Resonator and resonator device having the same

Abstract

The present application relates to a resonator and a resonant device provided with the resonator. The resonator (10) is provided with: a vibrating portion (120) having two portions (121A, 121B) that vibrate in opposite phases to each other; a holding portion (140) formed to surround at least a portion of the vibrating portion (120); and a holding unit (110) that supports a boundary of the two portions (121A, 121B) and connects the vibrating portion (120) and the holding portion (140), and a frequency adjustment film (E3) is provided in a region between a connecting portion (111B, 112B) of the holding unit (110) that is connected to the vibrating portion (120) and an end portion opposite the connecting portion (111B, 112B) along the boundary of the two portions (121A, 121B) in a surface of the vibrating portion (120).

Description

Technical Field

[0001] The present invention relates to a resonator and a resonant device having the resonator. Background Technology

[0002] Resonant devices are used in various electronic devices such as mobile communication terminals, communication base stations, and home appliances for purposes such as timing devices, sensors, and oscillators. A resonant device is, for example, a type of MEMS (Micro Electro Mechanical Systems). Such a resonant device typically includes a lower cover, an upper cover forming an internal space between the upper and lower cover, and a resonator having a vibrating section held oscillatingly within that internal space. The vibrating section may contain, for example, a temperature-correcting layer that corrects for frequency variations depending on temperature, or a frequency-adjusting film that changes frequency by removing a portion of the vibrating section.

[0003] Patent document 1 discloses a resonator in which a frequency adjustment film is formed in a region of large displacement and a protective film is formed in a region of small displacement.

[0004] Patent document 2 discloses a resonator in which two films are formed in the region of small displacement: a first temperature characteristic adjustment film with a positive frequency temperature coefficient and a second temperature characteristic adjustment film with a negative frequency temperature coefficient; and a frequency adjustment film is formed in the region of large displacement.

[0005] Patent Document 1: Japanese Patent No. 6241684

[0006] Patent Document 2: International Publication No. 2019 / 058632

[0007] However, after implementing the frequency adjustment process using ion milling in the resonators described in Patent Documents 1 and 2, there is a situation where the frequency change per unit time is smaller than that of the resonator without a frequency adjustment film. Summary of the Invention

[0008] The present invention was made in view of the following situation, and the object of the present invention is to provide a resonator that improves productivity and a resonant device having the resonator.

[0009] One aspect of the resonator according to the present invention includes: a vibrating part having two parts vibrating with opposite phases; a holding part formed to surround at least a portion of the vibrating part; and a holding unit supporting the boundary of the two parts and connecting the vibrating part to the holding part, wherein a frequency adjustment film is provided in a region between the connecting portion of the holding unit connected to the vibrating part and the end opposite the connecting portion along the boundary of the two parts on the surface of the vibrating part.

[0010] Another aspect of the present invention relates to a resonator comprising: a vibrating portion having two portions vibrating with opposite phases; and a frequency adjustment film disposed on the surface of the vibrating portion in a region closer to the boundary between the two portions than the respective center portions of the two portions of the vibrating portion.

[0011] Another aspect of the resonator according to the present invention includes: a vibrating portion having two parts vibrating with opposite phases; a holding portion formed to surround at least a portion of the vibrating portion; and a holding unit connecting the vibrating portion and the holding portion. The vibrating portion has: a piezoelectric film; a lower electrode disposed on one side of the piezoelectric film; two upper electrodes disposed on the other side of the piezoelectric film and facing the lower electrode across the piezoelectric film in each of the two parts of the vibrating portion; a protective film covering the two upper electrodes; and a frequency adjustment film facing the lower electrode across the piezoelectric film and the protective film. When the surface of the vibrating portion is viewed from above, the frequency adjustment film is disposed in a region closer to the opposing ends of the two upper electrodes than the center of each of the two upper electrodes.

[0012] According to the present invention, a resonator with improved productivity and a resonant device having the resonator can be provided. Attached Figure Description

[0013] Figure 1 This is a perspective view that briefly shows the appearance of the resonant device according to the first embodiment.

[0014] Figure 2 It is along Figure 1 A cross-sectional view of the resonant device along line II-II.

[0015] Figure 3 This is a top view that briefly illustrates the construction of the resonator according to the first embodiment.

[0016] Figure 4 This is a top view that briefly shows the structure of the vibrating part according to the first embodiment.

[0017] Figure 5 It is along Figure 4 The cross-sectional view of the vibrating part along the VV line is shown.

[0018] Figure 6 This is a cross-sectional view showing the structure to which a voltage is applied to the vibrating part according to the first embodiment.

[0019] Figure 7 This is a perspective view schematically illustrating the vibration mode of the vibrating part according to the first embodiment.

[0020] Figure 8 It is a graph showing the relationship between the change in frequency and the ion beam irradiation time.

[0021] Figure 9 It is a graph showing the relationship between the change in TCF and the ratio of the frequency-adjustable membrane width.

[0022] Figure 10 This is a cross-sectional view that briefly shows the structure of the vibrating part according to the second embodiment.

[0023] Figure 11 This is a cross-sectional view that briefly shows the structure of the vibrating part according to the third embodiment.

[0024] Figure 12 This is a cross-sectional view that briefly shows the structure of the vibrating part according to the fourth embodiment.

[0025] Figure 13 This is a top view that briefly shows the structure of the resonator according to the fifth embodiment.

[0026] Figure 14 This is a perspective view schematically illustrating the vibration mode of the vibrating part according to the fifth embodiment.

[0027] Figure 15 This is a top view that briefly illustrates the structure of the resonator involved in the modified example of the fifth embodiment.

[0028] Figure 16 This is a top view that briefly illustrates the structure of the resonator involved in the modified example of the fifth embodiment.

[0029] Figure 17 This is a top view that briefly illustrates the structure of the resonator involved in the modified example of the fifth embodiment.

[0030] Figure 18 This is a top view that briefly illustrates the structure of the resonator involved in the modified example of the fifth embodiment.

[0031] Figure 19 This is a top view that briefly illustrates the structure of the resonator involved in the modified example of the fifth embodiment.

[0032] Figure 20 This is a top view that briefly illustrates the structure of the resonator involved in the modified example of the fifth embodiment.

[0033] Figure 21 This is a top view that briefly illustrates the structure of the resonator involved in the modified example of the fifth embodiment.

[0034] Figure 22 This is a cross-sectional view showing the structure to which a voltage is applied to the vibrating part according to the sixth embodiment.

[0035] Figure 23 This is a perspective view schematically illustrating the vibration mode of the vibrating part according to the sixth embodiment.

