JP2010038678A - Stage apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously achieve both the purposes that a stage is allowed to move in another driving direction when the stage is driven by another drive device and that a driving force is transmitted along a single axis direction when the stage is driven. <P>SOLUTION: A drive device 20 of a stage apparatus 10 has a pair of folded beams 23R, 23L, a coupling section 26, an interdigital electrode 22 and a straight beam 25. The pair of folded beams 23R, 23L are oppositely disposed along a first direction with the coupling section 26 therebetween. The coupling section 26 floats from a substrate and couples the pair of folded beams 23R, 23L to the straight beam 25. The interdigital electrode 22 can move the coupling section 26 along a second direction perpendicular to the first direction. The straight beam 25 extends along the second direction and can transmit the movement of the coupling section 26 to the stage 60. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stage apparatus including a stage that is driven two-dimensionally, three-dimensionally, or rotationally.

  With the development of MEMS (Micro-Electro-Mechanical Systems) technology, various micromachines can be manufactured. As an example, a stage apparatus having a multi-axis driven stage on a semiconductor substrate has been developed. This type of stage device drives the stage in multiple axes by the driving force transmitted from the driving device. As the driving device, for example, a device using electrostatic attraction is used. This type of stage device is used in, for example, a probe memory device and a surface scanning microscope.

  Multi-axis driving of the stage can be realized by combining single-axis driving. For example, the stage can be driven two-dimensionally on the XY plane by combining single-axis driving in the X-axis direction and the Y-axis direction. The stage is fixed to the substrate via a beam in order to be movable in multiple axes. Patent Document 1 discloses an example in which a stage is fixed to a substrate via an S-shaped or L-shaped beam.

JP 2007-48330 A (see FIGS. 3 and 11 of that publication)

  The S-shaped beam has a small spring constant in the beam repetition direction and a high spring constant in the direction orthogonal thereto. For this reason, the S-shaped beam is elastically deformed in the repeating direction, but is hardly elastically deformed in the direction orthogonal to the repeating direction. Therefore, when the stage is driven in a direction orthogonal to the repetitive direction by the driving device of the other axis, the S-shaped beam not only becomes resistance to driving the stage but also twists other than the plane occur. Cheap. For this reason, a component in the rotation direction is added separately from the driving direction when the beam is deformed. Since an extra component is added to the driving force transmitted to the stage, it is difficult to accurately drive the stage. Therefore, the S-shaped beam is not suitable for multi-axis driving.

  The L-shaped beam is composed of a combination of two straight beams and has a small spring constant in two directions. However, when the stage is driven with an L-shaped beam, a component in the rotational direction is added in addition to the driving direction. Since an extra component is added to the driving force transmitted to the stage, it is difficult to accurately drive the stage.

As described above, in the prior art, (1) when the stage is driven by a driving device of another axis, allowing the stage to move in the driving direction, and (2) when driving the stage, Both of transmitting the driving force to the stage along the single axis direction cannot be solved simultaneously.
An object of the present invention is to provide a stage apparatus that simultaneously solves the above (1) and (2).

The stage apparatus disclosed in this specification includes a stage and a driving apparatus that transmits a driving force to the stage. The driving device has a pair of folded beams, a coupling portion, driving means, and a straight beam. The pair of folded beams are disposed to face each other in the first direction with the coupling portion interposed therebetween. Each folded beam has a pair of beams extending in parallel with the first direction and a connection portion to which one end of the pair of beams is connected. The other end of one of the pair of beams is fixed to the substrate, and the other end of the other beam is connected to the coupling portion. The coupling portion floats with respect to the substrate and couples the pair of folded beams and straight beams. The driving means is configured to be able to swing the coupling portion along a second direction orthogonal to the first direction. The straight beam extends along the second direction and is configured to be able to transmit the swing of the coupling portion to the stage. The folded beam has a high spring constant in the first direction and a small spring constant in the second direction. The straight beam has a small spring constant in the first direction and a high spring constant in the second direction.
The stage device can drive the stage two-dimensionally, three-dimensionally or rotationally based on the arrangement of the driving device. The drive device includes a device using electrostatic attraction, a device using electromagnetic force, and thermal expansion.

  Here, in order to help understanding of the technology disclosed in the present specification, FIG. 27 shows a schematic diagram of the stage apparatus. As shown in FIG. 27A, 3 in the figure is a folded beam, and 3a in the figure is its connecting portion. A pair of folded beams 3 are arranged opposite to each other with the coupling portion 7 therebetween. In the figure, reference numeral 4 denotes a fixed portion where the other end of the folded beam 3 is fixed to the substrate. In the figure, 5 is a straight beam, and 6 is a stage in the figure. The longitudinal direction of the folded beam 3 is parallel to the X-axis direction, and the longitudinal direction of the straight beam 5 is parallel to the Y-axis direction. In this example, the stage 6 is driven two-dimensionally on the XY plane. The folded beam 3 has a high spring constant in the X-axis direction and a small spring constant in the Y-axis direction. The straight beam 5 has a high spring constant in the Y-axis direction and a small spring constant in the X-axis direction.

