Acoustic wave resonator and electronic device

Abstract

The invention relates to the field of semiconductor devices and provides an acoustic resonator and electronic equipment. The acoustic wave resonator comprises an acoustic wave resonance part and a substrate provided with the acoustic wave resonance part. The substrate comprises a central substrate provided with the acoustic wave resonance part, a peripheral substrate located on the periphery of the central substrate and a buffer substrate connected with the central substrate and the peripheral substrate. The buffer substrate comprises a strip-shaped part, one end of the strip-shaped part is connected with the central substrate, and the other end of the strip-shaped part is connected with the peripheral substrate; and grooves located on both sides of the elongated portion in the width direction. Thus, stress conducted from the peripheral substrate is absorbed by the elongated buffer substrate to suppress the stress from being conducted to the central substrate provided with the acoustic wave resonance part, thereby reducing the drift of the resonance frequency of the acoustic wave resonance part due to the stress.

Description

Technical Field

[0001] The present application relates to the field of semiconductor devices, and in particular to an acoustic wave resonator and an electronic device. Background Art

[0002] Micro-resonators have been widely used in various miniaturized electronic devices. Among them, thin film bulk acoustic wave resonators are widely used in high-performance oscillators and frequency sources due to their advantages of high quality factor, small size and low cost.

[0003] The working part of a film bulk acoustic wave resonator usually includes a piezoelectric film and electrode layers attached to both sides of the piezoelectric film. When an alternating voltage is applied to the electrode layers on both sides of the piezoelectric film, the piezoelectric effect and inverse piezoelectric effect of the piezoelectric film are used to realize the conversion of electrical energy and mechanical energy to achieve vibration.

[0004] The structure consisting of a piezoelectric film and electrode layers on both sides thereof is usually called a "sandwich structure". There is usually an acoustic impedance mismatch structure such as a cavity or a Bragg reflection layer under the sandwich structure. The acoustic impedance mismatch structure reflects sound waves to reduce energy loss.

[0005] In the prior art, the edges of the sandwich structure are usually overlapped on the surface of the substrate wafer or the dielectric layer to provide support for the sandwich structure.

[0006] This section is intended to provide a background or context to the embodiments of the present application as recited in the claims. No admission is made that the description herein is prior art by inclusion in this section. Summary of the invention

[0007] The inventors found that the substrate or dielectric layer will inevitably be deformed due to the influence of temperature change, chemical environment and mechanical force coupling during the manufacturing process, packaging process, installation process and use process, and the peripheral part of the sandwich structure in the prior art is connected to the substrate, and the stress generated by the deformation will be transmitted to the sandwich structure itself through the substrate through the edge of the sandwich structure overlapped on the substrate. The resonant frequency of the thin film bulk acoustic resonator is very sensitive to stress. The stress transmitted from the outside to the sandwich structure will cause the resonant frequency to drift significantly, thereby causing the resonant frequency to drift uncontrollably, thereby affecting the frequency stability of the oscillator and the frequency source.

[0008] In order to solve at least one of the above problems or other similar problems, embodiments of the present application provide an acoustic wave resonator and an electronic device.

[0009] According to a first aspect of an embodiment of the present application, there is provided an acoustic wave resonator, the acoustic wave resonator comprising an acoustic wave resonator portion and a substrate on which the acoustic wave resonator portion is disposed, wherein:

[0010] The substrate includes a central substrate on which the acoustic wave resonance portion is disposed, a peripheral substrate located at the periphery of the central substrate, and a buffer substrate connecting the central substrate and the peripheral substrate;

[0011] The buffer substrate comprises:

[0012] a strip-shaped portion, one end of which is connected to the central substrate, and the other end of which is connected to the peripheral substrate; and

[0013] The grooves are located on both sides of the elongated portion in the width direction.

[0014] According to a second aspect of the embodiments of the present application, an electronic device is provided, wherein the electronic device comprises the acoustic wave resonator described in the embodiments of the first aspect.

[0015] One of the beneficial effects of the embodiments of the present application is that the stress transmitted from the peripheral substrate is absorbed by the long strip buffer substrate to suppress the stress from being transmitted to the central substrate provided with the acoustic wave resonance part, thereby reducing the drift of the resonance frequency of the acoustic wave resonance part caused by the stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 4 is a top view of an implementation of an acoustic wave resonator according to an embodiment of the present application.

