JP5406507B2 - Planar moving stage device - Google Patents

Description

  The present invention relates to a planar moving stage apparatus, and more particularly to a planar moving stage apparatus used for three-dimensional measurement using a semiconductor manufacturing apparatus, a precision machine tool, and an optical instrument.

  2. Description of the Related Art Conventionally, an XY two-axis to one-axis stage (hereinafter referred to as a “plane movement stage”) that moves on a plane such as a surface plate is used for precise processing, inspection, and the like of the above-described article. The planar moving stage is supported and moved by a linear guide mechanism that guides the stage in the XY biaxial to uniaxial directions while supporting the stage from below (see, for example, Patent Documents 1 and 2).

  In addition, there are also plane moving stage devices that support the surface moving stage itself with a hydrostatic bearing or the like and make it float in a non-contact state with respect to a flat surface such as a surface plate or realize a high degree of parallel movement of the stage. . In particular, the planar moving stage device described in Non-Patent Document 1 is configured such that all guide mechanisms and drive sources are configured in a non-contact manner by an air slide and a linear motor, and the planar moving stage is completely in a non-contact state. Guide in the axial direction.

JP-A-4-304946 Japanese Patent No. 2952458 Precision Engineering Society, Super Precision Positioning Technical Committee Regular Meeting Preprint (No. 2007-1), April 20, 2007, p29

  However, since the planar moving stages described in Patent Documents 1 and 2 are supported by the linear motion guide mechanism, the load capacity of the stage depends on the linear motion guide mechanism, and vertical displacement occurs depending on the loading load. To do. Therefore, a large-sized linear motion guide mechanism is required, and the entire stage device tends to be large.

  On the other hand, in a device that supports the planar moving stage itself with a hydrostatic bearing or the like, when the drive source is rigidly connected to the stage, the operation accuracy of the stage directly reflects the operation accuracy of the linear motion guide mechanism. Further, when the bottom surface of the stage is supported by the hydrostatic bearing, the stage always floats, so the stability of the stage when it is stationary depends on the stability of the drive source. Therefore, in order to maintain a stable stationary state in a non-contact state with respect to the lower support surface, there is a problem that a high degree of stationary control is required so that hunting does not occur. Therefore, as described in Non-Patent Document 1, if all the guide mechanisms and the drive source are configured in a non-contact manner, stability at the time of stationary, positioning accuracy and the like are remarkably improved, but the manufacturing cost of the device increases. .

  As described above, various non-contact type planar moving stage devices using air slides or linear motors have been proposed in the past, but only the movement parallelism is controlled with high accuracy (a level of several μm or less). As for positioning accuracy, there is no suitable planar moving stage device for applications that do not require high accuracy (level of about several tens of μm).

  Therefore, the present invention has been made in view of the problems in the above-described conventional planar moving stage device, and can reduce the size of the drive guide mechanism, and does not require complicated stationary control by the drive means. The manufacturing cost can be kept low, and the parallelism of movement can be controlled with high accuracy. On the other hand, the positioning accuracy is intended to provide a planar moving stage device suitable for applications that do not require high accuracy. To do.

In order to achieve the above object, the present invention provides a plane movement stage device, which is movable on the plane by receiving a force in a direction parallel to the plane, and the plane movement stage. A floating support means for supporting the bottom surface in a state of floating from the plane and the plane moving stage are surrounded , and a force in a direction parallel to the plane is applied to the plane moving stage in a non-contact manner. a first stage driving unit, a first guide mechanism for guiding in a first direction parallel to the first stage drive means the plane, in a direction parallel to said first guide mechanism a first drive screw provided, screwed to the first drive screw while being fixed to the first stage drive means, said by moving by rotating the first drive screw the first of the stay A first driving source for the driving means is moved along the first guide mechanism, and the second stage drive means said first guide mechanism and the first driving screw is provided, the second A stage driving means is provided in a direction parallel to the plane and in a direction parallel to the second guide mechanism and a second guide mechanism that guides in a second direction perpendicular to the first direction. The second driving screw fixed to the second stage driving means and screwed into the second driving screw, and rotating the second driving screw to move the second driving screw. And a second drive source for moving the second stage drive means along the second guide mechanism .

