JP2008014855A - Stage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stage device capable of inclining a stage in high accuracy while suppressing deformation and displacement of the stage. <P>SOLUTION: When a supporting member 17 inclines, a supporting section 17b also inclines according to it because the rigidity of link sections 17c of the direction (width direction of link sections 17c, namely direction perpendicular to plane of the stage 21) is relatively high. The link sections 17c for linking relative displacement sections 17a to the supporting section 17b have low rigidity in the direction perpendicular to the plane, namely in the direction along the stage 21, and adjacent relative displacement section 17a and 17a are inter-linked by a spring plate 17d, so that it is apt to deform in the direction along the plane of the stage 21 with respect to a fixed relative displacement section 17a. As shown with exaggeration by chain double-dashed lines of Fig. 4, the displacement of the direction along the plane of the stage 21 in the displaced relative displacement section 17a is allowed, and the stress is released. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stage device for tilt adjustment used, for example, in various manufacturing and inspections.

For example, an interferometer may be used to measure variations in flatness, parallelism, and thickness of a semiconductor silicon wafer. However, in order to accurately measure each dimension of the semiconductor silicon wafer to be measured, it is necessary to accurately irradiate the surface of the measurement object with a predetermined angle with the inspection light of the interferometer. Therefore, a stage device is used to tilt the measurement object with high accuracy. Patent document 1 is disclosing the prior art stage apparatus used for such a use.
JP 2003-121572 A

  Here, according to the technique of Patent Document 1, the tilt of the stage is adjusted by pushing up the tilting rod with the eccentric shaft and pushing up the spherical seat on the lower surface of the stage with its round tip. However, while the contact position between the tilt rod and the stage changes according to the tilt of the stage, the tilt rod remains engaged with the spherical seat, so that the tilt rod is pushed up to tilt the stage. In this case, the stage may be deformed or displaced, and the measurement object placed on the stage may not be measured with high accuracy.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stage device that can be tilted with high accuracy while suppressing deformation and displacement of the stage.

In order to achieve the above object, the stage apparatus of the present invention includes:
Stage,
A support member for supporting the stage;
Three spherical seats attached to the support member;
Drive means for driving at least one of the spherical seats in a direction intersecting the surface of the stage;
The support member includes a relative displacement part connected to the spherical seat, a support part connected to the stage, and a connection part that connects the relative displacement part and the support part. The rigidity in the direction along the surface of the stage is lower than the rigidity in the direction orthogonal to the surface of the stage.

  According to the present invention, the support member includes a relative displacement portion connected to the spherical seat, a support portion connected to the stage, and a connection portion connecting the relative displacement portion and the support portion. Since the rigidity of the connecting portion in the direction along the surface of the stage is lower than the rigidity in the direction orthogonal to the surface of the stage, in order to incline the stage, When the height position is changed, the support portion is inclined efficiently because of the high rigidity of the connecting portion in the height direction (for example, the direction orthogonal to the surface of the stage), but the horizontal direction (on the surface of the stage) The horizontal displacement of the relative displacement portion is restrained from being transmitted to the support portion due to the low rigidity of the connecting portion in the direction along the horizontal direction). It can be suppressed.

  The connecting part preferably includes a plate-like part extending in a direction perpendicular to the surface of the stage.

  It is preferable that three relative displacement portions are provided and the support portion is disposed between the relative displacement portions.

  The driving means preferably drives the two spherical seats independently.

  The driving means includes a first wedge member that moves in a direction along the surface of the stage, and is connected to the relative displacement portion and is driven by the first wedge member in a direction orthogonal to the surface of the stage. It is preferable to include a second wedge member that moves.

  It is preferable to have guide means for guiding the second wedge member in a direction perpendicular to the surface of the stage, because the relative displacement portion can be accurately guided in a direction perpendicular to the surface of the stage.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a top view of the stage apparatus according to the present embodiment. FIG. 2 is a top view showing a state in which the stage is removed from the stage apparatus according to the present embodiment. FIG. 3 is a view of the stage apparatus of FIG. 1 as viewed in the direction of arrow III. FIG. 4 is a top view of the support member.

  As shown in FIG. 2, in the present embodiment, two drive devices D and D ′, which are drive means, are arranged side by side. Only the lower drive device D will be described.

