JP2014204352A - Vibration element, vibrator, oscillator, manufacturing method of vibration element, electronic apparatus and mobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vibration element in which a desired natural vibration frequency is obtained, rigidity of a vibration body is improved, a facing area between electrodes is widened and electric characteristics are improved.SOLUTION: A vibration element comprises: a substrate 10; a first electrode part 20 and a fixed part 40 which are provided on one surface of the substrate; a pedestal part 50 which is provided on the one surface and includes a recess; and a second electrode part 30 which is partially overlapped with the first electrode part in a planar view in a direction vertical to the one surface and extends from the fixed part while being spaced apart from the first electrode part. On a surface of the second electrode part opposing the first electrode part, a protrusion 36 is provided oppositely to a recess 52.

Description

  The present invention relates to a vibration element, a vibrator, an oscillator, a method for manufacturing the vibration element, an electronic device, and a moving body.

  As a typical example of a conventional vibration element, a beam-type vibration element that vibrates in the thickness direction of a substrate is known. The beam-type vibration element is a vibration element including a fixed electrode provided on a substrate and a movable electrode provided with a gap with respect to the fixed electrode. Known beam-type vibrating elements include cantilevered (clamped-free beam), clamped-clamped beam, and free-free beam at both ends, depending on the method of supporting the movable electrode. It has been.

  In such a vibration element, the natural vibration frequency is determined by the length of the movable electrode and the beam supporting the movable electrode. Therefore, when it is desired to increase the natural vibration frequency, shortening the movable electrode and the beam length is a common method. Patent Document 1 discloses a vibration element that adjusts the natural vibration frequency by a method in which the angle formed by the side surfaces of the fixed electrode is different and a method in which the area where the fixed electrode and the movable electrode overlap, that is, the extension of the movable electrode is different. Is disclosed.

JP 2007-160495 A

  However, when the movable electrode and the beam length are shortened, the facing area between the movable electrode and the fixed electrode is reduced, and the capacitance generated between these electrodes is reduced, so that the equivalent series resistance of the vibration element is increased. There was a problem that oscillation was reduced.

  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 forms or application examples.

[Application Example 1]
The vibration element according to this application example includes a substrate, a first electrode portion provided on one surface of the substrate, a fixing portion, a pedestal portion provided on one surface and having a recessed portion, and perpendicular to the one surface. A second electrode portion that partially overlaps the first electrode portion in plan view from the direction and that extends from the fixed portion with a gap with respect to the first electrode portion. A protrusion is provided on the surface of the second electrode portion facing the electrode portion so as to face the recess.

According to such a vibration element, the first electrode portion and the second electrode portion are provided so as to overlap each other with a gap therebetween, and the second electrode portion is formed by the electric charge generated between these electrode portions. The first electrode portion can vibrate when an electrostatic attractive force acts on the first electrode portion. Further, since the protrusion is provided on the second electrode portion, the rigidity thereof is increased, and sticking to the first electrode portion due to vibration can be suppressed.
In addition, according to such a vibration element, the second electrode portion can be lengthened by increasing the rigidity of the second electrode portion, and the facing area overlapping the first electrode portion can be increased. As a result, it is possible to increase the change in capacitance between the first electrode portion and the second electrode portion that occurs when the second electrode portion vibrates, thereby improving the electrical characteristics of the vibration element and generating oscillation. Implementation can be facilitated.

[Application Example 2]
In the resonator element according to the application example, it is preferable that the first electrode portion, the second electrode portion, the fixing portion, and the pedestal portion are formed of polysilicon.

  According to such a vibration element, the first electrode portion, the second electrode portion, the fixing portion, and the pedestal portion are formed of conductive polysilicon, so that the first electrode portion is not provided. An electric charge is generated between the first electrode portion and the second electrode portion, and electrostatic attraction can be obtained in the second electrode portion. In addition, since the fixed portion and the pedestal portion are formed of the same material, the linear expansion coefficient and the like become substantially equal, and even if stress occurs in the fixed portion and the pedestal portion, the distortion between them can be suppressed. it can. Therefore, it is possible to obtain a resonator element that suppresses the change in the vibration frequency of the second electrode portion due to the distortion between the fixed portion and the pedestal portion.

[Application Example 3]
In the fixed portion of the vibration element according to the application example, the first fixed portion extending in the first direction in parallel along the substrate, and the second direction intersecting the first direction, A second fixing portion extending from the first fixing portion; a third fixing portion extending from the second fixing portion along the pedestal portion toward the first direction; and a second direction. And a fourth fixing portion extending from the third fixing portion, and the second electrode portion extends from the fourth fixing portion in the first direction toward the pedestal portion and the first fixing portion. It is preferable to extend with a gap with respect to the electrode part.

  According to such a vibration element, the fixing portion is provided such that the third fixing portion comes into contact with the pedestal portion, and the second electrode portion extends from the fourth fixing portion extending from the third fixing portion. Therefore, when the vibration of the second electrode portion leaks to the fixed portion, it is conducted to the pedestal portion via the third fixed portion. Since the fixed portion and the pedestal portion are formed of the same material, when stress is generated between the fixed portion and the pedestal portion due to leaked vibration, the fixed portion and the pedestal portion are distorted approximately equally. Therefore, it is possible to obtain a vibration element that suppresses the change in the vibration frequency of the second electrode portion due to the difference in distortion between the fixed portion and the pedestal portion.

[Application Example 4]
In the resonator element according to the application example described above, it is preferable that a plurality of second electrode portions extend from the fixed portion.

  According to such a vibration element, since vibrations of adjacent vibration elements are coupled, vibration leakage is suppressed, and a vibration element with less loss can be obtained.

[Application Example 5]
The vibration element according to the application example includes a plurality of fixed portions, and the second movable electrode is provided with a gap from the first electrode portion toward the other fixed portion from one fixed portion. Preferably it is.

  According to such a vibrating element, both ends of the second electrode portion are supported by the fixing portions, and the protrusions are provided on the second electrode portion. Even if the second electrode portion is provided long for adjusting the natural vibration frequency, it is possible to suppress the occurrence of sticking and increase the area facing the first electrode portion. As a result, it is possible to increase the change in capacitance between the first electrode portion and the second electrode portion that occurs when the second electrode portion vibrates, thereby improving the electrical characteristics of the vibration element and generating oscillation. Implementation can be facilitated.

[Application Example 6]
The vibrator according to the application example includes a substrate, a first electrode portion provided on one surface of the substrate, a fixing portion, a pedestal portion provided on one surface and having a recessed portion, and one surface. A second electrode portion that partially overlaps the first electrode portion in plan view from the vertical direction and that extends from the fixed portion with a gap from the first electrode portion; and the first electrode A circuit unit for applying an electric potential between the first electrode unit and the second electrode unit and amplifying an electric signal generated between the first electrode unit and the second electrode unit, A protrusion is provided on the surface of the opposing second electrode portion so as to oppose the recess.

According to such a vibrator, a potential is applied to the first electrode portion and the second electrode portion by the circuit portion, and the second electrode portion is An electrostatic attractive force acts on the electrode portion of the second electrode portion, and the second electrode portion can vibrate. In addition, since the rigidity of the second electrode portion is enhanced by providing the protrusion, sticking to the first electrode portion due to vibration can be suppressed.
Further, according to such a vibrator, since the rigidity of the second electrode portion is increased, it is possible to lengthen the second electrode portion and increase the facing area overlapping with the first electrode portion. As a result, when the second electrode portion vibrates, it is possible to increase the change in capacitance generated between the respective electrode portions, and suppress the power consumption of the circuit portion that amplifies the change in capacitance due to vibration. can do.

