Acoustic resonator

Abstract

An acoustic resonator, relating to the technical field of resonators. The acoustic resonator comprises: a substrate (1), a piezoelectric layer (2), and a plurality of metal electrodes (3). The piezoelectric layer (2) is arranged on the surface of one side of the substrate (1); the plurality of metal electrodes (3) are arranged on the surface of the piezoelectric layer (2); the ratio of the center distance of every two adjacent metal electrodes (3) to the thickness of the piezoelectric layer (2) is smaller than or equal to 1; and in a preset tangential direction, the piezoelectric layer (2) reaches a coupling mode in which at least two piezoelectric coefficients jointly act, wherein the piezoelectric coefficients comprise at least one non-zero shear piezoelectric coefficient. Therefore, the electric field distribution is changed by designing the ratio of the center distance of every two adjacent metal electrodes (3) to the thickness of the piezoelectric layer (2), that is, the ratio of the center distance of every two adjacent metal electrodes (3) to the thickness of the piezoelectric layer (2) is smaller than or equal to 1, so that the performance of the acoustic resonator is improved.

Description

An acoustic wave resonator

[0001] The present invention claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on June 28, 2023, with application number 202310780324.0 and invention name “A Sound Wave Resonator”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of resonators, and in particular to an acoustic wave resonator. Background Art

[0003] 5G wireless communications are currently booming, placing extremely high demands on RF front-end signal processing capabilities. For example, enhanced mobile broadband (eMBB) aims to increase mobile data volumes by 1,000 times, requiring ultra-large bandwidth at high center frequencies. 3GPP deployments in 5G frequency bands also aim to provide a large available bandwidth for front-end design. In the future, with the advent of 6G and 7G systems, high frequencies and large bandwidths will pose even greater challenges. As a critical component of the RF front-end, RF filters are expected to provide greater bandwidth as they move toward higher frequencies, thereby enhancing the signal processing capabilities of the entire system.

[0004] At present, acoustic wave filters have become one of the most popular components in RF filters due to their advantages of small size, high frequency, low insertion loss, and large bandwidth. However, as the frequency continues to increase, the system's requirements for large bandwidth are also getting higher and higher. For example, the relative bandwidth (FBW) required by the 5GNR band exceeds 24% (n77 band, 3.3GHz-4.2GHz), which requires the electromechanical coupling coefficient (k 2 ) reaches 50%. The relative bandwidth of acoustic wave filters based on traditional surface acoustic waves (SAW) or film bulk acoustic resonators (FBAR) cannot achieve a significant breakthrough, resulting in obvious fatigue in the large bandwidth indicator of acoustic wave filters.

[0005] In summary, how to improve the performance of acoustic wave resonators is an urgent problem that those skilled in the art need to solve.

[0006] Summary of the Invention

[0007] In view of this, the present application provides an acoustic wave resonator, aiming to improve the performance of the acoustic wave resonator.

[0008] The present application provides an acoustic wave resonator, comprising:

[0009] a substrate, a piezoelectric layer, and a plurality of metal electrodes;

[0010] The piezoelectric layer is provided on one side surface of the substrate;

[0011] The plurality of metal electrodes are arranged on the surface of the piezoelectric layer;

[0012] The ratio of the distance between the centers of two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1;

[0013] The piezoelectric layer achieves a coupled mode under a preset tangential direction in which at least two piezoelectric coefficients act together, and the piezoelectric coefficients include at least one non-zero shear piezoelectric coefficient.

[0014] Optionally, the piezoelectric layer is provided on one side surface of the substrate, including:

[0015] The surface of the piezoelectric layer facing the substrate is fixed and tightly connected to the substrate, or the surface of the piezoelectric layer facing the substrate is free and a cavity exists between the piezoelectric layer and the substrate.

[0016] Optionally, the substrate is a silicon substrate, or a sapphire substrate, or a gallium nitride substrate, or a silicon carbide substrate.

[0017] Optionally, the material of the metal electrode is gold, silver, copper, aluminum, molybdenum, chromium, nickel, platinum, titanium gold, titanium aluminum, chromium gold, or chromium aluminum.