  In FIG. 3, a plate-like base 2 is attached on a pedestal 1 fixed to a surface plate or the like. A motor 4 is attached to the right upper surface of the base 2 via a bracket 3. The rotation shaft 4 a of the motor 4 is connected to the right end of the support shaft 6 a of the support bearing 6 attached on the base 2 via the coupling 5. The left end of the support shaft 6a is connected to a screw shaft 7a of a ball screw mechanism 7 that converts rotational motion into axial motion.

  A guide rail 8 is arranged on the left upper surface of the base 2 so as to extend in the left-right direction in FIG. Sliders 9 and 9 are movably disposed on the guide rail 8. The sliders 9 are attached to the horizontal lower surface 10 a of the triangular wedge-shaped first wedge member 10. A nut 7 b of the ball screw mechanism 7 is embedded in the right end surface 10 b of the first wedge member 10. A guide rail 11 is disposed on the slope 10 c facing the upper left of the first wedge member 10. Sliders 12 and 12 are movably disposed on the guide rail 11. The sliders 12 and 12 are attached to the slope 13c of the triangular wedge-shaped second wedge member 13 that faces the slope 10c.

  Sliders 14 are attached to the left end surface 13 b of the second wedge member 13. The sliders 14, 14 are disposed on a vertical wall 25 erected on the base 2 and are movable along a guide rail 26 extending in the vertical direction. The motor 4, the coupling 5, the support bearing 6, the ball screw mechanism 7, the first wedge member 10, and the second wedge member 13 constitute the driving devices D and D '. The sliders 14 and 14 and the guide rail 26 constitute guide means.

  A spherical seat 15 having a spherical recess 15 a on the upper surface is fixed to the horizontal upper surface 13 a of the second wedge member 13. The spherical concave portion 15a of the spherical seat 15 is engaged with a spherical convex portion 16a having the same diameter as the slidable but non-separable portion. The spherical convex portion 16 a is formed at the lower end of the connecting shaft 16, and the upper end of the connecting shaft 16 is screwed to the support member 17.

  On the upper surface of the base 2, a support column 18 is provided between the two motors 4, 4 (see FIG. 2). A spherical seat 19 having a spherical recess 19 a is fixed to the upper end of the support column 18. The spherical concave portion 19a of the spherical seat 19 is engaged with a spherical convex portion 20a having the same diameter as that which can slide but cannot be separated. The spherical protrusion 20 a is formed at the lower end of the connecting shaft 20, and the upper end of the connecting shaft 20 is screwed to the support member 17. In other words, the support member 17 is supported at three points of the connecting shafts 16 and 16 and the connecting shaft 20 (the apex of the equilateral triangle), and is a disc-shaped stage such as a suction chuck that supports the measurement object. 21 is supported.

  In FIG. 4, the support member 17 includes a relative displacement portion 17a to which the connection shafts 16, 16 and the connection shaft 20 are respectively attached to the lower surface, a support portion 17b disposed between the three relative displacement portions 17a, and a relative displacement portion. It has the connection part 17c which connects 17a and the support part 17b, and the spring plate 17d which connects the adjacent relative displacement parts 17a. The support portion 17b is concentrically fixed to the lower surface of the stage 21 with three bolts.

  The relative displacement portion 17a has a V-shaped plate shape, the support portion 17b has a hollow cylindrical shape, and the connecting portion 17c has a thin plate shape that connects the V-shaped center of the relative displacement portion 17a and the cylindrical outer periphery of the support portion 17b. is there. The relative displacement portion 17a, the support portion 17b, and the connecting portion 17c are integrally formed from metal, but both ends of the spring plate 17d are bolted to the side surface of the relative displacement portion 17a. The longitudinal direction of the connecting portion 17 c and the spring plate 17 d is parallel to the surface of the stage 21, and the width direction thereof is perpendicular to the surface of the stage 21. Therefore, the rigidity of the connecting portion 17c in the direction along the upper surface of the stage 21 is lower than the rigidity in the direction orthogonal to the upper surface of the stage.

  Next, the operation of the stage apparatus of the present embodiment will be described. First, consider a case where the stage 21 is tilted so as to lower the left end side in FIG. In such a case, the motors 4 and 4 of the two drive devices D and D 'are controlled to drive the rotary shafts 4a and 4a so as to rotate at the same angle at the same time. Then, the screw shafts 7a and 7a of the ball screw mechanisms 7 and 7 are simultaneously rotated by the same angle via the couplings 5 and 5 and the support shafts 6a and 6a. When the screw shafts 7a and 7a rotate, the rotational motion is converted into the axial motion of the nuts 7b and 7b, so that the first wedge members 10 and 10 connected to the nuts 7b and 7b are moved to the guide rails 11 and 11, respectively. Guided and moved to the right in FIG.