According to the present invention, since the bottom surface of the plane moving stage is supported by the levitating support means in a state of being levitated from the lower plane, the first stage driving means need not bear a vertical load. Therefore, it is not necessary to consider the variation of the first stage driving unit, a first stage drive means can be miniaturized. Further, since the stage is supported in a non-contact manner by the floating support means and is also in a non-contact manner with the first stage drive means, there is no occurrence of a height accuracy error due to the combination with the drive means. Furthermore, when the plane moving stage is stationary, the plane moving stage is stably lifted by friction with the plane by placing the plane moving stage on the plane without floating from the lower plane. Therefore, complicated stationary control by the driving means becomes unnecessary.

Further, in the plane moving stage apparatus, the plane moving stage is not in contact with the first stage driving means, and therefore is a driving means that generates minute vibrations due to rolling elements or the like during the operation of the plane moving stage apparatus. In addition, the vibration can be mitigated, and the moving parallelism and positioning accuracy of the stage can be improved.

  Furthermore, when a high-precision moving parallelism of several μm level is required and the plane position accuracy is not required to be as high as several tens of μm level, as in the conventional case, If the guide mechanism and the drive source are configured in a non-contact manner with the air slide and the linear motor, the cost increases. However, according to the present invention, only the bottom surface and the side surface of the stage need to be in the non-contact state. Since the selection range of the driving source is wide, the planar moving stage device can be manufactured at low cost.

In the plane movement stage device, the plane movement stage may be formed in a rectangular parallelepiped shape, and the first stage driving unit may be formed in a frame shape so as to surround the plane movement stage.

Further, in the plane movement stage device, the first stage driving means can be configured to include an alignment means for positioning the plane movement stage around an axis perpendicular to the plane, Positioning accuracy is further improved.

  In the plane moving stage device, the levitation support means may be configured to include a hydrostatic bearing that is fixed to the bottom surface of the plane moving stage and blows air to the plane. The pressure bearing can be configured to include suction means for sucking the planar moving stage in a floating state toward the plane. Thereby, even when the planar moving stage is used in a floating state, a more stable floating state can be obtained.

  Furthermore, in the above planar moving stage device, the hydrostatic bearing can be made of a copper alloy or a carbon material as a surface material. Thereby, even when the stage contacts the lower plane during movement for any reason, it is possible to avoid fatal damage, and in particular, it is possible to greatly reduce the risk of damaging the plane.

In the planar moving stage device, the first stage driving unit may include a static pressure bearing that blows air to the planar moving stage.

  Furthermore, in the plane moving stage device, the plane can be used as the surface of a surface plate, and by using a granite surface plate, even a large granite can be obtained relatively easily and has a flatness of several μm. However, since it is inexpensive and easily available, it is possible to provide a planar moving stage device that is easy to use and can control the movement parallelism with high accuracy.

  As described above, according to the present invention, the manufacturing cost of the apparatus can be kept low, and the movement parallelism can be controlled with high accuracy, while the positioning accuracy is used for applications that do not require high accuracy. A suitable planar moving stage device can be provided.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an embodiment of a planar moving stage device according to the present invention. The planar moving stage device 1 is a plane that can move a surface 2a (hereinafter referred to as a "support surface") 2a of a surface plate 2. FIG. A moving stage (hereinafter abbreviated as “stage”) 3, a plurality of first hydrostatic bearings 4 that support the stage 3 in a state of being levitated from the support surface 2 a, and a first frame 5 that surrounds the stage 3; A plurality of second hydrostatic bearings 6 fixed to the first frame 5 and applying a force in a direction parallel to the support surface 2 a in a non-contact state to the stage 3, and fixed to the second frame 7, The X-direction linear motion guides 8 and 9 and the X-direction drive source 13 etc. for guiding and driving in the X direction, and the Y-direction linear motion guides 11 and 12 and the Y-direction drive source 15 and the like for guiding and driving the second frame 7 in the Y direction. Composed.

