JP2014132716A - Vibrator, electronic apparatus and moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibrator which is capable of further miniaturization, which is further suppressed in deterioration of vibration characteristics due to vibration leakage and heat stress, and which is stably manufactured in a manufacturing process without causing sticking by a movable electrode.SOLUTION: A MEMS vibrator 100 includes: a substrate 1; a support part 22; and an upper electrode 21 (vibrating body) which is supported in an isolated manner on the main surface of a substrate 1 by the support part 22. In the support part 22, one end is connected to a node 40 of vibration of the upper electrode 21 and the other end is fixed onto the main surface of the substrate 1 in an area between the main surface of the substrate 1 and the main surface of the upper electrode 21 opposite to the main surface of the substrate 1.

Description

  The present invention relates to a vibrator, an electronic device, and a moving body.

In recent years, MEMS (Micro Electro Mechanical System) has been steadily growing in acceleration sensors and video devices. MEMS is sometimes referred to as a micromachine, MST (Micro System Technology), but is usually meant to mean “a micro functional element manufactured using semiconductor manufacturing technology”. They are manufactured on the basis of microfabrication technology cultivated with conventional semiconductors.
By the way, MEMS are roughly classified into surface MEMS and bulk MEMS. The former forms a plurality of thin films on a silicon substrate, and makes a MEMS structure using a sacrificial layer etching (release etching) technique. As a feature, it has high affinity with semiconductor manufacturing technology and is suitable for integration with CMOS (Complementary Metal Oxide Semiconductor) circuits. On the other hand, the latter forms a MEMS structure by processing such as deeply digging the substrate itself such as an SOI (Silicon on Insulator) substrate. As a feature, a three-dimensional structure with a high degree of freedom can be realized. Currently, both are being developed and commercialized. In particular, a one-chip MEMS resonator is known in which a MEMS resonator is created in the same chip as an IC (Integrated Circuit) using surface MEMS technology. .

  As a typical example of a conventional MEMS vibrator, a comb vibrator that vibrates in a direction parallel to the substrate surface and a beam vibrator that vibrates in the thickness direction of the substrate are known. A beam type vibrator is a vibrator composed of a lower electrode (fixed electrode) formed on a substrate and an upper electrode (movable electrode) disposed above the lower electrode with a gap therebetween. Depending on the method, a cantilever beam type (clamped-free beam), a clamped-clamped beam type, a free-free beam type on both ends, and the like are known.

  For example, in a free-beam MEMS vibrator at both ends, the vibration node portion of the upper electrode that vibrates is supported by the support member, so that vibration to the substrate is small and vibration efficiency is high. Patent Document 1 proposes a technique for improving the vibration characteristics by setting the length of the support member to an appropriate length with respect to the vibration frequency.

US Patent No. US6930569B2 Specification

  However, the above-described conventional beam-type vibrators including the MEMS vibrator described in Patent Document 1 cannot sufficiently meet the needs of downsizing, thinning, power saving, high frequency, and the like. was there. Specifically, in order to cope with downsizing, thinning, power saving, high frequency, etc., both ends of the free electrode type MEMS vibrator is used to reduce the stiffness of the upper electrode and the support part. It was effective to reduce the gap between the electrodes, but as a result, there was a problem that the upper electrode was stuck in the manufacturing process and a sufficient manufacturing yield could not be obtained. Sticking is a phenomenon in which a fine structure adheres to a substrate or another structure when a sacrificial layer is removed by etching in order to form a MEMS structure. That is, in the prior art, the problem that the upper electrode sticks to the lower electrode in the manufacturing process has become apparent along with the response to the above needs.

  Further, there has been a problem that stable vibration characteristics cannot be obtained when further miniaturization and miniaturization are promoted. Specifically, a beam-type vibrator is a vibrator composed of a fixed electrode formed on a substrate and a movable electrode arranged with a slight gap with respect to the fixed electrode. When the process is advanced, the problem is that vibration characteristics fluctuate due to the influence of residual stress (internal stress including thermal stress) generated between the base layer on which these electrodes are arranged. Variations in the vibration characteristics are due to variations in the gap between the electrodes caused by receiving stress, fluctuations in the stiffness of the movable electrode, etc., and there are also problems such as thermal hysteresis showing temperature hysteresis in the vibration characteristics. It was.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 The vibrator according to this application example includes a substrate, a support portion, and a vibrating body supported by the support portion so as to be separated from the main surface of the substrate, and the support portion includes: In a region between the main surface of the substrate and the main surface of the vibrating body facing the main surface of the substrate, one end is connected to a vibration node of the vibrating body, and the other end is the It is fixed on the main surface of the substrate.

  According to this application example, in the region between the main surface of the substrate and the main surface of the vibrating body facing the main surface of the substrate, the support portion is connected to the vibration node of the vibrating body. The other end is fixed on the main surface of the substrate. That is, the support part is located between the substrate and the vibrating body and functions as a spacer. Therefore, for example, in the manufacturing process of forming a free vibration body on the main surface of the substrate, the vibration body adheres to the main surface of the substrate even when the surface tension of the etching liquid or the cleaning liquid works. The sticking phenomenon that occurs is less likely to occur. As a result, yield reduction due to sticking can be suppressed.

  Further, even if the support portion is configured between the substrate and the vibrating body, the support portion is connected to the vibration node of the vibrating body, so that vibration leakage of the vibrating body is suppressed, and vibration efficiency is reduced. Can be further enhanced. Suppression of vibration leakage transmitted from the vibrator to the substrate means that stress from the substrate with respect to leakage vibration from the support portion is suppressed. As a result, for example, even when the vibrator is subjected to thermal stress and residual stress (residual stress due to internal stress including thermal stress) is generated between the substrate and the support portion, the residual stress is The degree of influence on body vibration is reduced, and the degree of temperature hysteresis in the vibration characteristics is reduced.

  Application Example 2 In the vibrator according to the application example described above, the vibrating body is a plate-like body having a rotationally symmetric shape, and the vibration nodes are a peripheral portion of the vibrating body and a central portion of the vibrating body. Are formed between the peripheral portion and the central portion by vibrating in the opposite phase in the thickness direction of the vibrating body.