[Application Example 7]
The oscillator according to this application example includes a substrate, a first electrode portion provided on one surface of the substrate, a fixed portion, a pedestal portion provided on one surface and having a recessed portion, and perpendicular to the one surface. A second electrode portion partially overlapping the first electrode portion in plan view from the direction and extending from the fixed portion with a gap with respect to the first electrode portion, and the first electrode portion And a circuit portion for applying an electric potential between the first electrode portion and the second electrode portion and amplifying an electric signal generated between the first electrode portion and the second electrode portion, a substrate, a fixing portion, a pedestal portion, and a first electrode And a housing in which the second electrode part is accommodated, and a surface of the second electrode part facing the first electrode part is provided with a protrusion facing the recess Features.

According to such an oscillator, a potential is applied to the first electrode portion and the second electrode portion housed in the casing by the circuit portion, and electric charges are generated between the respective electrode portions. The electrode portion can vibrate when an electrostatic attractive force acts on the first electrode portion. In addition, the second electrode portion is provided with a protrusion, so that the rigidity thereof can be increased and sticking to the first electrode portion due to vibration can be suppressed.
According to such an oscillator, the rigidity of the second electrode portion is increased, so that the second electrode portion is lengthened to adjust the natural vibration frequency, and the facing area overlapping the first electrode portion is increased. Can do. As a result, when the second electrode portion vibrates, the change in capacitance generated between the respective electrode portions is increased, so that the power consumption of the circuit portion that amplifies the change in capacitance due to vibration is suppressed. it can. In addition, the addition of a housing can avoid interference with peripheral circuits, and can increase the resistance of the circuit to external noise.
Therefore, such an oscillator can suppress the occurrence of sticking even when the second electrode portion is lengthened in order to adjust the natural vibration frequency, and can realize a circuit highly resistant to external noise.

[Application Example 8]
The vibration element manufacturing method according to this application example includes a step of preparing a substrate, a step of forming a fixing portion on one surface of the substrate, a step of forming a pedestal portion having a recess on one surface, and In the step of forming the first electrode part and in plan view from the direction perpendicular to the one surface, a part of the first electrode part overlaps the first electrode part, and the first electrode part is spaced from the fixed part. Forming a second electrode portion that includes a step of forming a second electrode portion to be extended, and a step of forming an intermediate layer between the second electrode portion and the first electrode portion and the pedestal portion. The step of performing is characterized in that a protrusion is formed on the surface of the second electrode portion facing the first electrode portion, corresponding to the recess.

According to such a method for manufacturing a vibration element, the step of forming the first electrode portion and the pedestal portion having the depression on one surface of the substrate, and the intermediate layer on the pedestal portion and the first electrode portion are formed. And forming a second electrode portion on the intermediate layer.
As a result, the intermediate layer has a depression on the surface on which the second electrode portion is formed according to the depression, and the second electrode portion is formed along the depression. A protrusion corresponding to the portion can be formed on the second electrode portion. The second electrode portion is provided with a protrusion, so that its rigidity can be increased and sticking to the first electrode portion due to vibration can be suppressed. Also, according to such a method for manufacturing a vibration element, the second electrode portion is lengthened to adjust the natural vibration frequency by increasing the rigidity of the second electrode portion, and is opposed to the first electrode portion. The area can be increased.
Therefore, such a manufacturing method suppresses the occurrence of sticking without adding a new process, and when the second electrode portion vibrates, changes in capacitance generated between the respective electrode portions are suppressed. It is possible to manufacture a vibration element that can increase the electrical characteristics of the vibration element and facilitate the realization of oscillation.

[Application Example 9]
An electronic apparatus according to this application example is characterized in that any one of the above-described vibration elements is mounted.

  According to such an electronic device, the occurrence of sticking is suppressed, the change in capacitance due to vibration is increased, the electrical characteristics of the vibration element are improved, and oscillation can be easily realized. When the vibration element is mounted on the electronic device, the reliability of the electronic device can be increased.

[Application Example 10]
The moving body according to this application example is characterized in that any one of the above-described vibration elements is mounted.

  According to such a moving body, the occurrence of sticking is suppressed, the change in capacitance due to vibration is increased, the electrical characteristics of the vibration element are improved, and oscillation can be easily realized. When the vibration element is mounted on the moving body, the reliability of the moving body can be increased.

The top view and side view which show typically the vibration element which concerns on 1st Embodiment. FIG. 6 is a side view schematically showing the manufacturing process of the vibration element according to the first embodiment. FIG. 6 is a side view schematically showing the manufacturing process of the vibration element according to the first embodiment. The top view and side view which show typically the vibration element which concerns on 2nd Embodiment. The top view and side view which show typically the vibration element which concerns on 3rd Embodiment. The block diagram which shows typically the vibrator | oscillator concerning 4th Embodiment. The block diagram which shows typically the oscillator which concerns on 5th Embodiment. FIG. 3 is a diagram schematically showing a personal computer as an electronic apparatus according to an example. FIG. 3 is a diagram schematically illustrating a mobile phone as an electronic apparatus according to an example. The figure which shows typically the digital still camera as an electronic device which concerns on an Example. The figure which shows typically the motor vehicle as a moving body which concerns on an Example.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure shown below, the size and ratio of each component may be described differently from the actual component in order to make each component large enough to be recognized on the drawing. is there.

(First embodiment)
The vibration element according to the first embodiment will be described with reference to FIGS. 1 to 3.
1 to 3 illustrate the X axis, the Y axis, and the Z axis as three axes orthogonal to each other. The Z axis is an axis indicating the thickness direction in which the substrate and each electrode are laminated. FIG. 1 is a plan view and a side view schematically showing an outline of the resonator element according to the first embodiment. FIG. 1A is a plan view schematically showing the resonator element 1 viewed in plan from the Z-axis direction. FIG. 1B is a side view schematically showing the resonator element 1 viewed from the side in the Y-axis direction. FIG. 1C is a side view schematically showing the resonator element 1 viewed from the side in the X-axis direction. FIG. 1D is an enlarged schematic view showing a part of the side surface of the vibration element shown in FIG. 2 and 3 are diagrams schematically showing a manufacturing process on the side surface of the vibration element in the portion shown in FIG.

(Structure of the vibration element 1)
The vibration element 1 according to the first embodiment is a so-called cantilever type vibration element.
As shown in FIG. 1, the vibration element 1 includes a substrate 10, an insulating portion 12, a fixed electrode 20 as a first electrode portion, a movable electrode 30 as a second electrode portion, a fixed portion 40, A pedestal 50 is provided.

(Substrate 10)
The substrate 10 is provided with an insulating portion 12, a fixed electrode 20, a movable electrode 30, a fixed portion 40, and a pedestal portion 50, which will be described later, on one surface thereof. As the material of the substrate 10, for example, a silicon substrate or a glass substrate can be used. In the vibration element 1 of the present embodiment, a silicon substrate is used as the substrate 10.
In the following description, one surface on which the insulating portion 12, the fixed electrode 20, the movable electrode 30, the fixed portion 40, and the pedestal portion 50 are provided will be referred to as a main surface 10a.

(Insulation part 12)
The insulating portion 12 is provided by being laminated on the main surface 10 a of the substrate 10.
The insulating part 12 includes a first insulating part 121 and a second insulating part 122 that are sequentially arranged from the main surface 10a side.
As the material of the first insulating portion 121, silicon oxide (SiO ₂ ) or the like can be used. The second insulating portion 122 can be made of silicon nitride (Si ₃ N ₄ ) or the like as the material. The configuration and material of the insulating portion 12 are not particularly limited, and the insulation between the substrate 10 and the fixed electrode 20 and the like which will be described later, and the protection of the substrate 10 when forming the movable electrode 30 and the like which will be described later. If possible, it may be changed as appropriate.
In FIG. 1, the first insulating portion 121 and the second insulating portion 122 are collectively shown as the insulating portion 12.
In the following description, when referred to as the main surface 12a side, it will be described as the one surface side on which the second insulating portion 122 is provided.

(Fixed electrode 20, movable electrode 30, fixed part 40, pedestal part 50)
On the substrate 10 of the vibration element 1, the fixed electrode 20, the movable electrode 30, the fixed portion 40, and the pedestal portion 50 are provided via the main surface 12 a of the insulating portion 12.