[0036] Figure 24 This is a perspective view schematically illustrating the vibration mode of the vibrating part involved in a variation of the sixth embodiment. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The drawings for each embodiment are illustrative, and the dimensions and shapes of the parts are schematic and should not be construed as limiting the technical scope of the present invention to these embodiments.

[0038] In the various accompanying drawings, to clarify the relationships between the drawings and aid in understanding the positional relationships of the components, an orthogonal coordinate system consisting of the X-axis, Y-axis, and Z-axis is sometimes added for convenience. The directions parallel to the X-axis, Y-axis, and Z-axis are respectively referred to as the X-axis direction, Y-axis direction, and Z-axis direction. The surface defined by the X-axis and Y-axis is called the XY plane, and the same applies to the YZ plane and ZX plane. Additionally, for convenience, the direction of the arrow in the Z-axis direction (positive Z-axis direction side) is sometimes referred to as "up," and the direction opposite to the arrow in the Z-axis direction (negative Z-axis direction side) is referred to as "down." However, this does not limit the orientation of the resonant device 1.

[0039] <First Implementation>

[0040] First, refer to Figure 1 and Figure 2 The general structure of the resonant device 1 according to the first embodiment of the present invention will be described. Figure 1 This is a perspective view that briefly shows the appearance of the resonant device according to the first embodiment. Figure 2 It is along Figure 1 A cross-sectional view of the resonant device along line II-II.

[0041] The resonant device 1 includes a resonator 10, and a lower cover 20 and an upper cover 30 disposed opposite to each other with respect to the resonator 10. The lower cover 20, the resonator 10, and the upper cover 30 are stacked sequentially along the Z-axis. The lower cover 20 and the upper cover 30 constitute a cover housing the resonator 10 and are joined together with respect to the resonator 10. The internal space of the cover housing formed between the lower cover 20 and the upper cover 30 is hermetically sealed under vacuum. Alternatively, the internal space of the cover housing may be filled with a gas such as an inert gas.

[0042] The resonator 10 is a MEMS resonant element manufactured using MEMS technology. The frequency of the resonator 10 is, for example, above 1 kHz and below 10 MHz. The resonator 10 includes a vibrating section 120, a holding section 140, and a pair of holding units 110. The vibrating section 120 is vibratingly held within the interior space of the cover. The holding section 140 engages with the lower cover 20 and the upper cover 30, holding the resonator 10 within the cover. The holding section 140 is, for example, frame-shaped to surround the vibrating section 120. The pair of holding units 110 connect the vibrating section 120 and the holding section 140. Alternatively, there may be only one holding unit.

[0043] The lower cover 20 has a rectangular flat base plate 22 arranged along the XY plane and a side wall 23 extending from the periphery of the base plate 22 to the upper cover 30. The side wall 23 engages with the holding portion 140 of the resonator 10. In the lower cover 20, a cavity 21 enclosed by the base plate 22 and the side wall 23 is formed in the surface opposite to the vibrating portion 120 of the resonator 10. The cavity 21 is an upward-opening cuboid opening. The cavity 21 is part of the internal space of the cover.

[0044] The top cover 30 has a rectangular flat base plate 32 arranged along the XY plane, and sidewalls 33 extending from the periphery of the base plate 32 down to the top cover 20. The sidewalls 33 engage with the holding portion 140 of the resonator 10. A chamber 31, enclosed by the base plate 32 and the sidewalls 33, is formed in the top cover 30 on the surface opposite the vibrating portion 120 of the resonator 10. The chamber 31 is a downward-opening cuboid opening. The chamber 31 is part of the internal space of the cover.

[0045] When viewed from above in the XY plane, the shapes of the base plate 22 of the lower cover 20 and the base plate 32 of the upper cover 30 are not limited to rectangular shapes; they can also be circular, elliptical, polygonal, or a combination thereof. Furthermore, the shapes of the chamber 21 of the lower cover 20 and the chamber 31 of the upper cover 30 are not limited to cuboids; they can also be cylindrical or conical shapes, or combinations thereof, of any shape that is circular, elliptical, or polygonal.

[0046] Alternatively, an air-absorbing layer may be provided on the inner surface of at least one of the chambers 21 of the lower cover 20 and 31 of the upper cover 30. The air-absorbing layer adsorbs residual gas in the internal space of the cover to improve the vacuum level, for example, by using a metal film formed of nickel (Ni), molybdenum (Mo), titanium (Ti), tantalum (Ta), tungsten (W), barium (Ba), etc.

[0047] The resonator 10, lower cover 20, and upper cover 30 are each formed using a silicon (Si) substrate as examples. Alternatively, the resonator 10, lower cover 20, and upper cover 30 can also be formed using an SOI (Silicon On Insulator) substrate with a silicon layer and a silicon oxide film stacked on top of each other. Furthermore, the resonator 10, lower cover 20, and upper cover 30 can also be formed using substrates other than silicon substrates, such as compound semiconductor substrates, glass substrates, ceramic substrates, resin substrates, and other substrates capable of being processed using microfabrication techniques.

[0048] Next, refer to Figure 3 The structure of the resonator 10 (vibrating part 120, holding part 140 and a pair of holding units 110) will be described in more detail. Figure 3 This is a top view that briefly illustrates the construction of the resonator according to the first embodiment.

[0049] When viewed from above on the surface opposite the top cover 30 (hereinafter referred to as "top view"), the vibrating part 120 has a rectangular outline extending along the XY plane. The vibrating part 120 has a long side extending along the Y-axis and a short side extending along the X-axis. The vibrating part 120 is disposed inside the holding part 140, and a space is formed between the vibrating part 120 and the holding part 140 at a predetermined interval.

[0050] When viewed from above, the vibrating part 120 has a length L1 (hereinafter referred to as "length L1") along the Y-axis and a width W1 (hereinafter referred to as "width W1") along the X-axis. The length L1 corresponds to the length of the long side of the vibrating part 120, and the width W1 corresponds to the length of the short side of the vibrating part 120. As an example, the length L1 is about 240 μm, and the width W1 is, for example, about 190 μm.

[0051] The vibrating section 120 has two adjacent portions 135A and 135B. The first portion 135A and the second portion 135B are arranged along the X-axis. The second portion 135B is located on the negative X-axis side of the first portion 135A. When viewed from above, the boundary between the first portion 135A and the second portion 135B corresponds to the bisector of the vibrating section 120, which extends along the Y-axis at the center of the vibrating section 120 in the X-axis direction. Therefore, when viewed from above, the lengths of the first portion 135A and the second portion 135B along the Y-axis are approximately equal to the length L1 of the vibrating section 120. Furthermore, the widths of the first portion 135A and the second portion 135B along the X-axis are approximately half the width W1 of the vibrating section 120.