As shown in FIG. 27B, when the stage 6 is driven in the X-axis direction by the drive device of the other axis, the stage 6 is movable in the X-axis direction by the straight beam 5 being deformed in the X-axis direction. Can be tolerated. At this time, the coupling portion 7 is hardly displaced. Therefore, the drive unit connected to the coupling unit 7 is hardly affected by the displacement of the stage 6 in the X direction. Further, since both ends of the straight beam 5 are connected by the coupling portion 7 and the stage 6, the folded beam 3 has a structure in which internal stress such as expansion due to temperature is released. For this reason, the linearity of the spring constant of the straight beam 5 is also maintained well. As shown in FIG. 27C, when the stage 6 is driven along the Y-axis direction, the pair of folded beams 3 are deformed to drive the stage 6 parallel along the Y-axis direction. be able to. At this time, since the rigidity of the straight beam 5 in the Y direction is extremely high, the Y direction driving force of the driving unit connected to the coupling unit 7 can be accurately transmitted to the stage 6 and the stage 6 can be driven in the Y axis direction. .
As described above, the technique disclosed in the present specification solves the above (1) and (2) simultaneously by using a structure in which the straight beam 5 and the pair of folded beams 3 are combined in the driving device. Can do.

  It is preferable to use a drive device that utilizes electrostatic attraction. In this case, the driving means preferably has a fixed electrode fixed to the substrate and a movable electrode fixed to the coupling portion. According to this drive device, the coupling portion is oscillated by the electrostatic attractive force acting between the fixed electrode and the movable electrode.

The stage device that performs two-dimensional driving or three-dimensional driving preferably further includes a driving voltage generation circuit. In this case, it is preferable that the pair of driving devices are arranged to face each other with the stage interposed therebetween. The drive voltage generation circuit applies a first drive voltage between the fixed electrode and the movable electrode of one drive device, applies a second drive voltage between the fixed electrode and the movable electrode of the other drive device, and The stage is driven based on the voltage difference between the drive voltage and the second drive voltage.
According to this stage device, the direction in which one driving device pulls the stage is opposite to the direction in which the other driving device pulls the stage. As a result, reverse traction forces always act on the stage, so that the stage can be driven stably.

The first drive voltage and the second drive voltage are preferably a combined voltage of a DC voltage and an AC voltage. It is preferable that the AC voltage included in the first drive voltage and the AC voltage included in the second drive voltage have opposite phases. Here, the reverse phase means that the AC voltage included in the first drive voltage is shifted in phase by π (rad) from the AC voltage included in the second drive voltage.
In this case, the DC voltage is set to position the stage, and the AC voltage is set to vibrate the stage. When the synthesized voltage is used for the first drive voltage and the second drive voltage, for example, after the stage is driven to the target position, the stage can be vibrated at the target position. A technique for vibrating the stage is required for various purposes. In addition, since the AC voltage is set in an opposite phase, a reverse traction force acts when the stage reciprocates due to vibration. For this reason, for example, the stage can be vibrated by the driving force of the driving device as compared with the case where the vibration is repeated by the restoring force of the spring, and the responsiveness becomes faster.

The stage is preferably square when viewed in plan. In this case, it is preferable that the driving devices are respectively arranged corresponding to the four corners of the stage. Furthermore, it is preferable that the straight beam of each driving device is connected to a corresponding corner of the stage.
According to this embodiment, it is difficult for rotational moments around the X axis and the Y axis to occur on the stage. According to this embodiment, the stage can be driven stably.

In the stage device that is driven to rotate, the second direction in which the straight beam of the driving device extends is preferably parallel to the rotational tangent direction of the stage.
Here, the rotational tangent direction is the tangential direction of the virtual circle when a virtual circle having a radius from the rotation axis at the center of the stage to the end of the stage is drawn. According to this embodiment, the stage can be driven to rotate. Note that an extension may be provided from the end of the stage, and the straight beam of the driving device may be connected to the extension. If the extension portion is provided, stages having various shapes can be driven to rotate.

In the stage device that is rotationally driven, the stage includes a base portion having an opening at the center, a rotation shaft that is disposed in the opening and fixed to the substrate, a rotation shaft that is disposed in the opening, and the rotation shaft and base. And a connecting beam extending between the sections.
According to this embodiment, the torsional rotation around the Z axis of the stage is extremely stable.

It is also possible to drive the stage in a direction perpendicular to the surface of the substrate. In this case, it is preferable that the stage device further includes a vertical direction driving device that drives the stage in a direction perpendicular to the surface of the substrate. The vertical drive device has a movable electrode provided on the stage and a fixed electrode provided on the substrate. The movable electrode referred to here includes a case where the stage itself functions as a movable electrode.
According to this stage apparatus, it is possible to realize a drive that combines the three-dimensional drive of the stage, the rotational drive of the stage, and the z-axis drive.

  According to the stage apparatus disclosed in the specification of the present application, (1) when the stage is driven by a driving device of another axis, allowing the stage to move in another driving direction; (2) driving the stage In this case, both of transmitting the driving force to the stage along the single axis direction can be solved simultaneously.

The features of the technology disclosed in this embodiment are summarized below.
(First Feature) The folded beam has three beams extending in parallel to the first direction and a connecting portion to which one end of the three beams is connected. The other end of each of the three beams is fixed to the substrate, and the other end of the central beam is connected to the coupling portion.
(Second Feature) In the first feature, the width of the central beam is larger than the width of the beams on both sides.
(Third Feature) A Z-axis driving electrode is provided on the substrate surface facing the back surface of the stage. When an electrostatic attractive force is applied between the Z-axis driving electrode and the stage, the stage is driven in the Z-axis direction.
(4th characteristic) The drive device is provided with the detection means which detects the displacement of a coupling | bond part. The displacement of the stage is indirectly detected from the displacement of the coupling portion. The detection result of the stage displacement is feedback-controlled to drive the stage to the target position with higher accuracy.
(5th characteristic) When rotating a stage, the stage has the extension part which protrudes from a side surface. The straight beam of the drive device is connected to the extension.

