An ultrahigh frequency elastic wave device and a communication device

Abstract

This invention relates to the field of microelectronics technology, and particularly to an ultra-high frequency elastic wave device and communication equipment. The ultra-high frequency elastic wave device includes a supporting substrate; at least one resonator group suspended on the supporting substrate; each resonator group includes at least one resonant unit and a first connector; the resonant unit includes a bottom electrode, a piezoelectric layer, and a top electrode arranged sequentially from bottom to top; the first connector is disposed on the sidewall of the piezoelectric layer; wherein the top electrode and bottom electrode in the same resonator unit have opposite potentials, and the thickness of the first connector is less than the sum of the thicknesses of the top electrode, the bottom electrode, and the piezoelectric layer. This enhances the mechanical stability and heat dissipation capacity of the resonant unit and increases the power tolerance of the device while essentially maintaining the mode vibration distribution.

Description

Technical Field

[0001] This invention relates to the field of microelectronics technology, and in particular to an ultra-high frequency elastic wave device and communication equipment. Background Technology

[0002] As a core component of radio frequency filters, the performance of acoustic resonators directly determines the signal processing capabilities of modern wireless communication systems. With the evolution of communication technology towards higher frequencies, wider bandwidths, and higher power, the industry has placed increasingly stringent demands on the operating frequency, bandwidth, power capacity, and reliability of acoustic devices.

[0003] While current mainstream bulk acoustic wave (BAW) resonators are easy to achieve high-frequency resonance, their bandwidth is limited by the electromechanical coupling coefficient of the piezoelectric material; while surface acoustic wave (SAW) devices face limitations in physical principles and manufacturing processes to further increase the frequency. To overcome these limitations, various novel structures have been proposed.

[0004] Specifically, prior art (CN120281286A) discloses a resonator composed of a strip-shaped piezoelectric layer and top and bottom electrodes, with through-etched grooves on both sides. A longitudinal electric field excites a double-shear body acoustic wave mode with vibrations distributed at the four corners of the cross-section, thus possessing both high frequency and large bandwidth potential. However, this through-groove structure significantly weakens the device's mechanical strength and heat dissipation capacity, posing a challenge to its long-term reliability and power tolerance. Another prior art (CN108540105A) discloses a radio frequency resonator structure, which fabricates groove structures on both the upper and lower surfaces of the piezoelectric layer and uses upper and lower interdigitated electrodes to excite Lamb wave modes. This groove structure helps suppress parasitic modes and improve the electromechanical coupling coefficient. The target mode is a Lamb wave that propagates horizontally and reflects at the free boundary to form a standing wave. However, this mode has a limited electromechanical coupling coefficient, and its horizontal propagation easily forms higher-order longitudinal parasitic modes, typically requiring a large number of interdigitated pairs, increasing the area of ​​the suspended region, and affecting mechanical stability.

[0005] It is evident that while pursuing higher frequencies and wider bandwidths, acoustic resonators in related technologies often compromise on mechanical strength, heat dissipation, clutter suppression, or structural stability, or face new challenges. Therefore, there is an urgent need for an innovative resonator design that can simultaneously ensure the structural reliability, power handling capability, and long-term operational stability of the device while achieving excellent high-frequency broadband performance. Summary of the Invention

[0006] To address the aforementioned technical problems, in one aspect, an ultra-high frequency elastic wave device is provided, comprising: a supporting substrate; at least one resonator group suspended on the supporting substrate; each resonator group including at least one resonant unit and a first connector; the resonant unit including a bottom electrode, a piezoelectric layer, and a top electrode arranged sequentially from bottom to top; the first connector being disposed on the sidewall of the piezoelectric layer; wherein the potentials of the top electrode and the bottom electrode in the same resonator unit are opposite, and the thickness of the first connector is less than the sum of the thickness of the top electrode, the thickness of the bottom electrode, and the thickness of the piezoelectric layer.

[0007] Optionally, adjacent resonant units are connected to each other via the first connector.

[0008] Optional, including at least two resonator groups; Each of the resonator groups includes at least two of the resonant units; Adjacent resonant units within the same resonator group are connected via the first connector; resonant units in different resonator groups are not connected.

[0009] Optionally, each of the resonant units has a first connector on each of its opposite sides.

[0010] Optionally, the material of the first connector is the same as the material of the piezoelectric layer, and the thickness of the first connector is less than or equal to 0.8h1 and greater than or equal to 0.1h1; h1 represents the thickness of the piezoelectric layer; Alternatively, the material of the first connector is different from the material of the piezoelectric layer, and the thickness of the first connector is greater than or equal to 0.1h1.

[0011] Optionally, when the material of the first connection is the same as the material of the piezoelectric layer, the thickness of the first connector is less than or equal to 0.6h1; When the material of the first connection is different from the material of the piezoelectric layer, the thickness of the first connection is less than or equal to 0.8h1.

[0012] Optionally, the target mode of the ultra-high frequency elastic wave device is a higher-order mode of horizontal shear mode, vertical shear mode, or thickness expansion mode; the higher-order mode is a mode with an order greater than or equal to 1.

[0013] Optionally, when the target mode is a first-order vertical shear mode, the vibration of the target mode of the ultra-high frequency elastic wave device is concentrated at the four corners of the piezoelectric layer cross section.

[0014] Optionally, when the target mode of the ultra-high frequency elastic wave device is a first-order vertical shear mode, the width of the first connector satisfies [0.1W1, 3W1]; where W1 represents the width of the resonant unit. When the target mode is a first-order horizontal shearing mode or a first-order thickness expansion mode, the width of the first connector is greater than or equal to 0.1W1.

[0015] Optionally, the top electrode covers the top of the piezoelectric layer and the top of the first connector; The bottom electrode covers the bottom of the piezoelectric layer and the bottom of the first connector.

[0016] Optionally, in any resonator group, the potentials of the top electrodes of adjacent resonator units are opposite, and the potentials of the bottom electrodes of adjacent resonator units are opposite.

[0017] Optionally, in any resonator group, the top electrodes of adjacent resonator units have the same potential, and the bottom electrodes of adjacent resonator units have the same potential.

[0018] Optionally, in any resonator group, the potentials of the top electrodes of adjacent resonator units are opposite; The bottom electrode of all resonant units is at a floating potential; the bottom electrode is short-circuited outside the resonant region; the resonant region is the area where the top electrode, the piezoelectric layer, and the bottom electrode overlap.

[0019] Optionally, a second connector may also be included; One end of the second connector is connected to the first connector, and the other end of the second connector is connected to the supporting substrate.