[0052] The first part 135A and the second part 135B vibrate primarily in an out-of-plane bending vibration mode relative to the XY plane, and vibrate in opposite phases. Details regarding the vibrations of the first part 135A and the second part 135B will be described later. Furthermore, the vibration modes of the first part 135A and the second part 135B are not limited to the modes described above.

[0053] The retaining part 140 is a portion used to retain the vibrating part 120 within the internal space formed by the lower cover 20 and the upper cover 30, and is, for example, formed in a frame shape to surround the vibrating part 120. Figure 3 In the example shown, spaces are formed not only between the holding portion 140 and the vibrating portion 120, but also between the holding portion 140 and the pair of holding units 110 at predetermined intervals. In other words, when viewed from above, the holding portion 140 is formed along the outline of the vibrating portion 120 and the pair of holding units 110. Furthermore, the width of the intervals formed between the vibrating portion 120, the holding portion 140, and the pair of holding units 110 is approximately 10 μm.

[0054] The retaining part 140 only needs to be configured to surround at least a portion of the vibrating part 120, and is not limited to a frame shape. For example, the retaining part 140 only needs to be provided around the vibrating part 120 to a degree that can retain the vibrating part 120 and engage with the lower cover 20 and the upper cover 30.

[0055] A pair of retaining units 110 clamp the boundaries of the two portions 135A and 135B, and connect the vibrating part 120 to the retaining part 140. The pair of retaining units 110 have a first retaining unit 111 and a second retaining unit 112. The first retaining unit 111 is located at the end of the vibrating part 120 on the negative Y-axis side ( Figure 3 The left end of the second holding unit 112 is connected to the end of the vibration unit 120 on the positive Y-axis side. Figure 3 (connect the right end of the middle).

[0056] The first holding unit 111 has a node generating section 111A and arms 111B and 111C. Arm 111B is disposed between the node generating section 111A and the vibration section 120, and arm 111C is disposed on the side of the node generating section 111A opposite to the vibration section 120. The second holding unit 112 has a node generating section 112A and arms 112B and 112C. Arm 112B is disposed between the node generating section 112A and the vibration section 120, and arm 112C is disposed on the side of the node generating section 112A opposite to the vibration section 120.

[0057] When viewed from above, the node generating portions 111A and 112A are each formed into a semi-circular shape with a radius R11. The node generating portions 111A and 112A each have a straight end on the vibrating portion 120 side and an arc-shaped end on the opposite side of the vibrating portion 120. As an example, the radius R11 is approximately 80 μm.

[0058] Arm 111B connects node generation unit 111A to vibration unit 120, and arm 112B connects node generation unit 112A to vibration unit 120. Arm 111C connects node generation unit 111A to holding unit 140, and arm 112C connects node generation unit 112A to holding unit 140. Arm 111B corresponds to the connection portion of one holding unit 111 connected to vibration unit 120, and arm 112B corresponds to the connection portion of the other holding unit 112 connected to vibration unit 120. Arms 111B, 111C, and 112B, 112C are located on the extension lines of the boundaries of the two parts 135A, 135B of vibration unit 120. That is, arms 111B, 112B are connected to the center portions of the ends of node generation units 111A, 112A on the vibration unit 120 side, respectively, and to the center portions of the ends of vibration unit 120 including the short sides. Arms 111C and 112C are respectively connected to the center portions of the ends of the node generating units 111A and 112A on the opposite side of the vibrating unit 120. Arms 111B, 111C and 112B, 112C each have a width W11 (hereinafter simply referred to as "width W11") along the X-axis direction. Width W11 corresponds to the width along the X-axis of the connection portion of each pair of holding units 110 connected to the vibrating unit 120. As an example, width W11 is 10 μm.

[0059] Furthermore, the shapes of the node generating portions 111A and 112A are not limited to the shapes described above. When viewed from above, the node generating portions 111A and 112A can have a width along the X-axis that is largest closer to the vibrating portion 120 than the center along the Y-axis, and decreases in size as it moves away from that point. For example, the node generating portions 111A and 112A can each have an arc-shaped end on the vibrating portion 120 side and a straight end on the opposite side of the vibrating portion 120. Additionally, as long as the boundaries of the two portions 135A and 135B of the vibrating portion 120 can be supported, the first holding unit 111 or the second holding unit 112 can be omitted. For example, the second holding unit 112 can be omitted, and the vibrating portion 120 can be supported only by the first holding unit 111.

[0060] Next, refer to Figure 4 and Figure 5 The structure of the vibrating part 120 will be explained in more detail. Figure 4 This is a top view that briefly shows the structure of the vibrating part according to the first embodiment. Figure 5 It is along Figure 4 The cross-sectional view of the vibrating part along the VV line is shown.

[0061] The vibrating part 120, the holding part 140, and a pair of holding units 110 are integrally formed using the same process. In the resonator 10, a silicon oxide film F21 is formed on the lower cover 20 side of one example of the substrate, namely the silicon substrate F2, to cover the silicon substrate F2. A silicon oxide film F22 is formed on the upper cover 30 side of the silicon substrate F2 to cover the silicon substrate F2. A metal film E1 is stacked on the silicon oxide film F22. A piezoelectric film F3 is stacked on the metal film E1 to cover the metal film E1. In addition, metal films E2A and E2B are stacked on the piezoelectric film F3. A protective film F4 is stacked on the metal films E2A and E2B to cover the metal films E2A and E2B. A metal film E3 is stacked on the protective film F4. The shapes of the vibrating part 120, the holding part 140 and the pair of holding units 110 are formed by removing the laminate composed of the silicon oxide film F21, silicon substrate F2, silicon oxide film F22, metal film E1, piezoelectric film F3, metal films E2A, E2B, protective film F4 and metal film E3 by, for example, dry etching using an argon (Ar) ion beam, and then patterning it.

[0062] The silicon substrate F2 is formed, for example, from a degenerate n-type silicon (Si) semiconductor with a thickness of about 10 μm, and may contain phosphorus (P), arsenic (As), antimony (Sb), etc., as n-type dopants. The resistivity of the degenerate silicon (Si) used in the silicon substrate F2 is, for example, less than 16 mΩ·cm, more preferably less than 1.2 mΩ·cm.

[0063] Silicon oxide films F21 and F22 are insulating films primarily composed of silicon dioxide (SiO2). Silicon oxide films F21 and F22 function as temperature characteristic correction layers to reduce the temperature coefficient of frequency (TCF) of the resonator 10. Specifically, silicon oxide films F21 and F22 reduce the change in frequency relative to temperature near room temperature. Therefore, by having silicon oxide films F21 and F22 in the vibration section 120, the temperature characteristics of the resonator 10 are improved. Furthermore, since silicon dioxide, the main component of silicon oxide film F22, has low thermal conductivity, silicon oxide film F22 also functions as a thermal conductivity suppression layer to extend heat conduction time and reduce thermoelastic damping (TED). Therefore, by having silicon oxide film F22 in the vibration section 120, the Q value (hereinafter simply referred to as "Q value") of the resonant vibration of the resonator 10 is improved.