[0018] Figure 2 4 is a top view of another embodiment of the acoustic wave resonator of the present application.

[0019] Figure 3 4 is a top view of another embodiment of the acoustic wave resonator of the present application.

[0020] Figure 4 yes Figure 1 A cross-sectional view of the acoustic wave resonator along the AA direction is shown.

[0021] Figure 5 It is a cross-sectional view of another implementation of the acoustic wave resonator of the embodiment of the present application.

[0022] Figure 6 It is a cross-sectional view of another implementation of the acoustic wave resonator of the embodiment of the present application.

[0023] Figure 74 is a top view of another embodiment of the acoustic wave resonator of the present application.

[0024] Figure 8 4 is a top view of another embodiment of the acoustic wave resonator of the present application.

[0025] Fig. 9 4 is a top view of another embodiment of the acoustic wave resonator of the present application.

[0026] Fig.10 It is a cross-sectional view of another implementation of the acoustic wave resonator of the embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application more clear, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not intended to limit the present application.

[0028] In the embodiments of the present application, the terms "first", "second", "upper", "lower", etc. are used to distinguish different elements in terms of title, but do not indicate the spatial arrangement or time order of these elements, etc., and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having", etc. refer to the presence of the stated features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.

[0029] In the embodiments of the present application, the singular forms "a", "the", etc. include plural forms and should be broadly understood as "a kind" or "a type" rather than being limited to the meaning of "one"; in addition, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. In addition, the term "according to" should be understood as "at least in part according to...", and the term "based on" should be understood as "at least in part based on...", unless the context clearly indicates otherwise.

[0030] Embodiments of the first aspect

[0031] An embodiment of a first aspect of the present application provides an acoustic wave resonator. Figure 1 4 is a top view of an implementation of an acoustic wave resonator according to an embodiment of the present application.

[0032] like Figure 1As shown, the acoustic wave resonator 1 includes an acoustic wave resonator 10 and a substrate 20 on which the acoustic wave resonator 10 is disposed. The acoustic wave resonator 10 is used to generate an oscillation signal. For example, the acoustic wave resonator 10 can be formed based on the principle of a bulk acoustic wave resonator, but the embodiment of the present application is not limited thereto. The structure of the acoustic wave resonator 10 will be described in detail later.

[0033] In at least one embodiment, the substrate 20 may be formed of a semiconductor material, and the embodiments of the present application do not limit the specific material forming the substrate 20. For example, the substrate 20 may be formed of a single crystal silicon material, for example, a high-resistance silicon material, the resistivity of the silicon material is, for example, greater than 1000Ω·cm, for example, the resistivity is greater than 5000Ω·cm, and may also be formed of materials such as silicon carbide (SiC), sapphire, and quartz. In addition, the substrate 20 may also be formed by stacking single crystal silicon material and dielectric material, for example, a dielectric layer composed of dielectric material is formed on the surface of a base composed of single crystal silicon material, and the dielectric layer may be formed of semiconductor materials such as silicon dioxide, silicon nitride, polycrystalline silicon, and amorphous silicon, or a composite material composed of silicon dioxide, silicon nitride, polycrystalline silicon, and amorphous silicon. In addition, the substrate 20 may also be a substrate formed by a composite of multiple layers of materials, and is not limited to a single material.

[0034] In at least one embodiment, Figure 1 As shown, the substrate 20 includes a central substrate 210 , a buffer substrate 220 and a peripheral substrate 230 . The central substrate 210 is provided with an acoustic wave resonance portion 10 . The peripheral substrate 230 is located at the periphery of the central substrate 210 . The buffer substrate 220 connects the central substrate 210 and the peripheral substrate 230 .

[0035] In at least one embodiment, the projection of the buffer substrate on the surface of the substrate may be a centrally symmetrical figure centered on the geometric center of the projection of the central substrate on the surface of the substrate. Figure 1 As shown, the buffer substrate 220 is centrally symmetrical about the geometric center O of the central substrate 210. Thus, the stability and impact resistance of the entire substrate structure can be improved.