According to this application example, since the vibrating body is a plate-like body having a rotationally symmetric shape, the vibrating body can be vibrated with a better balance. As a result, it is possible to obtain a vibrator having less vibration leakage and exhibiting stable vibration characteristics.
In addition, a vibration node formed when the peripheral portion of the vibrating body and the central portion of the vibrating body vibrate in opposite phases in the thickness direction of the vibrating body is located between the peripheral portion and the central portion of the vibrating body. ing. A plurality of support portions can be arranged along the vibration node, or can be configured to extend along the vibration node (that is, the support portion is configured without being arranged outside the vibration body). Therefore, the vibrator can be configured more compactly, and a vibrator supported by a more rigid support structure can be formed. In addition, since the support portion is disposed along the vibration node between the vibrating body and the substrate, it can function as a spacer that more effectively suppresses sticking as described above.

  Application Example 3 In the vibrator according to the application example, the vibrator is an upper electrode, and a first lower electrode is provided between the substrate and a region surrounded by the vibration node of the vibrator. It is characterized by providing.

  According to this application example, the vibrator includes the upper electrode and the first lower electrode arranged at a position overlapping the central portion of the upper electrode (the region surrounded by the vibration node). With this configuration, it is possible to configure an electrostatic vibrator in which the peripheral portion and the center portion of the vibrating body (upper electrode) vibrate as vibration antinodes.

  Application Example 4 In the vibrator according to the application example described above, the vibrating body is an upper electrode, and a second electrode is formed between the substrate and a region outside the region surrounded by the vibration node of the vibrating member. Two lower electrodes are provided.

  According to this application example, the vibrator includes the upper electrode and the second lower electrode arranged at a position overlapping the peripheral region of the upper electrode (the region outside the region surrounded by the vibration node). The With this configuration, it is possible to configure an electrostatic vibrator in which the peripheral portion and the center portion of the vibrating body (upper electrode) vibrate as vibration antinodes.

  Application Example 5 In the vibrator according to the application example, the vibrating body is an upper electrode, and a first lower electrode is provided between the substrate and a region surrounded by the vibration node of the vibrating body. And a second lower electrode is provided between the substrate and a region outside the region surrounded by the vibration node of the vibrating body.

  According to this application example, the vibrator includes the upper electrode, the first lower electrode arranged at a position overlapping the central portion of the upper electrode (the region surrounded by the vibration node), and the peripheral region of the upper electrode ( And a second lower electrode disposed at a position overlapping the outer region of the region surrounded by the vibration node. With this configuration, it is possible to configure an electrostatic vibrator in which the peripheral portion and the center portion of the vibrating body (upper electrode) vibrate as vibration antinodes.

  Application Example 6 In the vibrator according to the application example described above, it is preferable that the vibrating body is a plate-like body having a circular shape.

  As in this application example, when the vibrating body is formed of a circular plate-like body, it is possible to configure a vibrator in which the peripheral portion and the central portion of the vibrating body vibrate as vibration antinodes. Since the vibrating body is configured in a circular shape, not only can the position of the vibration node and the vibration characteristics be designed more easily, but the vibrating body can be vibrated in a more balanced manner. As a result, it is possible to obtain a vibrator having less vibration leakage and exhibiting stable vibration characteristics.

  Application Example 7 In the vibrator according to the application example described above, the vibration body is a rectangular plate-like body, and the vibration node includes two side surface portions facing the vibration body and a center of the vibration body. The portion is formed between the two side surface portions and the central portion of the vibrating body by vibrating in the opposite phase in the thickness direction of the vibrating body.

  According to this application example, the vibrating body is a rectangular plate-like body, and the two side surfaces facing the vibrating body and the central portion of the vibrating body vibrate in opposite phases in the thickness direction of the vibrating body. A node forms a so-called free-free beam at both ends formed between two side portions and the central portion of the vibrating body. By configuring as a double-ended free beam type vibrator, it is possible to obtain a vibrator having less vibration leakage and exhibiting stable vibration characteristics.

  In addition, a vibration node formed by the two side surfaces facing the vibrating body and the central portion of the vibrating body vibrating in opposite phases in the thickness direction of the vibrating body has two side portions and the central portion of the vibrating body. Is located between. A plurality of support portions can be arranged along the vibration node, or can be configured to extend along the vibration node (that is, the support portion is configured without being arranged outside the vibration body). Therefore, the vibrator can be configured more compactly, and a vibrator supported by a more rigid support structure can be formed. In addition, since the support portion is disposed along the vibration node between the vibrating body and the substrate, it can function as a spacer that more effectively suppresses sticking as described above.

  Application Example 8 In the vibrator according to the application example, the vibrating body is an upper electrode, and a first lower electrode is provided between the substrate and a region sandwiched by the vibration nodes of the vibrating body. It is characterized by providing.

  According to this application example, the vibrator includes the upper electrode and the first lower electrode arranged at a position overlapping the central portion of the upper electrode (a region sandwiched between vibration nodes). With this configuration, the vibrator can be configured as an electrostatic vibrator that vibrates as an antinode of the two side portions and the central portion of the vibrating body (upper electrode).

  Application Example 9 In the vibrator according to the application example described above, the vibrating body is an upper electrode, and a first electrode is disposed between the substrate and a region outside the region sandwiched by the vibration nodes of the vibrating member. Two lower electrodes are provided.

  According to this application example, the vibrator includes the upper electrode and the second lower electrode arranged at a position overlapping the peripheral region of the upper electrode (the region outside the region sandwiched by the vibration nodes). The With this configuration, the vibrator can be configured as an electrostatic vibrator that vibrates as an antinode of the two side portions and the central portion of the vibrating body (upper electrode).

  Application Example 10 In the vibrator according to the application example, the vibrating body is an upper electrode, and a first lower electrode is provided between the substrate and a region sandwiched by the vibration nodes of the vibrating body. And a second lower electrode is provided between the substrate and a region outside the region sandwiched between the vibration nodes of the vibrating body.