[0064] The thickness of the silicon oxide films F21 and F22 is, for example, about 0.5 μm. The silicon oxide films F21 and F22 can be formed by thermal oxidation of the silicon substrate F2, thus reducing manufacturing costs. However, insulating films with a main component other than silicon dioxide can also be used instead of silicon oxide films F21 and F22. As a temperature characteristic correction layer, a material with an appropriate frequency temperature coefficient can be selected. Furthermore, as a thermal conductivity suppression layer, there are no particular limitations as long as the material has low thermal conductivity. The temperature characteristic correction layer and the thermal conductivity suppression layer can also be formed using a preferred method selected from film formation techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD).

[0065] Metal films E1, E2A, and E2B function as excitation electrodes for the piezoelectric film F3 in the vibration section 120, and as lead-out electrodes for connecting the excitation electrodes to an external power supply or ground in the holding section 140 and a pair of holding units 110. In the vibration section 120, metal film E1, located on one side of the piezoelectric film F3, corresponds to the lower electrode, while metal films E2A and E2B, located on the other side of the piezoelectric film F3, correspond to the two upper electrodes. Metal film E1 is continuously disposed throughout the entire vibration section 120, covering both sections 135A and 135B. Metal film E2A is disposed in the first section 135A, and metal film E2B is disposed in the second section 135B.

[0066] The thicknesses of the metal films E1, E2A, and E2B are, for example, approximately 0.1 μm to 0.2 μm. After deposition, the metal films E1, E2A, and E2B are patterned into excitation electrodes and lead-out electrodes by etching or other removal processes. The metal films E1, E2A, and E2B are formed, for example, from a metal material with a body-centered cubic crystal structure. Specifically, they are formed from Mo (molybdenum) or tungsten (W). Furthermore, if the silicon substrate F2 has high conductivity and the silicon oxide film F22 is omitted, the metal film E1 can be omitted, and the silicon substrate F2 can serve as the lower electrode.

[0067] Piezoelectric film F3 is a thin film formed from a piezoelectric material that converts electrical energy into mechanical energy. Piezoelectric film F3 is formed from materials with a wurtzite-type hexagonal crystal structure, such as aluminum nitride (AlN), scandium aluminum nitride (ScAlN), zinc oxide (ZnO), gallium nitride (GaN), indium nitride (InN), and other nitrides or oxides as the main components. Furthermore, scandium aluminum nitride is a material formed by replacing a portion of the aluminum in aluminum nitride with scandium; it can also replace scandium with magnesium (Mg) and niobium (Nb), or magnesium (Mg) and zirconium (Zr) in combination. The thickness of piezoelectric film F3 is, for example, about 0.8 μm, but can also be about 0.2 μm to 2 μm.

[0068] The protective film F4 protects the metal film E2 from oxidation. The protective film F4 is integrally disposed throughout the vibrating section 120 to cover the metal films E2A and E2B. The protective film F4 is formed, for example, from oxides, nitrides, or oxynitrides containing aluminum (Al), silicon (Si), or tantalum (Ta). The protective film F4 can also be made of the same material as the piezoelectric film F3. The thickness of the protective film F4 is, for example, about 0.2 μm. Unevennesses reflecting the thickness of the metal films E2A and E2B are formed on the surface of the protective film F4. The protective film F4 can also be formed such that the surface unevenness is minimized by making the thickness sufficiently thick.

[0069] Metal film E3 is disposed in the area between the connecting portions 111B and 112B of each of the pair of holding units 110 connected to the vibrating part 120 on the surface of the vibrating part 120. When viewed from above, metal film E3 is disposed in a region closer to the boundary of the two portions 135A and 135B than the center of each of the two portions 135A and 135B of the vibrating part 120. Additionally, metal film E3 is disposed in a region closer to the opposing ends of the two metal films E2A and E2B than the center of each of the two metal films E2A and E2B. Between the two metal films E2A and E2B, metal film E3 is positioned opposite metal film E1, separated by piezoelectric film F3 and protective film F4. When viewed from above, metal film E3 overlaps with the boundary of the two portions 135A and 135B and the opposing ends of the two metal films E2A and E2B.

[0070] The metal film E3 is equivalent to a frequency adjustment film. In the frequency adjustment process, which is one of the manufacturing steps, the frequency of the resonator 10 is adjusted by a finishing process that removes a portion of the metal film E3. This finishing process is, for example, dry etching by irradiation with an argon (Ar) ion beam. To effectively adjust the frequency of the resonator 10, the metal film E3 is preferably formed of a material whose etching mass reduction rate is faster than that of the protective film F4. The mass reduction rate is represented by the product of the etching rate and the density. The etching rate refers to the thickness removed per unit time. As long as the relationship between the mass reduction rates of the protective film F4 and the metal film E3 is as described above, the magnitude relationship between the etching rates of the protective film F4 and the metal film E3 is arbitrary. The metal film E3 is formed, for example, of metallic materials such as molybdenum (Mo), tungsten (W), gold (Au), platinum (Pt), nickel (Ni), or titanium (Ti). Furthermore, during the finishing process, sometimes a portion of the protective film F4 is also removed.

[0071] Furthermore, the location of the metal film E3 is not limited to the area between the connecting portions 111B and 112B on the surface of the vibrating part 120. The metal film E3 can be provided only in the area between the connecting portion of the holding unit 110 connected to the vibrating part 120 and the ends opposite the connecting portion along the boundaries of the two portions 135A and 135B of the vibrating part 120. In other words, the metal film E3 can be provided only in the area along the boundaries of adjacent portions of the vibrating part 120 that are supported by at least one holding unit. For example, if the vibrating part 120 has three or more portions vibrating in opposite phases, and a pair of holding units 110 each supports different boundaries, the metal film E3 can be provided only in the area along the boundary supported by at least one of the holding units of the pair of holding units 110, or it can be provided in the area along the boundary supported by the other holding unit. If the vibrating part 120 is supported by one holding unit, the metal film E3 can be provided only in the area along the boundary supported by that one holding unit. Alternatively, if it is to function as a frequency adjustment film, an insulating film or a semiconductor film can be used to replace the metal film E3.

[0072] like Figure 5 As shown, the width of metal film E1 along the X-axis is equal to the width W1 of vibrating section 120. Metal film E2A has a width W2A (hereinafter simply referred to as "width W2A") along the X-axis. Metal film E2B has a width W2B (hereinafter simply referred to as "width W2B") along the X-axis. A gap G2 is formed between the two metal films E2A and E2B. Metal film E3 has a width W3 (hereinafter simply referred to as "width W3") along the X-axis. Width W2A corresponds to the width of the first upper electrode, width W2B corresponds to the width of the second upper electrode, and gap G2 corresponds to the gap between the two upper electrodes.