[0036] In at least one embodiment, the buffer substrate 220 includes a strip-shaped portion 221 and a groove portion 222. One end of the strip-shaped portion 221 is connected to the central substrate 210, and the other end is connected to the peripheral substrate 230. The groove portion 222 is located on both sides of the strip-shaped portion in the width direction. The groove portion 222 is, for example, a slit. Figure 1 As shown, the buffer substrate 220 includes long strip portions 221-1 to 221-4 and groove portions 222-1 to 222-8. The structures of the long strip portions 221-1 to 221-4 are the same or similar. Taking the long strip portion 221-1 as an example, as shown in FIG. Figure 1As shown, one end a of the strip-shaped portion 221 - 1 in the length direction is connected to the central substrate 210 , and the other end b is connected to the peripheral substrate 230 . Grooves 222 - 1 and 222 - 8 are provided on both sides of the strip-shaped portion 221 - 1 in the width direction.

[0037] In the embodiment of the present application, the direction extending along the long strip portion is referred to as the "length direction", and the direction crossing or perpendicular to the "length direction" is referred to as the "width direction". Figure 1 As shown, the direction in which the long strip-shaped portion 221-3 extends is, for example, the direction from point p1 to point p2 to point p3, and the length of the long strip-shaped portion 221-3 is, for example, the sum of the length of the line segment p1p2 and the length of the line segment p2p3. In addition, the width direction of the long strip-shaped portion 221-3 includes, for example, the direction perpendicular to the line segment p1p2 and the direction perpendicular to the line segment p2p3, and the width of the long strip-shaped portion 221-3 includes, for example, the width at the line segment p1p2 and the width at the line segment p2p3. Taking the long strip-shaped portion 221-1 as an example, the width of the long strip-shaped portion 221-1 includes, for example, the width D10 at the end a and the width D11 at the end b. For another example, the width of the long strip-shaped portion 221-4 includes, for example, D20 and D21.

[0038] In at least one embodiment, the length of the long strip portion 221 may be 10 to 100 times its width. Thus, the buffering performance and structural stability of the buffer substrate 220 can be taken into account. In addition, the embodiment of the present application does not limit the length and width of the long strip portion, which can be set according to actual needs. For example, the length of the long strip portion ranges from 100 microns to 3000 microns, and the width of the long strip portion ranges from 20 microns to 500 microns.

[0039] In addition, those skilled in the art should understand that due to the constraints of the production process, the "long strip shape" described in the embodiments of the present application is roughly strip-shaped, that is, the outer contour of the long strip portion can be an approximate straight line or a curve; in addition, the "length direction" and "width direction" described in the embodiments of the present application are rough directions, that is, the "length direction" can be the rough direction extending along the long strip portion, and the "width direction" can be a direction roughly perpendicular to the "length direction".

[0040] Since the strip-shaped substrate has better flexibility and elasticity than the block-shaped substrate, the stress transmitted from the peripheral substrate can be absorbed by the strip-shaped buffer substrate to suppress the stress from being transmitted to the central substrate where the acoustic wave resonance part is provided, thereby reducing the drift of the resonant frequency of the acoustic wave resonance part caused by the stress.

[0041] In addition, the long strip portion 221 and the groove portion 222 form an acoustic reflection structure, which can reduce the loss of acoustic energy to the surrounding substrate 230, thereby improving the Q value of the acoustic wave resonator.

[0042] In at least one embodiment, the substrate 20 is divided into a central substrate 210, a buffer substrate 220, and a peripheral substrate 230 by forming a groove 222 on the substrate 20. In addition, the groove 222 can be formed on the substrate 20, for example, by a patterning process and an etching process. For the specific process, reference can be made to the relevant technology, and the embodiments of the present application are not limited thereto.

[0043] In at least one embodiment, the width of the groove 222 can be set according to the size of the buffer substrate 220, thereby taking into account both the buffer performance and the structural stability of the buffer substrate 220. For example, if the width of the groove is too narrow, the buffer substrate may be damaged by contact and mutual compression with the surrounding structure under the action of strain; if the width of the groove is too wide, the material of the substrate structure will become fragile due to lack of sufficient support.

