JP2006186161A - Driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device where long life is realized in an environment different from atmosphere. <P>SOLUTION: Since a rotary stand 24 and a driving unit 25 are separately arranged on a surface side and a rear face side of a moving table 4, weight balance can appropriately be maintained, and life can be prolonged much more by suppressing burden of a slider 3. Since low rigidity of the moving table 4 supporting the rotary stand 24 and the driving unit 25 is required, a structure can be made compact by miniaturizing the table. Rated output of a motor 9 can be made small and cost can be reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive device, and more particularly to a drive device suitable for use in ion implantation used to form a plurality of regions having different ion implantation amounts in a semiconductor wafer.

  In the ion implantation method, impurities are ionized, electrically accelerated as an ion beam, and implanted into a wafer such as silicon (Si). Since impurities can be introduced into a fine region with high accuracy, Widely used in manufacturing processes.

  In this ion implantation method, (1) an ion beam is deflected by applying an electric field, and electrostatic scanning is performed to scan the wafer surface. (2) an ion beam is deflected by applying a magnetic field, and the wafer surface is deflected. Magnetic field scanning for scanning, (3) mechanical scanning for scanning the ion beam by moving the wafer side placed on the holder by a motor, etc. are performed, and any one of (1) to (3) The scanning method is applied to each scanning in the X and Y directions orthogonal to each other in the wafer surface.

If the ion implantation method as described above is used, ions can be uniformly implanted over the entire surface of the wafer. In addition, when a wafer on which a mask is formed in advance using a photoresist is used, desired impurities can be selectively and accurately injected into a desired region (see Patent Document 1).
JP 2003-86530 A Japanese Patent Laid-Open No. 7-86118

  Here, when performing the above-mentioned (3) mechanical scan, since ion beam implantation is generally performed in a vacuum atmosphere, a driving device for moving the wafer in the vacuum atmosphere is required. However, when the turntable holding the wafer is moved in a vacuum, it is common to use a solid lubricant, vacuum grease, or the like for the guide device in order to suppress the generation of outgas. However, solid lubricants and vacuum greases can suppress outgassing in a high vacuum, but there is a problem that the lubrication performance is inferior to that of ordinary lubricants. There is a demand to supplement the life of the guide device by some method. In particular, when a power source for rotating a turntable that holds a wafer is moved together with the turntable, how the drive source is arranged has a great influence on the life of the guide device.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a drive device that can realize a long life in an environment different from the atmosphere.

In order to achieve the above-mentioned object, the drive device of the present invention is a drive device attached to a housing that separates an atmospheric environment from an environment maintained at a pressure different from the atmospheric pressure.
A frame fixed to one surface of the housing;
A table arranged to be movable with respect to the frame;
A turntable attached to one side of the table;
And a drive source that is attached to the other surface of the table facing the one surface and generates power for rotating the turntable.

  For example, when a turntable and a drive source are arranged on a movable table guided by a linear guide rail or the like, the arrangement becomes a problem. If the turntable and the drive source are arranged on one surface with respect to the table, the balance becomes poor, a moment load is applied, the load on the linear guide rail and the like is increased, and the life is shortened. On the other hand, as in the present invention, if a turntable is attached to one side of the table and a drive source is attached to the other side, the balance between the two can be achieved and the moment load of the table is reduced, thereby reducing the linear guide rail. It is possible to ensure a long life.

  If the frame is provided with an escape hole that does not interfere with the driving source that moves with the table, the balance of the table can be improved while allowing arbitrary arrangement of the driving source. However, a notch may be provided instead of the escape hole.

  A connecting member that connects the frame and the housing, wherein the elastic coefficient in a connecting direction connecting the frame and the other surface of the housing is greater than an elastic coefficient in a direction intersecting the connecting direction. Low is preferable.

  For example, when the housing is an elongated housing, the frame is attached with one of the longitudinal end surfaces of the housing as the one surface, and the other of the longitudinal end surfaces of the housing is the other surface via the connecting member. When connected to the frame, a relatively large deformation occurs on a surface other than the longitudinal end surface of the housing according to the differential pressure generated inside and outside the housing, thereby changing the distance between the longitudinal end surfaces of the housing. . However, according to the drive device of the present invention, since the elastic coefficient in the connecting direction of the connecting member is low, the elastic deformation of the connecting member can cope with the change in the distance between the longitudinal end faces of the housing. In addition, since the elastic modulus of the connecting member in the direction intersecting the connecting direction is high, even when the connecting member is deformed in the connecting direction, the displacement in the intersecting direction is suppressed as much as possible to increase the positioning accuracy. be able to.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a drive device according to the present embodiment applicable to a semiconductor manufacturing apparatus used in, for example, a vacuum environment, but the turntable is not shown. FIG. 2 is a view of the configuration of FIG. 1 taken along the line II-II and viewed in the direction of the arrow. FIGS. 3 and 4 are perspective views of the drive device according to the present embodiment when the housing is removed. In FIG. 4, a part of the frame is removed for easy understanding. FIG. 5 is a top view of the driving device.

