Acoustic resonator, preparation method thereof and electronic equipment

Abstract

The invention discloses an acoustic resonator, a preparation method thereof and electronic equipment, and relates to the field of resonators. A piezoelectric layer disposed on the surface of the substrate; the sound velocity compensation layer is arranged on the surface of one side, away from the substrate, of the piezoelectric layer and is provided with a plurality of grooves which are sequentially arranged along the first direction; the first direction is parallel to the plane of the piezoelectric layer; the interdigital electrode is formed on the surface of one side, away from the substrate, of the piezoelectric layer based on the sound velocity compensation layer with a groove; the interdigital electrode comprises a plurality of finger strips which are arranged in one-to-one correspondence with the grooves; and the finger strips are in electric contact with the piezoelectric layer based on the corresponding grooves. According to the technical scheme of the invention, the size of the interdigital electrode does not need to be reduced while the frequency is improved, the resistance of the interdigital electrode is not increased, the reduction of the quality factor of the acoustic resonator can be avoided, the performance of the acoustic resonator can be effectively improved, and the high-quality acoustic resonator is realized.

Description

Technical Field

[0001] The present application relates to the technical field of resonators, and in particular to an acoustic wave resonator, a preparation method thereof, and an electronic device. Background Art

[0002] Currently, acoustic wave resonators are widely used in the communications industry due to their small size, large bandwidth and high quality factor (Q value). However, with the advancement of communication technology, the frequency band has become increasingly crowded, and it is particularly important to explore higher frequency wireless communication technology. Therefore, the research on higher frequency acoustic wave resonators is particularly critical.

[0003] Taking the interdigital acoustic wave resonator as an example, in practical applications, as the frequency increases, the size of the interdigital electrodes will shrink, which will lead to an increase in electrode resistance. The increase in resistance will significantly reduce the quality factor, resulting in a decrease in the performance of the acoustic wave resonator. Summary of the invention

[0004] In view of the above problems, the present application provides an acoustic wave resonator and a method for preparing the same, and an electronic device, so as to achieve the purpose of improving the performance of the acoustic wave resonator. The specific scheme is as follows:

[0005] In a first aspect, the present application provides an acoustic wave resonator, comprising:

[0006] substrate;

[0007] A piezoelectric layer disposed on a surface of a substrate;

[0008] An acoustic velocity compensation layer is arranged on a surface of the piezoelectric layer facing away from the substrate, and the acoustic velocity compensation layer has a plurality of grooves arranged in sequence along a first direction; the first direction is parallel to the plane where the piezoelectric layer is located;

[0009] The interdigitated electrode is formed on the surface of the piezoelectric layer away from the substrate based on the acoustic velocity compensation layer with grooves; the interdigitated electrode includes a plurality of fingers arranged one by one corresponding to the grooves; the fingers are in electrical contact with the piezoelectric layer based on the corresponding grooves.

[0010] Optionally, in the above acoustic wave resonator, the acoustic velocity of the acoustic velocity compensation layer is not less than the acoustic velocity of the piezoelectric layer and the interdigital electrodes.

[0011] Optionally, in the above-mentioned acoustic wave resonator, the thickness of the acoustic velocity compensation layer is h1, and the material density of the acoustic velocity compensation layer is ρ1;

[0012] The thickness of the interdigital electrode is h2, and the material density of the interdigital electrode is ρ2;

[0013] in, ; Where A is the set constant.

[0014] Optionally, in the above acoustic wave resonator, 2≤A≤10.

[0015] Optionally, in the above acoustic wave resonator, the thickness of the acoustic velocity compensation layer is h1, the thickness of the interdigital electrode is h2,

[0016] in, .

[0017] Optionally, in the above acoustic wave resonator, in the direction from the substrate to the piezoelectric layer, the width of the groove remains unchanged; or, the width of the groove gradually increases.

[0018] Optionally, in the above-mentioned acoustic wave resonator, the thickness of the acoustic velocity compensation layer ranges from 10 nm to 10000 nm;

[0019] The thickness of the finger strips ranges from 10nm to 10000nm;

[0020] The thickness of the piezoelectric layer ranges from 10nm to 10000nm.

[0021] Optionally, in the above acoustic wave resonator, the Young's modulus of the acoustic velocity compensation layer is in the range of 5×10 10 Pa~1×10 12 Pa;

[0022] The density range of the sound velocity compensation layer is 2000kg / m 3 ~6000kg / m 3 .

[0023] A second aspect of the present application provides a method for preparing an acoustic wave resonator, comprising:

[0024] providing a substrate;

[0025] forming a piezoelectric layer on a surface of a substrate;

[0026] A sound velocity compensation layer is formed on a surface of the piezoelectric layer facing away from the substrate, wherein the sound velocity compensation layer has a plurality of grooves arranged in sequence along a first direction; the first direction is parallel to the plane where the piezoelectric layer is located;

[0027] Based on the acoustic velocity compensation layer with grooves, a forked electrode is formed on the surface of the piezoelectric layer away from the substrate. The forked electrode includes a plurality of fingers arranged one by one corresponding to the grooves. The fingers are in electrical contact with the piezoelectric layer based on the corresponding grooves.

[0028] A third aspect of the present application provides a filter, comprising an acoustic wave resonator provided by any of the above methods.

[0029] A fourth aspect of the present application provides an electronic device, comprising an acoustic wave resonator provided by any of the above methods.

[0030] By means of the above technical scheme, in the acoustic wave resonator and its preparation method and electronic device provided by the present application, the acoustic wave resonator is formed with a sound velocity compensation layer on the surface of the piezoelectric layer, and the sound velocity compensation layer has a plurality of grooves arranged in sequence along the first direction. Based on the sound velocity compensation layer with grooves, a forked electrode can be formed on the surface of the piezoelectric layer, and the forked electrode has a plurality of fingers corresponding to the grooves one by one, and each groove can be used to set a forked electrode, and the fingers are in electrical contact with the piezoelectric layer based on the corresponding grooves. Since the forked electrode is prepared based on the sound velocity compensation layer with grooves, the sound velocity compensation layer, the forked electrode and the piezoelectric layer can be constructed into an integral waveguide, so that the forked electrode can more effectively participate in the propagation of the sound wave, and the energy scattering caused by scattering can be reduced. Therefore, the technical scheme of the present application can increase the frequency without reducing the size of the forked electrode, and the resistance of the forked electrode will not increase, which can avoid the reduction of the quality factor of the acoustic wave resonator, and can effectively improve the performance of the acoustic wave resonator, and realize a high-quality acoustic wave resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, 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 embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0032] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0033] Figure 1 A schematic diagram of the structure of an acoustic wave resonator provided in an embodiment of the present application;

[0034] Figure 2 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application;

[0035] Figure 3 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application;

[0036] Figure 4 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application;

[0037] Figure 5A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application;

[0038] Figure 6 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application;

[0039] Figure 7 A top view of an electrode pattern in an acoustic wave resonator provided in an embodiment of the present application;

[0040] Figure 8 A schematic cross-sectional view of an acoustic wave resonator for operating at a frequency of 6.2 GHz provided in an embodiment of the present application;

[0041] Fig. 9 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 6.2 GHz;

[0042] Fig.10 A schematic cross-sectional view of an acoustic wave resonator for operating at a frequency of 4.6 GHz provided in an embodiment of the present application;

[0043] Fig.11 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 4.6 GHz;

[0044] Fig.12 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 6.9 GHz;

[0045] Fig.13 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 7.8 GHz;

[0046] Fig.14 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 8.4 GHz;

[0047] Fig.15 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 7.6 GHz;

[0048] Fig.16 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 8.6 GHz;

[0049] Fig.17 A cross-sectional view of another acoustic wave resonator provided in an embodiment of the present application;

[0050] Fig.18 A cross-sectional view of another acoustic wave resonator provided in an embodiment of the present application;

[0051] Fig.19 A schematic flow chart of a method for preparing an acoustic wave resonator provided in an embodiment of the present application.