[0020] Optionally, a dielectric layer may also be included; The dielectric layer is disposed between the second connector and the supporting substrate; The dielectric layer may be a single-layer material or a multi-layer material; The material of the dielectric layer includes one or more of silicon oxide, silicon nitride, polycrystalline silicon, amorphous silicon, aluminum oxide, and aluminum nitride; The dielectric layer is one or more of the following: temperature compensation layer, heat dissipation layer, trap-rich layer, bonding layer, low sound velocity layer, and dispersion modulation layer.

[0021] Optionally, a third connector may also be included; One end of the third connector is connected to the bottom electrode, and the other end of the third connector is connected to the supporting substrate; the width of the third connector is less than or equal to half the width of the bottom electrode.

[0022] Optionally, the materials of the first connector, the second connector, and the third connector may be different, or they may all be the same, or any two connectors may be made of the same material.

[0023] Optionally, in each of the resonant units, the sidewall of the piezoelectric layer can be one or more combinations of straight lines, broken lines, and arcs.

[0024] Optionally, the material of the piezoelectric layer is one of lithium tantalate, lithium niobate, aluminum nitride, aluminum nitride-doped, lead zirconate titanate, or lead magnesium niobate-lead titanate. At least one of the absolute values ​​of the piezoelectric coefficients e33, e34, and e35 along the first direction of the piezoelectric layer is not less than 1 C / m. 2 Alternatively, the sum of the absolute values ​​of the piezoelectric coefficients e31, e33, and e35 is not less than 1 C / m. 2 The first direction is the normal direction of the plane formed by the long side of the resonant unit and the thickness direction of the piezoelectric layer.

[0025] On the other hand, a communication device is provided, characterized in that it at least includes the above-mentioned ultra-high frequency elastic wave device; The communication device includes one of the following: a filter, a duplexer, a multiplexer, and a filter module.

[0026] This application provides an ultra-high frequency elastic wave device, comprising a supporting substrate; at least one resonator group suspended on the supporting substrate; each resonator group comprising at least one resonant unit and a first connector; the resonant unit comprising a bottom electrode, a piezoelectric layer, and a top electrode arranged sequentially from bottom to top; the first connector being disposed on the sidewall of the piezoelectric layer; wherein the top electrode and bottom electrode in the same resonator unit have opposite potentials, and the thickness of the first connector is less than the sum of the thicknesses of the top electrode, the bottom electrode, and the piezoelectric layer. This enhances the mechanical stability and heat dissipation capacity of the resonant unit and increases the power tolerance of the device while essentially maintaining the mode vibration distribution. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a first type of ultra-high frequency elastic wave device exemplified in this application; Figure 2 This is a schematic diagram of the structure of a second type of ultra-high frequency elastic wave device exemplified in this application; Figure 3 This is a schematic diagram of the structure of an existing elastic wave device exemplified by this application; Figure 4 This is a schematic diagram of another existing frequency elastic wave device exemplified by this application; Figure 5 The admittance curve of an existing elastic wave device is exemplified in this application; Figure 6 This is a schematic diagram of the structure of a third type of ultra-high frequency elastic wave device exemplified in this application; Figure 7 for Figure 2 Top view of the intermediate voltage layer; Figure 8 for Figure 2 Top view of the intermediate voltage layer and the first connector; Figure 9 This is an exemplary positional relationship diagram between a piezoelectric layer and a first connector in this application; Figure 10 Admittance curves for a first set of exemplary examples of this application; Figure 11 for Figure 10 The corresponding mode shape diagram; Figure 12 Admittance curves for a second set of exemplary examples of this application; Figure 13 for Figure 12 The corresponding mode shape diagram; Figure 14 This is a schematic diagram of the structure of a fourth type of ultra-high frequency elastic wave device exemplified in this application; Figure 15 Admittance curves for a third set of examples exemplified in this application; Figure 16 Admittance curves for a fourth set of examples exemplified in this application; Figure 17 This application provides an exemplary set of displacement distribution curves; Figure 18 Admittance curves for a fifth set of examples exemplified in this application; Figure 19 for Figure 18 The corresponding mode shape diagram; Figure 20 Admittance curves for the sixth group of examples exemplified in this application; Figure 21 This is a schematic diagram of the structure of a fifth type of ultra-high frequency elastic wave device exemplified in this application; Figure 22 An admittance curve is provided as an example of one instance of this application; Figure 23This is a schematic diagram of the structure of a sixth type of ultra-high frequency elastic wave device exemplified in this application; Figure 24 This is a schematic diagram of the structure of the seventh type of ultra-high frequency elastic wave device exemplified in this application; Figure 25 This is a schematic diagram of the structure of the eighth type of ultra-high frequency elastic wave device exemplified in this application; Figure 26 Admittance curves for the seventh group of examples exemplified in this application; Figure 27 Admittance curves for the eighth set of examples exemplified in this application; Figure 28 This is a top view of an exemplary top electrode and bottom electrode of this application; Figure 29 This is a top view of another exemplary top electrode of this application; Figure 30 This is a top view of another exemplary bottom electrode of this application; Figure 31 This is a schematic diagram of the structure of the ninth type of ultra-high frequency elastic wave device exemplified in this application; Figure 32 This is a schematic diagram of the structure of the tenth type of ultra-high frequency elastic wave device exemplified in this application; Figure 33 This is a schematic diagram of the eleventh type of ultra-high frequency elastic wave device exemplified in this application; Figure 34 This is a schematic diagram of the structure of the twelfth type of ultra-high frequency elastic wave device exemplified in this application; Figure 35 This is a schematic diagram of the thirteenth ultra-high frequency elastic wave device exemplified in this application; Figure 36 This is a schematic diagram of the structure of the fourteenth ultra-high frequency elastic wave device exemplified in this application; Figure 37 Admittance curves for the ninth exemplary instance of this application; Figure 38 for Figure 37 The corresponding mode shape diagram; Figure 39 for Figure 37 The corresponding mode shape diagram; Figure 40 An admittance curve for another exemplary instance of this application; Figure 41 Admittance curves for the tenth group of examples exemplified in this application; Figure 42 for Figure 41 The corresponding mode shape diagram; Figure 43This is a schematic diagram of the structure of the fifteenth type of ultra-high frequency elastic wave device exemplified in this application; Figure 44 This is a schematic diagram of the structure of the sixteenth type of ultra-high frequency elastic wave device exemplified in this application; Figure 45 This is a schematic diagram of the structure of the seventeenth type of ultra-high frequency elastic wave device exemplified in this application; Figure 46 Admittance curves for the eleventh exemplary instance of this application; Figure 47 for Figure 46 The corresponding mode shape diagram.