[0044] In some embodiments, the width of the groove 222 ranges from 5 micrometers to 50 micrometers. Alternatively, the width of the long strip 221 can be set to be 2 to 40 times the width of the groove 222. Figure 1 As shown, the structures of the grooves 222-1 to 222-8 are similar. For example, taking the grooves 222-1 and 222-2 as examples, the width of the groove 222-2 is recorded as d20, and the width of the groove 222-1 is recorded as d21. For example, the width d21 of the groove 222-1 can be 1 / 2 of the width D11 of the long strip portion 221-1. In addition, the values ​​of the widths d20 and d21 can be the same or different. For another example, taking the groove 2 22-7 and 222-8 as examples, the width of the groove 222-8 is recorded as d10, and the width of the groove 222-7 is recorded as d11. The width d10 of the groove 222-8 can also be 1 / 2 of the width D11 of the long strip 221-1. In addition, the width d11 of the groove 222-7 can be 1 / 5 of the width D21 of the long strip 221-4. In addition, the values ​​of the widths d10 and d11 can be the same or different. The embodiment of the present application is not limited to this.

[0045] Figure 2 is a top view of another embodiment of the acoustic wave resonator of the embodiment of the present application, Figure 3 4 is a top view of another embodiment of the acoustic wave resonator of the present application.

[0046] In the embodiment of the present application, the shape of the long strip portion is a long strip. Figure 1 As shown, the long strip portions 221-1 to 221-4 are "L" shaped. Figure 3 As shown, the long strip portions 221-1 and 221-2 are "L" shaped, and the ratio of the long side to the short side of the "L" shape is, for example, greater than 1. Figure 2As shown, the long strip portions 221 - 1 to 221 - 4 are arc-shaped strips, which is not limited in the present embodiment.

[0047] In addition, the shape of the groove portion of the embodiment of the present application corresponds to the shape of the elongated portion, for example, Figure 1 As shown, the grooves 222-1 to 222-8 are rectangular. Figure 3 As shown, the grooves 222-1 to 222-4 are rectangular. Figure 2 As shown, the grooves 222-1 to 222-8 are arc-shaped. In addition, the grooves may be connected or not connected. In addition, for example, Figure 1 As shown, the grooves 222-1 and 222-2, the grooves 222-3 and 222-4, the grooves 222-5 and 222-6, and the grooves 222-7 and 222-8 may be directly connected; for example, Figure 2 As shown, the grooves 222-1 and 222-2, the grooves 222-3 and 222-4, the grooves 222-5 and 222-6, and the grooves 222-7 and 222-8 can be connected through the connecting parts 223-1 to 223-4, respectively; for example, Figure 3 As shown, the grooves 222-1 and 222-2, and the grooves 222-3 and 222-4 can be connected through the connecting parts 223-1 and 223-2, respectively. This embodiment of the present application is not limited to this.

[0048] In at least one embodiment, the number of the elongated strips may be at least one, and the number of the grooves may be at least two. Figure 1 and Figure 2 As shown, the number of the long strip portions 221 is 4, and the number of the groove portions 222 is 8; Figure 3 As shown, the number of the long strip portions is 2 and the number of the groove portions is 4. However, the embodiment of the present application is not limited thereto, and the buffer substrate 1 may also include other numbers of long strip portions and groove portions, and the specific number may be set according to actual needs, and the embodiment of the present application is not limited thereto. Optionally, the number of the long strip portions may be an even number and symmetrical about the center of the acoustic wave resonance portion 10, thereby evenly suppressing the stress from being transmitted to the acoustic wave resonance portion.

[0049] In at least one embodiment, the elongated portion extends along the periphery of the central substrate. Figure 1 and Figure 3 As shown, the central substrate 210 is rectangular, and the long strip portion 221 extends along the outline of the rectangle at the periphery of the central substrate 210, that is, extends in a straight line; for example, Figure 2As shown, the central substrate 210 is circular, and the long strip portion 221 extends along the circular contour at the periphery of the central substrate 210, that is, extends in an arc shape. However, the embodiment of the present application is not limited thereto, and the contour of the central substrate 210 can also be other shapes, and the long strip portion 221 can extend along the contour of the central substrate 210 at the periphery thereof.