Embodiments will be described below with reference to the drawings. In addition, about the component which is substantially common, a common code | symbol is attached | subjected through each Example and description is abbreviate | omitted.
(First embodiment)
FIG. 1 shows a plan view of the stage apparatus 10. The stage device 10 includes a circular stage 60 and a plurality of driving devices 20, 30, 40, 50, and drives the stage 60 two-dimensionally on the XY plane. FIG. 2 is a longitudinal sectional view corresponding to the line AA in FIG. FIG. 3 is a longitudinal sectional view corresponding to the line BB in FIG. FIG. 4 shows an enlarged plan view of the driving device 20.

  As shown in FIGS. 2 and 3, the stage apparatus 10 is manufactured by processing an insulating layer and a silicon layer stacked on the silicon substrate 110 using MEMS (Micro-Electro-Mechanical Systems) technology. Has been. For production of the stage apparatus 10, it is preferable to use an SOI (Silicon On Insulator) substrate.

  As shown in FIG. 1, the driving device 20 and the driving device 40 are arranged to face each other along the Y-axis direction with a stage 60 interposed therebetween. The driving device 20 and the driving device 40 drive the stage 60 uniaxially in the Y-axis direction. The driving device 30 and the driving device 50 are arranged to face each other along the X-axis direction with the stage 60 interposed therebetween. The driving device 30 and the driving device 50 drive the stage 60 uniaxially in the X-axis direction. The stage 60 is swingably supported on the silicon substrate 110 by the beams of the driving devices 20, 30, 40, and 50. The stage 60 is two-dimensionally driven on the XY plane by a combination of single-axis driving in the X-axis direction and the Y-axis direction.

  The drive devices 20, 30, 40, and 50 all have the same form. Hereinafter, embodiments of the drive devices 20, 30, 40, and 50 will be described using the drive device 20 as an example. As shown in FIG. 4, the drive device 20 includes a drive voltage electrode terminal 21, a comb electrode 22 (an example of a drive unit), a pair of folded beams 23R and 23L, and a pair of fixing portions 24R and 24L. The straight beam 25, the coupling portion 26, and the fixed electrode support portion 27 are provided.

  The drive voltage electrode terminal 21 is a metal terminal coated on the silicon layer of the SOI substrate. The drive voltage electrode terminal 21 is electrically connected to the underlying silicon layer.

  The comb-tooth electrode 22 includes a plurality of fixed comb teeth 22a and a plurality of movable comb teeth 22b. The plurality of fixed comb teeth 22 a are fixed to the fixed electrode support portion 27. As shown in FIG. 2, the fixed electrode support portion 27 is fixed to the silicon substrate 110 via an insulating layer therebelow. For this reason, the plurality of fixed comb teeth 22 a are also fixed to the silicon substrate 110. The plurality of fixed comb teeth 22 a and the fixed electrode support portion 27 are electrically connected to the drive voltage electrode terminal 21. Therefore, a driving voltage is applied to the plurality of fixed comb teeth 22 a via the driving voltage electrode terminal 21.

  The plurality of movable comb teeth 22 b are fixed to the coupling portion 26. As shown in FIG. 2, the movable comb teeth 22 b and the insulating layer below the coupling portion 26 are removed, and the movable comb teeth 22 b and the coupling portion 26 are floating on the silicon substrate 110.

  The pair of folded beams 23R and 23L are disposed to face each other along the X-axis direction with the coupling portion 26 interposed therebetween. The folded beam 23R disposed on the right side with respect to the coupling unit 26 and the folded beam 23L disposed on the left side have a bilaterally symmetric form. Hereinafter, the form of the folded beam 23R arranged on the right side will be described as an example.

  The folded beam 23R has a planar U-shape and includes a pair of beams 23Ra and 23Rb and a connecting portion 23Rc. The pair of beams 23Ra and 23Rb extend in parallel along the X-axis direction. The connecting portion 23Rc extends in parallel along the Y-axis direction. One end of the pair of beams 23Ra and 23Rb is connected to the connection portion 23Rc. The insulating layers below the pair of beams 23Ra and 23Rb and the connection portion 23Rc are removed, and the pair of beams 23Ra and 23Rb and the connection portion 23Rc are floating on the silicon substrate 110. The other end of the beam 23Ra is connected to the side surface of the coupling portion 26. The other end of the beam 23Rb is connected to the fixed portion 24R. As shown in FIG. 2, the fixing portion 24 </ b> R is fixed to the silicon substrate 110 via an insulating layer therebelow. Therefore, the other end of the beam 23Rb of the folded beam 23R is fixed to the silicon substrate 110 via the fixing portion 24R.

  The folded beams 23R and 23L have a small spring constant in the Y-axis direction and a high spring constant in the X-axis direction. For this reason, the folded beams 23R and 23L are elastically deformed in the Y-axis direction and hardly elastically deformed in the X-axis direction.

  The straight beam 25 extends along the Y-axis direction, one end is connected to the side surface of the coupling portion 26, and the other end is connected to the stage 60. The other end of the straight beam 25 is connected to the stage 60 in a direction perpendicular to the tangential direction of the stage 60. The insulating layer below the straight beam 25 is removed, and the straight beam 25 is floating on the silicon substrate 110.