[0052] Reference numerals:

[0053] 1-substrate; 2-piezoelectric layer; 3-interdigitated electrode; 30-finger; 31-first bus bar; 32-second bus bar; 4-acoustic velocity compensation layer; 41-groove; 5-isolation gap; 6-reflection grid. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the embodiments of the present application. It is known to those skilled in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0055] Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. The terms used in the embodiments of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0056] With the rapid development of communication technology, the demand for new frequency bands is increasing. Especially under the leadership of the fifth generation of mobile communication technology (5G), communication systems need to support a wider range of frequency bands and meet higher performance requirements. 5G networks introduce multiple new frequency bands, such as millimeter wave bands, which have a bandwidth far exceeding that of previous generations of technology, providing higher data transmission rates and lower latency. These new frequency bands pose higher challenges and requirements to communication systems, including higher frequency accuracy, lower signal interference, and greater bandwidth support.

[0057] In this context, the quality factor of the acoustic wave resonator has become a key factor in improving system performance. The high quality factor of the acoustic wave resonator can effectively improve the performance of the filter, reduce insertion loss, enhance out-of-band suppression, and improve signal stability and clarity. In addition, the quality factor of the acoustic wave resonator directly affects the selectivity and bandwidth characteristics of the filter, which in turn affects the performance of the overall RF system. In order to cope with the high-frequency band requirements brought by the new frequency band and ensure the efficient operation of the communication system, it is particularly important to design and manufacture acoustic wave resonators with higher quality factors. This not only helps to improve the performance of the filter, but also improves the overall stability and reliability of the system.

[0058] In the process of increasing the frequency of the traditional interdigital acoustic wave resonator, the interdigital electrodes will shrink, which will increase the resistance of the interdigital electrodes. The larger resistance will seriously deteriorate the quality factor, resulting in a decrease in the quality of the acoustic wave resonator. Therefore, how to improve the quality factor of the acoustic wave resonator in the process of increasing the frequency is an urgent problem that technicians in this field need to solve.

[0059] In order to solve the above problems, an embodiment of the present application provides an acoustic wave resonator, comprising:

[0060] substrate;

[0061] A piezoelectric layer disposed on a surface of a substrate;

[0062] An acoustic velocity compensation layer is arranged on a surface of the piezoelectric layer facing away from the substrate, and the acoustic velocity compensation layer has a plurality of grooves arranged in sequence along a first direction; the first direction is parallel to the plane where the piezoelectric layer is located;

[0063] The interdigitated electrode is formed on the surface of the piezoelectric layer away from the substrate based on the acoustic velocity compensation layer with grooves; the interdigitated electrode includes a plurality of fingers arranged one by one corresponding to the grooves; the fingers are in electrical contact with the piezoelectric layer based on the corresponding grooves.

[0064] In the acoustic wave resonator provided in the embodiment of the present application, the sound velocity compensation layer, the interdigital electrodes and the piezoelectric layer can be formed into an integral waveguide, and the interdigital electrodes can more effectively participate in the propagation of the acoustic wave, and can reduce the energy dissipation caused by scattering. Therefore, when the acoustic wave resonator increases the frequency, it is not necessary to reduce the size of the interdigital electrodes, and the resistance of the interdigital electrodes will not be increased, which can avoid the reduction of the quality factor of the acoustic wave resonator, and can effectively improve the performance of the acoustic wave resonator, thereby realizing a high-quality acoustic wave resonator.

[0065] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0066] refer to Figure 1 , Figure 1 A schematic diagram of the structure of an acoustic wave resonator provided in an embodiment of the present application, the acoustic wave resonator includes:

[0067] Substrate 1;

[0068] A piezoelectric layer 2 is arranged on the surface of the substrate 1;

[0069] The acoustic velocity compensation layer 4 is arranged on the surface of the piezoelectric layer 2 facing away from the substrate 1, and the acoustic velocity compensation layer 4 has a plurality of grooves 41 arranged in sequence along a first direction x; the first direction x is parallel to the plane where the piezoelectric layer 2 is located;

[0070] The interdigitated electrode 3 is formed on the surface of the piezoelectric layer 2 facing away from the substrate 1 based on the acoustic velocity compensation layer 4 having grooves 41; the interdigitated electrode 3 includes a plurality of fingers 30 arranged one by one corresponding to the grooves 41; the fingers 30 are in electrical contact with the piezoelectric layer 2 based on the corresponding grooves 41.

[0071] In the acoustic wave resonator provided in the embodiment of the present application, since the interdigitated electrodes 3 are prepared based on the acoustic velocity compensation layer 4 having the grooves 41, the acoustic velocity compensation layer 4, the interdigitated electrodes 3 and the piezoelectric layer 2 can be constructed into an integral waveguide. Based on the integral waveguide, the interdigitated electrodes 3 can more effectively participate in the propagation of the acoustic wave, and the energy scattering caused by scattering can be reduced. Therefore, the technical solution of the present application can increase the frequency without reducing the size of the interdigitated electrodes 3, and the resistance of the interdigitated electrodes 3 will not increase, which can avoid the reduction of the quality factor of the acoustic wave resonator, and can effectively improve the performance of the acoustic wave resonator, thereby realizing a high-quality acoustic wave resonator.

[0072] In one implementation of the embodiment of the present application, the sound velocity of the sound velocity compensation layer 4 is set to be no less than the sound velocity of the piezoelectric layer 2 and the interdigital electrode 3, that is, the sound velocity of the sound velocity compensation layer 4 is greater than or equal to the sound velocity of the piezoelectric layer 2, and greater than or equal to the sound velocity of the interdigital electrode 3.

[0073] If the sound velocity of the sound velocity compensation layer 4 is less than the sound velocity of the piezoelectric layer 2 and the interdigital electrode 3, the propagation speed of the sound wave in the acoustic wave resonator cannot be effectively adjusted. In the embodiment of the present application, the sound velocity of the sound velocity compensation layer 4 is set to be not less than the sound velocity of the piezoelectric layer 2 and the interdigital electrode 3, so that the overall waveguide constructed by the sound velocity compensation layer 4, the interdigital electrode 3 and the piezoelectric layer 2 can better adjust the propagation speed of the sound wave in the acoustic wave resonator, which can effectively improve the performance of the acoustic wave resonator.