  The surface plate 2 is generally used, and one made of a stone material such as cast iron or granite can be used. In particular, granite is preferable because it is relatively easy to obtain even if it is large and has good flatness.

  The stage 3 is formed in a rectangular parallelepiped shape, and four first hydrostatic bearings 4 are fixed to the bottom surface, and can float from the support surface 2a. The stage 3 is configured such that the side surface is surrounded by the first frame 5, and the stage 3 can be moved in the XY directions on the support surface 2 a by the air blown from the eight second hydrostatic bearings 6 fixed to the first frame 5. Is done.

  Air is supplied to each of the first hydrostatic bearings 4 from an air pipe (not shown), and the air blows out from the first hydrostatic bearings 4 toward the support surface 2a, so that the stage 3 is floated. The first hydrostatic bearing 4 preferably includes suction means for sucking the floating stage 3 toward the support surface 2a. Moreover, it is preferable that the 1st hydrostatic bearing 4 uses a copper alloy or a carbon material as a surface material (sintered layer). In addition, it can replace with the 1st hydrostatic bearing 4 provided with the copper alloy etc., and can also use a squeeze film bearing for the same objective.

  The first frame 5 has an internal space in which the stage 3 can be surrounded, and a second hydrostatic bearing 6 for moving the stage 3 is fixed inside. Air is supplied to the second static pressure bearing 6 through an air pipe (not shown), and air blows out from the second static pressure bearing 6 toward the stage 3. As shown in FIG. 3, the second hydrostatic bearing 6 includes a base portion 6 a and a sintered layer 6 b, and is attached to the first frame 5 via a nut 18, a bolt 19, a ball seat 20 at the tip of the bolt, and an O-ring 25. The stage 3 is fixed and positioned around an axis perpendicular to the support surface 2 a of the surface plate 2.

  The second frame 7 is supported above the support surface 2a so as to be movable in the Y direction on the support surface 2a via the Y-direction linear motion guides 11 and 12, the Y-direction drive source 15, and the drive motor 22. The second frame 7 supports the first frame 5 through the X-direction linear guides 8 and 9, the X-direction drive source 13, and the drive motor 21 so that they can be guided.

  The X-direction drive source 13 is fixed to the side surface of the first frame 5, is screwed into the X-direction drive screw 14 supported on the second frame 7, and moves in the X direction when the drive motor 21 rotates. . As the X-direction drive source 13 moves, the first frame 5 moves in the X direction along the X-direction linear guides 8 and 9.

  The Y-direction drive source 15 is fixed to the side surface of the second frame 7, is screwed into the Y-direction drive screw 16 supported on the support surface 2 a, and moves in the Y direction as the drive motor 22 rotates. As the Y-direction drive source 15 moves, the second frame 7 moves in the Y direction along the Y-direction linear motion guides 11 and 12.

  Next, the operation of the planar moving stage apparatus 1 having the above configuration will be described with reference to the drawings. In the following description, a case where the three-dimensional measurement of the measurement object 24 placed on the surface of the plate-shaped measurement object base 23 fixed to the upper surface of the stage 3 is performed will be described as an example. Although illustration is omitted, it is assumed that an optical measurement device for performing three-dimensional measurement is disposed above the measurement object 24.

  After the planar moving stage device 1 is assembled as shown in FIG. 1, the stage 3 is not supplied with air to the first hydrostatic bearing 4, that is, with the bottom surface of the first hydrostatic bearing 4 in contact with the support surface 2a. The measurement object pedestal 23 is fixed to the upper surface of the measurement object 24, and the measurement object 24 is placed on the upper surface of the measurement object pedestal 23. Then, air is supplied to the 1st hydrostatic bearing 4, and the stage 3 is levitated.