[0018] Optionally, the number of the metal electrodes is 2-500.

[0019] Optionally, the thickness of the metal electrode is 5-500 nm.

[0020] Optionally, the width of the metal electrode is 0.001-5 μm.

[0021] Optionally, the length of the metal electrode is 1-500 μm.

[0022] Optionally, the piezoelectric layer is a lithium niobate layer, or a lithium tantalate layer, or a composite layer consisting of at least two layers of a lithium niobate layer, an aluminum nitride layer, a scandium-doped aluminum nitride layer, a lithium tantalate layer, and a zinc oxide layer.

[0023] Optionally, the piezoelectric layer has a thickness of 10-5000 nm.

[0024] The present application provides an acoustic wave resonator. The acoustic wave resonator includes: a substrate, a piezoelectric layer, and a plurality of metal electrodes. The piezoelectric layer is arranged on one side surface of the substrate, and the plurality of metal electrodes are arranged on the surface of the piezoelectric layer. The ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1. The piezoelectric layer reaches a coupled mode under a preset tangential direction in which at least two piezoelectric coefficients act together, wherein the piezoelectric coefficients include at least one non-zero shear piezoelectric coefficient. In this way, by designing the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer, the electric field distribution is changed, that is, the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1, thereby improving the performance of the acoustic wave resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the following briefly introduces the drawings required for use in the embodiment or the prior art description. 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 creative work.

[0026] FIG1a is a cross-sectional view of an acoustic wave resonator provided in an embodiment of the present application;

[0027] FIG1b is a cross-sectional view of another acoustic wave resonator provided in an embodiment of the present application;

[0028] FIG2 is a cross-sectional view of an acoustic wave resonator provided by an embodiment of the present application, in which the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1;

[0029] FIG3 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided in an embodiment of the present application. 11 , d 34 and d 35 Sectional vibration diagram of the coupled modes acting together;

[0030] FIG4 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided in an embodiment of the present application. 11 , d 34 and d 35 Top-down vibration diagram of the coupled modes acting together;

[0031] FIG5 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided in an embodiment of the present application. 11 , d 34 and d 35 Simulation performance diagram of coupled modes acting together;

[0032] FIG6 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided in an embodiment of the present application. 11 , d 16 , d 34 and d 35 Sectional vibration diagram of the coupled modes acting together;

[0033] FIG7 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided in an embodiment of the present application. 11 , d 16 , d 34 and d 35 Top-down vibration diagram of the coupled modes acting together;

[0034] FIG8 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided in an embodiment of the present application. 11 , d 16 , d 34 and d 35 The upward vibration diagram of the coupled modes acting together;

[0035] FIG9 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided in an embodiment of the present application. 11 , d 16 , d 34 and d 35 Simulation performance diagram of coupled modes acting together;

[0036] FIG10 is a cross-sectional view of an acoustic wave resonator provided in an embodiment of the present application, in which the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2;

[0037] FIG11 shows the piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, provided in an embodiment of the present application. 11 and d 35 Sectional vibration diagram of the coupled modes acting together;

[0038] FIG12 shows the piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, provided in an embodiment of the present application. 11 and d 35 Top-down vibration diagram of the coupled modes acting together;

[0039] FIG13 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, provided in an embodiment of the present application. 11 and d 35 Simulation performance diagram of coupled modes acting together;

[0040] FIG14 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, provided in an embodiment of the present application. 11 , d 13 , d 16 , d 34 and d 35 Sectional vibration diagram of the coupled modes acting together;

[0041] FIG15 shows the piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, provided in an embodiment of the present application. 11 , d 13 , d 16 , d 34 and d 35 Top-down vibration diagram of the coupled modes acting together;

[0042] FIG16 shows the piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, provided in an embodiment of the present application. 11 , d 13 , d 16 , d 34 and d 35 A plot of the simulation performance of the coupled modes acting together. DETAILED DESCRIPTION

[0043] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of this application. This application provides an acoustic wave resonator for use in the field of resonator technology. The above is merely an example and does not limit the application areas of the methods and devices provided in this application.