  FIG. 5 shows a drive voltage control circuit 70 that drives the stage apparatus 10. The drive voltage control circuit 70 applies a drive voltage to the drive voltage electrode terminals 21, 31, 41, 51 of the drive devices 20, 30, 40, 50. A Y (+) drive voltage is applied to the drive voltage electrode terminal 21 of the drive device 20. An X (+) drive voltage is applied to the drive voltage electrode terminal 31 of the drive device 30. A Y (−) drive voltage is applied to the drive voltage electrode terminal 41 of the drive device 40. An X (−) drive voltage is applied to the drive voltage electrode terminal 51 of the drive device 50. Further, the fixed portion 54 of the driving device 50 is provided with a stage terminal, and the stage terminal is grounded. As described above, since the folded beam, the coupling portion, the movable comb teeth, the straight beam, and the stage of the drive devices 20, 30, 40, and 50 are all formed of the silicon layer of the SOI substrate, these are electrically It is connected. For this reason, by grounding the stage terminal of the driving device 50, the folded beam, the coupling portion, the movable comb teeth, the straight beam, and the stage of all the driving devices 20, 30, 40, 50 are substantially fixed to the ground potential. .

  The drive voltage control circuit 70 outputs a drive voltage that combines a direct current (DC) voltage and an alternating current (AC) voltage. A direct current (DC) voltage is set to position the stage 60 and an alternating voltage is set to vibrate the stage 60. If not required, no alternating voltage is applied.

  For example, when the drive voltage Y (+) drive voltage is applied to the drive voltage electrode terminal 21 of the drive device 20, electrostatic attraction works between the fixed comb teeth 22a and the movable comb teeth 22b. The fixed comb teeth 22 a are fixed to the silicon substrate 110, and the movable comb teeth 22 b are floating with respect to the silicon substrate 110. For this reason, when the drive voltage Y (+) drive voltage is applied, the movable comb teeth 22b are drawn to the fixed comb teeth 22a side, so that the stage 60 is connected to the Y (+) via the coupling portion 26 and the straight beam 25. ) Driven in the direction. In this case, the Y (+) driving voltage works as a driving force for driving the stage 60 in the Y (+) direction. Similarly, the Y (−) drive voltage acts as a drive force in the Y (−) direction, the X (+) drive voltage acts as a drive force in the X (+) direction, and the X (−) drive voltage becomes X (−). Acts as a driving force in the direction.

  In the stage device 10, the driving device 20 and the driving device 40 cooperate to position the stage 60 in the Y-axis direction. On the other hand, the driving device 30 and the driving device 50 cooperate to position the stage 60 in the X-axis direction. For example, when the stage 60 is driven in the Y (+) direction by a predetermined distance, a driving voltage corresponding to the predetermined distance is generated as a difference between the Y (+) driving voltage and the Y (−) driving voltage. By setting the Y (+) drive voltage to be larger than the Y (−) drive voltage by a predetermined value, the stage 60 can be driven by a predetermined distance in the Y (+) direction. In this case, the direction in which the driving device 20 pulls the stage 60 in the Y (+) direction is opposite to the direction in which the driving device 40 pulls the stage 60 in the Y (−) direction. As a result, reverse traction forces always act on the stage 60, so that the spring and stage are prevented from buckling and mechanical play is eliminated, so that the stage 60 can be driven stably. it can.

  As described with reference to FIG. 27, the drive devices 20, 30, 40, and 50 of the stage device 10 are characterized by having a straight beam. The straight beam works as a soft spring (small spring constant) against displacement perpendicular to the longitudinal direction. For example, when the driving devices 20 and 40 drive the stage 60 in the Y-axis direction, the straight beams of the driving devices 30 and 50 are elastically deformed in the Y-axis direction, and the stage 60 is allowed to move in the Y-axis direction. Similarly, when the driving devices 30 and 50 drive the stage 60 in the X-axis direction, the straight beams of the driving devices 20 and 40 are elastically deformed in the X-axis direction, allowing the stage 60 to move in the X-axis direction. . This allows the stage 60 to be driven two-dimensionally on the XY plane.

  Generally, in such a case, there is a problem that unnecessary other axial force is transmitted to the comb electrode 22 via a beam coupled to the stage 60. If the other axial force is transmitted to the comb electrode 22, the distance between the fixed comb teeth 22a and the movable comb teeth 22b may deviate from the designed value. Further, when the other axial force is transmitted to the comb electrode 22, the fixed comb tooth 22 a and the movable comb tooth 22 b may not be able to face each other in parallel. Furthermore, when the other axial force is transmitted to the comb-teeth electrode 22, there is a risk of causing a failure or a malfunction due to sticking or an electrical short circuit.

  On the other hand, in the stage apparatus 10, the other axial force of the stage 60 is relaxed by elastic deformation in a direction perpendicular to the longitudinal direction of the straight beam 25, and the transmission of the other axial force to the comb electrode 22 is suppressed. Thereby, the positional relationship between the fixed comb teeth 22a and the movable comb teeth 22b can be maintained. Further, the structure constituted by the fixed portion 24, the folded beam 23, and the coupling portion 26 can also prevent the other axial force of the stage 60 from being transmitted to the comb-teeth electrode 22. As a result, the positional relationship between the fixed comb teeth 22a and the movable comb teeth 22b can be prevented from changing more than the other axial forces, and as a result, a stable single-axis driving force can be generated and the stage 60 can be single-axis driven with high accuracy. Can do.