[0029] The following is supplementary explanation of the attached figures: 1-Supporting substrate; 2-Resonator group; 201-Resonant unit; 202-First connector; 3-Bottom electrode; 4-Piezoelectric layer; 5-Top electrode; 6-Second connector; 7-Third connector; 8-Dielectric layer; 9-Busbar; 10-Electrode finger; 11-Cavity; 12-Knockout area. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. In the description of this application, it should be understood that the terms "upper," "lower," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0032] Although the numerical ranges and parameters illustrating the broad scope of the invention are approximate, the values ​​listed in the specific examples are reported as precisely as possible. However, any numerical value inherently contains some error that is necessarily caused by the standard deviation found in their respective test measurements.

[0033] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Optionally, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Furthermore, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. For example, a specified range from “1 to 10” should be considered to include any and all subranges between the minimum value 1 and the maximum value 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0034] Please see Figure 1 The diagram shows a schematic representation of the structure of a first exemplary ultra-high frequency elastic wave device of this application. This application provides an ultra-high frequency elastic wave device, comprising: a supporting substrate 1; at least one resonator group 2 suspended on the supporting substrate 1; each resonator group 2 includes at least one resonant unit 201 and a first connector 202; the resonant unit 201 includes a bottom electrode 3, a piezoelectric layer 4, and a top electrode 5 arranged sequentially from bottom to top; the first connector 202 is disposed on the sidewall of the piezoelectric layer 4; wherein the potentials of the top electrode 5 and the bottom electrode 3 in the same resonator unit are opposite, and the thickness of the first connector 202 is less than the sum of the thicknesses of the top electrode 5, the bottom electrode 3, and the piezoelectric layer 4.

[0035] For example, please continue reading Figure 1 A cavity 11 is provided on the supporting substrate 1, and the resonator group 2 is disposed on the cavity 11, thereby suspending it on the supporting substrate 1. The specific structure and method of forming the cavity 11 are described in detail below.

[0036] In one exemplary embodiment, the piezoelectric layer 4 is made of one of lithium tantalate, lithium niobate, aluminum nitride, aluminum nitride-doped aluminum nitride, lead zirconate titanate, or lead magnesium niobate-lead titanate; at least one of the absolute values ​​of the piezoelectric coefficients e33, e34, and e35 along the first direction of the piezoelectric layer 4 is not less than 1 C / m. 2 Alternatively, the sum of the absolute values ​​of the piezoelectric coefficients e31, e33, and e35 is not less than 1 C / m. 2 The first direction is the normal direction of the plane formed by the long side of the resonant unit 201 and the thickness direction of the piezoelectric layer 4. Please continue reading. Figure 1 In the resonant unit 201, the long side can be the y direction perpendicular to the xz plane, the first direction is the x direction, and the thickness direction of the piezoelectric layer 4 is the z direction.

[0037] In one exemplary embodiment, the bottom electrode 3 and the top electrode 5 are made of conductive materials; the conductive materials include one or more combinations of copper, aluminum, gold, silver, tungsten, platinum, nickel, chromium, molybdenum, titanium, graphene, copper-aluminum alloy, aluminum-silicon alloy, doped silicon, silicon carbide, and gallium nitride.

[0038] In one exemplary embodiment, the material of the support substrate 1 can be a high resistivity material, such as sapphire or silicon carbide.

[0039] In one exemplary embodiment, in each of the resonant units 201, the sidewall of the piezoelectric layer 4 can be one or more combinations of straight lines, broken lines, and arcs. See also... Figure 1 The sidewalls of the piezoelectric layer 4 are straight lines, but in the actual photolithography process, the sidewalls of the piezoelectric layer 4 can also be broken lines or arcs depending on the process conditions.

[0040] In one exemplary implementation, please refer to Figure 2 Adjacent resonant units 201 are connected via the first connector 202. Optionally, the thickness h2 of the first connector 202 is less than the sum of the thickness h1 of the piezoelectric layer 4, the thickness of the top electrode 5, and the thickness of the bottom electrode 3. Optionally, the potentials of the top electrode 5 and the bottom electrode 3 of the same resonant unit 201 are opposite, and the potentials of the top electrodes 5 of adjacent resonant units 201 are the same, and the potentials of the bottom electrodes 3 of adjacent resonant units 201 are the same.

[0041] To better demonstrate the beneficial effects of this solution, specific proportions and examples are provided below: Provide a pair of comparative examples 1, 2, and 3, wherein the structure of comparative example 1 is as follows: Figure 3 The structure shown includes, from bottom to top, a supporting substrate 1, a bottom electrode 3, a piezoelectric layer 4, and a top electrode 5. The structures of Comparative Examples 2 and 3 are as follows... Figure 4As shown, the structure includes a support substrate 1, a bottom electrode 3, a piezoelectric layer 4, and a top electrode 5 arranged sequentially from bottom to top. The layer structure formed by the bottom electrode 3, the piezoelectric layer 4, and the top electrode 5 is divided by multiple through-holes spaced apart along a first direction, thereby forming multiple spaced resonant units 201. Specifically, in Comparative Examples 1, 2, and 3, the support substrate 1 is made of silicon carbide, the top electrode 5 and the bottom electrode 3 are made of aluminum, both with a thickness of 50 nm, and the piezoelectric layer 4 is made of X-cut lithium niobate with a thickness h1 of 400 nm. The width W1 of the resonant unit 201 in Comparative Examples 2 and 3 is 400 nm. The in-plane orientation of Comparative Example 2 has an angle of 38° with the crystal Y-axis, and the in-plane orientation of Comparative Example 3 has an angle of 119° with the crystal Y-axis. Through relevant calculations, the following can be obtained: Figure 5 The admittance curve shown is from Figure 5 As can be seen, for the thin-film bulk acoustic resonator structure composed of X-cut lithium niobate, there exists a coupling between two shear waves: vertical and horizontal shear waves. In this case, the strong parasitic modes cannot meet the requirements of filter applications. When a through-hole is present and a suitable in-plane orientation is chosen, the two shear waves decouple. For example, in Comparative Example 2, the first-order vertical shear mode disappears, leaving only the first-order horizontal shear mode, with an electromechanical coupling coefficient as high as 100.5%. In Comparative Example 3, the first-order horizontal shear mode disappears, leaving only the first-order vertical shear mode, with an electromechanical coupling coefficient as high as 61.5%. Both modes can meet the bandwidth requirements of any frequency band below 12 GHz, but the through-hole will cause a serious decrease in the structural stability of the device.

[0042] Furthermore, by introducing a connector in the middle of the resonant unit 201, this scheme can enhance structural stability and improve heat dissipation without significantly altering the mode vibration distribution. The connector can also be directly connected to the supporting substrate 1, thereby introducing parasitic modes into the substrate, weakening out-of-band parasitic responses, and improving out-of-band suppression levels.

