SAW device and manufacturing method thereof

Abstract

The present invention relates to the field of surface acoustic wave (SAW) devices. Specifically, the SAW device of the present invention suppresses parasitic modes, specifically transverse modes. The SAW device of the present invention comprises: a piezoelectric layer (101) for propagating SAW; at least one electrode (102) arranged on the piezoelectric layer and used to couple an electrical signal to the SAW propagating in the piezoelectric layer (101). The SAW device also comprises at least one busbar (103) for routing the electrical signal to the electrode (102). The SAW device also comprises a decoupling layer (104) that separates the piezoelectric layer (101) and the electrode (102) from the busbar (103). The decoupling layer (104) has an acoustic impedance different from that of the electrode (102) and the busbar (103).

Description

Technical Field

[0001] The present invention relates to the technical field of surface acoustic wave (SAW) devices. Specifically, the present invention proposes a SAW device with a new design for suppressing lateral parasitic modes. Furthermore, the present invention relates to a method for manufacturing the SAW device. Background Art

[0002] Acoustic wave devices are key components used in modern electronic circuits. Since such acoustic wave devices require high-frequency selectivity while maintaining low electronic insertion loss, high-quality-factor mechanical resonators need to be coupled in filter topologies.

[0003] SAW devices couple time-varying electrical signals to mechanical waves traveling on the surface of a piezoelectric material (layer). Traditional SAW resonators are produced on a piezoelectric layer with alternating metal interdigital transducer (IDT) electrodes on its surface.

[0004] When a stimulated wave triggers a desired vibration mode, a SAW resonator generates in-band parasitic vibration modes. These are caused by the placement of the IDT electrodes above the piezoelectric layer, the geometry of the metal busbars that route the electrical signals and confine the resonator, and the double-sided acoustic confinement of the Bragg reflectors. All of these factors promote the growth of parasitic modes within the frequency band of interest. The limited dimensions in the lateral direction of wave propagation also contribute to the development of parasitic electroacoustic modes within the resonator.

[0005] Due to modal coupling, such parasitic modes with frequencies close to the desired operating frequency may affect the achievable mechanical quality factor Q. When SAW resonators are arranged in filter configurations (e.g. ladder structures, lattices, dual-mode resonators, etc.), the presence of in-band parasitic modes can also affect the in-band ripple metric of these electrical filter circuits. To date, unwanted parasitic modes have been addressed in the following ways:

[0006] IDT electrode apodization: This can reduce the efficiency of excitation of higher-order modes. Alternatively, lower-order mode shapes can be matched by excitation. However, scattering at discontinuities can significantly increase losses.

[0007] Virtual Electrode Weighting: Using virtual electrodes, parasitic modes can penetrate and leak into the busbar region. However, reflections at the gap create strong wave confinement in the gap region, guiding the vibration and allowing parasitic modes to reappear.

[0008] Piston mode design: For example, devices on quartz (or high-coupling substrates) are combined with apodization of virtual electrodes to maintain a flat mode shape. The shape of the excitation remains constant along the aperture, and the mode shape can be matched to the shape of the excitation. Electromechanical coupling with these parasitic modes is then greatly reduced. However, this approach makes the resonator design more complex. Summary of the Invention

[0009] In view of the above shortcomings, an object of the embodiments of the present invention is to improve the conventional SAW device and the method for solving the parasitic mode.

[0010] The goal is to provide a SAW device that suppresses lateral parasitic modes. Therefore, the present invention aims to reduce passband ripple and increase achievable out-of-band suppression. Parasitic modes should be suppressed without requiring a more complex SAW resonator / device design. Furthermore, the SAW device should exhibit low losses.