[0074] The shear mode sound velocity of the metal material used to prepare the interdigital electrodes 3 is set to V1, the shear mode sound velocity of the piezoelectric material used to prepare the piezoelectric layer 2 is set to V2, and the sound velocity of the sound velocity compensation layer 4 is set to V0.

[0075] If V1>V2, then V0≥V2, if V1<V2, then V0≥V1. In this method, V0 is not less than the smaller one of V1 and V2. At this time, V0 can be between V1 and V2, or V0 is greater than V1 and greater than V2.

[0076] When V0 is not less than the smaller of V1 and V2, if V0 is between V1 and V2, the electromechanical coupling coefficient of the acoustic wave resonator can be Larger. The larger the value of is, the larger the bandwidth of the acoustic wave resonator is and the better the passband rectangularity is. This method can better optimize the bandwidth performance of the acoustic wave resonator.

[0077] When V0 is not less than the smaller one of V1 and V2, if V0 is greater than V1 and greater than V2, the operating frequency of the acoustic wave resonator can be greatly increased. This method can improve the high-frequency performance of the acoustic wave resonator.

[0078] The thickness and material density of the acoustic velocity compensation layer 4 and the thickness and material density of the interdigital electrodes 3 satisfy a matching relationship, so that the acoustic wave resonator has a higher operating frequency.

[0079] In the embodiment of the present application, in order to facilitate the process of preparing the interdigital electrode 3, the thickness of each finger 30 in the interdigital electrode 3 can be set to be the same.

[0080] The thickness of the acoustic velocity compensation layer 4 can be set to h1, and the material density of the acoustic velocity compensation layer 4 can be set to ρ1; the thickness of the interdigital electrode 3 can be set to h2, and the material density of the interdigital electrode can be set to ρ2. The thickness and material density of the acoustic velocity compensation layer 4 and the thickness and material density of the interdigital electrode 3 satisfy the matching relationship shown in the following formula (1).

[0081] (1)

[0082] Among them, A is a set constant.

[0083] It is easy to know that the sound velocity compensation layer 4 is an insulating material, and the interdigital electrode 3 is a conductive material. For the interdigital electrode 3 with a given material and thickness, based on the above formula (1), it can be known that the material density ρ1 and the thickness h1 of the sound velocity compensation layer 4 need to have an inverse relationship, and the inverse coefficient is A, so that the performance of the acoustic wave resonator can be better optimized through the sound velocity compensation layer 4, the sound wave propagation speed can be better adjusted, the bandwidth of the acoustic wave resonator can be better adjusted, and the acoustic performance can be better improved.

[0084] For the acoustic velocity compensation layer 4 and the interdigital electrode 3 with determined materials, the material densities of the two are determined values, that is, ρ1 and ρ2 are constants that can be determined. At this time, the thickness of the acoustic velocity compensation layer 4 and the interdigital electrode 3 can be adjusted, that is, the values ​​of h1 and h2 can be adjusted, so that the thickness and material density of the acoustic velocity compensation layer 4 and the thickness and material density of the interdigital electrode 3 satisfy the matching relationship shown in the following formula (1), so that the acoustic wave resonator has a higher operating frequency.

[0085] Based on the above formula (1), it can be known that in the embodiment of the present application, the thickness values ​​of the sound velocity compensation layer 4 and the interdigital electrode 3 can be pre-set, that is, the values ​​of h1 and h2 can be pre-given. Under the given h1 and h2, the sound velocity compensation layer 4 and the interdigital electrode 3 whose material density satisfies the above matching relationship are selected, and by adjusting ρ1 and / or ρ2, the thickness and material density of the sound velocity compensation layer 4 and the thickness and material density of the interdigital electrode 3 can satisfy the matching relationship shown in the following formula (1), so that the acoustic wave resonator has a higher operating frequency.

[0086] It can be seen from the above description that in the embodiment of the present application, by adjusting at least one of h1, h2, ρ1 and ρ2, the thickness and material density of the sound velocity compensation layer 4 and the thickness and material density of the interdigital electrode 3 can satisfy the matching relationship shown in the following formula (1), so that the acoustic wave resonator has a higher operating frequency.

[0087] Optionally, 2≤A≤10. The inventors have found that when 2≤A≤10, the acoustic wave resonator can have a higher operating frequency. If the value of A is less than 2 or greater than 10, the operating frequency of the acoustic wave resonator will be lower.

[0088] In one implementation of the present application, the Figure 1 As shown, it is set that h1<h2.

[0089] In the acoustic wave resonator provided in the embodiment of the present application, the thickness h1 of the interdigital electrode 3 and the depth of the groove 41 can be adjusted based on usage requirements, and the thickness h1 of the interdigital electrode 3 and the depth of the groove 41 can be adaptively increased to optimize the performance of the acoustic wave resonator.

[0090] refer to Figure 2 , Figure 2 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application, in Figure 2 In the method shown, h1=h2.

[0091] refer to Figure 3 , Figure 3 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application, Figure 3 In the manner shown, h1>h2.

[0092] In the embodiment of the present application, the thickness of the acoustic velocity compensation layer 4 and the interdigital electrode 3 are set to satisfy the following relationship:

[0093] (2)

[0094] When the thicknesses of the acoustic velocity compensation layer 4 and the interdigital electrodes 3 satisfy the above formula (2), the acoustic wave resonator can have a relatively large operating frequency.

[0095] like If it is less than 0.1 or greater than 10, the operating frequency of the acoustic wave resonator will be greatly reduced, which will greatly affect the high-frequency performance of the acoustic wave resonator. Therefore, the thickness of the acoustic velocity compensation layer 4 and the interdigital electrode 3 can be further set to satisfy the following relationship:

[0096] (3)

[0097] When the thicknesses of the acoustic velocity compensation layer 4 and the interdigital electrodes 3 satisfy the above formula (3), the acoustic wave resonator can have a relatively large operating frequency.

[0098] When the acoustic velocity compensation layer 4 is made of silicon oxide and the thickness ratio of the acoustic velocity compensation layer 4 to the finger strip 30 is 1:4, that is, , an acoustic wave resonator is used to operate at a frequency of 6.2 gigahertz.

[0099] When the acoustic velocity compensation layer 4 is made of silicon oxide and the thickness ratio of the acoustic velocity compensation layer 4 to the interdigital electrode 3 is 11:4, that is, , the acoustic wave resonator is used to operate at a frequency of 4.6 gigahertz.

[0100] When the acoustic velocity compensation layer 4 is made of silicon oxide and the thickness ratio of the acoustic velocity compensation layer 4 to the interdigital electrode 3 is 5:2, that is, , an acoustic wave resonator is used to operate at a frequency of 6.9 gigahertz.