  Next, in order to position the measurement object 24 with respect to the upper optical measurement device, air is supplied to the second hydrostatic bearing 6 to bring the stage 3 and the first frame 5 into a non-contact state, and then the X direction. The stage 3 is moved in the XY direction by moving the first frame 5 in the X direction along the linear motion guides 8 and 9 and moving the second frame 7 in the Y direction along the linear motion guides 11 and 12 in the Y direction. Move.

  More specifically, in order to move the stage 3 in the X direction, the X direction driving screw 13 is rotated by rotating the driving motor 21 to be screwed with the X direction driving screw 14. The first frame 5 is moved in the X direction along with the movement of the first frame 5, and the stage 3 is moved in the X direction via the second hydrostatic bearing 6 by the movement of the first frame 5 without being in contact with the first frame 5. On the other hand, in order to move the stage 3 in the Y direction, the Y-direction drive screw 16 is rotated by rotating the drive motor 22, and the Y-direction drive source 15 engaged with the Y-direction drive screw 16 is moved. Since the second frame 7 is moved in the Y direction, and the first frame 5 on the second frame 7 is also moved in the Y direction, the stage 3 is moved via the second hydrostatic bearing 6 by the movement of the first frame 5. The first frame 5 can be moved in the Y direction in a non-contact state.

  When the stage 3 is moved in the X and Y directions, the second hydrostatic bearing 6 is aligned via the ball seat 20 shown in FIG. 3, so that the stage 3 is rotated around an axis perpendicular to the support surface 2a. Can be positioned.

  Although not shown in the drawings, the first hydrostatic bearing 4 is provided with suction means for sucking the stage 3 toward the support surface 2a, so that the stage 3 in a floating state is sucked toward the support surface 2a, A stable floating state of the stage 3 can be obtained.

  When the positioning of the measurement object 24 is completed, the supply of air to the first hydrostatic bearing 4 is stopped, and the stage 3 is lifted while the bottom surface of the first hydrostatic bearing 4 is in contact with the support surface 2a. In a stopped state, three-dimensional measurement is performed by an optical measurement device.

  If the measurement object 24 is large and three-dimensional measurement by the optical measurement device cannot be performed at a time, the measurement object pedestal 23 is moved in parallel while keeping a constant focal length. Specifically, after observing and measuring one field of view in a stationary state (a state where air supply to the first hydrostatic bearing 4 is stopped), air is supplied to the first hydrostatic bearing 4 and the stage 3 is lifted. And move to the adjacent field of view, and continue to perform three-dimensional measurement.

  As described above, in the present embodiment, the first hydrostatic bearing 4 supports the stage 3 in a state where the bottom surface of the stage 3 is levitated from the support surface 2a. Therefore, the first frame 5 and the second frame 7 have a vertical load. It is not necessary to bear. Therefore, it is not necessary to consider the deformation of the stage driving means as in the prior art, and the stage driving means (the first frame 5, the second frame 7, etc. in the present embodiment) can be reduced in size.

  Further, since the stage 3 is supported in a non-contact manner by the first hydrostatic bearing 4 and is also in a non-contact manner with the first frame 5, a height accuracy error may occur due to the combination with the first frame 5. Absent. Furthermore, the stage 3 can be stopped in a stable state by friction with the support surface 2a by placing the stage 3 on the support surface 2a without floating from the support surface 2a of the surface plate 2 when the stage 3 is stationary. Therefore, the complicated stationary control by the driving means as in the prior art becomes unnecessary.

  Further, since the stage 3 is not in contact with the first frame 5, even if the first frame 5 generates a slight vibration during the operation of the planar moving stage device 1, the vibration can be mitigated and the movement of the stage 3 can be reduced. Parallelism and positioning accuracy can be improved.

  The plane moving stage device 1 can achieve a moving parallelism of several μm level and a plane position accuracy of several tens μm level with respect to the stage 3, and the linear motion guide and driving source of the stage 3 are shown in the above embodiment. Since other than the above can be selected, the plane moving stage device can be manufactured at low cost.