[0011] The first aspect of the present invention provides a SAW device, comprising: a piezoelectric layer for propagating SAW; at least one electrode, arranged on the piezoelectric layer and used to couple an electrical signal to the SAW propagating in the piezoelectric layer; at least one busbar, used to route the electrical signal to the electrode; and a decoupling layer, separating the piezoelectric layer and the electrode from the busbar, wherein the decoupling layer has an acoustic impedance different from that of the electrode and the busbar, respectively.

[0012] In particular, the decoupling layer may include a piezoelectric material, a dielectric material or any semiconductor material.

[0013] The decoupling layer decouples the busbar and the SAW resonator (the piezoelectric layer and the one or more electrodes).Thus, spurious modes can be suppressed in the SAW device of the first aspect, and an improved low-loss SAW device is provided.

[0014] In an implementation of the first aspect, the at least one bus bar is at least partially arranged above the piezoelectric layer and the electrode, and the decoupling layer vertically separates the piezoelectric layer and the electrode from the bus bar.

[0015] Vertical decoupling effectively suppresses lateral parasitic modes.

[0016] In an implementation of the first aspect, the SAW device further includes a vertical interconnect access (VIA) formed to pass through the decoupling layer, for electrically connecting the busbar to the electrode.

[0017] The VIA can control one or more SAW resonators. Multiple VIAs can be provided. Multiple VIAs can also be used to form a periodic arrangement in the decoupling layer, for example to form a phononic crystal.

[0018] In an implementation manner of the first aspect, the decoupling layer is a patterned layer and / or a passivation layer.

[0019] In particular, if the SAW resonator comprises an optional passivation layer (eg above the IDT arrangement), then in this case it is not used to reduce spurious modes.

[0020] In an implementation of the first aspect, one or more material elements are embedded in the decoupling layer, the embedded elements having an acoustic impedance and / or electrical and / or optical properties different from surrounding materials of the decoupling layer.

[0021] In an implementation of the first aspect, a plurality of the material elements are embedded in the decoupling layer in a periodic arrangement.

[0022] In an implementation of the first aspect, a spatial periodicity of the periodic arrangement of the embedded elements is approximately the wavelength of the SAW propagating in the decoupling layer at an operating frequency of the SAW device.

[0023] The embedded elements may be identical, or may include one or more of the aforementioned VIAs that contact the busbar to one or more electrodes.

[0024] In an implementation of the first aspect, a plurality of embedded elements form a phononic crystal in the decoupling layer.

[0025] Specifically, the sizes of the members of the plurality of embedded elements are selected based on Bloch's theorem, the operating frequency of the resonator, and the operating bandwidth of the filter.

[0026] As a result, an acoustic band gap can be formed, supporting the decoupling and suppression of parasitic modes. In addition, the size of the phononic crystal allows the acoustic energy to partially penetrate within the frame structure to generate a "piston-like" vibration mode in the core resonator. This greatly reduces the triggering of parasitic modes.

[0027] In an implementation manner of the first aspect, the phononic crystal in the decoupling layer has a band gap centered at an operating frequency of the SAW device.

[0028] Therefore, parasitic modes are specifically suppressed close to the desired operating frequency and thus have no impact on the achievable mechanical quality factor Q due to modal coupling.

[0029] In an implementation of the first aspect, the length of the phononic crystal (also referred to as a phononic crystal frame structure) at an operating frequency of an acoustic wave that it can support is within a range of one quarter of a wavelength.

[0030] In an implementation manner of the first aspect, a sign of a temperature coefficient of the decoupling layer is opposite to a sign of a temperature coefficient of the piezoelectric layer.

[0031] The precise geometry and implementation of the phononic crystal (eg, described below with reference to the figures) is illustrative only, and asymmetric periodic arrangements may be implemented in different portions of a SAW device.

[0032] Ideally, the temperature coefficients of the decoupling layer and the piezoelectric layer have the same absolute value and opposite signs, thereby achieving temperature compensation.

[0033] In an implementation manner of the first aspect, the decoupling layer includes a dielectric material.