[0101] When the acoustic velocity compensation layer 4 is made of silicon nitride and the thickness ratio of the acoustic velocity compensation layer 4 to the interdigital electrode 3 is 2:1, that is, , the acoustic wave resonator is used to operate at a frequency of 7.8 gigahertz.

[0102] When the acoustic velocity compensation layer 4 is made of silicon carbide and the thickness ratio of the acoustic velocity compensation layer 4 to the interdigital electrode 3 is 3:1, that is, , the acoustic wave resonator is used to operate at a frequency of 8.4 gigahertz.

[0103] When the acoustic velocity compensation layer 4 is made of zinc oxide and the thickness ratio of the acoustic velocity compensation layer 4 to the interdigital electrode 3 is 2:1, that is, , the acoustic wave resonator is used to operate at a frequency of 7.6 gigahertz.

[0104] When the acoustic velocity compensation layer 4 is made of aluminum oxide and the thickness ratio of the acoustic velocity compensation layer 4 to the interdigital electrode 3 is 9:4, that is, , the acoustic wave resonator is used to operate at a frequency of 8.6 gigahertz.

[0105] The inventors have found that, as shown in the test results of the above seven groups of comparative experimental examples, the thickness ratio of the acoustic velocity compensation layer 4 and the interdigital electrode 3 has a great influence on the operating frequency of the acoustic wave resonator. By adjusting the ratio of the thicknesses of the two, the high-frequency working performance of the acoustic wave resonator can be optimized.

[0106] Based on the above description, it can be seen that when When , the acoustic wave resonator can have a larger operating frequency.

[0107] In other implementations, it is also possible to set Although the frequency is reduced to a certain extent at this time, it can be used in work scenarios with lower requirements for high-frequency work.

[0108] In the embodiment of the present application, the groove 41 may be a rectangular groove. In this case, Figure 1-Figure 3 In any of the embodiments shown, in the direction from the substrate 1 to the piezoelectric layer 2 , the width of the groove 41 remains constant.

[0109] refer to Figure 4 , Figure 4 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application, based on the above implementation, Figure 4 In the manner shown, the width of the groove 41 gradually increases in the direction from the substrate 1 to the piezoelectric layer 2. In this manner, the groove 41 may be an inverted trapezoidal groove, the bottom width of the groove 41 is the smallest, the top opening width of the groove 41 is the largest, and the size of the groove 41 in the first direction x gradually increases from the bottom of the groove 41 to the top opening.

[0110] like Figure 4 As shown, in the direction from the substrate 1 to the piezoelectric layer 2, if the width of the groove 41 gradually increases, the interdigitated electrode 3 can cover the shaped film on the surface of the groove 41. At this time, h1>h2, and the shaped film covers the bottom of the groove 41 and at least part of the side wall.

[0111] Furthermore, you can Figure 4 As shown, a shaped film is provided to cover the side wall of the groove 41 and extends to the outside of the groove 41 to cover part of the upper surface of the sound velocity compensation layer 4. The fingers 30 in two adjacent grooves 41 in the first direction x are provided with an isolation gap 5 on the upper surface of the sound velocity compensation layer 4 between the two grooves 41 to prevent the two adjacent fingers 30 in the first direction x from short-circuiting.

[0112] exist Figure 4 In the manner shown, h1>h2 is used as an example for illustration. In the direction from the substrate 1 to the piezoelectric layer 2, if the width of the groove 41 gradually increases, the structure of the acoustic wave resonator can also be as follows: Figure 5 or Figure 6 shown.

[0113] refer to Figure 5 , Figure 5 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application, based on the above implementation, Figure 5 In the manner shown, in the direction from the substrate 1 to the piezoelectric layer 2 , the width of the groove 41 gradually increases, and h1=h2.

[0114] refer to Figure 6 , Figure 6 A schematic diagram of the structure of another acoustic wave resonator provided in an embodiment of the present application, based on the above implementation, Figure 6In the manner shown, in the direction from the substrate 1 to the piezoelectric layer 2, the width of the groove 41 gradually increases, and h1<h2.

[0115] In the direction from the substrate 1 to the piezoelectric layer 2, if the width of the groove 41 gradually increases, the two opposite side walls of the groove 41 in the first direction x can have an inclination angle a relative to the plane where the piezoelectric layer 2 is located. By adjusting the value range of the inclination angle a, the overall waveguide formed by the acoustic velocity compensation layer 4, the interdigitated electrodes 3 and the piezoelectric layer 2 can better adjust the propagation speed of the acoustic wave in the acoustic wave resonator, which can effectively improve the performance of the acoustic wave resonator.

[0116] Optionally, 10°<a<90° can be set, and further, 30°<a<80° can be set, so that the overall waveguide formed by the sound velocity compensation layer 4, the interdigital electrode 3 and the piezoelectric layer 2 can better adjust the propagation speed of the sound wave in the sound wave resonator.

[0117] In the embodiment of the present application, the thickness range of the acoustic velocity compensation layer 4 is 10nm~10000nm, such as 50nm, 100nm, 200nm, 2500nm, 4000nm, 7900nm or 9000nm, etc.; the thickness range of the interdigital electrode 3 is 10nm~10000nm, such as 20nm, 300nm, 1900nm, 4000nm, 8000nm or 9500nm, etc.; the thickness range of the piezoelectric layer 2 is 10nm~10000nm, such as 10nm, 100nm, 2900nm, 5000nm, 8900nm or 10000nm, etc. The embodiment of the present application does not limit the specific values ​​of different film layers.

[0118] The thickness range of the acoustic velocity compensation layer 4, the interdigital electrodes 3 and the piezoelectric layer 2 is 10nm~10000nm, which can avoid the problem of large size of the acoustic wave resonator due to excessive film thickness, and can also avoid affecting the acoustic wave propagation speed due to too small film thickness.

[0119] In the embodiment of the present application, the Young's modulus of the acoustic velocity compensation layer 4 can be set to have a value range of 5×10 10 Pa~1×10 12 Pa; the density of the sound velocity compensation layer 4 is in the range of 2000kg / m 3 ~6000kg / m 3 By selecting different materials within the above parameter range to adjust the Young's modulus and / or material density of the acoustic velocity compensation layer 4, the acoustic velocity compensation layer 4 can be used to better optimize the bandwidth performance of the acoustic wave resonator and adjust the bandwidth of the acoustic wave resonator; the acoustic velocity compensation layer 4 can also be used to improve the acoustic performance, increase the Q value and reduce the insertion loss.

[0120] Optionally, the material of the substrate 1 may include a single-layer substrate made of any one of silicon, aluminum oxide, silicon oxide, glass, aluminum nitride, scandium aluminum nitride, quartz or silicon carbide, or a multi-layer composite substrate formed of multiple of the above materials. The embodiment of the present application does not limit the implementation method of the substrate 1.

[0121] The material of the piezoelectric layer 2 includes any one of lithium niobate, lithium tantalate and aluminum nitride. The embodiment of the present application does not limit the implementation method of the piezoelectric layer 2.