(Fixed electrode 20)
As shown in FIG. 1, the fixed electrode 20 is provided so that a part thereof overlaps the movable electrode 30 when the fixed electrode 20 and a movable electrode 30 described later are viewed in a plan view from the Z-axis (vertical) direction. .
As the material of the fixed electrode 20, for example, a conductive material such as polysilicon (Polycrystalline Silicon) or amorphous silicon can be used. Polysilicon is used as the material for the fixed electrode 20 of the vibration element 1 of the present embodiment.

(Movable electrode 30)
The movable electrode 30 includes a beam portion 32 and a detection electrode portion 34 provided on the beam portion 32.
As shown in FIG. 1, when the movable electrode 30 is viewed in plan from the Z-axis direction of the fixed electrode 20 and the movable electrode 30, a part of the detection electrode part 34 is a part of the fixed electrode 20 and a part of the beam part 32 is. A gap 60 is provided so as to overlap the pedestal 50.
The beam portion 32 is provided with a protrusion 36. The projection 36 provided on the surface of the beam portion 32 that faces the pedestal portion 50 is provided to face a recess 52 that is provided in the pedestal portion 50 described later.

  Although details will be described later, the movable electrode 30 can vibrate (displace) by an electrostatic attractive force generated between the movable electrode 30 and the fixed electrode 20 when a potential is applied between the movable electrode 30 and the fixed electrode 20. That is, the movable electrode 30 is provided as a vibrating piece. Therefore, the movable electrode 30 has toughness, and a distal end extending from the fixed portion 40 is provided as a free end.

  As the material of the movable electrode 30, for example, a conductive material such as polysilicon or amorphous silicon can be used. The movable electrode 30 of the vibration element 1 of the present embodiment uses polysilicon as its material. The movable electrode 30 can be vibrated by electrostatic attraction by generating a charge between the movable electrode 30 and the fixed electrode 20 without using an electrode film on the detection electrode portion 34 by using polysilicon or the like as a conductive material. Become.

(Fixing part 40)
The fixing portion 40 is provided on the substrate 10 via the main surface 12a.
The fixing part 40 includes a first fixing part 40a, a second fixing part 40b, a third fixing part 40c, and a fourth fixing part 40d.
The first fixing portion 40 a is provided in contact with the insulating portion 12 in a first direction (X-axis direction) parallel to the substrate 10. The second fixing portion 40b extends from one end of the first fixing portion 40a in a second direction (Z-axis direction) that intersects the first direction. The third fixing portion 40c extends along the pedestal portion 50 from the other end different from the one end connected to the first fixing portion 40a in the second fixing portion 40b in the first direction. The fourth fixing portion 40d extends in the second direction from the other end of the third fixing portion 40c different from the one end connected to the second fixing portion 40b.
Note that the movable electrode 30 extends from the other end different from the one end connected to the third fixed portion 40c toward the first direction in the fourth fixed portion 40d.

  As the material of the fixing portion 40, for example, a conductive material such as polysilicon or amorphous silicon can be used. Polysilicon is used as the material of the fixing portion 40 of the vibration element 1 of the present embodiment. The fixing part 40 can improve the adhesion to the insulating part 12 by using polysilicon.

  Note that, when vibration leaks from the movable electrode 30 to the fixed portion 40, the third fixed portion 40 c is in contact with the pedestal portion 50, so that the vibration is conducted to the pedestal portion 50. Since both the fixed portion 40 and the pedestal portion 50 are made of polysilicon, the stress (distortion) due to the leaked vibration is generated approximately equally, and the shift of the natural vibration frequency of the movable electrode 30 due to the stress can be suppressed. .

(Pedestal 50)
The pedestal part 50 is provided on the substrate 10 via the insulating part 12.
The pedestal 50 has a recess 52 that faces the protrusion 36 provided on the movable electrode 30. The recessed portion 52 is provided with a smaller thickness in the Z-axis direction, which is the direction in which the substrate 10 and the insulating portion 12 are laminated, than the pedestal portion 50. The shape of the recess 52 is not limited to a rectangular shape (groove shape), and may be a spherical shape or a polygonal shape. For example, the depressed portion 52 suppresses the contact between the protrusion 36 and the pedestal portion 50 when displacement occurs due to the vibration of the movable electrode 30, and secures a larger space in which the movable electrode 30 can be displaced as the thickness is thinner. it can.

(Operation of vibrating element 1)
For example, the vibration element 1 of the present embodiment can apply a potential (excitation signal) generated by a circuit unit (not shown in FIG. 1) between the fixed electrode 20 and the movable electrode 30. An excitation signal can be applied to the movable electrode 30 via the fixed portion 40. In addition, an electric signal obtained by the vibration of the movable electrode 30 can be taken out via the fixed electrode 20 and the fixed portion 40 connected to the movable electrode 30.

By applying an excitation signal between the fixed electrode 20 and the movable electrode 30, the movable electrode 30 can be vibrated.
Specifically, when different polar potentials are applied between the fixed electrode 20 and the movable electrode 30, an electric charge is generated between the fixed electrode 20 and the movable electrode 30, and the movable electrode 30 (the detection electrode unit 34) is caused by electrostatic attraction. ) Is attracted and displaced to the fixed electrode 20 side.
Further, when the potential applied between the fixed electrode 20 and the movable electrode 30 is released, the electric charge generated between the fixed electrode 20 and the movable electrode 30 is eliminated, and the movable electrode 30 (detection electrode unit 34) is restored due to toughness. To do. As described above, the vibration element 1 can vibrate the movable electrode 30 (detection electrode unit 34) by repeating the application of the potential and the release of the potential.

Here, the vibration element 1 has a characteristic that the natural vibration frequency f ₀ varies depending on the length of the movable electrode 30.
Specifically, by providing long movable electrode 30 that extends from the fixed portion 40, it is possible to reduce the natural vibration frequency f _0, by providing the movable electrode 30 short, the natural vibration frequency f ₀ Can be high. When the length of the movable electrode 30 is increased in order to lower the natural vibration frequency f ₀ , there is a possibility that the “sticking” occurs in which the movable electrode 30 bends and sticks to the fixed electrode 20. Therefore, in the vibration element 1 of the present embodiment, the protrusion 36 provided on the beam portion 32 of the movable electrode 30 reinforces the movable electrode 30, so that the bending of the movable electrode 30 can be suppressed. Further, by providing the movable electrode 30 long, the “opposite area” which is an area overlapping the fixed electrode 20 with the gap 60 is increased, and the capacitance generated between these electrodes is increased. Therefore, the “equivalent series resistance” that is the electrical characteristic of the vibration element 1 can be reduced, and the output accompanying the vibration of the vibration element 1 can be increased.

(Manufacturing method of the vibration element 1)
The steps of manufacturing the vibration element 1 of the present embodiment include a step of preparing a substrate, a step of forming a fixed portion and a fixed electrode on one surface of the substrate, and a pedestal portion having a recess on one surface of the substrate. And a step of performing. In addition, the process of manufacturing the vibration element 1 includes a step of forming a movable electrode provided with a protrusion extending from the fixed portion with a gap so as to overlap with the fixed electrode, and having a protruding portion facing the depressed portion, the movable electrode, and a pedestal Forming an intermediate layer between the portion and the fixed electrode. A method for manufacturing the vibration element 1 will be described below in the order of steps.

(Preparation process of substrate 10)
FIG. 2A shows a state in which the substrate 10 on which the vibration element 1 is formed is prepared.
The step of preparing the substrate 10 is a step of preparing the substrate 10 on which the insulating portion 12, the fixed electrode 20, the movable electrode 30 and the like are formed in each step described later. For example, a silicon substrate can be used as the substrate 10.
In the description of the method for manufacturing the vibration element 1, one surface of the substrate 10 on which the insulating portion 12, the fixed electrode 20, the movable electrode 30 and the like are formed will be referred to as a main surface 10 a.