  According to this application example, the vibrator includes an upper electrode, a first lower electrode arranged at a position overlapping with a central portion of the upper electrode (a region sandwiched between vibration nodes), and a peripheral region of the upper electrode ( And a second lower electrode disposed at a position overlapping with a region outside the region sandwiched by the vibration nodes. With this configuration, the vibrator can be configured as an electrostatic vibrator that vibrates as an antinode of the two side portions and the central portion of the vibrating body (upper electrode).

  Application Example 11 In the vibrator according to the application example described above, the vibrating body includes a first AC voltage applied between the upper electrode and the first lower electrode, the upper electrode, and the second electrode. And a second AC voltage applied in a phase opposite to that of the first AC voltage.

  According to this application example, the first lower electrode disposed at a position overlapping the central portion of the upper electrode, and the second lower electrode disposed at a position overlapping the peripheral region of the upper electrode, By applying an AC voltage having an opposite phase between them, a vibrator having higher vibration energy can be configured. In addition, by allowing the application separated by the first AC voltage and the second AC voltage, it is possible to increase the degree of freedom of the control specifications such as changing the vibration characteristics.

  Application Example 12 In the vibrator according to the application example, the support portion is a columnar body that extends in a direction intersecting with the main surface of the substrate.

According to this application example, the support portion is a columnar body extending in a direction intersecting with the main surface of the substrate. That is, the vibrator is configured to be supported by the columnar body extending from the substrate at the vibration node of the vibration body, so that a vibration leakage is further suppressed and a vibrator with higher vibration efficiency can be configured.
Specifically, the support portion has a columnar structure that extends in a direction intersecting the main surface of the substrate in a region between the main surface of the substrate and the main surface of the vibrating body facing the main surface of the substrate. Supports the vibrating body. The direction of stress that prevents the vibrating body from sticking on the main surface of the substrate, and the direction of leakage vibration when the vibrating body vibrates in the thickness direction of the vibrating body are directions that intersect the main surface of the substrate. Therefore, a support part becomes a structure supported in the extension direction of a columnar body. That is, since it can be set as the structure supported in the compression direction of a columnar body, it can be set as a more rigid support structure. Therefore, unlike the case of supporting by the flexural rigidity of the support part, the number of support parts can be reduced, or the thickness of the support part can be reduced. As a result, for example, a configuration in which a vibration node portion of the vibrating body is supported by a pin point is possible, so that vibration leakage of the vibrating body is suppressed and vibration efficiency can be further improved. For example, even when the vibrator is subjected to thermal stress and residual stress (residual stress due to internal stress including thermal stress) is generated between the substrate and the support portion, the residual stress is The degree of influence on vibration is reduced, and the degree of temperature hysteresis in the vibration characteristics is reduced.

  Application Example 13 In the vibrator according to the application example, the support portion is a plate-like body extending in a direction intersecting with the main surface of the substrate.

  According to this application example, the support portion is a plate-like body extending in a direction intersecting with the main surface of the substrate. That is, the vibrator is configured to be supported on the substrate by the plate-like body extending along the vibration node of the vibrator. That is, since the structure is supported by the surface, the vibrator supported by the support structure having higher rigidity can be configured. In addition, since the plate-like body as the support portion extending along the vibration node functions as a more effective spacer located between the substrate and the vibration body, for example, vibration free on the main surface of the substrate In the manufacturing process for forming the body, even when the surface tension of the etching liquid or the cleaning liquid acts, the sticking phenomenon that the vibration body adheres to the main surface of the substrate is less likely to occur. As a result, yield reduction due to sticking can be suppressed.

  Application Example 14 An electronic apparatus according to this application example includes the vibrator according to the application example.

  According to this application example, a high-performance and low-cost electronic device can be obtained without degrading higher-performance characteristics, and by utilizing a resonator that is more compact and has a high manufacturing yield and stability. Electronic devices can be provided.

  Application Example 15 A moving object according to this application example includes the vibrator according to the application example.

  According to this application example, as a moving body, a high-performance and low-cost is obtained by using a vibrator that is more compact and has a high manufacturing yield without degrading higher-performance characteristics. Can be provided.

(A) The top view of the MEMS vibrator | oscillator which concerns on Embodiment 1, (b) The same AA sectional drawing. (A)-(f) The conceptual diagram which shows the main vibration modes of the vibrator | oscillator which has a disk-shaped movable electrode. (A) The top view of the MEMS vibrator concerning Embodiment 2, (b) Same as the above, BB sectional view, (c) Same as the above, The top view showing a vibration mode. FIG. 4A is a perspective view illustrating a configuration of a mobile personal computer as an example of an electronic apparatus, and FIG. 5B is a perspective view illustrating a configuration of a mobile phone as an example of an electronic apparatus. The perspective view which shows the structure of the digital still camera as an example of an electronic device. The perspective view which shows roughly the motor vehicle as a moving body provided with a MEMS vibrator. (A)-(c) The top view which shows the example of the variation of a lower electrode as a MEMS vibrator | oscillator concerning the modification 1. FIG. (A)-(c) The top view which shows the example of the variation of a lower electrode as a MEMS vibrator | oscillator concerning the modification 2. FIG. (A)-(d) As a MEMS vibrator which concerns on the modification 3, the perspective view which shows the example of the variation of a support part. (A)-(c) The top view which shows the example of the variation of an upper electrode as a MEMS vibrator which concerns on the modification 4. FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding.

(Embodiment 1)
First, the MEMS vibrator 100 as the vibrator according to the first embodiment will be described.
FIG. 1A is a plan view of the MEMS vibrator 100, and FIG. 1B is a cross-sectional view taken along the line AA in FIG.
The MEMS vibrator 100 is a MEMS vibrator (electrostatic vibrator) provided with a movable electrode that is formed free from a substrate by etching a sacrificial layer stacked on the main surface of the substrate.
Note that the sacrificial layer is a layer once formed of an oxide film or the like, and is removed by etching after forming necessary layers above and around it. By removing the sacrificial layer, necessary gaps and cavities are formed between the upper and lower layers and the surrounding layers, and necessary structures are liberated.

