaft that applies rotational torque to the θ-axis turntable gearhead input shaft 90 of the θ-axis turntable gearhead 5, and the θ-axis drive ball spline shaft 61 and drive force transmission unit 2 are provided to apply rotational torque to the θ-axis ball spline shaft 71, so that the sample stage 60 can be rotated in the θ-axis direction, the sample stage 60 can be moved in the Y-axis direction by the Y-axis actuator 3, and the sample stage 60 can be moved in the X-axis direction by the X-axis actuator 2. [Explanation of symbols]

[0033] 100: XYθ Stage Device 110: XYθ Stage Device 1: Cabinet 2: X-axis actuator 3: Y-axis actuator 4: X-axis support linear guide 5: θ-axis turntable gearhead 20: X-axis stage 21a: X-axis ball screw shaft 21b: X-axis ball screw nut 22a: X-axis linear guide stator 22b: X-axis linear guide slider 27: X-axis rotation introduction seal 28: X-axis coupling 29:X-axis electric motor 30: Y-axis stage 31a: Y-axis ball screw shaft 31b: Y-axis ball screw nut 32a: Y-axis linear guide stator 32b: Y-axis linear guide slider 33: Y-axis ball screw drive gear B 37: Y-axis rotation introduction seal 38: Y-axis coupling 39:Y-axis electric motor 40:Y-axis vacuum motor 51: Ball spline shaft for Y-axis drive 52: Ball spline nut for Y-axis drive 53: Y-axis ball screw drive gear A 54: Support bearing for ball spline nut for Y-axis drive 55: Support bearing housing for ball spline nut for Y-axis drive (first housing) 56: Y-axis θ-axis ball spline shaft holder A 57: Y-axis θ-axis ball spline shaft holder B 60: Sample stage 61: Ball spline shaft for θ-axis drive 62: Ball spline nut for θ-axis drive 63: Gear A for θ-axis drive 64: Support bearing for ball spline nut for θ-axis drive 65: Support bearing housing for θ-axis drive ball spline nut (second housing) 67: θ-axis rotation introduction seal 68: θ-axis coupling 69: θ-axis electric motor 70: θ-axis vacuum motor 71: Ball spline shaft for θ-axis drive 72: Ball spline nut for θ-axis drive 73: Gear B for θ-axis drive 74: Support bearing for ball spline nut for θ-axis drive 75: Support bearing housing for θ-axis drive ball spline nut (third housing) 76: Support bearing housing for ball spline shaft for θ-axis drive 77: Ball spline shaft holder A for θ-axis drive 78: Ball spline shaft holder B for θ-axis drive 79: Gear A for θ-axis drive 83: Gear B for θ-axis drive 90: θ-axis turntable gearhead input axis

Claims

[Claim 1] An XYθ stage device applicable to a vacuum chamber for moving a workpiece placed on a sample stage inside the vacuum chamber, An X-axis actuator for moving the workpiece in the X-axis direction, A Y-axis actuator for moving the workpiece in the Y-axis direction, A θ-axis turntable gearhead that rotates the workpiece in the θ-axis direction, An X-axis electric motor is provided outside the vacuum vessel, connected to the screw shaft of the X-axis actuator, and drives the X-axis actuator. A Y-axis electric motor is provided outside the vacuum vessel, connected to the first ball spline shaft, and applies rotational torque to the first ball spline shaft. A θ-axis electric motor is provided outside the vacuum vessel, connected to a second ball spline shaft, and applies rotational torque to the second ball spline shaft. A drive force transmission unit 1 is slidably mounted on the first ball spline shaft and converts the rotational torque transmitted from the first ball spline shaft into rotational torque around the Y axis, and transmits the rotational torque to the screw shaft of the Y axis actuator. A drive force transmission unit 2 is slidably mounted on the second ball spline shaft and converts the rotational torque around the X axis transmitted from the second ball spline shaft into rotational torque around the Y axis, and transmits the rotational torque to the third ball spline shaft. A drive force transmission unit 3 is slidably mounted on the third ball spline shaft and converts the rotational torque around the Y axis transmitted from the third ball spline shaft into rotational torque around the X axis, and applies the rotational torque to the θ axis turntable head. A component constituting the drive force transmission unit 1, comprising a first housing fixed to the end of the X-axis actuator, which causes the Y-axis actuator to be driven by the movement of the X-axis actuator in the X-axis direction along the first ball spline axis, A component constituting the drive force transmission unit 2, comprising a second housing fixed to the end of the Y-axis actuator, which causes the Y-axis actuator to be driven by the movement of the X-axis actuator in the X-axis direction along the second ball spline shaft, An XYθ stage device applicable to a vacuum vessel, characterized in that it comprises a member constituting the drive force transmission unit 3, which is fixed to the end of the Y-axis actuator and causes the θ-axis turntable gearhead to move along the third ball spline shaft in the Y-axis direction of the Y-axis actuator.

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