(Formation process of insulating part 12)
FIG. 2B shows a state where the insulating portion 12 is formed on the main surface 10 a of the substrate 10.
The step of forming the insulating portion 12 is a step of forming the insulating portion 12 on the main surface 10a side of the substrate 10.
The insulating portion 12 of the vibration element 1 of the present embodiment is formed in the order of the first insulating portion 121 and the second insulating portion 122 from the main surface 10a side of the substrate 10. In the description of the method for manufacturing the vibration element 1, one surface of the insulating portion 12 on which the second insulating portion 122 is formed will be referred to as a main surface 12 a.

In the step of forming the first insulating part 121, for example, a film containing silicon oxide (SiO ₂ ) can be formed as the first insulating part 121 by a CVD (chemical vapor deposition) method. The step of forming the first insulating portion 121 is not limited to the CVD method, and a film containing silicon oxide may be formed by oxidizing the main surface 10a of the substrate 10 by a thermal oxidation method.
The first insulating portion 121 is formed on substantially the entire surface corresponding to the main surface 10 a of the substrate 10.

In the step of forming the second insulating portion 122, for example, a film containing silicon nitride (Si ₃ N ₄ ) as the second insulating portion 122 can be formed by a CVD method. The step of forming the second insulating portion 122 is not limited to the CVD method, and a film containing silicon nitride is formed by heating the silicon substrate as the substrate 10 in an atmosphere of nitrogen gas and hydrogen gas. You may do it.
The second insulating portion 122 is formed on substantially the entire surface corresponding to the first insulating portion 121.

(Formation process of fixed electrode 20 and pedestal 50)
FIG. 2C shows a state in which the fixed electrode 20 and the pedestal portion 50 are formed on the substrate 10 via the main surface 12a of the insulating portion 12.
The step of forming the fixed electrode 20 is a step of forming the fixed electrode 20 on the main surface 12 a side of the insulating portion 12 described above, that is, on the second insulating portion 122.
The step of forming the fixed electrode 20 includes, for example, forming a mask pattern having an opening in the portion where the fixed electrode 20 is formed on the second insulating portion 122, and then using the conductive material such as polysilicon to form the fixed electrode 20 using a CVD method. Can be formed.
The method of forming the fixed electrode 20 is not limited to the CVD method, and the fixed electrode 20 is made of a conductive material such as gold (Au) or titanium (Ti) using a PVD (Physical Vapor Deposition) method or the like. You may form using. In the step of forming the fixed electrode 20, the fixed electrode 20 may be formed by patterning using a photolithography method.

The step of forming the pedestal portion 50 is a step of forming the pedestal portion 50 on the main surface 12 a side of the insulating portion 12 described above, that is, on the second insulating portion 122.
The step of forming the pedestal portion 50 includes, for example, forming a mask pattern having an opening in the portion where the pedestal portion 50 is formed on the second insulating portion 122, and using the conductive material such as polysilicon to form the pedestal portion 50 by a CVD method. Can be formed.

In the step of forming the pedestal portion 50, a recess 52 that faces the protrusion 36 formed on the movable electrode 30 is formed on the pedestal portion 50. The depression 52 can be formed, for example, by providing the above-described mask pattern in a portion where the depression 52 is formed.
The method of forming the pedestal portion 50 is not limited to the CVD method, and the pedestal portion 50 is made of a PVD (Physical Vapor Deposition) method using a conductive material such as gold (Au) or titanium (Ti). You may form using. In the step of forming the pedestal portion 50, the pedestal portion 50 and the recessed portion 52 may be formed by patterning using a photolithography method. In addition, the step of forming the pedestal portion 50 may be formed by forming a conductive layer as the pedestal portion 50 and so-called half-etching the portion that becomes the recess 52.

  In the step of forming the fixed electrode 20 and the pedestal portion 50 described above, the fixed electrode 20 and the pedestal portion 50 may be simultaneously formed by using the same material.

(Sacrificial layer 210 forming step)
FIG. 2D shows that the sacrificial layer 210 as an intermediate layer for providing the gap 60 between the movable electrode 30 and the fixed electrode 20 and the pedestal portion 50 covers the fixed electrode 20 and the pedestal portion 50. The state formed on the main surface 12a is shown.
The step of forming the sacrificial layer 210 is a step of forming the sacrificial layer 210 as an intermediate layer (release layer) for providing the gap 60 between the movable electrode 30, the fixed electrode 20 and the pedestal portion 50. Further, in the step of forming the sacrificial layer 210, the sacrificial layer 210 is formed with a recess 212 along the recess 52 of the pedestal 50.
As described above, the vibrating element 1 is provided with the movable electrode 30 with a gap 60 between the fixed electrode 20 and the pedestal portion 50. The sacrificial layer 210 is formed by forming a conductive layer 310 as a precursor of the movable electrode 30 on the sacrificial layer 210 in a process to be described later, and is removed after the movable electrode 30 is formed. Further, a gap 60 can be provided between the pedestal 50 and the pedestal 50.

In the step of forming the sacrificial layer 210, for example, the sacrificial layer 210 containing silicon oxide (SiO ₂ ) can be formed by a CVD method. The method for forming the sacrificial layer 210 is not limited to the CVD method, and the sacrificial layer 210 containing silicon oxide may be formed using a PVD method or the like.
Note that the sacrificial layer 210 is selectively removed while leaving the fixed electrode 20, the movable electrode 30, the fixed portion 40, and the pedestal portion 50 in a process described later. Therefore, the material constituting the sacrificial layer 210 is preferably silicon oxide or a compound containing silicon oxide that can selectively remove (etch) the sacrificial layer 210. The sacrificial layer 210 is not limited to silicon oxide or a compound containing silicon oxide, and may be appropriately changed as long as the material can selectively remove the sacrificial layer 210.

FIG. 3E shows that the sacrificial layer 210 formed on the portion where the main surface 12a and the fixing portion 40 abut (see FIG. 3G) and the portion where the pedestal portion 50 and the fixing portion 40 abut is removed. It shows the state that was done. In the step of partially removing the sacrificial layer 210, the sacrificial layer 210 formed in the portion where the main surface 12a and the fixing portion 40 abut and the portion where the base portion 50 and the fixing portion 40 abut is photolithography. It is the process of removing by.
In the step of removing the sacrificial layer 210, the fixing portion 40 is provided on the second insulating portion 122 in a step described later, and therefore the second insulating portion 122 that comes into contact with the first fixing portion 40a and the second fixing portion 40b is exposed. In this manner, the sacrificial layer 210 is removed. In addition, since the fixing portion 40 is provided on the pedestal portion 50, the sacrificial layer 210 is removed so that the pedestal portion 50 that contacts the third fixing portion 40c and the fourth fixing portion 40d is exposed.

(Formation process of movable electrode 30 and fixed part 40)
In FIG. 3F, a conductive layer 310 as a precursor of the movable electrode 30 and the fixed portion 40 and a mask pattern 312 for patterning the movable electrode 30 and the fixed portion 40 are formed on the conductive layer 310. Indicates the state.
The vibration element 1 of the present embodiment can be formed in the same process because polysilicon is used as a material for forming the movable electrode 30 and the fixed portion 40.
In the step of forming the movable electrode 30 and the fixed portion 40, the conductive layer 310 as a precursor of the movable electrode 30 and the fixed portion 40 is formed on the insulating portion 12, the pedestal portion 50, and the sacrificial layer 210, and the conductive layer 310 is formed. This is a step of forming the movable electrode 30 and the fixed portion 40 by patterning. In the step of forming the movable electrode 30 and the fixed portion 40, the conductive layer 310 as the movable electrode 30 and the fixed portion 40 can be formed by a CVD method using a conductive material such as polysilicon, for example. In the step of forming the movable electrode 30 and the fixed portion 40, the conductive layer 310 is formed so as to cover the sacrificial layer 210. Therefore, the conductive layer 310 is formed along the depression 212 generated on the sacrificial layer 210. The conductive layer 310 formed in the depression 212 becomes a protrusion 36 provided on the beam portion 32 of the movable electrode 30.