[0043] In another exemplary implementation, please continue to refer to Figure 1 The ultra-high frequency elastic wave device includes at least two resonator groups 2; each resonator group 2 includes at least two resonant units 201; adjacent resonant units 201 within the same resonator group 2 are connected by the first connector 202; resonant units 201 in different resonator groups 2 are not connected. In this embodiment, each resonator group 2 includes two resonant units 201; in other embodiments, each resonator group 2 includes three, four, or five or more resonant units 201; the number of resonant units 201 included in different resonator groups 2 may be the same or different. In this embodiment, each resonator group 2 includes two resonant units 201.

[0044] When there are no connecting parts between the resonator groups 2, and each resonator group 2 includes multiple resonant units 201, the ultra-high frequency elastic wave device may include the above-mentioned... Figure 1 , and the following text Figure 6 , Figure 24 and Figure 34 The structure shown.

[0045] In another exemplary implementation, please refer to Figure 6 Each of the resonant units 201 has a first connector 202 on each of its opposite sides. Optionally, the resonant units 201 within the same resonator group 2 are connected to each other via the first connector 202.

[0046] It is understandable that the first connector 202 can be provided only between the resonant units 201 (i.e., as shown in the image). Figure 1 The structure shown can also have a first connector 202 on each side of each resonant unit 201 (i.e., as shown). Figure 6 (The structure shown).

[0047] In another exemplary implementation, please refer to Figure 7 The piezoelectric layer 4 includes a plurality of hollow regions 12 spaced apart along a first direction, dividing the piezoelectric layer 4 into a plurality of piezoelectric regions arranged along the first direction. Each piezoelectric region has a top electrode 5 at its top and a bottom electrode 3 at its bottom, thereby forming a plurality of resonant units 201. Please refer to [link to relevant documentation]. Figure 8 The first connector 202 is specifically located in the hollow area 12, thereby placing the connector in the resonant region of the elastic wave device, i.e., corresponding to... Figure 2 The resonant region of the elastic wave device is the area where the bottom electrode 3, the top electrode 5, and the piezoelectric layer 4 overlap.

[0048] In another exemplary implementation, please refer to Figure 9 The piezoelectric layer 4 in the resonant region and the piezoelectric layer 4 in the non-resonant region are also connected by the first connector 202.

[0049] The above describes the connection method between the resonant unit 201 and the first connector 202. The following describes the correlation between the material of the first connector 202 and the material of the piezoelectric layer 4: In one exemplary embodiment, the material of the first connector 202 is the same as the material of the piezoelectric layer 4, and the thickness h2 of the first connector 202 is less than or equal to 0.8h1 and greater than or equal to 0.1h1; h1 represents the thickness of the piezoelectric layer 4. This ensures the structural stability of the device while avoiding noise.

[0050] In another exemplary embodiment, when the material of the first connection is the same as the material of the piezoelectric layer 4, the thickness h2 of the first connector 202 is less than or equal to 0.6h1. This can further improve the performance of the device.

[0051] In another exemplary embodiment, the material of the first connector 202 is different from the material of the piezoelectric layer 4, and the thickness of the first connector 202 is greater than or equal to 0.1h1. This ensures the structural stability of the device.

[0052] In another exemplary embodiment, when the material of the first connector is different from the material of the piezoelectric layer 4, the thickness h2 of the first connector 202 is less than or equal to 0.8h1. This avoids noise.

[0053] First, when the material of the first connector 202 is different from the material of the piezoelectric layer 4, the following example is provided.

[0054] Specifically, a set of examples is provided, with the following structure: Figure 2 The structure shown has a substrate 1 made of silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 is X-cut lithium niobate with a thickness h1 of 400 nm; the width of the resonant unit 201 is 400 nm, and its in-plane orientation forms a 38° angle with the crystal Y-axis; the first connector 202 is made of silicon nitride with a thickness h2 ranging from 0 to 400 nm (specifically including 0 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, and 400 nm), and its width is 400 nm; the target mode is a first-order horizontal shearing mode. Through relevant calculations, the following can be obtained: Figure 10 The admittance curves shown indicate that when the connector thickness is less than 300 nm, the two shear waves are essentially decoupled, and clutter is suppressed. Optional analysis... Figure 10 The corresponding mode shape, i.e. Figure 11 It can be seen that, Figure 11 Figure (a) shows the case where the thickness of the first connector 202 is 0. Figure 11 Figure (b) shows the case where the thickness of the first connector 202 is 200 nm. Figure 11 Figure (c) shows the case where the thickness of the first connector 202 is 400 nm. The vibration of the first-order horizontal shear mode is concentrated on the upper and lower surfaces of the cross-section, with very little distribution in the middle region. When the thickness of the first connector 202 is small (e.g., 200 nm), the master mode basically does not enter the region of the first connector 202. When the thickness of the first connector 202 is large (e.g., 400 nm), the master mode will enter the region of the first connector 202 (see Figure 200). Figure 11 In Figure (c), the upper and lower areas of the first connector 202 are highlighted.

[0055] Specifically, another set of examples is provided, with the following structure: Figure 2 The structure shown has a substrate 1 made of silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 is X-cut lithium niobate with a thickness h1 of 400 nm; the width of the resonant unit 201 is 400 nm, and its in-plane orientation forms an angle of 119° with the crystal Y-axis; the first connector 202 is made of silicon nitride with a thickness h2 ranging from 0 to 400 nm (specifically including 0 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm), and a width of 400 nm; the target mode is a first-order vertical shear mode. Through relevant calculations, the following can be obtained: Figure 12 The admittance curves shown indicate that when the thickness of the first connector 202 is less than 250 nm, the two shear waves are essentially decoupled, and clutter is suppressed. Optional analysis... Figure 12 The corresponding mode shape, i.e. Figure 13 It can be seen that, Figure 13 Figure (a) shows the case where the thickness of the first connector 202 is 0. Figure 13 Figure (b) shows the case where the thickness of the first connector 202 is 200 nm. Figure 13 Figure (c) shows the case where the thickness of the first connector 202 is 400 nm. The vibration of the first-order vertical shear mode is concentrated at the four corners of the cross-section, with very little distribution in the central region. When the thickness of the first connector 202 is small (e.g., 200 nm), the master mode basically does not enter the region of the first connector 202. When the thickness of the first connector 202 is large (e.g., 400 nm), the master mode will enter the region of the first connector 202 (see Figure 204). Figure 13 In Figure (c), the upper and lower areas of the first connector 202 are highlighted.

[0056] Secondly, when the material of the first connector 202 is the same as the material of the piezoelectric layer 4, the following example is provided.

[0057] Specifically, a set of examples is provided, with the following structure: Figure 14The structure shown has a silicon carbide substrate 1; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 and the first connector 202 are both made of X-cut lithium niobate, with the piezoelectric layer 4 having a thickness h1 of 400 nm; the in-plane orientation has an angle of 38° with the crystal Y-axis; the thickness h2 of the first connector 202 ranges from 0 to 400 nm (specifically including 0 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm), and the width of the first connector 202 is 400 nm; the target mode is a first-order horizontal shearing mode. Through relevant calculations, the following can be obtained: Figure 15 As shown in the admittance curve, it can be seen that when the thickness of the connector is less than 300nm, the two shear waves are basically decoupled, and the clutter near the main mode is suppressed.