[0073] Widths W2A and W2B are approximately equal in size. Gap G2 is larger than width W11. In this embodiment, width W3 is smaller than widths W2A and W2B, but larger than gap G2. As an example, widths W2A and W2B are approximately 60 μm, gap G2 is approximately 36 μm, and width W3 is approximately 40 μm.

[0074] Next, refer to Figure 6 and Figure 7 The operation of the vibrating part 120 will be explained. Figure 6 This is a cross-sectional view showing the structure to which a voltage is applied to the vibrating part according to the first embodiment. Figure 7 This is a perspective view schematically illustrating the vibration mode of the vibrating part according to the first embodiment.

[0075] The piezoelectric film F3 expands and contracts along the X-axis in the in-plane direction of the XY plane based on the electric field formed between the lower and upper electrodes. Through the expansion and contraction of the piezoelectric film F3, the two parts 135A and 135B of the vibrating part 120 displace their open ends toward the bottom plate 22 of the lower cover 20 and the bottom plate 32 of the upper cover 30, respectively, and vibrate in an out-of-plane bending vibration mode.

[0076] like Figure 6 As shown, in this embodiment, alternating voltages are applied to metal films E2A and E2B respectively. The phases of the voltage applied to metal film E2A and the voltage applied to metal film E2B are set to be opposite to each other. Metal film E1 is grounded, for example. Therefore, the phase of the alternating electric field formed between metal films E1 and E2A in the first part 135A is opposite to the phase of the alternating electric field formed between metal films E1 and E2B in the second part 135B. As a result, as... Figure 7 As shown, the first part 135A and the second part 135B are displaced in opposite directions. For example, when the center of the first part 135A is displaced toward the inner surface of the upper cover 30 in the positive Z-axis direction, the center of the second part 135B is displaced toward the inner surface of the lower cover 20 in the negative Z-axis direction. Furthermore, in Figure 7 In the diagram, lighter-colored areas represent regions with smaller displacements caused by vibration, while darker-colored areas represent regions with larger displacements caused by vibration.

[0077] The boundaries of the two parts 135A and 135B, lacking upper electrodes, become the fixed ends of each part 135A and 135B. In other words, the boundaries of the two parts 135A and 135B become nodes in the vibrating section 120. A pair of holding units 110 are connected to these nodes, thus reducing vibration holding losses or anchoring losses. Therefore, the decrease in Q value can be suppressed.

[0078] Next, refer to Figure 8 and Figure 9 The effects of the present invention will be explained. Figure 8 It is a graph showing the relationship between the change in frequency and the ion beam irradiation time. Figure 9 It is a graph showing the relationship between the change in TCF and the ratio of the frequency-adjustable membrane width.

[0079] Figure 8 This is a graph showing the frequency change relative to the irradiation time of the ion beam after removing the frequency-tuning film in a frequency-tuning process based on dry etching. The horizontal axis shows the irradiation time of the ion beam in seconds, and the vertical axis shows the frequency change in ppm. Figure 8 Two embodiments and one comparative example are illustrated. The two embodiments differ in their frequency adjustment films; one embodiment is a resonator where the width of the frequency adjustment film is larger than the gap of the upper electrodes, and the other embodiment is a resonator where the width of the frequency adjustment film is smaller than the gap of the upper electrodes. The comparative example is a resonator in which the frequency adjustment film is disposed at the end opposite to the boundary of the two parts.

[0080] The frequency change per unit time in both embodiments is greater than that in the comparative example. For example, to achieve a frequency change of -3000 ppm, more than 35 seconds of ion beam irradiation is required in the comparative example, but less than 15 seconds of ion beam irradiation is sufficient in the embodiments. This means that, according to this embodiment, the time required for the frequency adjustment process can be shortened, and energy consumption can be reduced.

[0081] Figure 9 This indicates how the TCF change changes during the frequency adjustment process when the width of the frequency adjustment diaphragm is changed in this embodiment. The horizontal axis shows the ratio of the width of the frequency adjustment diaphragm to the width of the vibrating section 120 (hereinafter referred to as "width ratio") in %. The vertical axis shows the change in TCF before and after the frequency adjustment process (hereinafter referred to as "TCF change") in ppm / deg.

[0082] Ideally, the TCF variation should be small. The TCF variation is approximately zero at a width ratio of 20%, and increases proportionally with the width ratio. For example, if the width ratio is designed to be between 10% and 30%, a resonator with a TCF variation within ±0.5ppm / deg can be manufactured.

[0083] As described above, in the first embodiment, the metal film E3, which corresponds to the frequency adjustment film, is disposed in the region between the connection portions 111B and 112B of each of the pair of holding units 110 connected to the vibrating part 120. When viewed from above, the metal film E3 is disposed in a region closer to the boundary of the two portions 135A and 135B than the center of each of the two portions 135A and 135B of the vibrating part 120. Furthermore, the metal film E3 is disposed in a region closer to the opposing ends of the two metal films E2A and E2B than the center of each of the two upper electrodes.

[0084] As a result, the efficiency of frequency adjustment is improved, thus increasing the productivity of resonator 10.

[0085] The width of the metal film E3 is 10% to 30% of the width of the vibrating part 120.

[0086] Therefore, the change in TCF before and after the frequency adjustment process is within ±0.5ppm / deg.

[0087] The resonator 10 has a silicon oxide film F22 between the silicon substrate F2 and the metal film E1.

[0088] As a result, thermoelastic damping decreases and the Q value increases.

[0089] The resonator 10 has a silicon oxide film F21 on the side of the silicon substrate F2 opposite to the metal film E1.

[0090] As a result, the TCF near room temperature decreases, and the temperature characteristics are improved.

[0091] Hereinafter, the structure of the resonator 10 or the vibrating part 120 according to other embodiments of the present invention will be described. Furthermore, in the following embodiments, matters common to the first embodiment described above will be omitted, and only the differences will be described. In particular, the same effects resulting from the same structure will not be mentioned sequentially.

[0092] <Second Implementation>

[0093] Next, refer to Figure 10 The structure of the vibration unit 120 according to the second embodiment will be described. Figure 10 This is a cross-sectional view that briefly shows the structure of the vibrating part according to the second embodiment.

[0094] When viewed from above, the metal film E3 is separated from the opposing ends of the two metal films E2A and E2B, and is located between the two metal films E2A and E2B. The width W3 of the metal film E3, which is equivalent to the frequency adjustment film, is larger than the width W11 of the connection portions 111B and 112B of each of the pair of holding units 110 that are connected to the vibrating part 120, and smaller than the gap G2 between the metal films E2A and E2B, which are equivalent to the two upper electrodes.