[0034] In an implementation of the first aspect, the SAW device further includes: a plurality of SAW resonators, each SAW resonator being formed by at least one IDT electrode and at least a portion of the piezoelectric layer.

[0035] In an implementation of the first aspect, the SAW device further comprises: one or more Bragg reflectors arranged adjacent to the SAW resonator, wherein the plurality of embedded elements in the decoupling layer are used to guide acoustic energy from the SAW resonator to the one or more Bragg reflectors.

[0036] This implementation prevents diffraction scattering in the lateral direction.

[0037] In an implementation of the first aspect, the decoupling layer is used to acoustically couple at least two SAW resonators, wherein the coupling direction is perpendicular to the SAW propagation direction.

[0038] The coupling strength between SAW resonators can be tuned by changing the geometry and structure of the decoupling layer.The SAW propagation direction (in implementation, the longitudinal direction) refers to the main propagation direction.

[0039] In an implementation of the first aspect, the distance between adjacent SAW resonators is selected to be between a quarter wavelength and a half wavelength of the induced acoustic wave at the operating frequency of the resonator.

[0040] In an implementation of the first aspect, the piezoelectric layer (also referred to as a substrate) includes at least one of the piezoelectric materials lithium tantalate oxide (LiTaO 3 ) or lithium niobate (LiNbO 3 ).

[0041] In an implementation of the first aspect, the at least one IDT electrode includes a metal material (eg, at least one of copper (Cu), tungsten (W), silver (Ag), platinum (Pt), titanium (Ti), or aluminum (Al)).

[0042] In an implementation manner of the first aspect, the decoupling layer may include a dielectric material (eg, at least one of SiO 2 and SiCOH).

[0043] In an implementation of the first aspect, the at least one electrode is an interdigital transducer (IDT) electrode.

[0044] A second aspect of the present invention provides a method for manufacturing a SAW device, the method comprising: providing a piezoelectric layer, the piezoelectric layer being used to propagate SAW; forming at least one electrode on the piezoelectric layer, wherein the electrode is used to couple an electrical signal to the SAW propagating in the piezoelectric layer; forming a decoupling layer; forming a busbar, the busbar being used to route the electrical signal to the electrode; wherein the decoupling layer separates the piezoelectric layer and the electrode from the busbar, wherein the decoupling layer has an acoustic impedance different from that of the electrode and the busbar, respectively.

[0045] The method of the second aspect can also be further implemented according to the implementation of the device of the first aspect. Accordingly, the method of the second aspect and its implementation achieve all the effects and advantages of the first aspect and its respective implementations.

[0046] It should be noted that all devices, elements, units and modules described in this application can be implemented in software or hardware elements or any type of combination thereof. All steps performed by the various entities described in this application and the described functions to be performed by the various entities are intended to indicate that the corresponding entities are suitable for or used to perform the corresponding steps and functions. Although in the description of the following specific embodiments, the specific functions or steps performed by the external entity are not reflected in the description of the specific elements of the entity that performs the specific steps or functions, it should be clear to the technician that these methods and functions can be implemented in corresponding hardware elements or software elements or any type of combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The following description of specific embodiments in conjunction with the accompanying drawings will illustrate the various aspects of the present invention and their implementation methods.

[0048] Figure 1 The SAW device provided by the embodiment of the present invention is shown;

[0049] Figure 2 (a) a top view and (b) a side view of a SAW device provided by an embodiment of the present invention are shown;

[0050] Figure 3 The steps of manufacturing a SAW device according to an embodiment of the present invention are shown;

[0051] Figure 4The steps of manufacturing a SAW device according to an embodiment of the present invention are shown;

[0052] Figure 5 The SAW device provided by the embodiment of the present invention is shown;

[0053] Figure 6 Components of a SAW device provided by an embodiment of the present invention are shown;

[0054] Figure 7 The SAW device provided by the embodiment of the present invention is shown;