  As shown in FIG. 4, in the driving device 20 of the stage apparatus 10, the coupling portion 26 is supported by a pair of folded beams 23R and 23L. For this reason, the coupling portion 26 is easily displaced in a direction perpendicular to the longitudinal direction of the folded beams 23R and 23L, and is not easily displaced in the longitudinal direction. The other end of the straight beam 25 connected to the coupling portion 26 is connected to the stage 60, and since the longitudinal rigidity (spring constant) of the straight beam 25 is extremely high, the displacement of the coupling portion 26 is directly transmitted to the stage 60. The stage 60 can be uniaxially driven.

  Thus, the driving devices 20, 30, 40, 50 of the stage device 10 have a combination structure of a straight beam and a folded beam, and (1) the stage 60 is driven by a driving device of another axis. In addition, it is possible to simultaneously solve both of allowing the stage 60 to move in another driving direction and (2) transmitting the driving force to the stage 60 along the single axis direction when the stage 60 is driven. can do.

  Further, the folded beam of the stage apparatus 10 is free from the influence of the internal stress because the internal stress which is a problem in the MEMS structure is released in the longitudinal direction, and therefore has excellent temperature stability and aging stability.

  According to the configuration of the stage apparatus 10, both ends of the straight beam 25 sensitive to internal stress are not fixed to the silicon substrate 110. For this reason, changes in internal stress are mitigated by the ease with which the folded beam 23 is deformed. Therefore, it is excellent in temperature stability and aging stability.

(Second embodiment)
In FIG. 6, the top view of the stage apparatus 11 of 2nd Example is shown. The stage apparatus 11 is characterized in that the stage 61 has a quadrangular shape. When the shape of the stage 61 is a quadrangle, a wide utilization area can be secured.

(Third embodiment)
In FIG. 7, the top view of the stage apparatus 12 of 3rd Example is shown. The stage device 12 is characterized in that the stage 62 has a quadrangular shape and the straight beams 25, 35, 45, and 55 of the driving devices 20, 30, 40, and 50 are connected to the corners of the stage 62. The stage device 12 is less likely to generate rotational moments about the X axis and the Y axis, and can stably drive the stage 62.

(Fourth embodiment)
In FIG. 8, the top view of the stage apparatus 13 of 4th Example is shown. One feature of the stage device 13 is that the folded beams 23R and 23L have three shapes. End portions of the beams 23Rb and 23Lb on both sides are fixed to the silicon substrate 110 via fixing portions 24R and 24L. In the stage device 13, the torsional rigidity of the folded beams 23R and 23L becomes extremely high, and the stability against other axial forces is improved.

  The stage device 13 is characterized in that the center beams 23Ra and 23La among the folded beams 23R and 23L are thicker than the beams 23Rb and 23Lb on both sides. In this case, the combined spring constant of the beams 23Rb and 23Lb on both sides and the spring constant of the central beams 23Ra and 23b are balanced. Thereby, the stability when the folded beams 23R and 23L are elastically deformed in a direction orthogonal to the longitudinal direction is increased.

(5th Example)
In FIG. 9, the top view of the stage apparatus 14 of 5th Example is shown. The stage device 14 is characterized in that the center beams 23Ra and 23La of the folded beams 23R and 23L have two shapes. Thereby, the stability when the folded beams 23R and 23L are elastically deformed in a direction orthogonal to the longitudinal direction is increased.

(Sixth embodiment)
In FIG. 10, the top view of the stage apparatus 15 of 6th Example is shown. FIG. 11 is a longitudinal sectional view corresponding to the line AA in FIG. The stage device 15 includes a Z-axis drive device 80. The stage device 15 drives the stage 61 in three dimensions.

  The Z-axis drive device 80 includes a plurality of Z-axis fixed electrodes 82, 84, 86, 88 provided on the silicon substrate 110 below the stage 61. The Z-axis fixed electrodes 82, 84, 86, 88 can be formed by introducing impurities at a high concentration into part of the surface of the high resistance silicon substrate 110. In this example, the stage 61 itself functions as a movable electrode. When a drive voltage is applied to the Z-axis fixed electrodes 82, 84, 86, 88, electrostatic attraction acts between the Z-axis fixed electrodes 82, 84, 86, 88 and the stage 61, and the stage 61 is driven in the Z-axis direction. can do.

  The driving of the stage 61 in the Z-axis direction is allowed by the spring system of the straight beam 25 and the folded beam 23 in the Z-axis direction. In addition, by making the spring constant of the straight beam 25 in the Z-axis direction smaller than the spring constant of the folded beam 23 in the Z-axis direction, the positional relationship between the fixed comb teeth 22a and the movable comb teeth 22b in the Z-axis direction changes. That can be suppressed.

(Seventh embodiment)
In FIG. 12, the top view of the stage apparatus 16 of 7th Example is shown. The stage device 16 is different from the stage device 15 of the sixth embodiment in that the folded beams 23R and 23L have three shapes. In the stage device 16, the torsional rigidity of the folded beams 23R and 23L becomes extremely high, and the stability against other axial forces is improved.

  FIG. 13 shows a drive voltage control circuit 70 that drives the stage device 16. The drive voltage control circuit 70 applies a Z (−) drive voltage to the Z-axis fixed electrodes 82, 84, 86, 88 of the Z-axis drive device 80. In this example, when a Z (−) drive voltage is applied to the Z-axis fixed electrodes 82, 84, 86, 88 of the Z-axis drive device 80, the stage 61 is drawn toward the silicon substrate 110 side. Further, a Z-axis fixed electrode is further provided so as to face the surface of the stage 61 (a configuration in which a pair of fixed electrodes face each other with the stage 61 in between), and a Z (+) drive voltage is applied to the Z-axis fixed electrode. If applied, the stage 61 can be driven to the positive side and the negative side in the Z-axis direction.