[0044] 5G wireless communications are currently booming, placing extremely high demands on RF front-end signal processing capabilities. For example, enhanced mobile broadband (eMBB) aims to increase mobile data volumes by 1,000 times, requiring ultra-large bandwidth at high center frequencies. 3GPP deployments in 5G frequency bands also aim to provide a large available bandwidth for front-end design. In the future, with the advent of 6G and 7G systems, high frequencies and large bandwidths will pose even greater challenges. As a critical component of the RF front-end, RF filters are expected to provide greater bandwidth as they move toward higher frequencies, thereby enhancing the signal processing capabilities of the entire system.

[0045] At present, acoustic wave filters have become one of the most popular components in RF filters due to their advantages of small size, high frequency, low insertion loss, and large bandwidth. However, as the frequency continues to increase, the system's requirements for large bandwidth are also getting higher and higher. For example, the relative bandwidth (FBW) required by the 5GNR band exceeds 24% (n77 band, 3.3GHz-4.2GHz), which requires the electromechanical coupling coefficient (k 2 ) reaches 50%. The relative bandwidth of acoustic wave filters based on traditional surface acoustic waves (SAW) or film bulk acoustic resonators (FBAR) cannot achieve a significant breakthrough, resulting in obvious fatigue in the large bandwidth indicator of acoustic wave filters.

[0046] After research, the inventors proposed the technical solution of this application. The acoustic wave resonator includes: a substrate, a piezoelectric layer, and a plurality of metal electrodes. The piezoelectric layer is arranged on one side surface of the substrate, and a plurality of metal electrodes are arranged on the surface of the piezoelectric layer. The ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1. Under a preset tangent direction, the piezoelectric layer achieves a coupled mode in which at least two piezoelectric coefficients act together, wherein the piezoelectric coefficients include at least one non-zero shear piezoelectric coefficient. In this way, by designing the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer, the electric field distribution is changed, that is, the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1, thereby improving the performance of the acoustic wave resonator.

[0047] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present application. It should be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0048] Referring to FIG. 1 a , FIG. 1 a is a cross-sectional view of an acoustic wave resonator provided in an embodiment of the present application, comprising:

[0049] A substrate 1, a piezoelectric layer 2 and a plurality of metal electrodes 3.

[0050] The substrate 1 may be a silicon substrate, a sapphire substrate (Al2O3), a gallium nitride substrate (GaN), or a silicon carbide substrate (SiC).

[0051] The piezoelectric layer 2 is provided on one side surface of the substrate 1;

[0052] The piezoelectric layer 2 is a lithium niobate layer, a lithium tantalate layer, or a composite layer consisting of at least two of a lithium niobate layer, an aluminum nitride layer, a scandium-doped aluminum nitride layer, a lithium tantalate layer, and a zinc oxide layer. The thickness of the piezoelectric layer 2 is 10-5000 nm.

[0053] A plurality of metal electrodes 3 are arranged on the surface of the piezoelectric layer 2. The material of the metal electrodes 3 is gold, silver, copper, aluminum, molybdenum, chromium, nickel, platinum, titanium gold, titanium aluminum, chromium gold, or chromium aluminum.

[0054] The number of the metal electrodes 3 is 2-500, such as 10 or 20. The specific number of the metal electrodes 3 depends on the specific situation.

[0055] The thickness of the metal electrode 3 is 5-500 nm;

[0056] The width of the metal electrode 3 is 0.001-5 μm;

[0057] The length of the metal electrode 3 is 1-500 μm.

[0058] The ratio of the center distance between two adjacent metal electrodes 3 to the thickness of the piezoelectric layer 2 is less than or equal to 1. Under a preset tangential direction, the piezoelectric layer 2 reaches a coupled mode in which at least two piezoelectric coefficients act together, and the piezoelectric coefficients include at least one non-zero shear piezoelectric coefficient.