In FIGS. 1 and 2, an elongated housing-like vacuum chamber C as a housing is installed with its longitudinal direction up and down. A frame 1 is arranged in a vacuum chamber C in which the inside is maintained at a vacuum of about 10 ⁻⁵ Pa. As shown in FIG. 2, the frame 1 includes a base plate 1a and an upper plate 1b that are arranged to face both ends in the longitudinal direction, a central connecting plate 1c that connects the centers of the base plate 1a and the upper plate 1b, and a base plate. 1a and side connection plates 1d and 1e for connecting the side edges of the upper plate 1b. The central connection 1c is provided with a long hole (also referred to as an escape hole) 1f so as to avoid interference with a drive unit 25 described later.

  A thick plate-like base plate 1a is attached to the bottom surface C1 of the vacuum chamber C. A pair of linear guide rails 2 and 2 extend along the longitudinal direction of the frame 1 on the surface of the central connecting plate 1c. A slider 3 is disposed on each of the linear guide rails 2 and 2 and is movable along the linear guide rails 2 and 2. The slider 3 is fixed to the back surface (the right side surface in FIG. 2) of the moving table 4. A turntable on which a wafer or the like can be mounted and rotated can be attached to the surface of the moving table 4 (left side in FIG. 2).

  More specifically, in FIG. 2, a support bracket 21 is fixed to the surface of the moving table 4. Bearings 22 and 22 are respectively disposed on the pair of arm portions 21 a and 21 a of the support bracket 21, and rotatably support the vicinity of both ends of the rotating shaft 23. A turntable 24 that can hold a wafer (not shown) is attached to the center of the rotation shaft 23 and is arranged to be tiltable with the rotation of the rotation shaft 23.

  On the other hand, a drive unit 25 as a drive source is attached to the back surface of the moving table 4. Although not shown, the drive unit 25 includes a motor and a speed reducer housed in a casing-like case 25 a fixed to the moving table 4. The case 25a is disposed so as to penetrate the long hole 1f of the central connecting plate 1c. By covering the drive unit 25 with the case 25a in this way, it is possible to prevent the outgas generated inside and the dust generated by the speed reducer from entering the vacuum chamber C. The power output from the motor via the speed reducer is taken out of the case 25 from the rotating shaft 25b. The rotary shaft 25b passes through the opening of the movable table 4 from the back surface side to the front surface side, and is connected to the rotary shaft 23 through the coupling 26 therewith, whereby the rotary table 24 is driven by the power from the drive unit 25. Can be tilted.

  A nut 5 is attached to the back surface of the moving table 4. The nut 5 surrounds a screw shaft 6 extending in parallel with the linear guide rails 2 and 2. A ball (not shown) is rotatably disposed between a female screw groove provided on the inner periphery of the nut 5 and a male screw groove (not shown) provided on the screw shaft 6. The nut 5, the screw shaft 6, and the ball constitute a ball screw mechanism that is a transmission means.

  The lower end of the screw shaft 6 that is rotatably supported at both ends by bearings 7 and 7 so as not to move in the axial direction is connected to the upper end of the shaft 11a of the magnetic seal unit 11 as a seal unit via the coupling 8. It is connected. The lower end of the shaft 11 a of the magnetic seal unit 11 is connected to the rotating shaft 9 a of the motor 9 attached to the frame 1 by the bracket 10 via the coupling 14. The cylindrical bracket 10 is fixed to the bottom plate 1a of the frame 1 with a bolt (not shown). The magnetic seal unit 11 prevents the atmosphere from entering through the opening 1g of the base plate 1a to which it is attached.

  A connecting member 12 is arranged so that the upper plate 1b of the frame 1 and the top plate lower surface C2 of the vacuum chamber C are connected (that is, the connecting direction is the vertical direction in the figure). FIG. 6 is an exploded view of the connecting member 12. As shown in FIG. 6, the connecting member 12 closes the opening portion of the first housing 12a whose upper portion is opened in the drawing and the second housing 12b whose lower portion is opened smaller than the first housing 12a. And a thin plate member 12c fixed to the second casing 12b with a bolt BT and fixed to the first casing 12a with a bolt BT. As shown in FIGS. 1 and 2, the first housing 12 a is fixed to the upper plate 1 b of the frame 1, and the second housing 12 b is fixed to the top plate lower surface C <b> 2 of the vacuum chamber C. As is apparent from the figure, the connecting member 12 has a relatively low elastic coefficient (easy to bend) because the thin plate member 12c is deformed in the vertical direction, but the front-rear or left-right direction perpendicular thereto is the surface direction of the thin plate member 12c. Therefore, the elastic modulus is extremely high.