The MEMS vibrator 100 includes a substrate 1, a first lower electrode 11, a second lower electrode 12, an upper electrode 21 as a vibrating body, a support portion 22, and the like. The upper electrode 21 is a disc-shaped movable electrode, and is supported by the support unit 22 so as to be separated from the substrate 1.
2A to 2F show main vibration modes of a vibrator having a disk-shaped movable electrode.
In the figure, a broken line represents a vibration node, and a symbol +-represents a portion that vibrates in the vertical direction (the thickness direction of the substrate 1) as a vibration antinode, including the phase relationship. For example, in the case where + is an upward movement, it is indicated that an adjacent area bordering on the vibration node is a downward movement of −.
The MEMS vibrator 100 is a vibrator in the vibration mode shown in FIG. 2D, and these electrodes are arranged based on the arrangement of the first lower electrode 11 and the second lower electrode 12 and an external circuit (illustration and description omitted). This vibration mode is realized by an AC voltage applied between the upper electrode 21 and the upper electrode 21.

The configuration of the MEMS vibrator 100 will be specifically described with reference to FIGS.
The MEMS vibrator 100 is a vibrator in which the peripheral portion 30 of the upper electrode 21 and the central portion 31 of the upper electrode 21 vibrate up and down in opposite phases as vibration antinodes. An annular vibration node 40 is formed between the central portion 31 and the center portion 31.

As the substrate 1, a silicon wafer is used as a suitable example. Note that the substrate 1 is not limited to a silicon wafer, and may be, for example, another semiconductor substrate or a glass substrate.
The first lower electrode 11, the second lower electrode 12, the upper electrode 21, and the support portion 22 are formed on the first oxide film 2 and the nitride film 3 formed on the main surface of the substrate 1.
Here, in the thickness direction of the substrate 1, the direction in which the first oxide film 2 and the nitride film 3 are sequentially stacked on the main surface of the substrate 1 is described as an upward direction.

The first lower electrode 11 and the second lower electrode 12 are formed by patterning a lower conductive layer stacked on the nitride film 3 by photolithography.
The first lower electrode 11 is a circular fixed electrode, and is formed on the main surface of the substrate 1 (the upper surface of the nitride film 3). The first lower electrode 11 is arranged so as to overlap the circular vibration node 40 and to be concentric with the circular upper electrode 21 at the periphery when the substrate 1 is viewed in plan.
The second lower electrode 12 is a donut-shaped fixed electrode, and is formed on the main surface of the substrate 1 (the upper surface of the nitride film 3). The second lower electrode 12 is disposed so as to be concentric with the upper electrode 21 when the substrate 1 is viewed in plan view, is insulated from the first lower electrode 11, and from the periphery of the first lower electrode 11. It is formed so as to surround the first lower electrode 11.

The upper electrode 21 is released from the substrate 1 by the four support portions 22 and is supported so that the main surface of the substrate 1 and the main surface of the upper electrode 21 face each other.
The support portion 22 is a columnar body extending in a direction (substantially perpendicular) intersecting the main surface of the substrate 1, and one end portion in a region between the main surface of the substrate 1 and the main surface of the upper electrode 21. Is connected to the position of the vibration node 40 of the upper electrode 21, and the other end is fixed to the upper surface of the peripheral edge of the first lower electrode 11.

The upper electrode 21 and the support portion 22 are formed by patterning an upper conductive layer, which is laminated on the lower conductive layer (the first lower electrode 11 and the second lower electrode 12) via a sacrificial layer, by photolithography. The Specifically, after a sacrificial layer is stacked on the lower conductive layer (first lower electrode 11 and second lower electrode 12), the sacrificial layer is matched with the shape and position of the support portion 22 by photolithography. A hole is formed to expose the first lower electrode 11. Next, the upper electrode 21 and the upper conductive layer constituting the support portion 22 are laminated and patterned by photolithography to form the upper electrode 21. As a result, the support portion 22 formed at the position of the hole of the sacrificial layer where the first lower electrode 11 is exposed and the upper electrode 21 supported by the support portion 22 are integrally formed.
Here, the thickness of the sacrificial layer is the size of the gap between the upper electrode 21 and the first lower electrode 11 (and the second lower electrode 12) formed by release etching the sacrificial layer.
The upper electrode 21 is electrically connected to the first lower electrode 11 via the support portion 22.

  For the lower conductive layer and the upper conductive layer, conductive polysilicon is used as a suitable example, but the present invention is not limited to this, and other conductive layers used in semiconductor circuits can be used. Note that the lower conductive layer and the upper conductive layer need to have the necessary conductivity as an electrostatic vibrator, and in the case of the upper conductive layer, it is necessary to have the necessary rigidity as a vibrating body. .

In the drawing, the electric wiring connected to the upper electrode 21, the first lower electrode 11, and the second lower electrode 12 is omitted.
The upper electrode 21 and the first lower electrode 11 are connected to an external circuit (not shown) from the periphery of the MEMS vibrator 100 by wiring that is insulated from the second lower electrode 12 and connected to the first lower electrode 11. Connect. The second lower electrode 12 is connected to an external circuit by wiring from around the MEMS vibrator 100.

  In such a configuration, the MEMS vibrator 100 is configured as an electrostatic vibrator, and the peripheral portion of the upper electrode 21 is caused by an alternating voltage applied between the upper electrode 21 and the second lower electrode 12 from an external circuit. The center part vibrates in the opposite phase as a vibration antinode.

  As described above, according to the MEMS vibrator 100 as the vibrator according to the present embodiment, the following effects can be obtained.

  The MEMS vibrator 100 includes an upper electrode 21, a first lower electrode 11 disposed at a position overlapping the central portion of the upper electrode 21 (a region surrounded by the vibration node 40), and a peripheral region of the upper electrode 21 ( The second lower electrode 12 is arranged at a position overlapping the outer region of the region surrounded by the vibration node 40. With this configuration, the vibrating body (upper electrode 21) can be configured as an electrostatic vibrator that vibrates as a vibration antinode between the peripheral portion and the central portion thereof.

  In addition, in the region between the main surface of the substrate 1 and the main surface of the upper electrode 21 facing the main surface of the substrate 1, the support portion 22 has one end connected to the vibration node 40 of the upper electrode 21. The other end is fixed on the main surface of the substrate 1. Since the support portion 22 can be configured without being disposed outside the upper electrode 21, the vibrator can be configured more compactly.