[0055] Figure 8 A method for manufacturing a SAW device provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0056] Specifically, an embodiment of the present invention proposes to form a decoupling layer (also called a "resonator frame") around the core electrode by using a specific deposited material. The frame decouples the SAW resonator electrode from the metal wiring and busbars of the SAW device. The frame can be patterned (for example, a tracked geometry can be formed). In addition, the frame can be embedded in a material area to form a vocal band gap near the operating frequency of the SAW device. The frame frequency temperature coefficient (TCF) can be selected to reduce the overall TCF of the SAW device. In addition, two different SAW resonators can be mechanically coupled in the lateral direction through the frame, where the acoustic coupling strength can be optimized by modifying the geometry of the frame. The following aspects and implementations describe embodiments of the present invention.

[0057] Figure 1 FIG. 1 shows a cross-section of a SAW device 100 provided by an embodiment of the present invention. The SAW device 100 includes a piezoelectric layer 101 for propagating a SAW and at least one electrode 102 disposed on the piezoelectric layer 101. The electrode 102 is configured to couple an electrical signal to the SAW propagating in the piezoelectric layer 101. The electrode 102 and the piezoelectric layer 101, or at least a portion of the piezoelectric layer 101, can form a SAW resonator of the SAW device 100. Multiple electrodes 102 and piezoelectric layers 101 can form multiple SAW resonators.

[0058] also, Figure 1 The SAW device 100 includes at least one bus bar 103 for routing electrical signals to the electrode 102. In addition, the SAW device 100 includes a decoupling layer 104 that separates the piezoelectric layer 101 and the electrode 102 from the bus bar 103. The decoupling layer 104 has an acoustic impedance different from that of the electrode 102 and the bus bar 103.

[0059] In the SAW device 100, the actuation electrode 102, which may be an IDT electrode, and the routing bus 103 are decoupled by a decoupling layer 104. The decoupling layer 104 may specifically be a passivation layer and may be referred to as a "resonator frame." The decoupling layer 104 may also be engineered / patterned, for example, to modify the acoustic environment of one or more electrodes 102 (IDT structures). Thus, the SAW device 100 may be additionally "optimized," particularly compared to conventional 1D metal designs.

[0060] For example, the decoupling layer 104 (which preferably has a different intrinsic surface wave reflectivity than the metal electrode 102) can be patterned to obtain a specific bandgap shape / acoustic mirror, e.g., except at the center resonant frequency. The decoupling layer 104 can also be designed to specifically leak energy in the transverse modes.

[0061] In terms of process complexity, the good quality of the electrode metallization is maintained. The patterned decoupling layer 104 is less dependent on process variations (i.e., it does not require as precise photolithography as required by conventional methods). The decoupling layer 104 also has the advantage of modifying the temperature characteristics of the SAW device 100, for example, in the case of a TC-SAW design.

[0062] Figure 2 The SAW device 100 provided by the embodiment of the present invention is shown. The SAW device 100 is based on Figure 1 The SAW device 100 is shown. Like elements are labeled with like reference symbols and their functions are the same. Figure 2 The SAW device 100 is particularly shown in a top view in (a) and in a side view in longitudinal section in (b).

[0063] Figure 2 The SAW device 100 further includes one or more VIAs 200 formed, for example, from metal, through the decoupling layer 104. The one or more VIAs are used to electrically connect the bus bar 103 to the one or more electrodes 102, so that electrical signals can be routed from the bus bar 103 to the one or more electrodes 102. Figure 2 It is also shown that the SAW device 100 may be disposed on a bulk wafer or substrate 201 .

[0064] like Figure 2As further exemplarily shown in FIG, one or more electrodes 102 may be IDT electrodes formed by / in the first metal layer M1. The decoupling layer 104 may be a passivation layer. The busbar 103 may be formed by / in the second metal layer M2. The passivation layer 104 is used to reduce the generation of parasitic modes. This is achieved by decoupling the one or more electrodes 102 / one or more SAW resonators from the boundary of the SAW device 100 (usually where the one or more busbars 103 are located). The passivation layer 104 having one or more VIAs 200 can be formed by depositing a specific material (e.g., a dielectric material).