  When the first wedge members 10, 10 move to the right, the second wedge members 13, 13 lose their supporting force from the inclined surfaces 10 c, 10 c of the first wedge members 10, 10. While moving relative to the members 10, 10, the guides 26, 26 descend vertically. At this time, when the spherical seats 15 and 15 attached to the second wedge members 13 and 13 are lowered by the same amount, the connecting shafts 16 and 16 are also lowered by the same amount. The displacement parts 17a and 17a (two on the left side in FIG. 4) are lowered. As the second wedge members 13 and 13 are lowered, the spherical concave portion 15a and the spherical convex portion 16a that are engaged with each other slide, so that the occurrence of stress in each portion can be suppressed.

  On the other hand, since the spherical seat 19 fixed on the base 2 via the support column 18 is not displaced, the relative displacement portion 17a (one on the right side in FIG. 4) of the support member 17 supported by the connecting shaft 20 is Maintain position. As is clear from the above, since the two relative displacement portions 17a and 17a on the left side in FIG. 4 are lowered and the right relative displacement portion 17a in FIG. 4 is fixed, the support member 17 is shown in FIG. As shown in FIG. As the support member 17 is tilted, the spherical concave portions 19a of the spherical seats engaged with each other and the spherical convex portions 20a of the connecting shaft 20 slide, so that it is possible to suppress the occurrence of stress in each portion.

  When the support member 17 is inclined, the rigidity of the connecting portion 17c in the inclined direction (the width direction of the connecting portion 17c, that is, the direction perpendicular to the surface of the stage 21) is relatively high. To do. Accordingly, the stage 21 is inclined with high accuracy so that the left end in FIG. 3 is lowered. Obviously, when the rotating shafts 4a and 4a of the motors 4 and 4 are rotated in the reverse direction, the second wedge members 13 and 13 are lifted, so that the stage 21 is accurately moved so that the left end in FIG. Can be tilted.

  Next, consider a case where the stage 21 is inclined so as to lower the upper end side in FIG. In such a case, the motor 4 of one drive device D '(upper in FIG. 2) is controlled to drive the rotating shaft 4a so as to simultaneously rotate by the same angle. Then, the screw shaft 7a of the ball screw mechanism 7 rotates through the coupling 5 and the support shaft 6a. When the screw shaft 7a rotates, the rotational motion is converted into the axial motion of the nut 7b. Therefore, the first wedge member 10 connected to the nut 7b is guided by the guide rail 11 and is shown in FIG. 3 to move right.

  When the first wedge member 10 moves to the right, the second wedge member 13 loses the supporting force from the inclined surface 10c of the first wedge member 10, so that the first wedge member 10 moves relatively to the first wedge member 10. It moves vertically along the guide rail 26 while moving. At this time, when the spherical seat 15 attached to the second wedge member 13 is lowered by the same amount, the connecting shaft 16 is also lowered by the same amount, so that the relative displacement portion 17a of the support member 17 supported by them (FIG. 4). 1) on the upper side goes down. As the second wedge member 13 descends, the spherical concave portion 15a and the spherical convex portion 16a that are engaged with each other slide, so that the occurrence of stress in each portion can be suppressed.

  On the other hand, since the spherical seat 19 fixed on the base 2 via the support column 18 is not displaced, the relative displacement portion 17a (one on the right side in FIG. 4) of the support member 17 supported by the connecting shaft 20 is Maintain position. Further, since the motor 4 of another driving device D (lower in FIG. 2) also remains stationary, the relative displacement portion 17a of the support member 17 supported by the connecting shaft 16 (one lower side in FIG. 4). ) Maintain its position. From the above, the upper relative displacement portion 17a is lowered in FIG. 4, and the right and lower relative displacement portions 17a, 17a are fixed in FIG. 4, so that the upper end side of the support member 17 is inclined in FIG. Become. As the support member 17 is tilted, the spherical concave portions 19a of the spherical seats engaged with each other and the spherical convex portions 20a of the connecting shaft 20 slide, so that it is possible to suppress the occurrence of stress in each portion.