[0050] In at least one embodiment, the groove portion includes a first groove portion located between the elongated portion and the central substrate and a second groove portion located between the elongated portion and the peripheral substrate. Figure 1 and Figure 2 As shown, the grooves 222-2, 222-4, 222-6 and 222-8 are respectively located between the long strips 221-1, 221-2, 221-3, 221-4 and the central substrate 210, and the grooves 222-1, 222-3, 222-5, 222-7 are respectively located between the long strips 221-1, 221-2, 221-3, 221-4 and the peripheral substrate 230. For the convenience of description below, the grooves 222-2, 222-4, 222-6, 222-8 are sometimes referred to as "first grooves S1", and the grooves 222-1, 222-3, 222-5 and 222-7 are sometimes referred to as "second grooves S2". For another example, Figure 3 As shown, the grooves 222-2 and 222-4 are respectively located between the long strip portions 221-1 and 221-2 and the central substrate 210. Similarly, the grooves 222-2 and 222-4 are sometimes referred to as "first grooves S1". The grooves 222-1 and 222-3 are respectively located between the long strip portions 221-1 and 221-2 and the peripheral substrate 230. The grooves 222-1 and 222-3 are sometimes referred to as "second grooves S2".

[0051] Figure 4 yes Figure 1 A cross-sectional view of the acoustic wave resonator along the AA direction is shown. Figure 5 is a cross-sectional view of another embodiment of the acoustic wave resonator of the present application embodiment, Figure 6 It is a cross-sectional view of another implementation of the acoustic wave resonator of the embodiment of the present application.

[0052] In at least one embodiment, the trench portion may be a groove penetrating the substrate, for example Figure 4 As shown, the depth h of the groove portion may be equal to the thickness H of the substrate. For example, the first groove portion S1 and the second groove portion S2 are grooves penetrating the substrate 20. Thus, the groove portion can be formed conveniently.

[0053] In at least one embodiment, the trench portion may also be a groove having a bottom, that is, the trench portion does not penetrate the substrate, for example, Figure 5 and Figure 6As shown, the depth h of the groove is less than the thickness H of the substrate. For example, the first groove S1 and the second groove S2 do not penetrate the substrate 20, that is, the first groove S1 and the second groove S2 are grooves with a bottom. Thus, the strength of the substrate 20 can be maintained while achieving stress buffering. In addition, the orientation of the opening can be selected according to different process requirements, for example, Figure 5 As shown, the opening of the groove may be toward the side of the substrate 20 where the acoustic wave resonator 10 is disposed; or Figure 6 As shown, the opening of the groove may also be oriented toward the other side of the substrate 20 opposite to the side where the acoustic wave resonator 10 is provided, and the embodiment of the present application does not limit the direction of the opening. In addition, the embodiment of the present application does not limit the depth of the groove portion, and it can be set according to actual needs. For example, the depth h of the groove portion may range from 50 microns to 500 microns, or the depth h of the groove portion may range from 10% to 100% of the thickness H of the substrate.

[0054] In addition, the first groove portion S1 and the second groove portion S2 may include both groove portions that penetrate the substrate 20 and groove portions that do not penetrate the substrate 20; in addition, the structure of the first groove portion S1 and the structure of the second groove portion S2 may be the same or different, and the structures of the first groove portion S1 and the second groove portion S2 may be set according to actual needs, and the embodiments of the present application do not limit this.

[0055] In at least one embodiment, the buffer substrate may further include a third groove formed in the long strip portion, and the third groove extends along the length direction of the long strip portion. Thus, the flexibility and elasticity of the long strip portion are further increased by the third groove, thereby further suppressing the conduction of stress and further reducing the drift of the resonance frequency of the acoustic wave resonance portion caused by stress.

[0056] Figure 7 is a top view of another embodiment of the acoustic wave resonator of the embodiment of the present application, Figure 8 4 is a top view of another embodiment of the acoustic wave resonator of the present application.