(Eighth embodiment)
FIG. 14 shows a plan view of the stage device 17. The stage device 17 includes drive devices 120, 130, 140, and 150 of a type different from the drive devices 20, 30, 40, and 50 described above. FIG. 15 is an enlarged plan view of the main part of the driving device 120.

  The driving device 120 includes a pair of displacement detection electrode terminals 121R and 121L and a pair of displacement detection comb electrodes 122R and 122L. The displacement detection electrode terminals 121R and 121L are metal terminals coated on the silicon layer of the SOI substrate. The displacement detection electrode terminals 121R and 121L are electrically connected to the underlying silicon layer. The displacement detection electrode terminals 121R and 121L and the drive voltage electrode terminal 21 are electrically insulated.

  The displacement detection comb-teeth electrodes 122R and 122L are composed of two displacement detection fixed comb teeth 122Ra and 122La and one displacement detection movable comb teeth 122Rb and 122Lb. The displacement detection fixed comb teeth 122Ra and 122La are fixed to the silicon substrate 110 via an insulating layer. The displacement detection movable comb teeth 122Rb and 122Lb are fixed to the coupling portion 26. The displacement detection movable comb teeth 122Rb and 122Lb are fixed to the coupling portion 26.

  FIG. 16 shows a displacement detection circuit 170 connected to the stage device 17. A capacitance detection circuit is connected to each displacement detection electrode terminal 121R, 121L, 131R, 131L, 141R, 141L, 151R, 151L. For example, the capacitance detection circuit connected to the displacement detection electrode terminal 121R detects a change in the distance between the displacement detection fixed comb teeth 122Ra and the displacement detection movable comb teeth 122Rb as a change in capacitance. The capacitance detection circuit connected to the displacement detection electrode terminal 121L detects a change in the distance between the displacement detection fixed comb teeth 122La and the displacement detection movable comb teeth 122Lb as a change in capacitance. The X (+) displacement detection circuit adds the output of the capacitance detection circuit connected to the displacement detection electrode terminal 121R and the capacitance detection circuit connected to the displacement detection electrode terminal 121L. Similarly, an addition result is obtained by the X (−) displacement detection circuit, the Y (+) displacement detection circuit, and the Y (−) displacement detection circuit. The addition result of the X (+) displacement detection circuit and the addition result of the X (−) displacement detection circuit are differentially detected by the X displacement detection circuit. The addition result of the Y (+) displacement detection circuit and the addition result of the Y (−) displacement detection circuit are differentially detected by the Y displacement detection circuit. Thus, the displacement in the X-axis direction and the Y-axis direction can be measured and detected independently with extremely high accuracy.

(Variation 1 of the drive voltage control circuit 70)
FIG. 17 shows an example of a modification of the drive voltage control circuit 70. The drive voltage control circuit 70 further includes a stage drive voltage distribution circuit, an X drive voltage distribution circuit, and a Y drive voltage distribution circuit. When the stage 62 is moved to an arbitrary position on the XY plane or is stably held, target position information is input to the stage drive voltage distribution circuit. The stage drive voltage distribution circuit decomposes the position information into X and Y components, and inputs them to the X drive voltage distribution circuit and the Y drive voltage drive distribution circuit, respectively. The X drive voltage distribution circuit synchronizes the drive voltage in the X (+) direction and the X (−) direction and the drive timing, and generates an electrostatic attractive force acting in the X (+) direction and an electrostatic attractive force acting in the X (−) direction. In combination, the stage 62 is driven or vibrated in the X-axis direction with high accuracy. The Y-axis direction operates similarly to the X-axis direction. As a result, the stage 62 can be pulled and pulled, and can be driven stably especially at high speed driving.

The “pull and pull operation” means that, for example, the stage 62 is driven in the right direction (X (+) direction) by the voltage applied to the driving device 130 in FIGS. The driving force in the-) direction) depends on the restoring force of the spring 23. This enables driving from the origin to the right side. On the other hand, the stage 62 is driven in the left direction (X (−) direction) by the voltage applied to the driving device 150 on the left side, and the driving force on the right side (X (+) direction) is the restoring force of the spring of the driving device 150. by. This enables driving from the origin to the left side. Accordingly, complementary driving is possible by the two driving devices 130 and 150 and the driving voltage control device. As a result, the restoring force and the electrostatic driving force in the spring system are superimposed, and faster driving becomes possible. Furthermore, by applying a DC bias to the drive voltage, the left and right drive devices 130 and 150 can simultaneously pull the stage 62, and as a result, internal stress during manufacturing, residual stress, and heat due to thermal expansion accompanying temperature changes. Absorbs the deflection and warpage, buckling, and backlash of the spring system and mass system due to changes in stress due to stress and aging. Therefore, improvement of electrical drive accuracy and responsiveness are improved, and stage drive with extremely high accuracy is realized.

The electrostatic attractive force F [N] can be expressed by the following mathematical formula. Here, electrostatic attractive force F [N], electric charge Q [C], electric field E [V / m], voltage V [V], dielectric constant ε [F / m] (vacuum 8.85 × 10 ⁻¹² [F / m ], Area S [m ² ], and electrode distance d [m].