  In addition, in the region between the main surface of the substrate 1 and the main surface of the upper electrode 21 facing the main surface of the substrate 1, the support portion 22 has one end connected to the vibration node 40 of the upper electrode 21. The other end is fixed on the main surface of the substrate 1. That is, the support portion 22 is located between the substrate 1 and the upper electrode 21 and functions as a spacer. Therefore, for example, in the manufacturing process of forming the upper electrode 21 released on the main surface of the substrate 1, the upper electrode 21 is on the main surface of the substrate 1 even when the surface tension of the etching solution or the cleaning solution is applied. The sticking phenomenon that adheres to the film is less likely to occur. As a result, yield reduction due to sticking can be suppressed.

  Further, since the support portion 22 is connected to the vibration node 40 of the upper electrode 21, vibration leakage of the upper electrode 21 is suppressed, and vibration efficiency can be further improved. Suppression of vibration leakage transmitted from the upper electrode 21 to the substrate 1, that is, stress from the substrate 1 against leakage vibration from the support portion 22 is suppressed. As a result, for example, even if the MEMS vibrator 100 is subjected to thermal stress and residual stress (residual stress due to internal stress including thermal stress) is generated between the substrate 1 and the support portion 22, this residual The degree of influence of the stress on the vibration of the upper electrode 21 is reduced.

  In addition, since the vibrating body (upper electrode 21) is formed of a circular plate-like body, it is possible to configure a vibrator in which the peripheral portion and the central portion of the vibrating body vibrate as vibration antinodes. Since the vibrating body is configured in a circular shape, not only can the position of the vibration node and the vibration characteristics be designed more easily, but the vibrating body can be vibrated in a more balanced manner. As a result, it is possible to obtain a vibrator having less vibration leakage and exhibiting stable vibration characteristics.

The support portion 22 is a columnar body that extends in a direction that intersects the main surface of the substrate 1. That is, the MEMS vibrator 100 is configured such that the vibration node 40 portion of the upper electrode 21 is supported by the columnar body extending from the substrate 1, and vibration leakage is further suppressed and vibration with higher vibration efficiency and vibration stability is achieved. Child can be configured.
Specifically, the support portion 22 extends in a direction intersecting with the main surface of the substrate 1 in a region between the main surface of the substrate 1 and the main surface of the upper electrode 21 facing the main surface of the substrate 1. The upper electrode 21 is supported by a columnar body structure. The direction of stress that prevents the upper electrode 21 from sticking on the main surface of the substrate and the direction of leakage vibration of the upper electrode 21 are directions that intersect the main surface of the substrate 1. Is configured to support these forces and vibrations in the extending direction of the columnar body. That is, since it can be set as the structure supported in the compression direction of a columnar body, it can be set as a more rigid support structure. Therefore, unlike the case where it is supported by the deflection rigidity of the conventional support part, the thickness of the columnar body of the support part 22 can be made thinner. As a result, vibration leakage of the upper electrode 21 is suppressed, and vibration efficiency can be further increased. Further, for example, even when the vibrator is subjected to thermal stress and residual stress (residual stress due to internal stress including thermal stress) is generated between the substrate 1 and the support portion 22, the residual stress is The degree of influence on the vibration of the upper electrode 21 is reduced, and the degree of temperature hysteresis in the vibration characteristics is reduced.

(Embodiment 2)
Next, the MEMS vibrator 101 as the vibrator according to the second embodiment will be described. In the description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.
3A is a plan view of the MEMS vibrator 101, FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A, and FIG. 3C shows a vibration mode of the MEMS vibrator 101. It is a top view.

  In the first embodiment (MEMS vibrator 100), as shown in FIG. 1A, the vibrating body (upper electrode 21) is formed of a circular plate-like body. The electrode 21s) is a rectangular plate. That is, the MEMS vibrator 101 is a free-free beam at both ends. The MEMS vibrator 101 includes a substrate 1, a first lower electrode 11s, a second lower electrode 12s, an upper electrode 21s as a vibrating body, a support portion 22s, and the like.

As shown in FIG. 3C, in the MEMS vibrator 101, the two side surface portions 30s facing the upper electrode 21s and the central portion 31s of the upper electrode 21s vibrate up and down at opposite phases as antinodes of vibration. The vibration node is formed as two vibration nodes 40s between the two side surface portions 30a and the central portion 31s.
The first lower electrode 11s is a rectangular fixed electrode, on the main surface of the substrate 1 (the upper surface of the nitride film 3) between the substrate 1 and a region sandwiched between the two vibration nodes 40s of the upper electrode 21s. ). That is, when the substrate 1 is viewed in plan, the first lower electrode 11s is formed in a region overlapping the central region of the upper electrode 21s including the two vibration nodes 40s.
The second lower electrode 12s is a rectangular fixed electrode, on the main surface of the substrate 1 between the substrate 1 and a region outside the region sandwiched by the vibration nodes 40s of the upper electrode 21s (nitride film 3 On the upper surface). That is, when the substrate 1 is viewed in plan, the second lower electrode 12s is disposed so as to be insulated from the first lower electrode 11s at a position overlapping the upper electrodes 21s on both sides of the first lower electrode 11s. .

The upper electrode 21s is released from the substrate 1 by the four support portions 22s, and is supported so that the main surface of the substrate 1 and the main surface of the upper electrode 21s face each other.
The support portion 22s is a columnar body extending in a direction (substantially perpendicular) intersecting the main surface of the substrate 1, and one end portion in a region between the main surface of the substrate 1 and the main surface of the upper electrode 21s. Is connected to the position of the vibration node 40 s of the upper electrode 21 s, and the other end is the peripheral portion of the first lower electrode 11 s (the two opposite sides that overlap the vibration node 40 s when the substrate 1 is viewed in plan view). It is fixed to the upper surface of the area. Further, two support portions 22s are arranged for each vibration node 40s.

In the drawing, the electric wiring connected to the upper electrode 21s, the first lower electrode 11s, and the second lower electrode 12s is omitted.
The upper electrode 21 s and the first lower electrode 11 s are connected to an external circuit (not shown) from the periphery of the MEMS vibrator 101 by wiring connected to the first lower electrode 11 s. The second lower electrode 12 s is connected to an external circuit by wiring from the periphery of the MEMS vibrator 101.