[0065] Figure 3 and Figure 4 Shows how to make Figure 2 SAW device 100 . Figure 3 and Figure 4 The SAW device 100 is thus shown in (a) a side view, (b) a front view (at the boundary where the busbar 103 is located), and (c) a back view (where the SAW resonator is located). Figure 8 Also shown is a general method 800 for manufacturing the SAW device 100. Steps I / IV to IV / IV will be described below.

[0066] Figure 8 The general manufacturing method 800 shown includes: step 801, providing a piezoelectric layer, wherein the piezoelectric layer is used to propagate SAW; step 802, forming at least one electrode 102 on the piezoelectric layer 101, wherein the electrode 102 is used to couple an electrical signal to the SAW propagating in the piezoelectric layer 101; step 803, forming a decoupling layer 104; step 804, forming a busbar 103, wherein the busbar 103 is used to route the electrical signal to the electrode 102; wherein the decoupling layer 104 separates the piezoelectric layer 101 and the electrode 102 from the busbar 103, wherein the decoupling layer 104 has an acoustic impedance different from that of the electrode 102 and the busbar 103, respectively.

[0067] exist Figure 3 In step I / IV, the piezoelectric layer 101 is provided on the wafer 201, and a plurality of electrodes 102 are formed on the piezoelectric layer. Therefore, the step I / IV involves Figure 8 Then, in step II / IV, the decoupling layer 104 is deposited on the piezoelectric layer 101 and the electrode 102, respectively, and forms the VIA 200. Therefore, this step II / IV involves Figure 8 Step 803.

[0068] exist Figure 4In step III / IV, the decoupling layer 104 is removed over the portion of the electrode where the core SAW resonator is formed. In step IV / IV, the busbar 103 is formed on the remaining decoupling layer 104. Thus, these steps involve Figure 8 Step 804.

[0069] Figure 5 The SAW device 100 provided by the embodiment of the present invention is shown. The SAW device 100 is based on Figure 1 and Figure 2 The SAW device 100 is shown. Like elements are labeled with like reference symbols and their functions are the same. Figure 5 The SAW device 100 is shown in a side view.

[0070] Figure 5 The SAW device 100 shows that the decoupling layer 104 (“resonator frame”) can be patterned by embedding one or more material elements 500 within the decoupling layer 104. The embedded elements 500 can have an acoustic impedance and / or can have electrical properties and / or optical properties that are different from the surrounding material of the decoupling layer 104. Multiple material elements 500 can be embedded in the decoupling layer 104 in a periodic arrangement. Specifically, the decoupling layer 104 can be provided with a periodic replica structure of a metal structure (e.g., VIA 200) (or any other material deposited within the decoupling layer 104 whose acoustic impedance is lower than or greater than the acoustic impedance of the decoupling layer 104). The material islands embedded in the decoupling layer 104 can have a unit length, for example, approximately a wavelength of the acoustic wave at the frequency of the SAW device 100 / a portion thereof. Thus, multiple embedded elements / islands 500 can form a phononic crystal in the decoupling layer 104.

[0071] Figure 6 A portion of a SAW device 100 provided by an embodiment of the present invention is shown. The SAW device 100 is based on Figure 1 and Figure 5 The SAW device 100 is shown. Like elements are labeled with like reference symbols and their functions are the same. Figure 5 The SAW device 100 is shown in a top view.

[0072] exist Figure 6 In the SAW device 100, the external Bragg reflector 600 is used to confine the acoustic energy within one or more core SAW resonators. In this case, one or more metal busbars 103 can be removed, and the decoupling layer 104 can be patterned into a two-dimensional periodic replicated structure 500 (for example, using metal VIA 200 or other materials) to effectively guide the acoustic vibration in the longitudinal direction and prevent diffraction scattering in the lateral direction.