[0058] Specifically, another set of examples is provided, with the following structure: Figure 14 The structure shown has a substrate 1 made of silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 and the first connector 202 are both made of X-cut lithium niobate, with the piezoelectric layer 4 having a thickness h1 of 400 nm; the in-plane orientation has an angle of 119° with the crystal Y-axis; the thickness h2 of the first connector 202 ranges from 0 to 400 nm (specifically including 0 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm), and the width of the first connector 202 is 400 nm; the target mode is a first-order vertical shear mode. Through relevant calculations, the following can be obtained: Figure 16 As shown in the admittance curve, it can be seen that when the thickness of the connector is less than 250nm, the two shear waves are basically decoupled, and the clutter near the main mode is suppressed.

[0059] By comparison Figure 15 and Figure 10 ,contrast Figure 16 and Figure 12 It can be observed that when the material of the first connector 202 is different from that of the piezoelectric layer 4, there are significantly fewer parasitic modes over a wide frequency range. This is because some of the electric field entering the first connector 202, which has a piezoelectric effect, will excite parasitic modes. In addition, when the material of the first connector 202 is different from that of the piezoelectric layer 4, the difference in acoustic impedance will also reduce the generation of parasitic modes.

[0060] In one exemplary embodiment, the target mode of the ultra-high frequency elastic wave device is one of a first-order horizontal shear mode, a first-order vertical shear mode, and a first-order thickness stretching mode.

[0061] In another exemplary embodiment, the target mode is a higher-order mode of a horizontal shearing mode, a vertical shearing mode, or a thickness stretching mode; the higher-order mode is a mode with an order greater than or equal to 1. For example, it can be a first-order horizontal shearing mode, a first-order vertical shearing mode, a third-order horizontal shearing mode, or a third-order vertical shearing mode.

[0062] In one exemplary embodiment, when the target mode is a first-order vertical shear mode, the vibration of the target mode of the ultra-high frequency elastic wave device is concentrated at the four corners of the piezoelectric layer 4 cross section.

[0063] In one exemplary embodiment, when the target mode of the ultra-high frequency elastic wave device is a first-order vertical shear mode, the width of the first connector 202 satisfies [0.1W1, 3W1], where W1 represents the width of the resonant unit 201; when the target mode is a first-order horizontal shear mode or a first-order thickness expansion mode, the width of the first connector 202 is greater than or equal to 0.1W1. This reduces noise and improves device performance while lowering manufacturing complexity.

[0064] Please see Figure 17 , with the above Figure 11 and Figure 13 Corresponding to the mode shape diagrams, it can be seen that the displacement amplitudes of the first-order vertical shear mode and the first-order horizontal shear mode are the largest at the upper and lower ends of the cross section, while the displacement amplitude near the central axis is close to 0.

[0065] Specifically, another set of examples is provided, with the following structure: Figure 2 The structure shown has a substrate 1 made of silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 is made of X-cut lithium niobate, with a thickness h1 of 400 nm and an in-plane orientation at an angle of 119° to the crystal Y-axis; the first connector 202 is made of silicon nitride, with a thickness h2 of 200 nm and widths of 400 nm, 1200 nm, and 2800 nm. The resonant unit 201 has a width of 400 nm; the target mode is a first-order vertical shear mode. Calculations yield the following results: Figure 18 The admittance curves shown indicate that clutter exists when the width of the first connector 202 is relatively wide. For example, there is no clutter at 400 nm, but clutter exists at 1200 nm and 2800 nm. Further analysis... Figure 18 The corresponding mode shape, i.e. Figure 19 It can be seen that, Figure 19 Figure (a) shows the case where the width of the first connector 202 is 1200 nm. Figure 19Figure (b) shows the case where the width of the first connector 202 is 2800 nm. It can be seen that when the width of the connector is too large (i.e. the width of the first connector 202 is 2800 nm), it causes parasitic response near the main mode frequency. For the first-order vertical shear mode, since it is mainly related to the piezoelectric coefficient e35 or e31, it will also excite the higher harmonics of the 0th-order antisymmetric Lamb wave mode.

[0066] Provide another set of instances, whose structure is as follows: Figure 2 The structure shown has a silicon carbide substrate 1; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 is made of X-cut lithium niobate, with a thickness h1 of 400 nm and an in-plane orientation at an angle of 38° to the crystal Y-axis; the first connector 202 is made of silicon nitride, with a thickness h2 of 200 nm and widths of 400 nm, 1200 nm, and 2800 nm. The resonant unit 201 has a width of 400 nm; the target mode is a first-order horizontal shearing mode. Calculations yield the following results: Figure 20 As shown in the admittance curve, it can be seen that for the first-order horizontal shear mode or the first-order thickness expansion mode, the width of the first connector 202 has almost no effect on the main mold.

[0067] The structure of the top electrode 5 and the bottom electrode 3 will be described in detail below: In one exemplary implementation, please refer to Figure 21 The top electrode 5 covers the top of the piezoelectric layer 4 and the top of the first connector 202; the bottom electrode 3 covers the bottom of the piezoelectric layer 4 and the bottom of the first connector 202. Alternatively, the thickness of the first connector 202 can be described as being comparable to the thickness of the resonant unit 201, and the first connector 202 includes a first electrode layer, a dielectric connection layer, and a second electrode layer arranged sequentially from bottom to top; wherein the dielectric connection layer is located on the sidewall of the piezoelectric layer 4, and the thickness of the dielectric connection layer is less than the thickness of the piezoelectric layer 4. The material of the first electrode layer can be the same as the material of the bottom electrode 3, and the material of the second electrode layer can be the same as the material of the top electrode 5.

[0068] Specifically, an example is provided, with the following structure: Figure 21 The structure shown has a substrate 1 made of silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 is made of X-cut lithium niobate, with a thickness h1 of 400 nm and an in-plane orientation at an angle of 38° to the crystal Y-axis; the first connector 202 is made of silicon nitride, with a thickness h2 of 200 nm; the target mode is a first-order horizontal shear mode. Calculations can be performed to obtain the following... Figure 22As shown in the admittance curve, it can be seen that since the connector does not have piezoelectric properties, even if the electrode covers the first connector 202, the two shear waves can still be decoupled.

[0069] In one exemplary implementation, please refer to Figure 23 and Figure 24 The potentials of the top electrode 5 of adjacent resonant units 201 are opposite, and the potentials of the bottom electrode 3 of adjacent resonant units 201 are opposite.