  In such a configuration, the MEMS vibrator 101 is configured as a free-beam electrostatic vibrator on both ends, and the upper electrode is applied by an alternating voltage applied between the upper electrode 21s and the second lower electrode 12s from an external circuit. Two opposing side surface portions 30s of 21s and the central portion 31s of the upper electrode 21s vibrate in the vertical direction in opposite phases as vibration antinodes.

  As described above, according to the MEMS vibrator 101 as the vibrator according to the present embodiment, the following effects can be obtained.

  The upper electrode 21s (vibrating body) is a rectangular plate-like body, and the two opposing side surface portions 30s of the upper electrode 21s and the central portion 31s of the upper electrode 21s vibrate in opposite phases in the thickness direction of the upper electrode 21s. The vibration node 40s constitutes a so-called free-end vibrator having both ends formed between the two side portions 30s and the central portion 31s of the upper electrode 21s. By configuring as a double-ended free beam type vibrator, it is possible to obtain a vibrator having less vibration leakage and exhibiting stable vibration characteristics.

  The support portion 22s has one end connected to the vibration node 40s of the upper electrode 21s in a region between the main surface of the substrate 1 and the main surface of the upper electrode 21s facing the main surface of the substrate 1. The other end is fixed on the main surface of the substrate 1. The vibration node 40s is linearly formed between the two side surface portions 30s and the central portion 31s of the upper electrode 21s. Since the support portion 22s can be configured without being arranged outside the upper electrode 21s, the vibrator can be configured more compactly.

  Further, since the support portion 22s is disposed between the upper electrode 21s and the substrate 1 along the vibration node 40s, it can function as a spacer that more effectively suppresses sticking as described above.

[Electronics]
Next, an electronic apparatus to which the MEMS vibrator 100 as an electronic component according to an embodiment of the present invention is applied will be described with reference to FIGS. 4 (a), 4 (b), and FIG.

  FIG. 4A is a perspective view showing an outline of the configuration of a mobile (or notebook) personal computer as an electronic apparatus including an electronic component according to an embodiment of the present invention. In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 1000. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 incorporates a MEMS vibrator 100 as an electronic component that functions as a filter, a resonator, a reference clock, and the like.

  FIG. 4B is a perspective view schematically showing a configuration of a mobile phone (including PHS) as an electronic apparatus including the electronic component according to the embodiment of the present invention. In this figure, a cellular phone 1200 is provided with a plurality of operation buttons 1202, an earpiece 1204 and a mouthpiece 1206, and a display unit 1000 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 incorporates a MEMS vibrator 100 as an electronic component (timing device) that functions as a filter, a resonator, an angular velocity sensor, or the like.

FIG. 5 is a perspective view schematically illustrating a configuration of a digital still camera as an electronic apparatus including the electronic component according to the embodiment of the present invention. In this figure, connection with an external device is also simply shown. The digital still camera 1300 generates an imaging signal (image signal) by photoelectrically converting an optical image of a subject using an imaging element such as a CCD (Charge Coupled Device).
A display unit 1000 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an image pickup signal from the CCD. The display unit 1000 displays an object as an electronic image. Functions as a viewfinder. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.
When the photographer confirms the subject image displayed on the display unit 1000 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 includes a MEMS vibrator 100 as an electronic component that functions as a filter, a resonator, an angular velocity sensor, or the like.

  As described above, a high-performance and inexpensive electronic device can be provided as an electronic device by utilizing the MEMS vibrator 100 that does not deteriorate the higher-performance characteristics and stabilizes the manufacturing yield. can do.

  Note that the MEMS vibrator 100 as an electronic component according to an embodiment of the present invention includes a personal computer (mobile personal computer) shown in FIG. 4A, a mobile phone shown in FIG. 4B, and a digital still camera shown in FIG. In addition, for example, an ink jet discharge device (for example, an ink jet printer), a laptop personal computer, a television, a video camera, a car navigation device, a pager, an electronic notebook (including a communication function), an electronic dictionary, a calculator, an electronic Game equipment, workstations, videophones, crime prevention TV monitors, electronic binoculars, POS terminals, medical equipment (eg electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices, ultrasonic diagnostic devices, electronic endoscopes), fish detection Machines, various measuring instruments, instruments (eg, vehicles, aircraft, ships Vessels such) can be applied to electronic devices such as flight simulators.

[Moving object]
Next, a moving body to which the MEMS vibrator 100 as a vibrator according to an embodiment of the present invention is applied will be described with reference to FIG.
FIG. 6 is a perspective view schematically showing an automobile 1400 as a moving body including the MEMS vibrator 100. The automobile 1400 is equipped with a gyro sensor including the MEMS vibrator 100 according to the present invention. For example, as shown in the figure, an automobile 1400 as a moving body is equipped with an electronic control unit 1402 incorporating the gyro sensor for controlling the tire 1401. As another example, the MEMS vibrator 100 includes a keyless entry, an immobilizer, a car navigation system, a car air conditioner, an antilock brake system (ABS), an air bag, a tire pressure monitoring system (TPMS: Tire Pressure Monitoring). System), engine control, battery monitors for hybrid vehicles and electric vehicles, vehicle body attitude control systems, and other electronic control units (ECUs).

  As a moving body, a high-performance and inexpensive moving body is provided by utilizing the MEMS vibrator 100 that is more compact and has a higher manufacturing yield without degrading higher performance characteristics. can do.

Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.
Moreover, although the electronic apparatus and the moving body described above have been described with the example in which the MEMS vibrator 100 is applied, the MEMS vibrator 101 and the modifications described below can also be applied.

(Modification 1)
7A to 7C are plan views illustrating examples of variations of the lower electrode as the MEMS vibrator according to the first modification.
In the first embodiment, as illustrated in FIG. 1A, the lower electrode is described as being configured by the first lower electrode 11 and the second lower electrode 12, but the configuration is not limited thereto.