  The step of forming the movable electrode 30 and the fixed portion 40 includes the step of forming a mask pattern 312 for removing unnecessary portions as the movable electrode 30 and the fixed portion 40 of the conductive layer 310 formed as the movable electrode 30 and the fixed portion 40. Form. In the step of forming the movable electrode 30 and the fixed portion 40, the mask pattern 312 having an unnecessary opening as the movable electrode 30 and the fixed portion 40 can be formed by photolithography.

(Step of removing conductive layer 310)
FIG. 3G shows a state where the conductive layer 310 unnecessary for the movable electrode 30 and the fixed portion 40 has been removed.

The step of removing the conductive layer 310 is a step of removing unnecessary portions of the conductive layer 310 as the movable electrode 30 and the fixed portion 40 from the conductive layer 310 formed as the movable electrode 30 and the fixed portion 40.
The step of removing the conductive layer 310 is performed by etching (removing) unnecessary portions of the conductive layer 310 patterned in the previous step as the movable electrode 30 having the mask pattern 312 open and the fixed portion 40. The shapes of the movable electrode 30 and the fixed portion 40 are adjusted. The step of removing the conductive layer 310 can be performed by, for example, a wet etching method. Note that the step of removing the conductive layer 310 is not limited to the wet etching method, and a dry etching method or the like may be used.

(Sacrificial layer 210 removal step)
FIG. 3H shows a state where the sacrificial layer 210 formed as the intermediate layer is removed.

The step of removing the sacrificial layer 210 is a step of selectively removing the sacrificial layer 210 formed in the previous step.
The step of removing the sacrificial layer 210 is required to selectively remove the sacrificial layer 210. Therefore, in the step of removing the sacrificial layer 210, for example, the sacrificial layer 210 is etched (removed) by a wet etching method. For removal of the sacrificial layer 210 by the wet etching method, it is preferable to use an etchant (cleaning liquid) containing hydrofluoric acid. The sacrificial layer 210 is removed by using an etchant containing hydrofluoric acid so that the etching rate for the sacrificial layer 210 containing silicon oxide is such that the fixed electrode 20, the movable electrode 30, the fixed portion 40, and the pedestal portion 50 containing polysilicon or the like. The sacrificial layer 210 can be selectively and efficiently removed because it is faster than the etching rate.

In addition, the second insulating portion 122 functions as a so-called etching stopper by including silicon nitride having hydrofluoric acid resistance in the second insulating portion 122 as a base film of the fixed electrode 20, the fixing portion 40, and the pedestal portion 50. Can do. Thereby, the insulation fall between the board | substrate 10 by the sacrificial layer 210 being etched, the fixed electrode 20, the fixing | fixed part 40, and the base part 50 can be suppressed. Note that the step of removing the sacrificial layer 210 is not limited to the wet etching method, and may be performed by a dry etching method.
In the vibration element 1, by removing the sacrificial layer 210, a gap 60 is generated between the movable electrode 30, the fixed electrode 20, and the pedestal portion 50, and the movable electrode 30 can be displaced.

  By removing the sacrificial layer 210 described above, the process of manufacturing the vibration element 1 is completed.

According to the first embodiment described above, the following effects can be obtained.
Such a vibrating element 1 is provided with the protrusion 36 on the beam portion 32 of the movable electrode 30 to increase the rigidity of the movable electrode 30 and suppress sticking of the movable electrode 30 sticking to the fixed electrode 20 due to vibration. can do. Therefore, even if the movable electrode 30 is lengthened to adjust the natural vibration frequency, the vibration element 1 that can suppress sticking can be obtained.
In addition, according to such a vibration element 1, the movable electrode 30 can be provided longer because the rigidity of the movable electrode 30 is increased, and the facing area overlapping the fixed electrode 20 can be increased.
Thereby, the change in the electrostatic capacitance between the fixed electrode 20 and the movable electrode 30 generated when the movable electrode 30 vibrates can be increased, and the equivalent series resistance that is the electrical characteristic of the vibration element 1 is reduced. Realization of oscillation of the vibration element 1 can be facilitated.

Further, in such a vibration element 1, since the fixed portion 40 and the pedestal portion 50 are formed of the same material, the linear expansion coefficient and the like are substantially equal, and even if stress occurs in the fixed portion 40 and the pedestal portion 50. The distortion between these can be suppressed. Therefore, it is possible to obtain the resonator element 1 in which the change of the natural vibration frequency of the movable electrode 30 due to the distortion between the fixed portion 40 and the pedestal portion 50 is suppressed.
Further, in such a vibration element 1, the sacrificial layer 210 as an intermediate layer has a recess 212 formed on the surface on which the movable electrode 30 is formed according to the recess 52, and the movable electrode 30 is formed along the recess 212. Is done. Therefore, the protrusion 36 corresponding to the depression 212 can be formed on the movable electrode 30.
Accordingly, such a manufacturing method suppresses the occurrence of sticking without adding a new process, and increases the change in capacitance generated between the electrodes when the movable electrode 30 vibrates, The vibration element 1 that can improve the electrical characteristics of the vibration element 1 and facilitate the realization of oscillation can be manufactured.

(Second Embodiment)
The vibration element 2 according to the second embodiment will be described with reference to FIG.
FIG. 4 is a plan view and a side view schematically showing an outline of the resonator element according to the second embodiment.
In FIG. 4, an X axis, a Y axis, and a Z axis are illustrated as three axes orthogonal to each other. The Z axis is an axis indicating the thickness direction in which the substrate and each electrode are laminated.

  FIG. 4A is a plan view schematically showing a resonator element viewed in plan from the Z-axis (vertical) direction. FIG. 4B and FIG. 4C are side views schematically showing the vibration element viewed from the side in the −X axis direction and the + X axis direction, respectively. FIG. 4D and FIG. 4E are side views schematically showing the vibration element viewed from the side in the −Y axis direction and the + Y axis direction, respectively. FIG. 4F is a cross-sectional view schematically showing a cross section of the vibration element along line A-A ′ shown in FIG.

The vibration element 2 of the present embodiment is different from the vibration element 1 described in the first embodiment with a base 345, a plurality of movable electrodes 330, a fixed electrode 320, a fixed part 340, and a pedestal part 350 corresponding thereto. It differs in that it is provided.
As shown in FIG. 4A, in the vibration element 2, the fixing portion 340 extends from the base portion 345 in the first direction and in the second direction intersecting the first direction, and further from the fixing portion 340. A movable electrode 330 is extended.
Since other configurations and formation methods are substantially the same, the same reference numerals are given to the same configurations, and a part of the description is omitted.
In the following description, the fixed electrode 320, the movable electrode 330, the fixed portion 340, and the pedestal portion 350 that are disposed in the respective directions from the base portion 345 are provided in the −X axis direction that is the first direction. Each component part will be described with reference numeral “b”. In addition, each component provided in the + X axis direction that is the first direction is described with reference numeral “c”. In addition, each component provided in the + Y-axis direction, which is the second direction that intersects the first direction, will be described with reference numeral “d”. In addition, each component provided in the −Y-axis direction that intersects the first direction will be described with reference numeral “e”.
In the case of general description, only the reference numerals are shown for explanation. In addition, although the movable electrodes 330 are illustrated with substantially the same size for convenience of illustration, the length and the area overlapping with the corresponding fixed electrode 320 may be appropriately changed depending on the desired natural vibration frequency.

The vibration element 2 according to the present embodiment is a cantilever type vibration element similarly to the vibration element 1 according to the first embodiment.
As shown in FIG. 4, the vibration element 2 includes a substrate 10, an insulating part 12, a plurality of fixed electrodes 320 as a first electrode part, a plurality of movable electrodes 330 as a second electrode part, and the movable element A plurality of fixing portions 340 and pedestal portions 350 corresponding to the electrodes 330 are provided.