[0070] In one exemplary implementation, please refer to Figure 14 The potentials of the top electrodes 5 of adjacent resonant units 201 are the same, and the potentials of the bottom electrodes 3 of adjacent resonant units 201 are the same.

[0071] In one exemplary implementation, please refer to Figure 25 The top electrodes 5 of adjacent resonant units 201 have opposite potentials; the bottom electrodes 3 of all resonant units 201 are at a floating potential; the bottom electrodes 3 are short-circuited outside the resonant region; the resonant region is the area where the top electrodes 5, the piezoelectric layer 4, and the bottom electrodes 3 overlap.

[0072] Specifically, another set of instances is provided, each instance corresponding to a structure, specifically corresponding to structure one (i.e. Figure 23 The structure shown), structure two (i.e. Figure 24 The structure shown), structure three (i.e. Figure 2 The structure shown), structure four (i.e. Figure 6 (As shown in the structure), in this set of examples, the material of the supporting substrate 1 is silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are aluminum, each with a thickness of 50 nm; the material of the piezoelectric layer 4 is X-cut lithium niobate, the thickness h1 of the piezoelectric layer 4 is 400 nm, and the in-plane orientation makes an angle of 38° with the crystal Y-axis; the material of the first connector 202 is silicon nitride, and the thickness h2 of the first connector 202 is 200 nm; the target mode is a first-order horizontal shear mode. Relevant calculations can be performed to obtain... Figure 26 As shown in the admittance curves, for structures one and two, the presence of a periodic electric field excites a high-frequency 0th-order mode and its harmonics (the frequency of the 0th-order mode is mainly determined by the electrode period; this type of parasitic mode can be removed by adjusting the period of the resonant unit 201). For structures three and four, since all electric fields are in the same direction, there are fewer parasitic modes, making them superior designs to structures one and two.

[0073] Provide another set of instances, each instance corresponding to a different structure, specifically corresponding to structure one (i.e. Figure 23 The structure shown), structure two (i.e. Figure 24 The structure shown), structure three (i.e. Figure 2 The structure shown), structure four (i.e. Figure 6 (As shown in the structure), in this set of examples, the material of the supporting substrate 1 is silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are aluminum, each with a thickness of 50 nm; the material of the piezoelectric layer 4 is X-cut lithium niobate, the thickness h1 of the piezoelectric layer 4 is 400 nm, and the in-plane orientation makes an angle of 119° with the crystal Y-axis; the material of the first connector 202 is silicon nitride, and the thickness h2 of the first connector 202 is 200 nm; the target mode is a first-order vertical shear mode. Relevant calculations can be performed to obtain the following... Figure 26 The admittance curves shown also reveal that structures one and two exhibit more parasitic modes due to the periodic electric field. Therefore, through comparison... Figure 26 and Figure 27 It can be seen that when the top electrode 5 and bottom electrode 3 of adjacent resonant units 201 have the same potential, the parasitic effect is smaller. This is because when the top electrode 5 and bottom electrode 3 of adjacent resonant units 201 have opposite potentials, there will be a transverse electric field. Then, because its period is relatively small, the transverse electric field will excite some low-order modes.

[0074] In another exemplary implementation, please refer to Figure 28 The top electrode 5 and bottom electrode 3 of the ultra-high frequency elastic wave device can each be a comb-shaped structure. For example, the top electrode 5 includes a busbar 9 and multiple electrode fingers 10 connected to the busbar 9 and spaced apart along the length extension direction (i.e., the x-direction) of the busbar 9. The length of each electrode finger 10 can be the same. The bottom electrode 3 is a mirror image of the top electrode 5 and will not be described in detail here. The electrodes of this comb-shaped structure can specifically correspond to... Figure 2 Elastic wave devices.

[0075] In another exemplary implementation, please refer to Figure 29 The top electrode 5 and bottom electrode 3 of the ultra-high frequency elastic wave device can both be interdigital transducers. Specifically, the interdigital transducer can include two busbars 9 arranged opposite each other. Each busbar 9 has multiple electrode fingers 10 spaced apart along a first direction, with the electrode fingers 10 on different busbars 9 arranged alternately. Specifically, it can correspond to... Figure 23 The ultra-high frequency elastic wave device shown.

[0076] In another exemplary embodiment, the top electrode 5 of the ultra-high frequency elastic wave device is an interdigital transducer, and the bottom electrode 3 is a floating potential electrode structure, i.e., as shown in the figure. Figure 30 The structure shown, specifically, the electrode structure for the floating potential may include two busbars 9 arranged opposite each other, and a plurality of electrode fingers 10 spaced apart along a first direction. One end of each electrode finger 10 is connected to one busbar 9, and the other end of each electrode finger 10 is connected to another busbar 9. Specifically, it can correspond to... Figure 25 The ultra-high frequency elastic wave device shown.

[0077] The above describes the structure of the top electrode 5 and the bottom electrode 3. The following will describe the specific suspension method of the resonant unit 201: In another exemplary implementation, please refer to Figure 31 The structure and connection method of the resonant unit 201 can be as follows: Figure 2 The structure shown has an upward-opening groove structure in the middle of the support substrate 1 to form a cavity 11, and the suspended piezoelectric layer 4 is connected to the support substrate 1 through the first connector 202.

[0078] For example, please refer to Figure 1 The support substrate 1 has an upward-facing groove structure in the middle to form a cavity 11. The suspended piezoelectric layer 4 is connected to the support substrate 1 through the piezoelectric layer 4 outside the resonant region.

[0079] In another exemplary implementation, please refer to Figure 32 The ultra-high frequency elastic wave device also includes a second connector 6; one end of the second connector 6 is connected to the first connector 202, and the other end of the second connector 6 is connected to the supporting substrate 1. Specifically, the structure and connection method of the resonant unit 201 can be as follows: Figure 2 The structure shown depicts adjacent resonant units 201 connected together. In other embodiments, the structure and connection method of the resonant units 201 can be as follows: Figure 6 The structure shown. If each resonant unit 201 is connected to the supporting substrate 1 on both sides through a second connection, and adjacent resonant units 201 are not connected, that is, as shown... Figure 33 The structure shown. Please refer to [link / reference]. Figure 34 Each resonator group 2 is connected to a second connector 6 only through a first connector 202 connecting adjacent resonant units 201, thereby realizing a suspended resonant unit 201. The structure and connection method of the resonant unit 201 can be as follows: Figure 1 The corresponding structure in [the text].

[0080] In another exemplary implementation, please refer to Figure 35 The ultra-high frequency elastic wave device also includes a dielectric layer 8; the dielectric layer 8 is disposed between the second connector 6 and the supporting substrate 1; the dielectric layer 8 is a single-layer material or a multi-layer material; the material of the dielectric layer 8 includes one or more of silicon oxide, silicon nitride, polycrystalline silicon, amorphous silicon, aluminum oxide, and aluminum nitride; the dielectric layer 8 is one or more of a temperature compensation layer, a heat dissipation layer, a trap-rich layer, a bonding layer, a low sound velocity layer, and a dispersion control layer.