[0095] Because the protective film F4 is thinned at the opposing ends of the two metal films E2A and E2B, defects sometimes occur in this part. Even in this case, according to this embodiment, short circuits between each of the two metal films E2A and E2B and the metal film E3 can be suppressed.

[0096] Furthermore, metal film E3 only needs to be separated from at least one of the opposing ends of the two metal films E2A and E2B. This allows for the suppression of short circuits between at least one of the two metal films E2A and E2B and metal film E3.

[0097] <Third Implementation Method>

[0098] Next, refer to Figure 11 The structure of the vibration unit 120 according to the third embodiment will be described. Figure 11 This is a cross-sectional view that briefly shows the structure of the vibrating part according to the third embodiment.

[0099] The width W3 of the metal film E3, which is equivalent to the frequency adjustment film, is smaller than the width W11 of the connection portions 111B and 112B of each of the pair of holding units 110 that are connected to the vibrating part 120.

[0100] Therefore, the same effect as the second embodiment can be obtained.

[0101] <Fourth Implementation>

[0102] Next, refer to Figure 12 The structure of the vibration unit 120 according to the fourth embodiment will be described. Figure 12 This is a cross-sectional view that briefly shows the structure of the vibrating part according to the fourth embodiment.

[0103] The frequency adjustment diaphragm is composed of two metal films E3A and E3B. Metal films E3A and E3B extend along the Y-axis and are arranged with a gap in the X-axis direction. When viewed from above, metal films E3A and E2A overlap, and metal films E3B and E2B overlap. Thus, even in a vibrating section 120 equipped with multiple frequency adjustment diaphragms, the same effect as in the first embodiment can be obtained.

[0104] When viewed from above, the ends of metal films E3A and E2A opposite to metal film E2B separate, and the ends of metal films E3B and E2B opposite to metal film E2A separate. Thus, the same effect as in the second embodiment can be obtained.

[0105] The two metal films E3A and E3B can overlap with the opposing ends of the two metal films E2A and E2B when viewed from above, or they can be placed between the two metal films E2A and E2B.

[0106] <Fifth Implementation>

[0107] Next, refer to Figure 13 and Figure 14 The structure of the vibration unit 120 according to the fifth embodiment will be described. Figure 13 This is a top view that briefly shows the structure of the resonator according to the fifth embodiment. Figure 14 This is a perspective view schematically illustrating the vibration mode of the vibrating part according to the fifth embodiment.

[0108] The vibrating part 120 has two portions 135A and 135B arranged along the Y-axis direction, and the boundaries of the two portions 135A and 135B extend along the X-axis direction. The first portion 135A is located on the positive Y-axis side of the second portion 135B.

[0109] The retaining part 140 has prism-shaped frames 140a to 140d. Frames 140a and 140b extend along the X-axis direction, with frame 140a located on the positive Y-axis side of the vibrating part 120 and frame 140b located on the negative Y-axis side of the vibrating part 120. Frames 140c and 140d extend along the Y-axis direction, with frame 140c located on the negative X-axis side of the vibrating part 120 and frame 140d located on the positive X-axis side of the vibrating part 120.

[0110] A pair of retaining units have prism-shaped retaining arms 111 and 112 extending along the X-axis. Retaining arm 111 corresponds to the connection portion of one retaining unit connected to the vibrating part 120, and retaining arm 112 corresponds to the connection portion of the other retaining unit connected to the vibrating part 120. Retaining arm 111 connects the frame 140c of the retaining part 140 to the center portion of the end of the vibrating part 120 including one long side. Retaining arm 112 connects the frame 140d of the retaining part 140 to the center portion of the end of the vibrating part 120 including the other long side.

[0111] like Figure 14As shown, even if the two parts 135A and 135B that vibrate in opposite phases are arranged along the long side of the vibration section 120, the same effect as the first embodiment can be obtained by providing a metal film E3, which is equivalent to a frequency adjustment film, in the area between the connecting parts 111 and 112 of each pair of holding units connected to the vibration section 120.

[0112] <Modifications of the Fifth Embodiment>

[0113] Next, refer to Figures 15-21 The structure of the vibration unit 120 involved in the modified example of the fifth embodiment will be described. Figures 15-21 These are top views that briefly illustrate the structure of the resonator involved in the modified example of the fifth embodiment.

[0114] Figure 15 The vibrating part 120 shown is located at the point where the slit SLA along the Y-axis direction is formed in the first part 135A, and... Figure 13 The vibrating part 120 shown is different. The slit SLA is formed from the end opposite to the boundary of the two parts 135A, 135B to the boundary of the two parts 135A, 135B. The two parts 135A, 135B have an asymmetrical structure with reference to the boundary of the two parts 135A, 135B.

[0115] Figure 16 The vibrating section 120 shown is characterized by having a slit SLA along the Y-axis in the first portion 135A and a slit SLB along the Y-axis in the second portion 135B. Figure 13 The vibrating section 120 shown is different. Slits SLA and SLB are formed on the same straight line from the ends opposite to the boundaries of the two sections 135A and 135B. Slits SLA and SLB are separated by a gap that is approximately equal in size to the width of the retaining arms 111 and 112.

[0116] Figure 17 The vibrating section 120 shown is similar to the two sections 135A and 135B in that they are approximately trapezoidal in shape. Figure 13 The vibrating part 120 shown is different. Figure 18 The vibrating part 120 shown is roughly triangular in shape in its two parts 135A and 135B, which is similar to... Figure 13 The vibrating part 120 shown is different. Figure 17 and Figure 18In the modified example shown, the widths of the two portions 135A and 135B along the X-axis decrease as they move away from the boundaries of the two portions 135A and 135B. The metal film E3 is approximately octagonal in shape to match the shape of the vibrating part 120. The metal film E3 may also be approximately hexagonal or rectangular in shape to match the shape of the vibrating part 120.

[0117] Figure 19 The vibrating section 120 shown in the diagram has a width along the X-axis that increases with distance from the boundaries of the two portions 135A and 135B, respectively. Figure 17 The vibrating part 120 shown is different. The metal film E3 is recessed from both ends along the X-axis direction.

[0118] Figure 20 and Figure 21 Regarding the fact that units 111 and 112 respectively have node generation units 111A and 112A, and Figure 13 The vibrating part 120 shown is different. Figure 20 The node generation units 111A and 112A shown are rectangular in shape. Figure 21 The node generation units 111A and 112A shown are semi-circular in shape. The node generation units 111A and 112A are connected to the vibration unit 120 through rectangular arms 111B and 112B, respectively, and are connected to the holding unit 140 through rectangular arms 111C and 112C.