  As shown in the above formula, the electrostatic attractive force F [N] is proportional to the square of the voltage V. Therefore, the driving force Fac is generated at a frequency 2 × fc that is twice the frequency fc of the AC driving voltage Vac. On the other hand, if a DC voltage Vdc that is at least twice the amplitude of Vac is added to the AC driving voltage Vac, a driving force (Fac + dc) is generated at the frequency fc. For this reason, not only driving becomes easy, but also linearity and distortion of driving force can be reduced.

(Modification 2 of the drive voltage control circuit 70)
FIG. 18 shows another example of the drive voltage control circuit 70. The drive voltage control circuit 70 further includes a stage position command circuit and a stage position feedback circuit. The stage position command circuit generates specific position information or driving direction information based on the target position information. This information is input to the stage position feedback circuit. On the other hand, the actual X and Y positions of the stage are output from the X displacement detection circuit and the Y displacement detection circuit, and these values are input to the stage position feedback circuit. The stage position feedback circuit inputs information corresponding to the specific position and direction in the XY directions to be driven from these values to the stage drive voltage distribution circuit. As a result, the stage 62 can be driven using the actual stage position information, so that the stage 62 can be stably held at the target position, and the stage can be driven quickly, and the stage can be driven with good responsiveness while preventing overshoot. .

(Ninth embodiment)
FIG. 19 shows a plan view of the stage device 18. The stage device 18 includes a plurality of free springs 162, 164, 166, and 168 that are free to deform at each of the four corners of the stage 61. One end of each of the free springs 162, 164, 166, 168 is fixed to the silicon substrate 110 via an insulating layer of the SOI substrate. The other ends of the free springs 162, 164, 166 and 168 are connected to the four corners of the stage 61. The free springs 162, 164, 166, and 168 are configured to allow the stage 61 to move in the XY plane. When the free springs 162, 164, 166, and 168 are provided, the rotation of the stage 61 around the X axis and the Y axis can be suppressed, and the stage 61 can be driven stably on the XY plane.

(Tenth embodiment)
FIG. 20 shows a plan view of the stage device 19. The stage device 19 includes a Z-axis drive device 80. The stage device 19 drives the stage 61 in three dimensions.

(Eleventh embodiment)
FIG. 21 shows a plan view of the stage apparatus 100. The stage apparatus 100 is characterized in that the stage 63 has a triangular shape, and the straight beams 25, 35, 45, and 55 of the driving devices 120, 130, and 140 are connected to the three corners of the stage 63. . The straight beams 25, 35, 45, and 55 of the driving devices 120, 130, and 140 are parallel to the rotational tangential direction of the stage 63. In the stage apparatus 100, the stage 63 can be rotationally driven around the Z axis.

(Twelfth embodiment)
FIG. 22 shows a plan view of the stage apparatus 101. In the stage apparatus 101, the stage 60 has four extension portions 60a, 60b, 60c, and 60d, and the straight beams 25 of the driving devices 120, 130, and 140 are connected to the four extension portions 60a, 60b, 60c, and 60d. It is characterized by being connected. The straight beams 25 of the driving devices 120, 130, and 140 are characterized by being parallel to the rotational tangential direction of the stage 6. In the stage apparatus 101, the circular stage 60 can be rotationally driven around the Z axis.

(Thirteenth embodiment)
FIG. 23 shows a plan view of the stage apparatus 102. One feature of the stage device 102 is that a pair of drive devices 20, 30, 40, and 50 are connected to the extended portions 60a, 60b, 60c, and 60d of the stage 64, respectively. Thereby, both the right twisting force and the left twisting force around the Z axis of the stage 64 can be generated.

  One feature of the stage device 102 is that the stage 64 has a donut shape. Specifically, the stage 64 includes a base portion 64a having an opening at the center, a rotating shaft 64c that is disposed in the opening and is fixed to the silicon substrate 110 when viewed from above, and a rotation. A plurality of connection beams 64b extending between the shaft 64c and the base portion 64a are provided. Since the rotation shaft 64c is fixed to the silicon substrate 110, rotation around the X axis and the Y axis is suppressed, and rotation around the Z axis is extremely stable. In addition, stability against external disturbances such as externalization speed is high.

(14th embodiment)
FIG. 24 shows a plan view of the stage device 103. FIG. 25 is a longitudinal sectional view corresponding to the line AA in FIG. The stage device 103 is characterized in that a probe 91 is provided in the center of the stage 61. The stage device 103 can be used in a surface scanning microscope such as an atomic microscope or a tunnel microscope, or a MEMS memory that moves charges, atoms, and molecules by driving the probe 91 in three dimensions. The voltage applied to the probe 91 is the same potential as the stage 61. Alternatively, the probe 91 is installed on the stage 61 through an insulating layer, and wiring is arranged on the surface of the stage 61, the straight beam 25, the coupling portion 26, the folded beam 23, and the fixed portion 24 through the insulating layer. Thus, the probe 91 can be electrically independent from the stage 61. In this case, a voltage different from that of the stage 61 can be applied to the probe 91, or the probe 91 can be used as an electrode for electrical detection.