[0122] The interdigitated electrodes 3 can be made of metal, and the conductivity of the metal material used is greater than 5×10 6 Siemens per meter. Select conductivity greater than 5×10 6 Siemens uses 3 interdigitated electrodes per meter of metal material to reduce energy loss, help improve signal quality, and improve the performance of the acoustic resonator.

[0123] The metal material for making the interdigital electrodes 3 includes any one of gold, silver, copper, aluminum, molybdenum, chromium, nickel, platinum, titanium gold, titanium aluminum, chromium gold and chromium aluminum.

[0124] The cross-sectional shape of the groove 41 parallel to the first direction x can be a rectangle (eg Figure 1-Figure 3 As shown in any of the above), trapezoidal (as shown in Figure 5 As shown), any one of a triangle, a partial ellipse, a partial circle and an irregular shape, is not limited to the diagrammatic representation in the embodiments of the present application.

[0125] The cross-sectional shape of the fingers of the interdigitated electrode 3 parallel to the first direction x can be a rectangle (eg Figure 1-Figure 3 As shown in any of the above), trapezoidal (as shown in Figure 5 As shown), a triangle, a partial ellipse, a partial circle, a shaped film having a thickness less than that of the sound velocity compensation layer 4 and covering the surface of the groove 41, etc., are not limited to the illustrated methods in the embodiments of the present application.

[0126] After the acoustic wave resonator prepares the patterned acoustic velocity compensation layer 4 , the interdigital electrodes 3 are prepared based on the pre-prepared acoustic velocity compensation layer 4 , so the pattern structure of the interdigital electrodes 3 is adapted to the pattern structure of the groove 41 .

[0127] In the implementation of the present application, the main mode of the acoustic wave excited by the acoustic wave resonator can be formed by coupling one or more shear modes, which can improve the electromechanical coupling coefficient of the acoustic wave resonator. It can also increase the quality factor Q of the acoustic wave resonator, expand the operating frequency band of the acoustic wave resonator, improve the filtering performance of the acoustic wave resonator, and enhance the sensing sensitivity of the acoustic wave resonator.

[0128] The main mode of the acoustic wave excited by the acoustic wave resonator can be optimized by selecting the acoustic velocity compensation layer 4, the interdigital electrodes 3 and the piezoelectric layer 2 of matching materials, or adjusting the pattern structure and pattern size of the interdigital electrodes 3.

[0129] refer to Figure 7 , Figure 7 A top view of an electrode pattern in an acoustic wave resonator provided in an embodiment of the present application, wherein the interdigitated electrode 3 includes a first interdigitated electrode and a second interdigitated electrode arranged opposite to each other, the first interdigitated electrode and the second interdigitated electrode may include one or more fingers 30 arranged in sequence in a first direction x, and the fingers 30 of the first interdigitated electrode and the second interdigitated electrode are arranged alternately in the first direction x.

[0130] If the first interdigital electrode includes a plurality of fingers 30 sequentially arranged in the first direction x, the first interdigital electrode further includes a first bus bar 31 , and all the fingers 30 in the first interdigital electrode are connected to the same side of the first bus bar 31 .

[0131] If the second interdigital electrode includes a plurality of fingers 30 sequentially arranged in the first direction x, the second interdigital electrode further has a second bus bar 32 , and all the fingers 30 in the second interdigital electrode are connected to the same side of the second bus bar 32 .

[0132] Under the premise that the fingers 30 in the first and second interdigital electrodes are periodically distributed and staggered with each other, the shape of the interdigital electrodes 3 can be set according to requirements and is not limited to the illustrated manner in the embodiment of the present application.

[0133] The first bus bar 31 and the second bus bar 32 are arranged parallel to each other in a second direction y. The second direction y is parallel to the plane where the piezoelectric layer 2 is located, and is perpendicular to the first direction x.

[0134] Optionally, two reflection gratings 6 arranged opposite to each other in the first direction x may be arranged on the piezoelectric layer 2, and the interdigital electrode 3 is located between the two reflection gratings 6. The reflection grating 6 can reflect sound waves to improve energy utilization, extend the sound wave propagation path, improve the quality factor of the sound wave resonator, and improve the out-of-band suppression and in-band insertion loss of the sound wave resonator, so that the response of the filter is smoother and the application range in high-frequency and high-performance environments is enhanced.

[0135] The reflective grating 6 includes a plurality of metal bars arranged in sequence in the first direction x and two bus bars arranged opposite to each other in the second direction y. The two opposite ends of the metal bars in the second direction y are respectively connected to a bus bar of the reflective grating 6. At this time, the reflective grating 6 is also located in the groove corresponding to the acoustic velocity compensation layer 4.

[0136] The reflective grating 6 and the interdigital electrodes 3 can be simultaneously manufactured based on the same metal layer. In order to facilitate the same process manufacturing of the reflective grating 6 , two reflective gratings 6 can be symmetrically arranged on both sides of the interdigital electrodes 3 .

[0137] The reflector 6 and the interdigital electrodes 3 can be made of the same material, and both have a conductivity greater than 5×10 6 Siemens per meter of metal.

[0138] In the same reflective grating 6 , the number of metal fingers may be 10 to 60, such as 10, 15, 30, 45 or 60, etc. The embodiment of the present application does not limit the number of metal fingers in the reflective grating 6 .

[0139] The thickness of the reflective grating 6 may be the same as or different from the thickness of the interdigital electrodes 3. The thickness of the reflective grating 6 may be 10 nm to 10000 nm. For example, it may be 10 nm, 100 nm, 2900 nm, 5000 nm, 8900 nm, 90000 nm or 10000 nm, etc. The embodiment of the present application does not limit the thickness of the reflective grating 6.

[0140] In the reflective grid 6 , the width of the metal grid in the first direction x can be 0.001 μm to 10 μm, such as 0.001 μm, 1 μm, 2.6 μm, 4.1 μm, 7 μm, 9.6 μm or 10 μm, etc. The embodiment of the present application does not limit the value of the metal grid.

[0141] The length of the metal grid in the second direction y may be equal to or different from the length of the finger 30 in the interdigital electrode 3. In order to improve the acoustic wave reflection effect, the length of the metal grid is preferably set to be greater than the length of the finger 30.

[0142] The length of the metal grid bar may range from 1 μm to 500 μm, such as 1 μm, 80 μm, 250 μm, 360 μm, 499 μm, and 500 μm. The embodiment of the present application does not limit the length of the metal grid bar.

[0143] The number of fingers 30 in the interdigital electrode 3 may be 2 to 500, such as 2, 100, 200, 250, 380 or 500.

[0144] The thickness of the finger strip 30 may be 10 nm to 10000 nm. For example, the thickness of the finger strip 30 may be 10 nm, 100 nm, 2900 nm, 5000 nm, 8900 nm or 10000 nm.

[0145] The width of the finger 30 in the first direction x may range from 0.001 μm to 10 μm. For example, the width of the finger 30 may be 0.001 μm, 1 μm, 2.6 μm, 4.1 μm, 7 μm, 9.6 μm or 10 μm.