[0119] <Sixth Implementation Method>

[0120] Next, refer to Figure 22 and Figure 23 The structure of the vibration unit 120 according to the sixth embodiment will be described. Figure 22 This is a cross-sectional view showing the structure to which a voltage is applied to the vibrating part according to the sixth embodiment. Figure 23 This is a perspective view schematically illustrating the vibration mode of the vibrating part according to the sixth embodiment.

[0121] The vibrating section 120 has four sections 135A to 135D that vibrate in opposite phases to each other, and vibrates primarily in a fourth-order out-of-plane bending vibration mode. The four sections 135A to 135D are arranged along the Y-axis. Metal films E2A to E2D, corresponding to upper electrodes, are respectively provided on sections 135A to 135D. The metal films E2A to E2D are separated from each other.

[0122] A metal film E3A is provided in a region closer to the boundary of adjacent portions 135A and 135B than the center of each of the adjacent portions 135A and 135B. Specifically, the metal film E3A is provided at the boundary of adjacent portions 135A and 135B. Similarly, the metal film E3B is provided at the boundary of adjacent portions 135B and 135C, and the metal film E3C is provided at the boundary of adjacent portions 135C and 135D.

[0123] Thus, even in the vibrating section 120 that vibrates in a high-order even-order mode, by providing a frequency adjustment film in a region closer to the boundary of the adjacent sections than the center of each adjacent section, the same effect as in the first embodiment can be obtained. Furthermore, it is not necessary to provide a frequency adjustment film at the boundary of all adjacent sections; if... Figure 22 In the example shown, any one or two of the metal films E3A to E3C can be omitted.

[0124] <Modifications of the Sixth Embodiment>

[0125] Next, refer to Figure 24 The structure of the vibration unit 120 in the modified example of the sixth embodiment will be described. Figure 24 This is a perspective view schematically illustrating the vibration mode of the vibrating part involved in a variation of the sixth embodiment.

[0126] Figure 24 The vibrating section 120 shown has six sections 135A to 135F that vibrate in opposite phases to each other, and vibrates primarily in a sixth-order out-of-plane bending vibration mode. Figure 23 The vibrating part 120 shown is different.

[0127] Thus, the present invention can also be applied to the vibration section 120, which vibrates primarily in a higher-order vibration mode of arbitrary order.

[0128] The following describes some or all of the embodiments of the present invention and their effects. However, the present invention is not limited to the following description.

[0129] According to one aspect of the present invention, a resonator is provided, comprising: a vibrating portion having two parts vibrating with opposite phases; a holding portion formed to surround at least a portion of the vibrating portion; and a holding unit supporting the boundary of the two parts and connecting the vibrating portion to the holding portion, wherein a frequency adjustment diaphragm is provided in a region on the surface of the vibrating portion, between the vibrating portion of the holding unit and an end opposite the connecting portion along the boundary of the two parts.

[0130] As one approach, the holding unit is a pair of holding units that clamp the boundary of the two parts, and the frequency adjustment diaphragm is disposed in the area between the connection part of each pair of holding units and the vibrating part.

[0131] As a result, the efficiency of frequency adjustment is improved, thus increasing the productivity of the resonator.

[0132] As one approach, the frequency adjustment diaphragm is positioned in a region closer to the boundary between the two parts than the center of each of the two parts of the vibrating section.

[0133] In one approach, the width of the frequency adjustment membrane in the arrangement direction of the two parts of the vibrating section is 10% to 30% of the width of the vibrating section.

[0134] Therefore, the change in TCF (temperature coefficient of frequency) before and after the frequency adjustment process is within ±0.5ppm / deg.

[0135] In one approach, the width of the frequency adjustment membrane in the arrangement direction of the two parts of the vibrating part is smaller than the width of the connection portion of the holding unit connected to the vibrating part in the arrangement direction of the two parts of the vibrating part.

[0136] As one embodiment, the vibrating part also includes: a piezoelectric film; a lower electrode disposed on one side of the piezoelectric film; and two upper electrodes disposed on the other side of the piezoelectric film, and the lower electrode is positioned opposite to the piezoelectric film in each of the two parts of the vibrating part.

[0137] In one approach, the width of the frequency adjustment membrane in the arrangement direction of the two parts of the vibrating section is smaller than the gap between the two upper electrodes.

[0138] In one way, when the surface of the vibrating part is viewed from above, the frequency adjustment diaphragm is separated from at least one of the opposing ends of the two upper electrodes.

[0139] This allows for the suppression of short circuits between the end of the upper electrode and the frequency adjustment film.

[0140] In one embodiment, the vibrating part also has a silicon substrate and a silicon oxide film disposed between the silicon substrate and the lower electrode.

[0141] As a result, thermoelastic damping decreases and the Q value increases.

[0142] In one embodiment, the vibrating part also has a silicon oxide film disposed on the side of the silicon substrate opposite to the lower electrode.

[0143] As a result, the TCF near room temperature decreases, and the temperature characteristics are improved.

[0144] In one manner, the vibrating part has four or more adjacent parts that vibrate with opposite phases to each other, and the frequency adjustment membrane is disposed in a region closer to the boundary of the adjacent parts than the center of each of the adjacent parts.

[0145] As one approach, a resonant device is provided, comprising: any of the aforementioned resonators; and a cover forming an internal space that allows the vibrating portion of the resonator to flex and vibrate.

[0146] According to another aspect of the invention, a resonator is provided, comprising: a vibrating portion having two parts vibrating with opposite phases; and a frequency adjustment diaphragm disposed on the surface of the vibrating portion in a region closer to the boundary between the two parts than the respective center portions of the two parts.

[0147] As a result, the efficiency of frequency adjustment is improved, thus increasing the productivity of the resonator.

[0148] According to another aspect of the present invention, a resonator is provided, comprising: a vibrating portion having two parts vibrating with opposite phases; a holding portion formed to surround at least a portion of the vibrating portion; and a holding unit connecting the vibrating portion and the holding portion. The vibrating portion has: a piezoelectric film; a lower electrode disposed on one side of the piezoelectric film; two upper electrodes disposed on the other side of the piezoelectric film and facing the lower electrode across the piezoelectric film in each of the two portions of the vibrating portion; a protective film covering the two upper electrodes; and a frequency adjustment film facing the lower electrode across the piezoelectric film and the protective film. When the surface of the vibrating portion is viewed from above, the frequency adjustment film is disposed in a region closer to the opposing ends of the two upper electrodes than the center of each of the two upper electrodes.

[0149] As a result, the efficiency of frequency adjustment is improved, thus increasing the productivity of the resonator.