(15th embodiment)
FIG. 26 shows a plan view of the stage device 104. One feature of the stage device 104 is that the stage 63 has a triangular shape, and the straight beams 25 of the driving devices 120, 130, and 140 are connected to the three corners. In this case, the stage 63 can be driven on the XY plane by the three driving devices 120, 130, and 140. Furthermore, the stage device 104 is characterized by including a Z-axis drive device 80. Thereby, the stage apparatus 104 can drive the stage 63 in three dimensions. One feature of the stage device 104 is that a light emitting element 92 is provided at the center of the stage 63. Thereby, the stage apparatus 104 can align the light source by driving the stage 63 in three dimensions. The stage device 104 can be used for focusing of a light source optical system and an afterimage display device. In addition, the light emitting element 92 is installed on the stage 63 through the insulating layer, and wiring is arranged on the surface of the stage 63, the straight beam 25, the coupling portion 26, the folded beam 23, and the fixed portion 24 through the insulating layer. By doing so, the light emitting element 92 can be electrically independent from the stage 63. If a light detection element is provided in place of the light emitting element 92, a high-resolution light position detection device can be configured by focusing the light detection device or moving the detection position.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

The top view of the stage apparatus of 1st Example is shown. The longitudinal cross-sectional view corresponding to the AA line of FIG. 1 is shown. The longitudinal cross-sectional view corresponding to the BB line of FIG. 1 is shown. The enlarged plan view of the drive device of the stage apparatus of 1st Example is shown. The drive voltage control circuit connected to the stage apparatus of 1st Example is shown. The top view of the stage apparatus of 2nd Example is shown. The top view of the stage apparatus of 3rd Example is shown. The top view of the stage apparatus of 4th Example is shown. The top view of the stage apparatus of 5th Example is shown. The top view of the stage apparatus of 6th Example is shown. The longitudinal cross-sectional view corresponding to the AA line of FIG. 10 is shown. The top view of the stage apparatus of 7th Example is shown. 9 shows a drive voltage control circuit connected to a stage device of a seventh embodiment. The top view of the stage apparatus of 8th Example is shown. The enlarged plan view of the drive device of the stage apparatus of 8th Example is shown. The displacement detection circuit connected to the stage apparatus of 8th Example is shown. Modification 1 of the displacement detection circuit connected to the stage device of the eighth embodiment is shown. Modification 2 of the displacement detection circuit connected to the stage device of the eighth embodiment is shown. The top view of the stage apparatus of 9th Example is shown. The top view of the stage apparatus of 10th Example is shown. The top view of the stage apparatus of 11th Example is shown. The top view of the stage apparatus of 12th Example is shown. The top view of the stage apparatus of 13th Example is shown. The top view of the stage apparatus of 14th Example is shown. The longitudinal cross-sectional view corresponding to the AA line of FIG. 24 is shown. The top view of the stage apparatus of 15th Example is shown. (A) The schematic of the drive device indicated by this specification is shown. (B) A state when the other axial force acts on the driving device is shown. (C) The state of the drive device that performs single-axis drive is shown.

Explanation of symbols

20, 30, 40, 50: Drive devices 21, 31, 41, 51: Drive voltage electrode terminals 22: Comb electrodes 22a: Fixed comb teeth 22b: Movable comb teeth 23, 23R, 23L: Folded beam 23Rc: Connection Portions 24, 24R, 24L: fixing portions 25, 35, 45, 55: straight beam 26: coupling portion 27: fixed electrode support portions 60, 61, 62, 63, 64: stage 64a: base portion 64b: connection beam 64c : Rotating shaft 70: Drive voltage control circuit

Claims (8)

A stage device including a stage and a driving device that transmits a driving force to the stage,
The driving device has a pair of folded beams, a coupling portion, driving means, and a straight beam,
The pair of folded beams are arranged to face each other along the first direction with the coupling portion interposed therebetween,
Each folded beam has a pair of beams extending in parallel to the first direction and a connecting portion to which one end of the pair of beams is connected, and the other end of one of the pair of beams is Fixed to the substrate, the other end of the other beam is connected to the coupling part,
The coupling part is floating with respect to the substrate, and couples a pair of folded beam and straight beam,
The driving means is configured to be able to swing the coupling portion along a second direction orthogonal to the first direction.
The straight beam extends along the second direction, and is configured to be able to transmit the swing of the coupling portion to the stage.
The folded beam has a high spring constant in the first direction and a small spring constant in the second direction.
The straight beam is a stage device having a small spring constant in the first direction and a high spring constant in the second direction.   The stage apparatus according to claim 1, wherein the driving unit includes a fixed electrode fixed to the substrate and a movable electrode fixed to the coupling portion. A drive voltage generation circuit;
A pair of drive units are placed opposite each other with the stage in between,
The drive voltage generation circuit applies a first drive voltage between the fixed electrode and the movable electrode of one drive device, applies a second drive voltage between the fixed electrode and the movable electrode of the other drive device, The stage apparatus according to claim 2, wherein the stage is moved based on a voltage difference between the first drive voltage and the second drive voltage. The first drive voltage and the second drive voltage are combined voltages of a DC voltage and an AC voltage,
The stage apparatus according to claim 3, wherein the AC voltage included in the first drive voltage and the AC voltage included in the second drive voltage are in opposite phases. The stage is square when viewed in plan,
The driving devices are respectively arranged corresponding to the four corners of the stage,
The stage apparatus according to any one of claims 2 to 4, wherein the straight beam of each driving apparatus is connected to a corresponding corner of the stage.   3. The stage apparatus according to claim 1, wherein a second direction in which the straight beam of the driving device extends is parallel to a rotational tangential direction of the stage.   The stage includes a base portion having an opening at a central portion, a rotation shaft that is disposed in the opening and is fixed to the substrate when viewed in plan, and extends between the rotation shaft and the base portion. The stage apparatus according to claim 6, further comprising a connecting beam. A vertical driving device for driving the stage in a direction perpendicular to the surface of the substrate;
The stage apparatus according to claim 1, wherein the vertical driving device includes a movable electrode provided on the stage and a fixed electrode provided on the substrate.

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