(Substrate 10 and insulating part 12)
The substrate 10 is provided with an insulating part 12, a fixed electrode 320, a movable electrode 330, a fixed part 340, and a base part 345, which will be described later, on one surface thereof. Similar to the vibration element 1 described in the first embodiment, the vibration element 2 uses a silicon substrate as the substrate 10.
The insulating portion 12 is provided by being laminated on the main surface 10 a of the substrate 10.
Similar to the vibration element 1 described in the first embodiment, the insulating portion 12 includes a first insulating portion 121 (not shown in FIG. 4) and a second insulating portion 122 (not shown in FIG. 4) arranged in order from the main surface 10a side. 4 (not shown in FIG. 4).

(Fixed electrode 320, movable electrode 330, fixed part 340, pedestal part 350)
On the substrate 10 of the vibration element 2, a fixed electrode 320, a movable electrode 330, a fixed portion 340, a base portion 345, and a pedestal portion 350 are provided via the main surface 12 a of the insulating portion 12.

As shown in FIG. 4A, the vibration element 2 includes a base 345, and a fixed portion 340 b extends from the base 345 toward the −X axis direction that is the first direction. The vibration element 2 further includes a movable electrode 330b extending from the fixed portion 340b, and a pedestal portion 350b corresponding to the movable electrode 330b and the fixed portion 340b.
Further, in the vibration element 2, a fixed portion 340 c extends from the base portion 345 toward the + X axis direction that is the first direction. Further, in the vibration element 2, a movable electrode 330c is further extended from the fixed portion 340c, and a pedestal portion 350c is provided corresponding to the movable electrode 330c and the fixed portion 340c.

Further, in the vibration element 2, a fixing portion 340 e is extended from the base portion 345 toward the −Y axis direction which is a second direction intersecting the first direction. The vibration element 2 further includes a movable electrode 330e extending from the fixed portion 340e, and a pedestal portion 350e corresponding to the movable electrode 330e and the fixed portion 340e.
In the vibration element 2, the fixed portion 340 d extends from the base portion 345 toward the + Y-axis direction that is the second direction, and the movable electrode 330 d extends from the fixed portion 340 d. The vibration element 2 is provided with a pedestal portion 350d corresponding to the movable electrode 330d and the fixed portion 340d.

(Fixed electrode 320)
As shown in FIGS. 4A and 4F, the fixed electrode 320 is partially movable electrode when the fixed electrode 320 and a movable electrode 330 described later are viewed in a plan view from the Z-axis (vertical) direction. 330 is provided to overlap. The fixed electrode 320 is disposed corresponding to the plurality of movable electrodes 330 provided.

(Movable electrode 330)
As shown in FIG. 4, the movable electrode 330 is provided with a gap 60 so that the fixed electrode 320 and a part of the movable electrode 330 overlap with the fixed electrode 320 when viewed in plan from the Z-axis direction.
The movable electrode 330 includes a beam portion 332 and detection electrodes 334 (334b, 334c, 334d, and 334e) provided on the beam portion 332. The movable electrode 330 extends from the fixed portion 340 and is disposed corresponding to the fixed electrode 320. Further, the movable electrode 330 faces a recess 352 provided on a pedestal 350, which will be described later, and a projection 336 (336b, 336c) is formed on a beam 332 (332b, 332c) as shown in FIG. Is provided.

(Fixing part 340)
The fixing portion 340 extends from a rectangular base portion 345 as shown in FIG. In the vibration element 2 of the present embodiment, as described above, the fixed portion 340 is extended from each side of the base portion 345 in the + X axis, the −X axis direction, the + Y axis, and the −Y axis direction, and is further movable from the fixed portion 340. An electrode 330 is extended.

(Pedestal 350)
As shown in FIG. 4, the pedestal portion 350 is provided corresponding to the fixed portion 340 and the movable electrode 330. The pedestal 350 is provided with a recess 352 (352b, 352c, 352d, 352e) corresponding to the protrusion 336 provided on the movable electrode 330 as shown in FIG. In addition, the recessed portion 352 is provided with a smaller thickness in the Z-axis direction, which is the direction in which the substrate 10 and the insulating portion 12 are laminated, than the pedestal portion 350. The shape of the recess 352 is not limited to a rectangular shape (groove shape), and may be a spherical shape or a polygonal shape.

(Manufacturing method of the vibration element 2)
The process of manufacturing the vibration element 2 of the present embodiment is different from the number of movable electrodes 330 provided and the base 345 provided on the substrate 10 via the insulating part 12 connected to the fixed part 340. However, since the other steps are the same as those of the vibration element 1 described in the first embodiment, the description thereof is omitted.

According to the second embodiment described above, the following effects can be obtained.
According to such a vibration element 2, a plurality of movable electrodes 330 are provided, and vibrations between adjacent movable electrodes 330 are coupled to each other, so that vibration leakage is suppressed and the vibration element 2 with less loss is obtained. Can do.

(Third embodiment)
The vibration element 3 according to the third embodiment will be described with reference to FIG.
FIG. 5 is a plan view and a side view schematically showing an outline of the resonator element according to the third embodiment.
In FIG. 5, an X axis, a Y axis, and a Z axis are illustrated as three axes orthogonal to each other. The Z axis is an axis indicating the thickness direction in which the substrate and each electrode are laminated.
FIG. 5A is a plan view schematically showing a resonator element viewed in plan from the Z-axis (vertical) direction. FIG. 5B is a side view schematically showing the resonator elements as viewed from the side in the −Y-axis direction.

The vibration element 3 according to this embodiment is different from the vibration element 1 according to the first embodiment in that the movable electrode 530 is supported by a plurality of fixed portions 540. In other words, it is different in that the movable electrode 530 extends from one fixed portion 540 toward the other fixed portion 540.
As shown in FIG. 5A, the vibration element 3 extends from one fixed portion 540 toward the other fixed portion 540, and a movable electrode 530 is provided with a gap 60 with respect to the fixed electrode 520. . Since other configurations and formation methods are substantially the same, the same reference numerals are given to the same configurations, and a part of the description is omitted.

The vibration element 3 according to the present embodiment is a so-called doubly-supported beam type vibration element.
As shown in FIG. 5, the vibration element 3 includes a substrate 10, an insulating portion 12, a plurality of fixed electrodes 520 as a first electrode portion, a movable electrode 530 as a second electrode portion, and a movable electrode 530. A fixed portion 540 and a pedestal portion 550 corresponding to the fixed portion 540 are provided at both ends.

(Substrate 10 and insulating part 12)
The substrate 10 is provided with an insulating part 12, a fixed electrode 520, a movable electrode 530, and a fixed part 540, which will be described later, on one surface thereof. Similar to the vibration element 1 described in the first embodiment, the vibration element 3 uses a silicon substrate as the substrate 10.
The insulating portion 12 is provided by being laminated on the main surface 10 a of the substrate 10. Similar to the resonator element 1 described in the first embodiment, the insulating portion 12 includes a first insulating portion 121 (not shown in FIG. 5) and a second insulating portion 122 (not shown in FIG. 5) disposed in order from the main surface 10a side. 5) (not shown).

(Fixed electrode 520, movable electrode 530, fixed part 540, pedestal part 550)
On the substrate 10 of the vibration element 3, a fixed electrode 520, a movable electrode 530, a fixed portion 540, and a pedestal portion 550 are provided via the main surface 12 a of the insulating portion 12.

(Fixed electrode 520)
As shown in FIGS. 5A and 5B, the fixed electrode 520 is partially movable electrode 530 when the fixed electrode 520 and a movable electrode 530 described later are viewed in plan from the Z-axis (vertical) direction. It is provided to overlap. The fixed electrode 520 is disposed corresponding to the movable electrode 530 with a gap 60 therebetween.