[0059] By changing the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer, that is, the ratio of the transverse wavelength to the longitudinal wavelength, the electric field distribution can be changed. When the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1, the coupled mode of the piezoelectric layer under a specific tangent direction, which is caused by the combined action of at least two piezoelectric coefficients, can be fully excited. The piezoelectric coefficient of the piezoelectric layer (d xy ), relative dielectric constant (ε xx ) and elastic modulus (c yy ) determines the electromechanical coupling coefficient (k 2 ), different piezoelectric coefficients often excite different vibration modes, such as d 11 Will produce S0 mode, d 16 Will produce SH0 mode, d 15 This will generate the A1 mode, etc. When multiple piezoelectric coefficients work together, will they significantly improve the energy coupling of the acoustic wave resonator? When the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1, multiple piezoelectric coefficients can be freely combined to stimulate multiple coupled modes, thereby improving the performance of the acoustic wave resonator.

[0060] Among them, the piezoelectric coefficient (d xy ), where x represents the direction of the electric field and y represents the vibration direction. When y is 4, 5 or 6, the piezoelectric coefficient is the shear piezoelectric coefficient.

[0061] Referring to FIG1b , FIG1b is a cross-sectional view of another acoustic wave resonator provided in an embodiment of the present application, comprising:

[0062] A substrate 1, a piezoelectric layer 2 and a plurality of metal electrodes 3.

[0063] The substrate 1 may be a silicon substrate, a sapphire substrate (Al2O3), a gallium nitride substrate (GaN), or a silicon carbide substrate (SiC).

[0064] The surface of the piezoelectric layer 2 facing the substrate 1 is fixed and tightly connected to the substrate 1, or the surface of the piezoelectric layer 2 facing the substrate 1 is free, and a cavity 4 exists between the piezoelectric layer 2 and the substrate. The piezoelectric layer 2 is a lithium niobate layer, a lithium tantalate layer, or a composite layer composed of at least two of a lithium niobate layer, an aluminum nitride layer, a scandium-doped aluminum nitride layer, a lithium tantalate layer, and a zinc oxide layer. The thickness of the piezoelectric layer 2 is 10-5000 nm.

[0065] A plurality of metal electrodes 3 are arranged on the surface of the piezoelectric layer 2. The material of the metal electrodes 3 is gold, silver, copper, aluminum, molybdenum, chromium, nickel, platinum, titanium gold, titanium aluminum, chromium gold, or chromium aluminum.

[0066] The number of the metal electrodes 3 is 2-500, such as 10 or 20. The specific number of the metal electrodes 3 depends on the specific situation.

[0067] The thickness of the metal electrode 3 is 5-500 nm;

[0068] The width of the metal electrode 3 is 0.001-5 μm;

[0069] The length of the metal electrode 3 is 1-500 μm.

[0070] The ratio of the center-to-center distance between two adjacent metal electrodes 3 to the thickness of the piezoelectric layer 2 is less than or equal to 1, and the piezoelectric layer 2, under a predetermined tangential direction, achieves a coupled mode in which at least two piezoelectric coefficients act together, wherein the piezoelectric coefficients include at least one non-zero shear piezoelectric coefficient. As shown in Figure 2, Figure 2 is a cross-sectional view of an acoustic wave resonator provided in an embodiment of the present application, in which the ratio of the center-to-center distance between two adjacent metal electrodes 3 to the thickness of the piezoelectric layer is equal to 1, and the ratio of the center-to-center distance p between two adjacent metal electrodes 3 to the thickness h of the piezoelectric layer 2 is 1.

[0071] As shown in FIG3 , FIG3 is a diagram of an embodiment of the present application providing a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1. 11 , d 34 and d 35 Sectional vibration diagram of the coupled modes acting together. Piezoelectric coefficient d 11 , d 34 and d 35The coupled modes acting together are shear-stretch vibrations on the upper surface away from the center of the two metal electrodes 3, and shear-contraction vibrations on the lower surface toward the center of the two metal electrodes 3. As shown in FIG4 , FIG4 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided by an embodiment of the present application. 11 , d 34 and d 35 Top view vibration diagram of the coupled modes acting together. Piezoelectric coefficient d 11 , d 34 and d 35 The coupled modes acting together are seen from the top view, and the surface is the stretching / contraction vibration in the width direction of the metal electrode 3. The overall stretching / contraction in the width direction of the metal electrode 3 is dominant. As shown in FIG5 , FIG5 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided by an embodiment of the present application. 11 , d 34 and d 35 Simulation performance diagram of the coupled modes, piezoelectric coefficient d 11 , d 34 and d 35 The frequency of the coupled mode acoustic resonator acting together is greater than 5 GHz, and the electromechanical coupling coefficient is higher than 10%.