  When the support member 17 is inclined, the rigidity of the connecting portion 17c in the inclined direction (the width direction of the connecting portion 17c, that is, the direction perpendicular to the surface of the stage 21) is relatively high. To do. Accordingly, the stage 21 is inclined with high accuracy so that the upper end in FIG. 2 is lowered. At this time, as the interaxial distance between the displaced spherical seat 15 and the non-displaced spherical seat 15 and the interaxial distance between the displaced spherical seat 15 and the fixed spherical seat 19 change, the support member 17. There is a case where a stress that tries to deform is applied.

  On the other hand, according to the present embodiment, the connecting portion 17c that connects the relative displacement portion 17a and the support portion 17b has low rigidity in the direction perpendicular to the surface, that is, the direction along the surface of the stage 21, and is adjacent to the connecting portion 17c. Since the relative displacement portions 17a and 17a are connected by the spring plate 17d, they are easily deformed in the direction along the surface of the stage 21 with respect to the fixed relative displacement portion 17a. As exaggeratedly indicated by a chain line, the relative displacement portion 17a displaced in the vertical direction is allowed to be displaced in the direction along the surface of the stage 21 (horizontal direction) to relieve stress. Further, the spring plate 17d connecting the relative displacement portions 17a suppresses the twist of the relative displacement portion 17a. Furthermore, since the support portion 17 b connected to the stage 21 is provided at the center of the support member 17, there is an advantage that the deformation of the support member 17 is not easily transmitted to the stage 21. Obviously, when the rotating shaft 4a of the motor 4 of the driving device D is rotated in the same direction, the second wedge member 13 is lowered, so that the stage 21 is accurate so that the lower end is lowered in FIG. Can tilt well. Thus, by independently driving the driving devices D and D ′, the stage 21 can be tilted in an arbitrary direction.

  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, although the spherical seat 19 is fixed, it may be movable like the spherical seat 16. Also, a linear actuator can be used for the driving device.

It is a top view of the stage apparatus concerning this Embodiment. It is a top view shown in the state where a stage was removed from a stage device concerning this embodiment. It is the figure which looked at the stage apparatus of FIG. 1 in the arrow III direction. It is a top view of a support member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Base 3 Bracket 4 Motor 4a Rotating shaft 5 Coupling 6 Support bearing 6a Support shaft 7 Ball screw mechanism 7a Screw shaft 7b Nut 8 Guide rail 9, 9 Slider 10 First wedge member 10a Horizontal lower surface 10b Right end surface 10c Slope 11 Guide rails 12, 12 Slider 13 Second wedge member 13a Horizontal upper surface 13b Left end surface 13c Slope 14, 14 Slider 15 Spherical seat 15a Spherical concave portion 16 Connecting shaft 16a Spherical convex portion 17 Support member 17a Relative displacement 17a Relative displacement portion 17a Relative Connecting part 17b Supporting part 17c Connecting part 17d Spring plate 18 Supporting column 19 Spherical seat 19a Spherical concave part 20 Connecting shaft 20a Spherical convex part 21 Stage 25 Vertical wall 26 Guide rails D and D 'Drive device

Claims (6)

Stage,
A support member for supporting the stage;
Three spherical seats attached to the support member;
Drive means for driving at least one of the spherical seats in a direction intersecting the surface of the stage;
The support member includes a relative displacement part connected to the spherical seat, a support part connected to the stage, and a connection part that connects the relative displacement part and the support part. A stage apparatus characterized in that rigidity in a direction along the surface of the stage is lower than rigidity in a direction perpendicular to the surface of the stage.   The stage device according to claim 1, wherein the connecting portion includes a plate-like portion extending in a direction orthogonal to the surface of the stage.   The stage apparatus according to claim 1, wherein three relative displacement portions are provided, and the support portion is disposed between the relative displacement portions.   The stage device according to claim 1, wherein the driving unit drives the two spherical seats independently.   The driving means includes a first wedge member that moves in a direction along the surface of the stage, and is connected to the relative displacement portion and is driven by the first wedge member in a direction orthogonal to the surface of the stage. The stage apparatus according to claim 1, further comprising a second wedge member that moves. 6. The stage apparatus according to claim 5, further comprising guide means for guiding the second wedge member in a direction orthogonal to the surface of the stage.

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