[0146] The length of the finger 30 in the second direction y may range from 1 μm to 500 μm. For example, the length of each interdigital electrode 3 may be 1 μm, 80 μm, 250 μm, 360 μm, 499 μm or 500 μm.

[0147] To facilitate the process of preparing the interdigital electrode 3, the fingers 30 in the interdigital electrode 3 are set to have the same length, thickness and width. In other embodiments, at least two fingers 30 may have different lengths, widths or thicknesses.

[0148] The performance of the acoustic wave resonator based on the technical solution of the present application is further described below in combination with relevant experimental simulation data.

[0149] refer to Figure 8 , Figure 8 A cross-sectional schematic diagram of an acoustic wave resonator for operating at a frequency of 6.2 GHz provided in an embodiment of the present application, in which the acoustic velocity compensation layer 4 is zinc oxide, the interdigitated electrodes 3 are metal aluminum, , h1=20nm, h2=80 nm, the finger 30 in the groove 41 is embedded in the groove 41. The duty cycle of the finger 30 (i.e., the ratio of the width of the finger 30 in the first direction x to the spacing between the fingers 30) is 50%. The piezoelectric layer 2 can be cut in the direction of X-cut lithium niobate, and the Euler angle of the piezoelectric layer 2 is -5°. The sum of twice the width of the finger 30 and twice the spacing between adjacent fingers 30 is taken as the horizontal wavelength λ, the horizontal wavelength λ is 600nm, and the ratio of the horizontal wavelength λ to the thickness of the piezoelectric layer 2 is 2:1. The acoustic wave resonator designed based on this embodiment can be used to operate at a frequency of 6.2 GHz.

[0150] refer to Fig. 9 , Fig. 9 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 6.2 GHz. Fig. 9 In the simulated admittance curve shown, the horizontal axis is frequency / GHZ and the vertical axis is admittance / dB. When the acoustic wave resonator operates at a frequency of 6.2 GHz, the electromechanical coupling coefficient About 35%. Among them, the electromechanical coupling coefficient It can be calculated by the following formula (4):

[0151] k 2 = π 8 • [ （ f p f s ） 2 − 1 ] (4)

[0152] In formula (4), is the frequency of the highest admittance point in the simulated admittance curve, is the frequency of the lowest point of admittance in the simulated admittance curve.

[0153] refer to Fig.10 , Fig.10 A schematic cross-sectional view of an acoustic wave resonator for operating at a frequency of 4.6 GHz provided in an embodiment of the present application. In this embodiment, the acoustic velocity compensation layer 4 is silicon oxide, and the interdigital electrodes 3 are metal aluminum. , h1=220nm, h2=80 nm, the finger 30 in the groove 41 is completely embedded in the groove 41. The duty cycle of the finger 30 is 50%. The piezoelectric layer 2 can be cut in an X-cut lithium niobate, and the Euler angle of the piezoelectric layer 2 is -5°. The sum of twice the width of the finger 30 and twice the spacing between adjacent fingers 30 is taken as the horizontal wavelength λ, the horizontal wavelength λ is 1000 nm, and the ratio of the horizontal wavelength λ to the thickness of the piezoelectric layer 2 is 10:3. The acoustic wave resonator designed based on this embodiment can be used to operate at a frequency of 4.6 GHz.

[0154] refer to Fig.11 , Fig.11 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 4.6 GHz. Fig.11 In the simulated admittance curve shown, the horizontal axis is frequency / GHZ and the vertical axis is admittance / dB. When the acoustic wave resonator operates at a frequency of 4.6 GHz, the electromechanical coupling coefficient About greater than 31%. Among them, the electromechanical coupling coefficient It can be calculated by the above formula (4).

[0155] refer to Fig.12 , Fig.12 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 6.9 GHz. Fig.12 In the simulated admittance curve shown, the horizontal axis is frequency / GHZ and the vertical axis is admittance / dB. When the acoustic wave resonator operates at a frequency of 6.9 GHz, the electromechanical coupling coefficient Greater than 25%. Among them, the electromechanical coupling coefficient It can be calculated by the above formula (4).

[0156] exist Fig.12 In the corresponding acoustic wave resonator, the acoustic velocity compensation layer 4 is silicon oxide, and the interdigital electrode 3 is metal aluminum. , h1=200nm, h2=80 nm, the finger 30 in the groove 41 is completely embedded in the groove 41. The duty cycle of the finger 30 is 50%. The piezoelectric layer 2 can be cut in an X-cut lithium niobate, and the Euler angle of the piezoelectric layer 2 is -5°. The sum of twice the width of the finger 30 and twice the spacing between adjacent fingers 30 is taken as the horizontal wavelength λ, and the horizontal wavelength λ is 600nm. The ratio of the horizontal wavelength λ to the thickness of the piezoelectric layer 2 is 2:1. Based on this design, the acoustic resonator can be used to operate at a frequency of 6.9 GHz, and the electromechanical coupling coefficient Greater than 25%.

[0157] refer to Fig.13 , Fig.13 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 7.8 GHz. Fig.13 In the simulated admittance curve shown, the horizontal axis is frequency / GHZ and the vertical axis is admittance / dB. When the acoustic wave resonator operates at a frequency of 7.8 GHz, the electromechanical coupling coefficient Greater than 25%. Among them, the electromechanical coupling coefficient It can be calculated by the above formula (4).

[0158] exist Fig.13 In the corresponding acoustic wave resonator, the acoustic velocity compensation layer 4 is silicon nitride, and the interdigital electrode 3 is metal aluminum. , h1=160nm, h2=80 nm, the finger 30 in each groove 41 is completely embedded in the groove 41. The duty cycle of the finger 30 is 50%. The piezoelectric layer 2 can be cut in an X-direction for lithium niobate, and the Euler angle of the piezoelectric layer 2 is -5°. The sum of twice the width of the finger 30 and twice the spacing between adjacent fingers 30 is taken as the horizontal wavelength λ, and the horizontal wavelength λ is 600nm. The ratio of the horizontal wavelength λ to the thickness of the piezoelectric layer 2 is 2:1. Based on the above design, the acoustic resonator can be used to operate at a frequency of 7.8 GHz, and the electromechanical coupling coefficient Greater than 14%.

[0159] refer to Fig.14 , Fig.14 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 8.4 GHz. Fig.14 In the simulated admittance curve shown, the horizontal axis is frequency / GHZ and the vertical axis is admittance / dB. When the acoustic wave resonator operates at a frequency of 8.4 GHz, the electromechanical coupling coefficient Greater than 9%. Among them, the electromechanical coupling coefficient It can be calculated by the above formula (4).