[0073] Figure 7The SAW device 100 provided by the embodiment of the present invention is shown. The SAW device 100 is based on Figure 1 and Figure 6 The SAW device 100 is shown. Like elements are labeled with like reference symbols and their functions are the same. Figure 7 The SAW device 100 is shown in a top view.

[0074] Figure 7 The SAW device 100 particularly has a layered design of mechanically coupled SAW resonators (i.e., the electrode 102 and the piezoelectric layer 101 form part of the SAW resonator), which are located near each other, for example, for filter applications. In this case, the decoupling layer 104 (which can be patterned and optimized as described above) can be used as a lateral acoustic coupler between adjacent SAW resonators. Changing the geometry and structure of the decoupling layer 104 can adjust the acoustic coupling strength between adjacent SAW resonators.

[0075] In the above-described embodiment of the SAW device 100, the substrate (bulk wafer 201) can be a substrate including silicon, glass, ceramic, etc. The piezoelectric layer 101 can be a thin film piezoelectric layer including one of lithium niobate, lithium tantalate, etc. The one or more electrodes 102 can be a low resistivity layer including a metal and / or metal alloy (e.g., copper, titanium, etc.) layer, or can be a highly doped silicon layer.

[0076] In the above-described embodiment of the SAW device 100, the decoupling layer 104 may include a dielectric material or may be made of a dielectric material. For example, the dielectric material of the decoupling layer 104 may include SiCOH, phosphosilicate glass, an oxide or nitride of aluminum, silicon, germanium, gallium, indium, tin, antimony, tellurium, bismuth, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, palladium, cadmium, helium, tantalum, or tungsten, or any combination thereof.

[0077] In the above-described embodiment of the SAW device 100, the metallization layers M1 and M2 (for one or more busbars 103 and / or one or more electrodes 102, respectively) may include copper, aluminum, tungsten, titanium, etc. BEOL dielectric layers may include a copper capping layer (CCL), an etch stop layer (ESL), a diffusion barrier (DB), an antireflection coating (ARC), and a low-k dielectric, such as SiCOH, SiOCN, SiCN, SiOC, or SiN. Materials available in CMOS BEOL layers may include copper metallization, tungsten, low-k dielectrics, silicon dioxide, a copper capping layer, an etch stop layer, an antireflection coating, etc.

[0078] In the above-described embodiments of the SAW device 100, the substrate may include silicon, an SOI technology substrate, gallium arsenide, gallium phosphide, gallium nitride and / or indium phosphide or other example substrates, alloy semiconductors including GaAsP, AlInAs, GaInAs, GaInP or GaInAsP, or combinations thereof.

[0079] The invention has been described with reference to various embodiments and implementations as examples. However, those skilled in the art will be able to understand and implement other variations in practicing the claimed invention, based on a study of the drawings, the present disclosure, and the independent claims. In the claims and the specification, the word "comprising" does not exclude other elements or steps, and "a" does not exclude a plurality. A single element or other unit may fulfil the functions of several entities or items recited in the claims. The recitation of certain measures in mutually different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

1. A surface acoustic wave (SAW) device (100), characterized in that: include: a piezoelectric layer (101) for propagating SAW; At least one electrode (102) is disposed on the surface of the piezoelectric layer (101) and is used to couple an electrical signal to the SAW propagating in the piezoelectric layer (101); at least one bus bar (103) for routing the electrical signal to the electrode (102); A decoupling layer (104), part of the decoupling layer (104) covers the surface of the electrode (102) at the edge of the electrode (102), and part of the decoupling layer (104) covers the surface of the piezoelectric layer (101), the busbar (103) is located on the surface of the decoupling layer (104), and the decoupling layer (104) is used to separate the piezoelectric layer (101) and the electrode (102) from the busbar (103). The decoupling layer (104) has an acoustic impedance different from that of the electrode (102) and the busbar (103).