[0072] As shown in FIG6 , FIG6 is a diagram of an embodiment of the present application, wherein the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, and the piezoelectric coefficient d is 11 , d 16 , d 34 and d 35 Sectional vibration diagram of the coupled modes acting together. Piezoelectric coefficient d 11 , d 16 , d 34 and d 35 The coupled modes acting together are in the direction of the cross section, and both the upper and lower surfaces are shear contraction vibrations toward the center of the two metal electrodes 3. As shown in Figures 7 and 8, Figure 7 shows an embodiment of the present application, provided that the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, and the piezoelectric coefficient d 11 , d 16 , d 34 and d 35 FIG8 is a top view of the vibration diagram of the coupled mode of the co-action, and FIG8 is a diagram of the piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 provided in an embodiment of the present application. 11 , d 16 , d 34 and d 35 The upward vibration diagram of the coupled modes, the piezoelectric coefficient d 11 , d 16, d 34 and d 35 The coupled modes acting together are shear-stretch vibrations in the width and length directions of the metal electrode 3 on both the upper and lower surfaces when viewed from above and below, but in opposite directions. As shown in FIG9 , FIG9 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1, provided by an embodiment of the present application. 11 , d 16 , d 34 and d 35 Simulation performance diagram of the coupled modes, piezoelectric coefficient d 11 , d 16 , d 34 and d 35 The frequency of the coupled mode acoustic resonator acting together is greater than 5 GHz, and the electromechanical coupling coefficient is higher than 15%.

[0073] As shown in Figure 10, Figure 10 is a cross-sectional view of an acoustic wave resonator provided in an embodiment of the present application, in which the ratio of the center distance p between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, and the ratio of the center distance p between two adjacent metal electrodes 3 to the thickness h of the piezoelectric layer 2 is equal to 1 / 2.

[0074] As shown in FIG11 , FIG11 is a diagram of a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2 provided in an embodiment of the present application. 11 and d 35 Sectional vibration diagram of the coupled modes, piezoelectric coefficient d 11 and d 35 The coupled modes acting together are shear-stretch vibrations on the upper surface away from the center of the two metal electrodes 3, and shear-contraction vibrations on the lower surface toward the center of the two metal electrodes 3. As shown in FIG12 , FIG12 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is 1 / 2, provided by an embodiment of the present application. 11 and d 35 Top view vibration diagram of the coupled modes, piezoelectric coefficient d 11 and d 35 The coupled modes acting together are viewed from the top, and the surface is the stretching / contraction vibration in the width direction of the metal electrode 3, with shear vibration being dominant. As shown in FIG13 , FIG13 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2 provided by an embodiment of the present application. 11 and d 35 Simulation performance diagram of the coupled modes, piezoelectric coefficient d 11 and d 35 The frequency of the coupled mode acoustic resonator acting together is greater than 5 GHz, and the electromechanical coupling coefficient is higher than 10%.

[0075] As shown in FIG14 , FIG14 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2 provided in an embodiment of the present application. 11 , d 13 , d 16 , d 34 and d 35 Sectional vibration diagram of the coupled modes, piezoelectric coefficient d 11 , d 13 , d 16 , d 34 and d 35 The coupled mode of the interaction is viewed in the direction of the cross section, and the upper surface is a shear contraction vibration toward the center of the two metal electrodes 3. As shown in FIG15 , FIG15 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2 provided by an embodiment of the present application. 11 , d 13 , d 16 , d 34 and d 35 Top view vibration diagram of the coupled modes, piezoelectric coefficient d 11 , d 13 , d 16 , d 34 and d 35 The coupled modes acting together are shear-stretch vibrations in the width and length directions of the metal electrode 3 when viewed from above. As shown in FIG16 , FIG16 shows a piezoelectric coefficient d when the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is equal to 1 / 2, provided in an embodiment of the present application. 11 , d 13 , d 16 , d 34 and d 35 Simulation performance diagram of the coupled modes, piezoelectric coefficient d 11 , d 13 , d 16 , d 34 and d 35 The frequency of the coupled mode acoustic resonator acting together is greater than 5 GHz, and the electromechanical coupling coefficient is higher than 30%.