[0057] In some embodiments, the third groove narrows the width of the elongated portion to increase the flexibility and elasticity of the elongated portion. Figure 7 As shown, the third grooves S3-1 to S3-4 are formed on the long strips 221-1 to 221-4, respectively, and the third grooves S3-1 to S3-4 extend along the length direction of the long strips 221-1 to 221-4, respectively. In addition, both ends of the third grooves S3-1 to S3-4 are not connected to other grooves. Therefore, by forming the third grooves S3-1 to S3-4 in the middle part of the long strips 221-1 to 221-4, the long strips 221-1 to 221-4 are made thinner, and the flexibility and elasticity of the long strips 221-1 to 221-4 are increased.

[0058] In some embodiments, the third groove portion increases the length of the strip-shaped portion to increase the flexibility and elasticity of the strip-shaped portion. For example, as Figure 8 shown, third groove portions S3-1 to S3-4 are respectively formed on strip-shaped portions 221-1 to 221-4. The third groove portions S3-1 to S3-4 respectively extend along the length direction of the strip-shaped portions 221-1 to 221-4. In addition, one ends of the third groove portions S3-1 to S3-4 are respectively communicated with the first groove portion. Taking the strip-shaped portion 221-1 as an example, the first groove portion S1-1, the second groove portion S2-1, and the connecting portion 223-1 are formed into a "冂"-shaped opening structure. The third groove portion S3-1 extends along the length direction of the strip-shaped portion 221-1, and one end of the third groove portion S3-1 near the opening of the above opening structure is communicated with another first groove portion S1-2. Thus, the strip-shaped portion 221-1 is divided into two parts near the central substrate 210 and near the peripheral substrate 230 by the third groove portion S3-1, and these two parts are communicated on the side opposite to the opening of the opening structure, that is, as Figure 8 shown, the strip-shaped portion 221-1 is composed of a bent portion 221-11, a bent portion 221-12, a bent portion 221-13, a bent portion 221-14, and a bent portion 221-15 connected in sequence. Among them, from the bent portion 221-11 through the bent portions 221-12 to 221-14 to the bent portion 221-15 is the extending direction of the strip-shaped portion 221-1. Thus, the third groove portion S3-1 doubles the length of the strip-shaped portion 221-1, thereby increasing the flexibility and elasticity of the strip-shaped portion 221-1.

[0059] In some embodiments, the third groove portion may be a groove penetrating the substrate, or the third groove portion may also be a groove having a bottom. For example, Figure 8 one or more of the third groove portions S3-1 to S3-4 shown may penetrate the substrate 20, for example, forming a groove having the same structure as the first groove portion S1 and the second groove portion S2 shown in Figure 4 ; or, Figure 8 one or more of the third groove portions S3-1 to S3-4 shown may not penetrate the substrate 20, for example, forming a groove having the same structure as the first groove portion S1 and the second groove portion S2 shown in Figure 6 . In addition, the third groove portion may include both a groove portion penetrating the substrate 20 and a groove portion not penetrating the substrate 20, which can be set according to actual needs, and the embodiments of the present application do not limit this.

[0060] Fig. 9 is a top view of another embodiment of the acoustic wave resonator according to the embodiment of the present application.

[0061] In at least one embodiment, the acoustic wave resonator 1 further includes an electrode portion 30 connected to the acoustic wave resonator portion 10, and the electrode portion 30 may extend from the central substrate 210 along the long strip portion 221 to the peripheral substrate 230, thereby forming an electrical connection portion electrically connected to other devices or elements on the peripheral substrate 230. For example, Fig. 9 As shown, the electrode portion 30 may include a first electrode 310 and a second electrode 320. The first electrode 310 includes a main body portion 311 located on the central substrate 210, an extension portion 312 extending along the long strip portion 221-1, and an electrical connection portion 313 connected to the end of the extension portion 312. The electrical connection portion 313 is located, for example, at Fig. 9 In the upper right corner of the peripheral substrate 230 shown in FIG. 1 , the second electrode 320 includes a main body portion 321 located on the central substrate 210, an extension portion 322 extending along the long strip portion 221 - 3 and an electrical connection portion 323 connected to the end of the extension portion 322. The electrical connection portion 323 is located at Fig. 9 The lower left corner of the peripheral substrate 230 is shown. In addition, the extension portion 312 of the first electrode 310 and the extension portion 322 of the second electrode 320 may also extend along the long strip portion 221-2 and the long strip portion 221-4, respectively.