[0081] In another exemplary implementation, please refer to Figure 36The ultra-high frequency elastic wave device also includes a third connector 7; one end of the third connector 7 is connected to the bottom electrode 3, and the other end of the third connector 7 is connected to the supporting substrate 1; the width of the third connector 7 is less than or equal to half the width of the bottom electrode 3. Specifically, the structure and connection method of the resonant unit 201 can be as follows: Figure 2 The structure shown has adjacent resonant units 201 connected together; one end of the second connector 6 is connected to the first connector 202, and the other end of the second connector 6 is connected to the supporting substrate 1.

[0082] Specifically, another set of instances is provided, each instance corresponding to a structure, specifically corresponding to structure three (i.e. Figure 2 The structure shown), structure five (i.e. Figure 32 The structure shown), structure six (i.e. Figure 33 (As shown in the structure), in this set of examples, the material of the supporting substrate 1 is silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are aluminum, each with a thickness of 50 nm; the material of the piezoelectric layer 4 is X-cut lithium niobate, the thickness h1 of the piezoelectric layer 4 is 400 nm, and the in-plane orientation makes an angle of 38° with the crystal Y-axis; the material of the first connector 202 is silicon nitride, the thickness h2 of the first connector 202 is 250 nm; the width of the first connector 202 is 1200 nm, and the target mode is a first-order horizontal shearing mode; the material of the second connector 6 is silicon oxide, and the height is 400 nm; the width of the second connector 6 in structure five is 800 nm, and the width of the second connector 6 in structure six is ​​400 nm. Relevant calculations can be performed to obtain the following... Figure 37 The admittance curve shown, and Figure 38 and Figure 39 ,in, Figure 38 express Figure 37 The mode shapes corresponding to the principal mode and clutter of the fifth structure are shown in detail below. Figure 38 Figure (a) in the figure shows the mode shape diagram corresponding to the first-order horizontal shear mode; Figure 38 Figure (b) in the figure shows the mode shape corresponding to the third-order horizontal shear mode. Figure 39 express Figure 37 The mode shapes corresponding to the principal mode and clutter of the middle structure 6 are shown in detail below. Figure 39 Figure (a) in the figure shows the mode shape diagram corresponding to the first-order horizontal shear mode; Figure 39 Figure (b) shows the mode shape corresponding to the third-order horizontal shear mode. It can be seen that after connecting the first connector 202 to the support substrate 1, the higher-order horizontal shear modes leak to the support substrate 1 through the connector because the vibrations are more distributed near the central axis of the cross section. As a result, the parasitic modes are greatly weakened, which is beneficial to improving the out-of-band suppression level.

[0083] Provide another example, whose structure is as follows: Figure 33 The structure shown has a substrate 1 made of silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are made of aluminum, each with a thickness of 50 nm; the piezoelectric layer 4 is made of X-cut lithium niobate, with a thickness h1 of 200 nm and an in-plane orientation at an angle of 38° to the crystal Y-axis; the first connector 202 is made of silicon oxide, with a thickness h2 of 150 nm and a width of 750 nm; the second connector 6 is made of silicon oxide, with a width of 550 nm and a height of 400 nm; the resonant unit 201 has a width of 250 nm; and the target mode is a first-order horizontal shearing mode. Calculations yield the following results: Figure 40 As shown in the admittance curve, it can be seen that the parasitic mode can be suppressed.

[0084] Specifically, another set of instances is provided, each instance corresponding to a structure, specifically corresponding to structure three (i.e. Figure 2 The structure shown), structure five (i.e. Figure 32 The structure shown), structure six (i.e. Figure 33 (As shown in the structure), in this set of examples, the material of the supporting substrate 1 is silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are aluminum, each with a thickness of 50 nm; the material of the piezoelectric layer 4 is X-cut lithium niobate, the thickness h1 of the piezoelectric layer 4 is 400 nm, and the in-plane orientation makes an angle of 119° with the crystal Y-axis; the material of the first connector 202 is silicon nitride, the thickness h2 of the first connector 202 is 200 nm; the width of the first connector 202 is 1200 nm, and the target mode is a first-order vertical shear mode; the material of the second connector 6 is silicon oxide, and the height is 400 nm; the width of the second connector 6 in structure five is 800 nm, and the width of the second connector 6 in structure six is ​​400 nm. Relevant calculations can be performed to obtain the following... Figure 41 The admittance curve shown, and Figure 42 The mode shape diagram shown is, specifically, Figure 42 Figure (a) in the figure shows the mode shape corresponding to the first-order vertical shear mode; Figure 42 Figure (b) in the diagram shows the mode shape corresponding to the third-order vertical shear mode, and also indicates... Figure 41 The mode shapes corresponding to the principal mode and clutter in structure five are shown. It can be seen that after connecting the connector to the supporting substrate 1, the higher-order modes are weakened due to leakage.

[0085] In another exemplary implementation, please refer to Figure 43 The first connector 202 is made of the same material as the piezoelectric layer 4, and the first connector 202 is made of a different material than the second connector 6.

[0086] In another exemplary implementation, please refer to Figure 44The first connector 202 is made of a different material than the piezoelectric layer 4, and the first connector 202 is made of the same material as the second connector 6.

[0087] In another exemplary implementation, please refer to Figure 45 The first connector 202 is made of a different material than the piezoelectric layer 4, and the first connector 202, the second connector 6, and the third connector 7 are made of the same material.

[0088] In other embodiments, the first connector 202 may be made of the same material as the second connector 6, but different from the material of the third connector 7; the first connector 202 may be made of the same material as the third connector 7, but different from the material of the second connector 6; the second connector 6 may be made of the same material as the third connector 7, but different from the material of the first connector 202; or the materials of the first connector 202, the second connector 6, and the third connector 7 may be different (e.g., ...). Figure 36 The structure shown is an example of such implementations.