The modification shown in FIG. 7A is an example in which the lower electrode is configured by only the first lower electrode 11a. Note that, by an alternating voltage applied between the upper electrode 21 and the first lower electrode 11a, a MEMS vibrator in which the peripheral portion and the center portion of the upper electrode 21 vibrate in opposite phases as vibration antinodes is configured. Therefore, it is necessary to insulate the upper electrode 21 and the first lower electrode 11a. Therefore, the first lower electrode 11 in Embodiment 1 is divided into a first lower electrode 11a and an upper electrode fixing portion 13a that is electrically connected to the upper electrode 21. As for the support part 22, the other edge part of the support part 22 is being fixed to the upper electrode fixing | fixed part 13a.
The upper electrode 21 is connected to an external circuit by wiring connected to the upper electrode fixing portion 13a. The first lower electrode 11a is connected to an external circuit through a wiring insulated from the upper electrode fixing portion 13a and connected to the first lower electrode 11a.

The modification shown in FIG. 7B is an example in which the lower electrode is composed of only the second lower electrode 12. Note that, by an alternating voltage applied between the upper electrode 21 and the second lower electrode 12, a MEMS vibrator in which the peripheral portion and the central portion of the upper electrode 21 vibrate in opposite phases as vibration antinodes is formed. Therefore, the above-described upper electrode fixing portion 13 a is also provided as an electrode for wiring to the upper electrode 21. As for the support part 22, the other edge part of the support part 22 is being fixed to the upper electrode fixing | fixed part 13a.
The upper electrode 21 is connected to an external circuit by wiring that is insulated from the second lower electrode 12 and connected to the upper electrode fixing portion 13a. The second lower electrode 12 is connected to an external circuit through a wiring connected to the second lower electrode 12.

The modification shown in FIG. 7C is an example in which the lower electrode is composed of the first lower electrode 11 a and the second lower electrode 12.
As described above, the first lower electrode 11 a is insulated from the upper electrode 21, and the upper electrode 21 is connected to the upper electrode fixing portion 13 a via the support portion 22. That is, the upper electrode 21 is insulated from both the first lower electrode 11 a and the second lower electrode 12. The upper electrode 21, the first lower electrode 11a, and the second lower electrode 12 are independently connected to an external circuit. With this configuration, it is possible to select a method for applying an AC voltage applied from an external circuit, and it is possible to increase the degree of freedom of control specifications such as changing the characteristics of vibration.

  As described above, even in the configurations shown in FIGS. 7A to 7C, although the vibration energy and the vibration characteristics are different, an electrostatic vibrator having the same vibration mode as that of the above-described embodiment can be configured.

(Modification 2)
8A to 8C are plan views illustrating examples of variations of the lower electrode as the MEMS vibrator according to the second modification.
In the second embodiment, as illustrated in FIG. 3A, the lower electrode is described as being configured by the first lower electrode 11s and the second lower electrode 12s. However, the present invention is not limited to this configuration.

The modification shown in FIG. 8A is an example in which the lower electrode is configured by only the first lower electrode 11sa. Note that, due to an alternating voltage applied between the upper electrode 21 and the first lower electrode 11sa, the two side surface portions 30s facing the upper electrode 21s and the central portion 31s of the upper electrode 21s (FIG. 3C) Therefore, it is necessary to insulate the upper electrode 21 and the first lower electrode 11sa in order to obtain a MEMS vibrator that vibrates in an opposite phase as a vibration antinode. For this reason, the first lower electrode 11s in the second embodiment is divided into an upper electrode fixing portion 13s and a first lower electrode 11sa that are electrically connected to the upper electrode 21s. In the support portion 22s, the other end portion of the support portion 22s is fixed to the upper electrode fixing portion 13s.
The upper electrode 21 is connected to an external circuit by wiring connected to the upper electrode fixing portion 13s. The first lower electrode 11sa is connected to an external circuit through a wiring insulated from the upper electrode fixing portion 13s and connected to the first lower electrode 11sa.

The modification shown in FIG. 8B is an example in which the lower electrode is configured by only the second lower electrode 12sa. It should be noted that, due to the alternating voltage applied between the upper electrode 21 and the second lower electrode 12sa, the two opposing side surface portions 30s of the upper electrode 21s and the central portion 31s of the upper electrode 21s are reversed as vibration antinodes. In order to configure a MEMS vibrator that vibrates in phase, the above-described upper electrode fixing portion 13 s is also provided as an electrode for wiring to the upper electrode 21. In the support portion 22s, the other end portion of the support portion 22s is fixed to the upper electrode fixing portion 13s.
The upper electrode 21s is connected to an external circuit through a wiring that is insulated from the second lower electrode 12sa and connected to the upper electrode fixing portion 13s. The second lower electrode 12sa is connected to an external circuit through a wiring connected to the second lower electrode 12sa.

The modification shown in FIG. 8C is an example in which the lower electrode is composed of the first lower electrode 11sa and the second lower electrode 12sa.
As described above, the first lower electrode 11sa is insulated from the upper electrode 21s, and the upper electrode 21s is connected to the upper electrode fixing portion 13s via the support portion 22s. That is, the upper electrode 21s is insulated from both the first lower electrode 11sa and the second lower electrode 12sa. The upper electrode 21s, the first lower electrode 11sa, and the second lower electrode 12sa are independently connected to an external circuit. With this configuration, it is possible to select a method for applying an AC voltage applied from an external circuit, and it is possible to increase the degree of freedom of control specifications such as changing the characteristics of vibration.

  As described above, even in the configurations as shown in FIGS. 8A to 8C, an electrostatic vibrator having the same vibration mode as that of the above-described embodiment can be configured although the vibration energy and the vibration characteristics are different.

(Modification 3)
FIGS. 9A to 9D are perspective views showing examples of variations of the support portion as the MEMS vibrator according to the third modification.
In the first and second embodiments, the upper electrodes 21 and 21s are separated from the substrate 1 by the four support portions 22 and 22s, respectively, and are supported so that the main surface of the substrate 1 and the main surfaces of the upper electrodes 21 and 21s face each other. However, the present invention is not limited to this configuration. The support portions 22 and 22 s are not limited to four each, and a plurality of support portions 22 and 22 s may be installed along the positions of the vibration nodes 40 and 40 s as necessary, or may be extended along the positions of the vibration nodes 40 and 40 s. You may comprise with the existing plate-shaped object.