[0062] In addition, the above description is made by taking the example that the electrode part 30 includes the first electrode 310 and the second electrode 320 , but the embodiments of the present application are not limited thereto, and a corresponding number of electrodes and their structures can be provided according to actual needs.

[0063] In addition, the above description uses the example that each electrode includes one extension portion, but the embodiments of the present application are not limited to this. Each electrode may also include multiple extension portions. In this case, the multiple extension portions may extend to the surrounding substrate along different long strip portions, and the multiple extension portions may also extend to the surrounding substrate along the same long strip portion. The embodiments of the present application are not limited to this.

[0064] In at least one embodiment, the acoustic wave resonator 1 may be a thin film bulk acoustic wave resonator, a surface acoustic wave resonator, a transverse vibration acoustic wave resonator, etc., which is not limited in the embodiments of the present application.

[0065] In at least one embodiment, the acoustic wave resonator 1 is, for example, a thin film bulk acoustic wave resonator, for example Figure 4 and Figure 5 As shown, the acoustic wave resonator 10 includes, for example, an acoustic impedance layer 110 and a piezoelectric film layer 120, which are stacked on a substrate 20, and the electrode 30 includes, for example, a first electrode 310 and a second electrode 320, the first electrode 310 may also be referred to as a "bottom electrode", which is located on the side of the piezoelectric film layer 120 close to the acoustic impedance layer 110, and the second electrode 320 may also be referred to as a "top electrode", which is located on the side of the piezoelectric film layer 120 away from the acoustic impedance layer 110.

[0066] Fig.10 It is a cross-sectional view of another implementation of the acoustic wave resonator of the embodiment of the present application.

[0067] In at least one embodiment, the acoustic impedance layer 110 may be a cavity, for example, Figure 4 As shown, the acoustic impedance layer 110 is a cavity formed by a groove formed in the central substrate 210 and the first electrode 310; the acoustic impedance layer 110 can also be a Bragg reflection layer, for example, Fig.10 As shown, the acoustic wave resonator 1 can be a solid-assembly type thin film bulk acoustic wave resonator, and the acoustic impedance layer 110 is, for example, a Bragg reflection layer composed of multiple thin film layers with large acoustic impedance differences. In addition, the acoustic impedance layer 110 can also be other acoustic reflection structures whose equivalent acoustic impedance characteristics are close to or similar to the acoustic impedance characteristics of the cavity or the acoustic impedance characteristics of the Bragg reflection layer. The embodiment of the present application does not limit the selection of which acoustic reflection structure is used as the acoustic impedance layer, and can be designed according to actual needs. For example, when the Q value of the resonator is required to be high, the cavity can be selected as the acoustic impedance layer; when the heat dissipation performance or power of the resonator is required to be high, the Bragg reflection layer can be selected as the acoustic impedance layer.

[0068] In at least one embodiment, the piezoelectric film layer 120 can be formed of a single crystal piezoelectric material, for example, a material having a large piezoelectric coupling coefficient corresponding to transverse electric field excitation is selected, for example, a single crystal piezoelectric material such as lithium niobate or lithium tantalate is selected. The embodiment of the present application can make lithium niobate or lithium tantalate have large d11, d15, and d16 piezoelectric coupling coefficients by selecting a suitable cut type and an angle between the in-plane interdigitated electrode and the crystal axis, thereby respectively enabling the acoustic wave resonator to excite a zero-order symmetric Lamb Wave mode, referred to as the S0 mode, a first-order antisymmetric Lamb Wave mode, referred to as the A1 mode, a zero-order horizontal shear mode, referred to as the SH0 mode, and high-order or low-order modes of the above modes. The embodiment of the present application does not limit the material forming the piezoelectric film layer 120, and can be selected according to actual needs or performance requirements.

[0069] It can be seen from the embodiments of the first aspect of the present application that the stress transmitted from the peripheral substrate is absorbed by the long strip buffer substrate to suppress the stress from being transmitted to the central substrate provided with the acoustic wave resonance part, thereby reducing the drift of the resonance frequency of the acoustic wave resonance part caused by the stress.