[0150] The embodiments involved in this invention can be appropriately applied as long as they are devices that utilize the piezoelectric effect for electromechanical energy conversion, such as timing devices, sound generators, oscillators, and load sensors, without any particular limitation.

[0151] As explained above, according to one aspect of the present invention, it is possible to provide a resonator with improved productivity and a resonant device having the resonator.

[0152] Furthermore, the embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit the invention. The present invention can be modified / improved without departing from its spirit, and the present invention also includes its equivalents. That is, those skilled in the art can make appropriate design changes to each embodiment, as long as they possess the features of the present invention, and these modifications are included within the scope of the present invention. For example, the elements, their configurations, materials, conditions, shapes, dimensions, etc., of each embodiment are not limited to those illustrated and can be appropriately modified. In addition, the elements of each embodiment can be combined as long as it is technically possible, and the structure formed by combining them is included within the scope of the present invention as long as it includes the features of the present invention.

[0153] Explanation of reference numerals in the attached figures

[0154] 1…Resonant device; 10…Resonator; 20…Lower cover; 30…Upper cover; 110…Holding unit; 111A, 112A…Node generation section; 111B, 112B…Arms (connection section connected to the vibrating section); 111C, 112C…Arms; 120…Vibrating section; 135A, 135B…Section; F2…Silicon substrate; F21, F22…Silicon oxide film; E1…Metal film (lower electrode); F3…Piezoelectric film; E2A, E2B…Metal film (upper electrode); F4…Protective film; E3…Metal film (frequency adjustment film); 140…Holding section.

Claims

1. A resonator, wherein, have: The vibrating part has two parts that vibrate with opposite phases to each other; The retaining portion is configured to surround at least a portion of the vibrating portion; as well as The retaining unit supports the boundary between the two parts and connects the vibrating part to the retaining part. A frequency adjustment diaphragm is provided in the area between the connecting portion of the holding unit connected to the vibrating part and the end opposite the connecting portion along the boundary of the two portions on the surface of the vibrating part. The frequency adjustment diaphragm is disposed in a region closer to the boundary of the two portions than the center of each of the two portions of the vibrating part.

2. A resonator, wherein, have: The vibrating part has two parts that vibrate with opposite phases to each other; The retaining portion is configured to surround at least a portion of the vibrating portion; as well as The retaining unit supports the boundary between the two parts and connects the vibrating part to the retaining part. A frequency adjustment diaphragm is provided in the area between the connecting portion of the holding unit connected to the vibrating part and the end opposite the connecting portion along the boundary of the two portions on the surface of the vibrating part. The width of the frequency adjustment diaphragm in the arrangement direction of the two parts of the vibrating part is 10% to 30% of the width of the vibrating part.

3. A resonator, wherein, have: The vibrating part has two parts that vibrate with opposite phases to each other; The retaining portion is configured to surround at least a portion of the vibrating portion; as well as The retaining unit supports the boundary between the two parts and connects the vibrating part to the retaining part. A frequency adjustment diaphragm is provided in the area between the connecting portion of the holding unit connected to the vibrating part and the end opposite the connecting portion along the boundary of the two portions on the surface of the vibrating part. The width of the frequency adjustment diaphragm in the arrangement direction of the two parts of the vibrating part is smaller than the width of the connecting portion of the holding unit connected to the vibrating part in the arrangement direction of the two parts of the vibrating part.

4. A resonator, wherein, have: The vibrating part has two parts that vibrate with opposite phases to each other; The retaining portion is configured to surround at least a portion of the vibrating portion; as well as The retaining unit supports the boundary between the two parts and connects the vibrating part to the retaining part. A frequency adjustment diaphragm is provided in the area between the connecting portion of the holding unit connected to the vibrating part and the end opposite the connecting portion along the boundary of the two portions on the surface of the vibrating part. The vibrating part also has: piezoelectric film; The lower electrode is disposed on one side of the piezoelectric film; and Two upper electrodes are disposed on the other side of the piezoelectric membrane and are positioned opposite the lower electrode in each of the two portions of the vibrating portion, separated by the piezoelectric membrane.

5. The resonator according to claim 4, wherein, The width of the frequency adjustment diaphragm in the arrangement direction of the two parts of the vibrating part is smaller than the gap between the two upper electrodes.

6. The resonator according to claim 4 or 5, wherein, When viewed from above, the surface of the vibrating part is separated from at least one of the opposing ends of the two upper electrodes.

7. The resonator according to claim 4 or 5, wherein, The vibrating part also has: Silicon substrate; and A silicon oxide film is disposed between the silicon substrate and the lower electrode.

8. The resonator according to claim 7, wherein, The vibrating part also has a silicon oxide film disposed on the silicon substrate on the side opposite to the lower electrode.

9. A resonator, wherein, have: The vibrating part has two parts that vibrate with opposite phases to each other; The retaining portion is configured to surround at least a portion of the vibrating portion; as well as The retaining unit supports the boundary between the two parts and connects the vibrating part to the retaining part. A frequency adjustment diaphragm is provided in the area between the connecting portion of the holding unit connected to the vibrating part and the end opposite the connecting portion along the boundary of the two portions on the surface of the vibrating part. The vibrating part has four or more adjacent parts that vibrate in opposite phases to each other. The frequency adjustment film is disposed in a region closer to the boundary of the adjacent portion than the center of each of the adjacent portions.

10. The resonator according to any one of claims 1 to 4, 9, wherein, The retaining unit is a pair of retaining units that clamp the boundaries of the two parts. The frequency adjustment diaphragm is disposed in the region between the connection portions of the pair of holding units and the vibrating part.

11. A resonant device, wherein, have: The resonator according to any one of claims 1 to 10; and The cover forms an internal space that allows the vibrating part of the resonator to bend and vibrate.

12. A resonator, wherein, have: The vibrating part has two sections that vibrate with opposite phases; and A frequency adjustment diaphragm is disposed on the surface of the vibrating part in a region closer to the boundary of the two parts than the center of each of the two parts of the vibrating part.

13. A resonator, wherein, have: The vibrating part has two parts that vibrate with opposite phases to each other; The retaining portion is formed to surround at least a portion of the vibrating portion; and The retaining unit connects the vibrating part to the retaining part. The vibrating part has: piezoelectric film; The lower electrode is disposed on one side of the piezoelectric film; Two upper electrodes are disposed on the other side of the piezoelectric membrane, and are positioned opposite the lower electrode in each of the two parts of the vibrating portion, separated by the piezoelectric membrane; A protective film covers the two upper electrodes; as well as The frequency adjustment film is positioned opposite the lower electrode, separated from the piezoelectric film and the protective film. When viewed from above, the frequency adjustment diaphragm is located in a region closer to the opposing ends of the two upper electrodes than to the center of each of the two upper electrodes.

Images