(Movable electrode 530)
As shown in FIGS. 5A and 5B, the movable electrode 530 includes a fixed electrode 520 and a gap so that a part of the movable electrode 530 overlaps the fixed electrode 520 when the movable electrode 530 is viewed in plan from the Z-axis direction. 60 is provided.
The movable electrode 530 is provided so as to extend from one fixed part 540 toward the other fixed part 540 and overlap with the fixed electrode 520 with a gap 60 therebetween. The movable electrode 530 includes a beam portion 532 connected to each fixed portion 540, and a detection electrode portion 534 provided on the beam portion 532 so as to overlap the fixed electrode 520 with a gap 60 therebetween. Yes. Further, the beam portion 532 is provided with a protrusion 536. A projection 536 provided on the surface of the beam portion 532 facing the pedestal portion 550 is provided in correspondence with a recess 552 provided on the pedestal portion 550 described later.

(Fixing part 540)
The fixed parts 540 are provided at both ends of the movable electrode 530 as shown in FIG.
Each fixing portion 540 includes a first fixing portion 540a, a second fixing portion 540b, a third fixing portion 540c, and a fourth fixing portion 550d, similarly to the vibration element 1 described in the first embodiment. Yes.

(Pedestal 550)
As shown in FIG. 5, the pedestal portion 550 is provided corresponding to the fixed portion 540 and the movable portion 550. The pedestal portion 550 is provided so as to contact the above-described third fixing portion 540c. Further, the pedestal 550 is provided with a recess 552 as shown in FIG. 5 so as to face the protrusion 536 provided on the movable electrode 530 described above. Further, the recessed portion 552 is provided with a smaller thickness in the Z-axis direction, which is the direction in which the substrate 10 and the insulating portion 12 are laminated, than the pedestal portion 550. The shape of the recess 552 is not limited to a rectangular shape (groove shape), and may be a spherical shape or a polygonal shape.

(Manufacturing method of the vibration element 3)
The process of manufacturing the vibration element 3 of the present embodiment is the same as the vibration element 1 described in the first embodiment in that the movable electrode 530 extends from one fixed part 540 toward the other fixed part 540. Although different, the manufacturing method is the same as that of the vibration element 1 described above, and thus the description thereof is omitted in this embodiment.

According to the third embodiment described above, the following effects can be obtained.
According to such a vibration element 3, the movable electrode 30 is supported by the fixed portions 540 at both ends, and the protrusion 536 is provided. Therefore, the movable electrode 30 is provided long to adjust the natural vibration frequency. Also, the occurrence of sticking can be suppressed, and the area facing the fixed electrode 20 can be increased. As a result, the change in capacitance between the fixed electrode 520 and the movable electrode 530 that occurs when the movable electrode 30 vibrates can be increased, and the equivalent series resistance that is the electrical characteristic of the vibration element 3 can be reduced. The oscillation of the vibration element 3 can be easily realized.

(Fourth embodiment)
A vibrator according to the fourth embodiment will be described with reference to FIG.
FIG. 6 is a block diagram schematically showing an outline of the vibrator according to the fourth embodiment.

  The vibrator 600 according to the fourth embodiment includes one of the vibration element 1 according to the first embodiment, the vibration element 2 according to the second embodiment, and the vibration element 3 according to the third embodiment (hereinafter, summarized). And the circuit portion 650 is provided on the substrate 10 provided with the vibration element 1.

  Although detailed illustration is omitted in the circuit unit 650, an excitation circuit for applying a potential to the vibration element 1 to oscillate, an amplification circuit for amplifying a signal associated with vibration of the vibration element 1, Is provided. The configuration of the circuit unit 650 is not particularly limited. For example, a Colpitts type oscillation circuit can be used.

  By providing the circuit portion 650, the vibrator 600 can vibrate the movable electrode 30 (see FIG. 1, FIG. 4, or FIG. 5), and can amplify and take out a signal associated with the vibration.

  The circuit portion 650 can use a general semiconductor device manufacturing technique as its manufacturing method. In the present embodiment, it is formed using a photolithography method or the like together with the manufacturing process of the vibration element 1.

  The other configurations of the vibrator 600 are the same as those in the first embodiment, the second embodiment, and the third embodiment described above, and thus the description thereof is omitted.

According to the fourth embodiment described above, the following effects can be obtained.
According to such a vibrator 600, by providing the circuit unit 650, an excitation signal can be given to the vibration element 1 and a signal accompanying the vibration can be amplified, and a signal accompanying the vibration of the vibration element 1 can be easily obtained. It can be taken out and used. In addition, the movable electrode 30 is provided with the protrusions 36 so that the rigidity of the movable electrode 30 can be increased, and sticking to the fixed electrode 20 due to vibration can be suppressed. Therefore, even if the movable electrode 30 is lengthened to adjust the natural vibration frequency, the vibrator 600 in which the occurrence of sticking is suppressed can be obtained.
In addition, according to such a vibrator 600, the movable electrode 30 can be lengthened by increasing the rigidity of the movable electrode 30, and the facing area overlapping the fixed electrode 20 can be increased. As a result, it is possible to increase the change in capacitance between the respective electrodes that occurs when the movable electrode 30 vibrates, and it is possible to reduce the power consumption of the circuit unit 650 that amplifies the electric signal caused by the vibration.

(Fifth embodiment)
A vibrator according to the fifth embodiment will be described with reference to FIG.
FIG. 7 is a block diagram schematically showing an outline of the oscillator according to the fifth embodiment.

  An oscillator 700 according to the fifth embodiment includes a vibrator 600 according to the fourth embodiment and a casing 750 that houses the vibrator 600.

  Although not shown in detail in the oscillator 700, the oscillator 700 includes a housing 750 having a hollow structure. In the oscillator 700, the vibrator 600 is disposed in the hollow structure portion of the housing 750, and a signal accompanying vibration of the vibration element 1 is amplified by the circuit unit 650, and taken out to the outside of the hollow structure by wiring not shown. it can.

  The housing 750 can be formed using silicon or the like as its material. In the oscillator 700 of this embodiment, a silicon substrate is used as the material of the housing 750. By using the silicon substrate for the housing 750, a hollow structure or the like can be easily processed by the semiconductor device manufacturing technique used in the manufacturing process of the vibration element 1 described above. Note that the material for forming the housing 750 is not limited to silicon, and glass or the like may be used.

  The housing 750 is preferably decompressed in the hollow structure. By reducing the pressure in the hollow structure, the air remaining in the hollow structure can be discharged, and the air resistance in the vibration (displacement) of the movable electrode 30 can be suppressed.

  For the housing 750, a silicon substrate can be prepared, and a hollow structure can be formed by a photolithography method. In addition, the housing 750 can form a hollow structure in the substrate 10 by photolithography simultaneously with the formation of the vibration element 1. The oscillator 700 accommodates the vibrator 600 in the formed hollow structure, and performs sealing by connecting a lid (not shown) to the hollow structure in a decompressed state.

  Since the other configurations of the oscillator 700 are the same as those in the first to fourth embodiments described above, description thereof is omitted.

According to the fifth embodiment described above, the following effects can be obtained.
According to such an oscillator 700, a potential is applied to the fixed electrode 20 and the movable electrode 30 accommodated in the housing 750 by the circuit unit 650, and electric charges are generated between the electrodes, whereby the movable electrode 30 is It can vibrate when an electrostatic attractive force acts on the fixed electrode 20. In addition, the movable electrode 30 is provided with the protrusions 36 so that the rigidity of the movable electrode 30 can be increased, and sticking to the fixed electrode 20 due to vibration can be suppressed.
Further, according to such an oscillator 700, the movable electrode 30 can be lengthened by increasing the rigidity of the movable electrode 30, and the facing area overlapping the fixed electrode 20 can be increased. As a result, a change in capacitance generated between the electrodes when the movable electrode 30 vibrates is increased, and thus the circuit unit 650 that amplifies an electric signal such as a change in capacitance due to vibration can be reduced in size. Further, the addition of the housing 750 can avoid interference with peripheral circuits, and the resistance of the circuit unit 650 to external noise can be increased.
Therefore, in such an oscillator 700, the occurrence of sticking is suppressed even when the movable electrode 30 is lengthened to adjust the natural vibration frequency, and the circuit unit 650 realizing the circuit unit 650 having high resistance to external noise. Can be obtained.