[0070] Embodiments of the second aspect

[0071] An embodiment of the second aspect of the present application provides an electronic device, which includes the acoustic wave resonator described in the embodiment of the first aspect. Since the structure and characteristics of the acoustic wave resonator have been described in detail in the embodiment of the first aspect, the content is incorporated herein and the description is omitted here.

[0072] The electronic device of the embodiment of the present application is, for example, an oscillator, a frequency source, a filter, etc., which is not limited in the embodiment of the present application. In addition, the embodiment of the present application does not limit the application scenario of the electronic device, and specific reference may be made to related technologies.

[0073] In addition, the electronic device of the embodiment of the present application may also include other electronic components as needed, for example, it may also include capacitors, inductors, resistors, etc. The selection of these electronic components can refer to relevant technologies, and the embodiment of the present application does not limit this.

[0074] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An acoustic wave resonator, comprising an acoustic wave resonator and a substrate on which the acoustic wave resonator is disposed, characterized in that: The substrate includes a central substrate on which the acoustic wave resonance portion is disposed, a peripheral substrate located at the periphery of the central substrate, and a buffer substrate connecting the central substrate and the peripheral substrate; The buffer substrate comprises: A strip-shaped portion, one end of which is connected to the central substrate, and the other end of which is connected to the peripheral substrate; as well as The grooves are located on both sides of the elongated portion in the width direction.

2. The acoustic wave resonator according to claim 1, characterized in that The long strip portion extends along the outer circumference of the central substrate.

3. The acoustic wave resonator according to claim 2, characterized in that The groove portion includes a first groove portion located between the long strip portion and the central substrate and a second groove portion located between the long strip portion and the peripheral substrate.

4. The acoustic wave resonator according to claim 1, characterized in that The groove portion is a groove penetrating the substrate.

5. The acoustic wave resonator according to claim 1, characterized in that The groove portion is a groove having a bottom.

6. The acoustic wave resonator according to claim 5, characterized in that The opening of the groove faces the side of the substrate where the acoustic wave resonance part is provided; or, The opening of the groove faces the other side of the substrate opposite to the side where the acoustic wave resonator is provided.

7. The acoustic wave resonator according to claim 3, characterized in that The buffer substrate further includes a third groove portion formed in the long strip portion, and the third groove portion extends along a length direction of the long strip portion.

8. The acoustic wave resonator according to claim 7, characterized in that The third groove portion is a groove penetrating the substrate, or the third groove portion is a groove having a bottom.

9. The acoustic wave resonator according to claim 1, characterized in that The acoustic wave resonator further includes an electrode portion connected to the acoustic wave resonator portion, wherein the electrode portion extends from the central substrate along the long strip portion to the peripheral substrate.

10. The acoustic wave resonator according to claim 9, characterized in that The acoustic wave resonator is a thin film bulk acoustic wave resonator, The acoustic wave resonance portion includes an acoustic impedance layer formed on the substrate and a piezoelectric film layer located on a surface of the acoustic impedance layer. The electrode portion includes a bottom electrode located on a side of the piezoelectric film layer close to the acoustic impedance layer and a top electrode located on a side of the piezoelectric film layer far from the acoustic impedance layer.

11. The acoustic wave resonator according to any one of claims 1 to 10, characterized in that: The projection of the buffer substrate on the surface of the substrate is a centrally symmetrical figure centered on the geometric center of the projection of the central substrate on the surface of the substrate.

12. The acoustic wave resonator according to any one of claims 1 to 10, characterized in that: The width of the groove portion ranges from 5 micrometers to 50 micrometers.

13. The acoustic wave resonator according to any one of claims 1 to 10, characterized in that: The ratio of the depth of the groove to the thickness of the substrate is in a range of 10% to 100%.

14. The acoustic wave resonator according to any one of claims 1 to 10, characterized in that: The width of the long strip portion is 2 to 40 times the width of the groove portion.

15. The acoustic wave resonator according to any one of claims 1 to 10, characterized in that: The length of the long strip portion is 10 to 100 times the width of the long strip portion.

16. An electronic device, characterized in that: The electronic device comprises the acoustic wave resonator according to any one of claims 1 to 15.

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