The modification shown in FIG. 9A is an example in which eight support portions 22 are installed along the position of the vibration node 40.
The modification shown in FIG. 9B is an example in which the support portion 22v is configured by a plate-like body. The support portion 22v is a plate-like body extending along the position of the vibration node 40 and extending in a direction intersecting with the extending direction of the main surface of the substrate 1. Since the vibration node 40 is circular, the support portion 22v is configured as a cylinder. Since the rigidity of the support portion 22v is drastically improved by using the cylinder, the plate-like body as the cylindrical side surface can be made thinner. As a result, an efficient vibrator with less vibration leakage can be obtained.
The modification shown in FIG. 9C is an example in which a total of eight support portions 22 are provided along the position of each vibration node 40s.
The modification shown in FIG. 9D is an example in which the support portion 22sv is configured by a plate-like body. The support portion 22sv is a plate-like body extending along the position of the vibration node 40s in a direction intersecting with the extending direction of the main surface of the substrate 1.

  As described above, by providing a plurality of support portions along the vibration nodes or by configuring the support portions with plate-like bodies extending along the vibration nodes, the support portions can be supported by a more rigid support structure. As a result, for example, in the manufacturing process of forming a free vibrating body on the main surface of the substrate, the vibrating body adheres to the main surface of the substrate even when the surface tension of the etching liquid or cleaning liquid is applied. Sticking phenomenon is less likely to occur. As a result, yield reduction due to sticking can be suppressed.

(Modification 4)
FIGS. 10A to 10C are plan views showing examples of variations of the upper electrode as the MEMS vibrator according to the modified example 4. FIG.

The modification shown in FIG. 10A is a modification to the first embodiment, and the upper electrode 21v has a rotationally symmetric octagonal shape when the substrate 1 is viewed in plan. As described above, it is not always necessary to have a circular shape and does not necessarily have to be an octagon, but in the case of a polygonal shape, it is preferably rotationally symmetric.
The modification shown in FIG. 10B is a modification to the first embodiment, and when the substrate 1 is viewed in plan, the upper electrode 21w has an elliptical shape. Thus, it is not necessarily circular, but is preferably rotationally symmetric.
When the upper electrode is a plate-like body having a rotationally symmetric shape, the vibrating body can be vibrated with a better balance. As a result, it is possible to obtain a vibrator having less vibration leakage and exhibiting stable vibration characteristics.
The modification shown in FIG. 10C is a modification to the second embodiment, and when the substrate 1 is viewed in plan, the upper electrode 21x has an elliptical shape. Thus, although it does not necessarily need to be a rectangle, it is preferable that it is line symmetrical.

  DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... 1st oxide film, 3 ... Nitride film, 11, 11a, 11s, 11sa ... 1st lower electrode, 12, 12s, 12sa ... 2nd lower electrode, 13a, 13s ... Upper electrode fixing | fixed part 21, 21 s, 21 v, 21 w ... upper electrode, 22, 22 s, 22 sv, 22 v ... support part, 30 ... peripheral part, 30 a, 30 s ... side part, 31, 31 s ... center part, 40, 40 s ... node of vibration, 100, 101... MEMS vibrator.

Claims (15)

A substrate,
A support part;
And a vibrating body supported by the support portion on the main surface of the substrate.
The support part is
In a region between the main surface of the substrate and the main surface of the vibrating body facing the main surface of the substrate, one end is connected to a vibration node of the vibrating body, and the other end is the A vibrator characterized by being fixed on a main surface of a substrate. The vibrating body is a plate-like body having a rotationally symmetric shape,
The vibration node is formed between the peripheral portion and the central portion by causing the peripheral portion of the vibrator and the central portion of the vibrator to vibrate in opposite phases in the thickness direction of the vibrator. The vibrator according to claim 1, wherein The vibrator is an upper electrode;
The vibrator according to claim 2, further comprising a first lower electrode between the substrate and a region surrounded by the vibration node of the vibrator. The vibrator is an upper electrode;
The vibrator according to claim 2, further comprising a second lower electrode between the substrate and a region outside the region surrounded by the vibration node of the vibrator. The vibrator is an upper electrode;
A first lower electrode provided between the substrate and a region surrounded by the vibration node of the vibrator;
The vibrator according to claim 2, further comprising a second lower electrode between the substrate and a region outside the region surrounded by the vibration node of the vibrator.   The vibrator according to claim 2, wherein the vibrator is a plate-like body having a circular shape. The vibrating body is a rectangular plate-shaped body,
The vibration node includes two side surface portions of the vibrating body facing each other and a central portion of the vibrating body vibrating in opposite phases in the thickness direction of the vibrating body, so that the two side surface portions, The vibrator according to claim 1, wherein the vibrator is formed between a center portion of the vibrating body. The vibrator is an upper electrode;
The vibrator according to claim 7, further comprising a first lower electrode between the substrate and a region sandwiched between the vibration nodes of the vibrating body. The vibrator is an upper electrode;
The vibrator according to claim 7, further comprising a second lower electrode between the substrate and a region outside the region sandwiched between the vibration nodes of the vibrating body. The vibrator is an upper electrode;
A first lower electrode provided between the substrate and a region sandwiched between the vibration nodes of the vibrator;
The vibrator according to claim 7, further comprising a second lower electrode between the substrate and a region outside the region sandwiched between the vibration nodes of the vibrating body. The vibrator is
A first AC voltage applied between the upper electrode and the first lower electrode;
11. The device according to claim 5, wherein the first and second lower electrodes are vibrated by a second alternating voltage applied in a phase opposite to that of the first alternating voltage. 11. The vibrator described.   The vibrator according to any one of claims 1 to 11, wherein the support portion is a columnar body extending in a direction intersecting with a main surface of the substrate.   The vibrator according to claim 1, wherein the support portion is a plate-like body extending in a direction intersecting with a main surface of the substrate.   An electronic apparatus comprising the vibrator according to any one of claims 1 to 13.   A moving body comprising the vibrator according to any one of claims 1 to 13.

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