[0076] From the above description, it can be seen that by designing the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer, that is, the ratio of the transverse wavelength to the longitudinal wavelength, when (1) is less than or equal to 1, the electric field distribution is changed, and the coupled mode caused by the joint action of at least two piezoelectric coefficients is fully excited, wherein the piezoelectric coefficient includes at least one non-zero shear piezoelectric coefficient, thereby realizing an acoustic wave resonator with a frequency greater than 5 GHz and an electromechanical coupling coefficient greater than 30%, which can well meet the performance requirements of high frequency and large bandwidth of filters in the current 5G and 6G frequency bands.

[0077] In the embodiments provided in the present application, an acoustic wave resonator is provided. The acoustic wave resonator includes: a substrate, a piezoelectric layer, and a plurality of metal electrodes. The piezoelectric layer is provided on one side surface of the substrate, and the plurality of metal electrodes are provided on the surface of the piezoelectric layer. The ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1. The piezoelectric layer achieves a coupled mode under a preset tangent direction in which at least two piezoelectric coefficients act together, wherein the piezoelectric coefficients include at least one non-zero shear piezoelectric coefficient. In this way, by designing the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer, the electric field distribution is changed, that is, the ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1, thereby improving the performance of the acoustic wave resonator. In this specification, the various embodiments are described in a progressive, parallel, or progressive and parallel manner. Each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. As for the manufacturing method disclosed in the embodiment, since it corresponds to the acoustic wave resonator disclosed in the embodiment, the description is relatively simple. For relevant parts, please refer to the description of the acoustic wave resonator.

[0078] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that an article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such article or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the article or device comprising the aforementioned elements.

[0079] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An acoustic wave resonator, characterized in that: include: A substrate, a piezoelectric layer, and a plurality of metal electrodes; The piezoelectric layer is disposed on one side surface of the substrate; The plurality of metal electrodes are disposed on the surface of the piezoelectric layer; The ratio of the center distance between two adjacent metal electrodes to the thickness of the piezoelectric layer is less than or equal to 1; The piezoelectric layer reaches a coupled mode under a preset tangent direction in which at least two piezoelectric coefficients act together, and the piezoelectric coefficients include at least one non-zero shear piezoelectric coefficient.

2. The acoustic wave resonator according to claim 1, characterized in that The piezoelectric layer is disposed on one side surface of the substrate, and includes: The surface of the piezoelectric layer facing the substrate is fixed and tightly connected to the substrate, or the surface of the piezoelectric layer facing the substrate is free and a cavity exists between the piezoelectric layer and the substrate.

3. The acoustic wave resonator according to claim 1, characterized in that The substrate is a silicon substrate, or a sapphire substrate, or a gallium nitride substrate, or a silicon carbide substrate.

4. The acoustic wave resonator according to claim 1, characterized in that The material of the metal electrode is gold, silver, copper, aluminum, molybdenum, chromium, nickel, platinum, titanium-gold, titanium-aluminum, chromium-gold, or chromium-aluminum.

5. The acoustic wave resonator according to claim 1, characterized in that The number of the metal electrodes is 2-500.

6. The acoustic wave resonator according to claim 1, characterized in that The thickness of the metal electrode is 5-500nm.

7. The acoustic wave resonator according to claim 1, characterized in that The width of the metal electrode is 0.001-5 μm.

8. The acoustic wave resonator according to claim 1, characterized in that The length of the metal electrode is 1-500 μm.

9. The acoustic wave resonator according to claim 1, characterized in that The piezoelectric layer is a lithium niobate layer, or a lithium tantalate layer, or a composite layer consisting of at least two layers of a lithium niobate layer, an aluminum nitride layer, a scandium-doped aluminum nitride layer, a lithium tantalate layer and a zinc oxide layer.

10. The acoustic wave resonator according to claim 1, characterized in that The thickness of the piezoelectric layer is 10-5000nm.

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