  Further, in the plane moving stage apparatus 1, by using a copper alloy or a carbon material as a surface material (sintered layer) for the first hydrostatic bearing 4 or a squeeze film bearing, Even when the stage 3 comes into contact with the support surface 2a during operation, fatal damage can be avoided, and the risk of damaging the support surface 2a of the surface plate 2 is greatly reduced.

  In the present embodiment, the stage 3 is formed in a rectangular parallelepiped shape, and the stage 3 is moved through the first frame 5 formed in a frame shape. However, the shape and the like of the stage 3 and the first frame 5 are as follows: For example, the stage may be formed in a circular shape in plan view, and the stage may be surrounded and moved by a frame having a circular inner space.

  Further, in the present embodiment, the first static pressure bearing 4 is used to float the stage 3, but other than the first static pressure bearing 4, other air levitation means, linear motors, etc. other than air levitation means The above-described levitation means can also be used, and this also applies to the second hydrostatic bearing 6 provided between the stage 3 and the first frame 5.

It is a figure which shows one Embodiment of the plane movement stage apparatus concerning this invention, Comprising: (a) is a top view, (b) is the sectional view on the AA line of (a). It is a disassembled perspective view of the plane movement stage apparatus of FIG. It is sectional drawing which shows the alignment apparatus of the plane movement stage apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planar movement stage apparatus 2 Surface plate 2a Support surface 3 Stage 4 1st hydrostatic bearing 5 1st flame | frame 6 2nd hydrostatic bearing 6a Base 6b Sintering layer 7 2nd flame | frame 8, 9 X direction linear motion guide 11, 12 Y-direction linear motion guide 13 X-direction drive source 14 X-direction drive screw 15 Y-direction drive source 16 Y-direction drive screw 18 Nut 19 Bolt 20 Ball seat 21 Drive motor 22 Drive motor 23 Measurement object base 24 Measurement object 25 O-ring

Claims (8)

A plane movement stage movable on the plane by receiving a force in a direction parallel to the plane;
Levitating support means for supporting the bottom surface of the plane moving stage in a state of levitating from the plane;
First stage driving means for enclosing the plane moving stage and applying a force in a direction parallel to the plane in a non-contact manner to the plane moving stage;
A first guide mechanism for guiding in a first direction parallel said first stage drive means with respect to said plane,
A first drive screw provided in a direction parallel to the first guide mechanism;
Screwed into the first drive screw while being fixed to the first stage drive unit, the first said first stage driving means by moving by rotating the first drive screw a first driving source for moving along the guide mechanism,
Second stage driving means provided with the first guide mechanism and the first driving screw;
A second guide mechanism for guiding the second stage driving means in a second direction parallel to the plane and perpendicular to the first direction;
A second drive screw provided in a direction parallel to the second guide mechanism;
The second stage driving means is fixed to the second stage driving means and screwed into the second driving screw, and the second driving screw is rotated and moved to move the second stage driving means to the second stage driving means. And a second drive source that moves along the guide mechanism . 2. The planar moving stage according to claim 1 , wherein the planar moving stage is formed in a rectangular parallelepiped shape, and the first stage driving means is formed in a frame shape so as to surround the planar moving stage. apparatus. The plane moving stage device according to claim 1, wherein the first stage driving unit includes an aligning unit that positions the plane moving stage around an axis perpendicular to the plane. .   4. The planar moving stage device according to claim 1, wherein the levitation support means includes a hydrostatic bearing that is fixed to a bottom surface of the planar moving stage and blows air toward the plane.   5. The planar moving stage device according to claim 4, wherein the hydrostatic bearing includes suction means for sucking the planar moving stage in a floating state toward the flat surface.   6. The plane moving stage device according to claim 4, wherein the hydrostatic bearing uses a copper alloy or a carbon material as a surface material. The planar moving stage device according to claim 1, wherein the first stage driving unit includes a hydrostatic bearing that blows air to the planar moving stage.   The planar moving stage device according to claim 1, wherein the flat surface is a surface of a surface plate.

Images