[0160] exist Fig.14 In the corresponding acoustic wave resonator, the structural acoustic velocity compensation layer 4 is made of silicon carbide, and the interdigital electrodes 3 are made of metal aluminum. , h1=180nm, h2=60 nm, the finger 30 in each groove 41 is completely embedded in the groove 41. The duty cycle of the finger 30 is 50%. The piezoelectric layer 2 can be cut in an X-cut lithium niobate, and the Euler angle of the piezoelectric layer 2 is -5°. The sum of twice the width of the finger 30 and twice the spacing between adjacent fingers 30 is taken as the horizontal wavelength λ, the horizontal wavelength λ is 600 nm, and the ratio of the horizontal wavelength λ to the thickness of the piezoelectric layer 2 is 2:1. Based on the above design, the acoustic resonator can be used to operate at a frequency of 8.4 GHz, and the electromechanical coupling coefficient is greater than 9%.

[0161] refer to Fig.15 , Fig.15 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 7.6 GHz. Fig.15 In the simulated admittance curve shown, the horizontal axis is frequency / GHZ and the vertical axis is admittance / dB. When the acoustic wave resonator operates at a frequency of 7.6 GHz, the electromechanical coupling coefficient Greater than 19%. Among them, the electromechanical coupling coefficient It can be calculated by the above formula (4).

[0162] exist Fig.15 In the corresponding acoustic wave resonator, the acoustic velocity compensation layer 4 is zinc oxide, and the interdigital electrode 3 is metal aluminum. , h1=120nm, h2=60 nm, the finger 30 in each groove 41 is completely embedded in the groove 41. The duty cycle of the finger 30 is 50%. The piezoelectric layer 2 can be cut in an X-cut lithium niobate, and the Euler angle of the piezoelectric layer 2 is -5°. The sum of twice the width of the finger 30 and twice the spacing between adjacent fingers 30 is taken as the horizontal wavelength λ, the horizontal wavelength λ is 600nm, and the ratio of the horizontal wavelength λ to the thickness of the piezoelectric layer 2 is 2:1. Based on the above design, the acoustic resonator can be used to operate at a frequency of 7.6 GHz, and the electromechanical coupling coefficient is greater than 19%.

[0163] refer to Fig.16 , Fig.16 is a simulated admittance curve for an acoustic wave resonator operating at a frequency of 8.6 GHz. Fig.16 In the simulated admittance curve shown, the horizontal axis is frequency / GHZ and the vertical axis is admittance / dB. When the acoustic resonator operates at a frequency of 8.6 GHz, the electromechanical coupling coefficient Greater than 16%. Among them, the electromechanical coupling coefficient It can be calculated by the above formula (4).

[0164] exist Fig.16 In the corresponding acoustic wave resonator, the acoustic velocity compensation layer 4 is made of aluminum oxide, and the interdigital electrodes 3 are made of metal aluminum. , h1=180nm, h2=80 nm, the interdigitated electrode 3 in each groove 41 is completely embedded in the groove 41. The duty cycle of the finger 30 is 50%. The piezoelectric layer 2 can be cut in an X-cut lithium niobate, and the Euler angle of the piezoelectric layer 2 is -5°. The sum of twice the width of the finger 30 and twice the spacing between adjacent fingers 30 is taken as the horizontal wavelength λ, the horizontal wavelength λ is 600nm, and the ratio of the horizontal wavelength λ to the thickness of the piezoelectric layer 2 is 2:1. Based on the above design, the acoustic wave resonator can be used to operate at a frequency of 8.6 GHz, and the electromechanical coupling coefficient is greater than 16%.

[0165] It can be known from the above simulation experimental data that in the embodiment of the present application, by designing the depth of the groove 41 in the sound velocity compensation layer 4, the thickness of the forked electrode 3 and the duty cycle, the sound velocity compensation layer 4, the forked electrode 3 and the piezoelectric layer 2 form an integral waveguide, so that the forked electrode 3 can more effectively participate in the propagation of the sound wave, and also reduce the energy dissipation caused by scattering. In this way, while increasing the frequency, there is no need to reduce the size of the forked electrode 3, and the resistance of the forked electrode 3 will not be increased, which can avoid the reduction of the quality factor of the acoustic wave resonator and realize a high-quality acoustic wave resonator. Moreover, when the ratio of the horizontal wavelength to the thickness of the piezoelectric layer 2 remains unchanged, the operating frequency of the acoustic wave resonator can be from more than ten MHz to more than ten GHz, and a large quality factor is maintained, which can well meet the current frequency band The performance requirements of high frequency and high quality of the filter can be well met.

[0166] In each of the above embodiments, the uniform thickness of the acoustic velocity compensation layer 4 is used as an example for illustration. In other embodiments of the present application, the acoustic velocity compensation layer 4 can also be set as a film layer with a regular and gradual thickness change. If the acoustic velocity compensation layer 4 is a film layer with a regular and gradual thickness change, in the first direction x, the thickness of the acoustic velocity compensation layer 4 between two adjacent grooves 41 is uniform and unchanged. At this time, in each of the above embodiments, the value of h1 can be the average thickness of the acoustic velocity compensation layer 4, or the minimum thickness of the acoustic velocity compensation layer 4 can be equivalent to h1.

[0167] refer to Fig.17 , Fig.17 A cross-sectional view of another acoustic wave resonator provided in an embodiment of the present application, based on the above embodiment, Fig.17 In the illustrated manner, along the first direction x, the acoustic velocity compensation layer 4 is a film layer with a regularly changing thickness, the thickness of the acoustic velocity compensation layer 4 between two adjacent grooves 41 is uniform and constant, and the thickness of the acoustic velocity compensation layer 4 between different grooves 41 changes periodically with alternating h11 and h12. Wherein, h11>h12. At this time, the thickness h2 of the interdigital electrode 3 is set to be no greater than h12.

[0168] exist Fig.17In the illustrated embodiment, the acoustic velocity compensation layer 4 with periodic thickness variation can optimize the performance of the acoustic velocity propagation of the overall waveguide formed by the acoustic velocity compensation layer 4, the interdigital electrodes 3 and the piezoelectric layer 2, thereby optimizing the performance of the acoustic wave resonator.

[0169] refer to Fig.18 , Fig.18 A cross-sectional view of another acoustic wave resonator provided in an embodiment of the present application, based on the above embodiment, Fig.18 In the illustrated embodiment, along the first direction x, the acoustic velocity compensation layer 4 is a film layer with a regularly changing thickness, the thickness of the acoustic velocity compensation layer 4 between two adjacent grooves 41 is uniform, and the thickness of the acoustic velocity compensation layer 4 between different grooves 41 gradually decreases from h to h', and then gradually increases from h' to h. At this time, the thickness h2 of the interdigital electrode 3 is set to be no greater than h'.

[0170] exist Fig.18 In the illustrated embodiment, based on the sound velocity compensation layer 4 with a gradual thickness, the performance of the overall waveguide sound propagation speed formed by the sound velocity compensation layer 4, the interdigital electrodes 3 and the piezoelectric layer 2 can also be optimized, thereby optimizing the performance of the acoustic wave resonator.