  The operation of this embodiment will be described. When a control device (not shown) supplies electric power to the motor 9, the rotating shaft 9a rotates, and when the screw shaft 6 rotates through the shaft 11a and the coupling 8, the nut 5 moves in the axial direction. Since the table 4 connected to can be moved in the axial direction (vertical direction in FIGS. 1 and 2), the drive unit 25 and the turntable 24 can be moved up and down accordingly.

  On the other hand, the power transmitted from the drive unit 25 via the rotation shaft 23 tilts the turntable 24, and therefore, appropriate processing such as ion beam implantation is performed on a wafer (not shown) placed on the turntable 24. Can do.

  7 and 8 are views similar to FIGS. 1 and 2 showing a driving device according to a comparative example. The components having the same functions as those in the embodiment of FIGS. In the comparative example shown in FIGS. 7 and 8, the main difference from the present embodiment is that the drive unit 25 and the turntable 24 are provided on the surface of the moving table 4 (that is, only one surface). In such a case, since the weight on the surface side of the moving table 4 increases, the moment force due to its own weight increases, and the burden on the slider 3 supporting this increases, which may shorten the life. Further, since the turntable 24 is supported in a cantilever state, vibration and amplitude increase at the tip of the turntable 24, which may adversely affect wafer processing.

  On the other hand, according to this Embodiment shown in FIGS. 1-6, since the turntable 24 and the drive unit 25 were arrange | positioned and distributed to the surface side and back surface side of the moving table 4, a weight balance should be taken appropriately. The life of the slider 3 can be extended by reducing the load on the slider 3. Further, since the movable table 4 supporting the turntable 24 and the drive unit 25 need only have low rigidity, the size of the movable table 4 can be reduced, and the configuration can be made compact, and the rated output of the motor 9 can be reduced. Can be reduced and cost can be reduced.

  Further, according to the driving apparatus of the present embodiment, the connecting member 12 connects the upper plate 1b of the frame 1 and the top plate lower surface C2 of the vacuum chamber C, but connects the frame 1 and the side surface of the vacuum chamber C. Therefore, even when a relatively large deformation occurs on the side surface of the vacuum chamber C in accordance with the differential pressure generated inside and outside the vacuum chamber C, the influence of the differential pressure on the frame 1 can be suppressed to a low level. Further, when the deformation occurs on the side surface of the vacuum chamber C, the distance between the bottom surface C1 of the vacuum chamber C and the top plate lower surface C2 changes. However, the thin plate member 12c of the connecting member 12 bends and A change in the distance from the top plate lower surface C2 can be accommodated.

  The connecting member 12 has a structure with a very high elastic coefficient in the front-rear direction (perpendicular to the paper surface) and the left-right direction in FIG. 1, and therefore the distance between the bottom surface C1 of the vacuum chamber C and the bottom surface C2 of the top plate changes. Accordingly, even when the thin plate member 12c of the connecting member 12 is bent, the displacement of the frame 1 in the front-rear direction (perpendicular to the paper surface) and the left-right direction in FIG. 1 can be suppressed.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. For example, the present invention can be applied not only to an ion beam implantation apparatus but also to a sputtering apparatus or a CVD apparatus as long as it is a semiconductor manufacturing apparatus used in a vacuum environment.

It is a front view of the drive device of the present embodiment. It is the figure which cut | disconnected the structure of FIG. 1 by the II-II line | wire, and looked at the arrow direction. It is the perspective view of the drive device of this Embodiment seen by removing a housing. It is the perspective view of the drive device of this Embodiment seen by removing a housing. It is a top view of a drive device. 3 is an exploded view of a connecting member 12. FIG. It is a front view of the drive device of Comparative Example 1. It is the figure which cut | disconnected the structure of FIG. 7 by the VIII-VIII line and looked at the arrow direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Frame 1a Base plate 1b Top plate 1c Center connection plate 1d, 1e Side connection plate 1f Long hole 1g Opening 2, 2 Linear guide rail 3 Slider 4 Moving table 5 Nut 6 Screw shaft 7, 7 Bearing 8 Coupling 9 Motor 9a Rotating shaft 10 Bracket 11 Magnetic seal unit 12 Connecting member 12a First housing 12b Second housing 12c Thin plate member 21 Support bracket 22, 22 Bearing 23 Rotating shaft 24 Rotating base 25 Drive unit C Vacuum chamber C1 Bottom C2 Top plate bottom surface

Claims (3)

In a drive unit attached to a housing that separates an atmospheric environment from an environment maintained at a pressure different from the atmospheric pressure,
A frame fixed to one surface of the housing;
A table arranged to be movable with respect to the frame;
A turntable attached to one side of the table;
And a drive source that is attached to the other surface of the table opposite to the one surface and generates power for rotating the turntable.   The drive device according to claim 1, wherein the frame is provided with an escape hole that does not interfere with a drive source that moves together with the table. A connecting member that connects the frame and the housing, wherein the elastic coefficient in a connecting direction connecting the frame and the other surface of the housing is greater than an elastic coefficient in a direction intersecting the connecting direction. The driving device according to claim 1, wherein the driving device is low.

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