(Example)
Next, with reference to FIGS. 8 to 11, an example to which either the vibration element 1 or the vibration element 2 (hereinafter collectively referred to as the vibration element 1) according to an embodiment of the present invention is applied. explain.

[Electronics]
An electronic apparatus to which the vibration element 1 according to an embodiment of the present invention is applied will be described with reference to FIGS.

  FIG. 7 is a perspective view schematically illustrating a configuration of a notebook (or mobile) personal computer as an electronic apparatus including the resonator element according to the embodiment of the invention. In this figure, a notebook personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 1008. The display unit 1106 is connected to the main body portion 1104 via a hinge structure portion. And is rotatably supported. For example, such a notebook personal computer 1100 incorporates a vibration element 1 that functions as an acceleration sensor or the like for detecting acceleration applied to the notebook personal computer 1100 and displaying the acceleration or the like on the display unit 1106. Has been.

  FIG. 9 is a perspective view schematically illustrating a configuration of a mobile phone (including PHS) as an electronic apparatus including the resonator element according to the embodiment of the invention. In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, a earpiece 1204, and a mouthpiece 1206, and a display portion 1208 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 incorporates a vibration element 1 that functions as an acceleration sensor or the like for detecting acceleration or the like applied to the cellular phone 1200 and assisting the operation of the cellular phone 1200.

FIG. 10 is a perspective view illustrating a schematic configuration of a digital still camera as an electronic apparatus including the vibration element according to the embodiment of the invention. In this figure, connection with an external device is also simply shown. Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.
A display unit 1308 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to perform display based on an imaging signal from the CCD. The display unit 1308 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 1308 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1310. 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 drawing, a liquid crystal display 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 1310 is output to the liquid crystal display 1430 or the personal computer 1440 by a predetermined operation. In such a digital still camera 1300, in order to operate a function of protecting the digital still camera 1300 from the fall, the vibration element 1 functioning as an acceleration sensor for detecting acceleration due to the fall is incorporated.

  The vibration element 1 according to an embodiment of the present invention is not limited to the personal computer (mobile personal computer) shown in FIG. 8, the mobile phone shown in FIG. 9, and the digital still camera shown in FIG. (For example, inkjet printers), TVs, video cameras, video tape recorders, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game devices, word processors, workstations, videophones, and crime prevention TV monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring devices, instruments (for example, , Vehicle, aircraft, ship instrumentation), flight simulator It can be applied to electronic devices and the like.

[Moving object]
FIG. 11 is a perspective view schematically showing an automobile as an example of a moving body. In the automobile 1500, the vibration element 1 that functions as an acceleration sensor is mounted on various control units. For example, as shown in the figure, an automobile 1500 as a moving body includes an electronic control unit (ECU) 1508 that incorporates a vibration element 1 that detects the acceleration of the automobile 1500 and controls the output of the engine. Is mounted on the vehicle body 1507. By detecting the acceleration and controlling the engine to an appropriate output corresponding to the posture of the vehicle body 1507, an automobile 1500 as an efficient moving body with reduced consumption of fuel and the like can be obtained.
In addition, the vibration element 1 can be widely applied to a vehicle body posture control unit, an antilock brake system (ABS), an air bag, and a tire pressure monitoring system (TPMS).

  DESCRIPTION OF SYMBOLS 1, 2, 3 ... Vibration element 10 ... Board | substrate 12 ... Insulation part, 20 ... Fixed electrode, 22 ... Depression part, 30 ... Movable electrode, 32 ... Beam part, 34 ... Detection electrode part, 36 ... Protrusion, 40 ... Fixed part, 50 ... pedestal part, 52 ... recessed part, 60 ... gap, 210 ... sacrificial layer, 212 ... recessed part, 310 ... conductive layer, 312 ... mask pattern, 320 ... fixed electrode, 330 ... movable electrode, 336 ... projection, 340 ... fixed part, 345 ... base part, 350 ... pedestal part, 352 ... recessed part, 520 ... fixed electrode, 530 ... movable electrode, 536 ... projection, 540 ... fixed part, 550 ... pedestal part, 552 ... recessed part, 600 ... Vibrator, 650... Circuit unit, 750... Casing, 1100... Notebook personal computer, 1200... Mobile phone, 1300.

Claims (10)

A substrate,
A first electrode portion provided on one surface of the substrate, and a fixing portion;
A pedestal having a recess provided on the one surface;
A part of the first electrode portion overlaps the first electrode portion in plan view from a direction perpendicular to the one surface, and extends from the fixed portion with a gap with respect to the first electrode portion. An electrode portion, and
A vibration element characterized in that a protrusion is provided on the surface of the second electrode portion facing the first electrode portion so as to face the recess. The vibration element according to claim 1,
The vibration element, wherein the first electrode portion, the second electrode portion, the fixing portion, and the pedestal portion are formed of polysilicon. The vibration element according to claim 1 or 2,
The fixing portion includes a first fixing portion that extends in the first direction along the substrate;
A second fixing portion extending from the first fixing portion toward a second direction intersecting the first direction;
A third fixing portion extending from the second fixing portion along the pedestal portion toward the first direction;
A fourth fixing portion extending from the third fixing portion toward the second direction, and
The second electrode portion extends from the fourth fixed portion toward the first direction with a gap from the pedestal portion and the first electrode portion;
A vibration element characterized by. In the vibration element according to any one of claims 1 to 3,
A plurality of said 2nd electrode parts are extended from the said fixing | fixed part, The vibration element characterized by the above-mentioned. In the vibration element according to any one of claims 1 to 3,
A plurality of the fixing portions are provided, and the second electrode portion is provided with the gap from the first electrode portion toward the other fixing portion from the one fixing portion. A characteristic vibration element. A substrate,
A first electrode portion provided on one surface of the substrate, and a fixing portion;
A pedestal having a recess provided on the one surface;
A part of the first electrode portion overlaps the first electrode portion in plan view from a direction perpendicular to the one surface, and extends from the fixed portion with a gap with respect to the first electrode portion. The electrode part of
A circuit unit that applies a potential between the first electrode and the second electrode and amplifies an electric signal generated between the first electrode and the second electrode unit, and
A vibrator characterized in that a protrusion is provided on the surface of the second electrode portion facing the first electrode portion so as to face the depressed portion. A substrate,
A first electrode portion provided on one surface of the substrate, and a fixing portion;
A pedestal having a recess provided on the one surface;
A part of the first electrode portion overlaps the first electrode portion in plan view from a direction perpendicular to the one surface, and extends from the fixed portion with a gap with respect to the first electrode portion. The electrode part of
A circuit unit that applies a potential between the first electrode unit and the second electrode unit and amplifies an electric signal generated between the first electrode unit and the second electrode unit;
A housing in which the substrate, the fixed portion, the pedestal portion, the first electrode portion, and the second electrode portion are accommodated,
An oscillator characterized in that a projection is provided on the surface of the second electrode portion facing the first electrode portion so as to face the recess. Preparing a substrate;
Forming a fixing portion on one surface of the substrate;
Forming a pedestal having a recess on the one surface;
Forming a first electrode portion on the one surface;
A second electrode that partially overlaps the first electrode portion in a plan view from a direction perpendicular to the one surface, and extends from the fixed portion with a gap from the first electrode portion. Forming a part;
Forming an intermediate layer between the second electrode portion, the first electrode portion and the pedestal portion, and
The step of forming the second electrode portion includes forming a protrusion on the surface of the second electrode portion facing the first electrode portion so as to face the recess. Production method.   An electronic device comprising the vibration element according to any one of claims 1 to 5.   A moving body on which the vibration element according to any one of claims 1 to 5 is mounted.

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