[0171] Along the first direction x, if the acoustic velocity compensation layer 4 is a film layer with a regularly changing thickness, the thickness of the acoustic velocity compensation layer 4 between two adjacent grooves 41 can also be set to be uniform and constant, and the thickness of the acoustic velocity compensation layer 4 between different grooves 41 gradually increases from h' to h, and then gradually decreases from h to h'. At this time, the thickness h2 of the interdigital electrode 3 is also set to be no greater than h'. This method can also be based on the acoustic velocity compensation layer 4 with a gradually changing thickness, and can optimize the performance of the overall waveguide propagation sound velocity formed by the acoustic velocity compensation layer 4, the interdigital electrode 3 and the piezoelectric layer 2, thereby optimizing the performance of the acoustic wave resonator.

[0172] Based on the acoustic wave resonator provided in the above embodiment, another embodiment of the present application further provides a method for preparing the acoustic wave resonator. The preparation method can be as follows: Fig.17 As shown, it can be used to prepare the acoustic wave resonator provided by any of the implementation methods of the above embodiments.

[0173] refer to Fig.19 , Fig.19 A schematic diagram of a method for preparing an acoustic wave resonator provided in an embodiment of the present application, combined with Fig.19 As shown in the accompanying drawings of the acoustic wave resonator provided in the above embodiment, the preparation method includes:

[0174] Step S11 : forming a piezoelectric layer 2 on the surface of the substrate 1 .

[0175] Step S12: forming an acoustic velocity compensation layer 4 on a surface of the piezoelectric layer 2 facing away from the substrate 1 , wherein the acoustic velocity compensation layer 4 has a plurality of grooves 41 sequentially arranged along a first direction x; the first direction x is parallel to the plane where the piezoelectric layer 2 is located.

[0176] Step S13: Based on the acoustic velocity compensation layer 4 having the grooves 41, a forked electrode 3 is formed on the surface of the piezoelectric layer 2 facing away from the substrate 1, and the forked electrode 3 includes a plurality of fingers 30 arranged one-to-one corresponding to the grooves 41; the fingers 30 are in electrical contact with the piezoelectric layer 2 based on the corresponding grooves 41.

[0177] In the embodiment of the present application, a patterned acoustic velocity compensation layer 4 having grooves 41 is first formed, and then a finger electrode 3 electrically contacting the piezoelectric layer 2 is formed based on the acoustic velocity compensation layer 4, so that the fingers 30 in the finger electrode 3 are respectively located in the corresponding grooves 41. In this way, the acoustic velocity compensation layer 4, the finger electrode 3 and the piezoelectric layer 2 can form an integral waveguide. Based on the integral waveguide, the performance of the acoustic wave resonator can be optimized.

[0178] The ratio of the thickness h1 of the acoustic velocity compensation layer 4 to the thickness h2 of the interdigital electrode 3 can be 1:4, 11:4, 5:2, 2:1, 3:1 or 9:4. The operating frequency of the acoustic wave resonator can be adjusted by adjusting the material and thickness ratio of the interdigital electrode 3 and the acoustic velocity compensation layer 4.

[0179] Based on the above embodiments, another embodiment of the present application further provides a filter, and the filter includes the acoustic wave resonator provided by any one of the above implementation modes.

[0180] Based on the above embodiments, another embodiment of the present application further provides an electronic device, and the electronic device includes the electronic device provided by any of the above implementation modes.

[0181] In the specification of this application, each embodiment is described in a progressive, parallel, or progressive and parallel manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. The embodiments provided in the embodiments of this application can be combined with each other if there is no contradiction.

[0182] It should be noted that in the description of the present application, it should be understood that the description of the drawings and embodiments is illustrative rather than restrictive. The same reference numerals throughout the embodiments of the specification identify the same structure. In addition, for the sake of understanding and ease of description, the drawings may exaggerate the thickness of some layers, films, panels, regions, etc. It is also understood that when an element such as a layer, film, region, or substrate is referred to as "on" another element, the element may be directly on the other element or there may be an intermediate element. In addition, "on" refers to positioning an element on or below another element, but does not essentially refer to positioning on the upper side of another element according to the direction of gravity.

[0183] The terms "upper", "lower", "top", "bottom", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0184] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0185] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those 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 will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An acoustic wave resonator, characterized in that: include: substrate; A piezoelectric layer disposed on the surface of the substrate; An acoustic velocity compensation layer is disposed on a surface of the piezoelectric layer facing away from the substrate, wherein the acoustic velocity compensation layer has a plurality of grooves arranged in sequence along a first direction; the first direction is parallel to the plane where the piezoelectric layer is located; The interdigitated electrodes are formed on the surface of the piezoelectric layer facing away from the substrate based on the acoustic velocity compensation layer having the grooves; the interdigitated electrodes include a plurality of fingers arranged one-to-one corresponding to the grooves; the fingers are in electrical contact with the piezoelectric layer based on the corresponding grooves.

2. The acoustic wave resonator according to claim 1, characterized in that The acoustic velocity of the acoustic velocity compensation layer is not less than the acoustic velocity of the piezoelectric layer and the interdigital electrodes.

3. The acoustic wave resonator according to claim 1, characterized in that The thickness of the sound velocity compensation layer is h1, and the material density of the sound velocity compensation layer is ρ1; The thickness of the interdigital electrode is h2, and the material density of the interdigital electrode is ρ2; in, ; Where A is the set constant.

4. The acoustic wave resonator according to claim 3, characterized in that 2≤A≤10。 5. The acoustic wave resonator according to claim 1, characterized in that The thickness of the acoustic velocity compensation layer is h1, the thickness of the interdigital electrode is h2, in, .

6. The acoustic wave resonator according to claim 1, characterized in that In the direction from the substrate to the piezoelectric layer, the width of the groove remains unchanged; or the width of the groove gradually increases.

7. The acoustic wave resonator according to any one of claims 1 to 6, characterized in that: The thickness of the acoustic velocity compensation layer is in the range of 10 nm to 10000 nm; The thickness of the finger strips ranges from 10 nm to 10000 nm; The thickness of the piezoelectric layer is in the range of 10 nm to 10000 nm.

8. The acoustic wave resonator according to any one of claims 1 to 6, characterized in that: The Young's modulus of the acoustic velocity compensation layer is in the range of 5×10 10 Pa~1×10 12 Pa; The density of the sonic velocity compensation layer is in the range of 2000 kg / m 3 ~6000kg / m 3 .

9. A method for preparing an acoustic wave resonator, characterized in that: include: providing a substrate; forming a piezoelectric layer on a surface of the substrate; A sound velocity compensation layer is formed on a surface of the piezoelectric layer facing away from the substrate, wherein the sound velocity compensation layer has a plurality of grooves arranged in sequence along a first direction; the first direction is parallel to the plane where the piezoelectric layer is located; Based on the acoustic velocity compensation layer having the grooves, a forked electrode is formed on the surface of the piezoelectric layer facing away from the substrate, and the forked electrode includes a plurality of fingers arranged one-to-one corresponding to the grooves; the fingers are in electrical contact with the piezoelectric layer based on the corresponding grooves.

10. An electronic device, characterized in that: Comprising the acoustic wave resonator according to any one of claims 1-8.

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