2. The SAW device (100) according to claim 1, characterized in that: The at least one busbar (103) is at least partially arranged above the piezoelectric layer (101) and the electrode (102), The decoupling layer (104) vertically separates the piezoelectric layer (101) and the electrode (102) from the busbar (103).

3. The SAW device (100) according to claim 1 or 2, characterized in that: include: A vertical interconnect access (VIA) (200) is formed through the decoupling layer (104) for electrically connecting the bus bar (103) to the electrode (102).

4. The SAW device (100) according to any one of claims 1 to 2, characterized in that: The decoupling layer (104) is a patterned layer and / or a passivation layer.

5. The SAW device (100) according to any one of claims 1 to 2, characterized in that: One or more material elements (500) are embedded in the decoupling layer (104), the embedded elements (500) having an acoustic impedance and / or having electrical and / or optical properties that are different from the surrounding material of the decoupling layer (104).

6. The SAW device (100) according to claim 5, characterized in that: A plurality of the material elements (500) are embedded in the decoupling layer (104) in a periodic arrangement.

7. The SAW device (100) according to claim 6, characterized in that: The spatial periodicity of the periodic arrangement of the embedded elements (500) is the wavelength of the SAW propagating in the decoupling layer (104) at the operating frequency of the SAW device (100).

8. The SAW device (100) according to claim 7, characterized in that: A plurality of embedded elements (500) form a phononic crystal in the decoupling layer (104).

9. The SAW device (100) according to claim 8, characterized in that: The phononic crystal in the decoupling layer has a band gap centered at an operating frequency of the SAW device (100).

10. The SAW device (100) according to any one of claims 1 to 2, characterized in that: The sign of the temperature coefficient of the decoupling layer (104) is opposite to the sign of the temperature coefficient of the piezoelectric layer (101).

11. The SAW device (100) according to any one of claims 1 to 2, characterized in that: The decoupling layer (104) includes a dielectric material.

12. The SAW device (100) according to any one of claims 1 to 2, characterized in that: include: A plurality of SAW resonators are provided, each SAW resonator being formed by at least one electrode (102) and at least a portion of a piezoelectric layer (101).

13. The SAW device (100) according to claim 12, characterized in that include: one or more Bragg reflectors (600) arranged adjacent to the SAW resonator, The plurality of embedded elements (500) in the decoupling layer (104) are used to guide acoustic energy from the SAW resonator to the one or more Bragg reflectors (600).

14. The SAW device (100) according to claim 13, characterized in that: The decoupling layer (104) is used for acoustically coupling at least two SAW resonators, wherein the coupling direction is perpendicular to the SAW propagation direction.

15. The SAW device (100) according to any one of claims 1 to 2, characterized in that: The at least one electrode (102) is an interdigital transducer (IDT) electrode.

16. A method (800) for manufacturing a surface acoustic wave (SAW) device (100), characterized in that: The method (800) include: Providing a piezoelectric layer (101), wherein the piezoelectric layer (101) is used to propagate SAW; At least one electrode (102) is formed on the surface of the piezoelectric layer (101), wherein the electrode (102) is used to couple an electrical signal to a SAW propagating in the piezoelectric layer (101); forming a decoupling layer (104), wherein a portion of the decoupling layer (104) covers the surface of the electrode (102) at the edge of the electrode (102), and a portion of the decoupling layer (104) covers the surface of the piezoelectric layer (101); forming a busbar (103), wherein the busbar (103) is located on the surface of the decoupling layer (104), and the busbar (103) is used to route the electrical signal to the electrode (102); wherein the decoupling layer (104) separates the piezoelectric layer (101) and the electrode (102) from the busbar (103), The decoupling layer (104) has an acoustic impedance different from that of the electrode (102) and the busbar (103).

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