[0089] Specifically, another set of examples is provided, including Example 1 and Example 2, both of which have the same structure. Figure 45 In the structure shown, in this set of examples, the material of the supporting substrate 1 is silicon carbide; the top electrode 5 and bottom electrode 3 of each resonant unit 201 are aluminum, each with a thickness of 50 nm; the material of the piezoelectric layer 4 is X-cut lithium niobate, the thickness h1 of the piezoelectric layer 4 is 400 nm, and the in-plane orientation makes an angle of 119° with the crystal Y-axis; the material of the first connector 202 is silicon nitride, the thickness h2 of the first connector 202 is 200 nm, the width of the first connector 202 is 1200 nm, and the target mode is a first-order vertical shear mode; the material of the second connector 6 is silicon oxide, and the height is 400 nm; the material of the third connector 7 is silicon nitride, and the width is 100 nm. In Example 1, the height of the third connector 7 is 250 nm, and in Example 2, the height of the third connector 7 is 50 nm. That is, Example 1 and Example 2 differ only in the height of the third connector 7. Relevant calculations can be performed to obtain the following... Figure 46 The admittance curve shown, and Figure 47 The mode shape diagram shown is, specifically, Figure 47 Figure (a) in the figure shows the mode shape corresponding to the first-order vertical shear mode; Figure 47 Figure (b) shows the mode shape corresponding to the third-order vertical shear mode. It can be seen that adding the third connector 7 enhances the leakage of higher-order vertical shear modes, thus further suppressing the higher-order vertical shear response. However, this method only applies to the vertical shear mode because its vibration is distributed at the four corners of the cross section.

[0090] On the other hand, a communication device is provided, characterized in that it at least includes the above-mentioned ultra-high frequency elastic wave device; the communication device includes one of a filter, a duplexer, a multiplexer, and a filter module.

[0091] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An ultra-high frequency elastic wave device, characterized in that, include: Support substrate; At least one resonator group suspended on the supporting substrate; each resonator group includes at least one resonant unit and a first connector; The resonant unit includes a bottom electrode, a piezoelectric layer, and a top electrode arranged sequentially from bottom to top; the first connector is disposed on the sidewall of the piezoelectric layer. In this embodiment, the top electrode and bottom electrode in the same resonator unit have opposite potentials, and the thickness of the first connector is less than the sum of the thickness of the top electrode, the thickness of the bottom electrode, and the thickness of the piezoelectric layer.

2. The ultra-high frequency elastic wave device according to claim 1, characterized in that, The adjacent resonant units are all connected by the first connector.

3. The ultra-high frequency elastic wave device according to claim 1, characterized in that, Includes at least two resonator groups; Each of the resonator groups includes at least two of the resonant units; Adjacent resonant units within the same resonator group are connected via the first connector; resonant units in different resonator groups are not connected.

4. The ultra-high frequency elastic wave device according to claim 3, characterized in that, Each of the resonant units has a first connector on each of its opposite sides.

5. The ultra-high frequency elastic wave device according to claim 1, characterized in that, The material of the first connector is the same as that of the piezoelectric layer, and the thickness of the first connector is less than or equal to 0.8h1 and greater than or equal to 0.1h1; h1 represents the thickness of the piezoelectric layer; Alternatively, the material of the first connector is different from the material of the piezoelectric layer, and the thickness of the first connector is greater than or equal to 0.1h1.

6. The ultra-high frequency elastic wave device according to claim 5, characterized in that, When the material of the first connection is the same as the material of the piezoelectric layer, the thickness of the first connection is less than or equal to 0.6h1; When the material of the first connection is different from the material of the piezoelectric layer, the thickness of the first connection is less than or equal to 0.8h1.

7. The ultra-high frequency elastic wave device according to claim 1, characterized in that, The target mode of the ultra-high frequency elastic wave device is a higher-order mode of horizontal shearing mode, vertical shearing mode, or thickness expansion mode; the higher-order mode is a mode with an order greater than or equal to 1.

8. The ultra-high frequency elastic wave device according to claim 7, characterized in that, When the target mode is a first-order vertical shear mode, the vibration of the target mode of the ultra-high frequency elastic wave device is concentrated at the four corners of the piezoelectric layer cross section.

9. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, When the target mode of the ultra-high frequency elastic wave device is the first-order vertical shear mode, the width of the first connector satisfies [0.1W1, 3W1]; where W1 represents the width of the resonant unit. When the target mode is a first-order horizontal shearing mode or a first-order thickness expansion mode, the width of the first connector is greater than or equal to 0.1W1.

10. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, The top electrode covers the top of the piezoelectric layer and the top of the first connector; The bottom electrode covers the bottom of the piezoelectric layer and the bottom of the first connector.

11. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, In any resonator group, the potentials of the top electrodes of adjacent resonator units are opposite, and the potentials of the bottom electrodes of adjacent resonator units are opposite.

12. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, In any resonator group, the top electrodes of adjacent resonator units have the same potential, and the bottom electrodes of adjacent resonator units have the same potential.

13. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, In any resonator group, the potentials of the top electrodes of adjacent resonator units are opposite; The bottom electrode of all resonant units is at a floating potential; the bottom electrode is short-circuited outside the resonant region; the resonant region is the area where the top electrode, the piezoelectric layer, and the bottom electrode overlap.

14. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, It also includes a second connector; One end of the second connector is connected to the first connector, and the other end of the second connector is connected to the supporting substrate.

15. The ultra-high frequency elastic wave device according to claim 14, characterized in that, It also includes a dielectric layer; The dielectric layer is disposed between the second connector and the supporting substrate; The dielectric layer may be a single-layer material or a multi-layer material; The material of the dielectric layer includes one or more of silicon oxide, silicon nitride, polycrystalline silicon, amorphous silicon, aluminum oxide, and aluminum nitride; The dielectric layer is one or more of the following: temperature compensation layer, heat dissipation layer, trap-rich layer, bonding layer, low sound velocity layer, and dispersion modulation layer.

16. The ultra-high frequency elastic wave device according to claim 15, characterized in that, It also includes a third connector; One end of the third connector is connected to the bottom electrode, and the other end of the third connector is connected to the supporting substrate; the width of the third connector is less than or equal to half the width of the bottom electrode.

17. The ultra-high frequency elastic wave device according to claim 16, characterized in that, The materials of the first connector, the second connector, and the third connector are different, or they are all the same, or any two connectors are made of the same material.

18. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, In each of the resonant units, the sidewalls of the piezoelectric layer can be one or more combinations of straight lines, broken lines, and arcs.

19. The ultra-high frequency elastic wave device according to any one of claims 1-8, characterized in that, The piezoelectric layer is made of one of the following materials: lithium tantalate, lithium niobate, aluminum nitride, aluminum nitride-doped, lead zirconate titanate, or lead magnesium niobate-lead titanate. At least one of the absolute values ​​of the piezoelectric coefficients e33, e34, and e35 along the first direction of the piezoelectric layer is not less than 1 C / m. 2 Alternatively, the sum of the absolute values ​​of the piezoelectric coefficients e31, e33, and e35 is not less than 1 C / m. 2 The first direction is the normal direction of the plane formed by the long side of the resonant unit and the thickness direction of the piezoelectric layer.

20. A communication device, characterized in that, It includes at least any one of the ultra-high frequency elastic wave devices according to claims 1-19; The communication device includes one of the following: a filter, a duplexer, a multiplexer, and a filter module.

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