Resonator having transverse-mode suppression structure, and method for manufacturing same

Abstract

A resonator having a transverse-mode suppression structure comprises: a piezoelectric substrate, and an electrode layer, a passivation layer and a suppression layer, which are located above the piezoelectric substrate. The electrode layer comprises two interdigital electrodes which are arranged opposite each other in a first direction, wherein each interdigital electrode comprises a busbar and a plurality of electrode fingers connected to the busbar, there being a gap between each of the plurality of electrode fingers in one interdigital electrode and a busbar in the other interdigital electrode, and the passivation layer is embedded between the two interdigital electrodes in the first direction and covers the electrode fingers and the gap; and the suppression layer comprises two suppression units which are arranged opposite each other in the first direction, wherein each suppression unit is connected to a busbar in one interdigital electrode and extends in the first direction, so as to cover the gap, and partially overlaps the projection of at least one electrode in the other interdigital electrode on the plane where the piezoelectric substrate is located. The additionally arranged suppression layer structure improves a quality factor while suppressing a transverse mode, thereby improving the operation stability and service life of a resonator.

Description

Resonator with transverse mode suppression structure and manufacturing method thereof Technical Field

[0001] The present application belongs to the technical field of resonators and relates to a resonator with a transverse mode suppression structure and a manufacturing method thereof. Background Art

[0002] During the operation of the surface acoustic wave resonator, the generation of the main mode is usually accompanied by the generation of the transverse mode. The transverse mode is an undesirable mode in the surface acoustic wave resonator because it will have a negative impact on the normal operation of the resonator. Therefore, how to achieve a good suppression effect on the transverse mode generated during the operation of the resonator has become an important technical problem that needs to be solved urgently by technical personnel in this field. Summary of the Invention

[0003] In view of this, the purpose of the present application is to provide a resonator with a transverse mode suppression structure and a manufacturing method thereof, so as to solve the problem that the transverse mode suppression method in the related art has limited suppression effect on the transverse mode.

[0004] To achieve the above-mentioned objectives and other related objectives, the present application provides a resonator with a lateral mode suppression structure, comprising: a piezoelectric substrate; an electrode layer, located above the piezoelectric substrate, the electrode layer comprising two interdigital electrodes arranged opposite to each other in a first direction, each of the two interdigital electrodes comprising a bus bar and a plurality of electrode fingers connected to the bus bar, the plurality of electrode fingers in the same interdigital electrode being spaced apart in a second direction, each of the plurality of electrode fingers in one interdigital electrode having a gap with the bus bar in the other interdigital electrode, the second direction being perpendicular to the first direction; a passivation layer, located above the piezoelectric substrate, the passivation layer being embedded between the two interdigital electrodes in the first direction and covering the plurality of electrode fingers in the two interdigital electrodes and the gap; a suppression layer, located above the piezoelectric substrate, the suppression layer comprising two suppression units arranged opposite to each other in the first direction, each of the two suppression units being connected to the bus bar in one interdigital electrode and extending along the first direction to cover the gap and partially overlap with the projection of at least one electrode finger in the other interdigital electrode on the plane where the piezoelectric substrate is located.

[0005] Optionally, when the spacing between two adjacent electrode fingers in the same interdigitated electrode is λ, the width along the first direction of the overlap between the projection of the suppression unit on the plane where the piezoelectric substrate is located and the projection of at least one electrode finger in another interdigitated electrode on the plane where the piezoelectric substrate is located is in the range of 0 to 1.0λ.

[0006] Optionally, a portion of the suppression unit located above the gap and above at least one electrode finger of another interdigitated electrode has a thickness in a vertical direction ranging from 1 to 100 nm, where the vertical direction is perpendicular to both the first direction and the second direction.

[0007] Optionally, the suppression unit is connected to a side of the bus bar in one interdigital electrode that is away from the piezoelectric substrate and extends above the passivation layer.

[0008] Optionally, in the vertical direction, a thickness of a portion of the suppression unit located above the bus bar in one interdigital electrode is greater than or equal to a thickness of a portion of the suppression unit located above the passivation layer.

[0009] Optionally, the suppression unit is further embedded in the passivation layer in the vertical direction, and a portion of the suppression unit embedded in the passivation layer in the vertical direction is located above the gap.

[0010] Optionally, the suppression unit is connected to a side surface of the bus bar in one interdigital electrode and is embedded in the passivation layer in the first direction.

[0011] Optionally, a portion of the suppression unit located above the gap has at least one blind groove, and each of the at least one blind groove opens from a surface of the suppression unit facing the piezoelectric substrate and / or a surface facing away from the piezoelectric substrate and extends vertically.

[0012] Optionally, the portion of the suppression unit located above the gap has at least one through groove, each of the at least one through groove opens from a side of the suppression unit facing away from the piezoelectric substrate, and at least one through groove exposes at least a portion of at least one electrode finger in an interdigitated electrode.

[0013] Optionally, the passivation layer has a groove, the projection of the groove on the plane where the piezoelectric substrate is located is located between the projections of the two suppression units on the plane where the piezoelectric substrate is located, and the portion of the passivation layer surrounding the groove constitutes a raised frame.

[0014] Optionally, the portion of the suppression unit located above the gap and above at least one electrode finger in the other interdigitated electrode includes a plurality of suppression blocks spaced apart in the second direction, and a projection of at least one of the plurality of suppression blocks on the plane where the piezoelectric substrate is located partially overlaps with a projection of at least one electrode finger in the other interdigitated electrode on the plane where the piezoelectric substrate is located.

[0015] Optionally, the plurality of suppression blocks include a plurality of first suppression blocks, which extend over the gap in the first direction and partially overlap with a projection of at least one electrode finger of another interdigitated electrode on the plane where the piezoelectric substrate is located.

[0016] Optionally, the plurality of suppression blocks further include a plurality of second suppression blocks, and the plurality of second suppression blocks extend in the first direction along and above the electrode fingers in one interdigital electrode.

[0017] Optionally, in the same suppression unit, multiple first suppression blocks and multiple second suppression blocks are alternately arranged, and in different suppression units, multiple first suppression blocks and multiple second suppression blocks are oppositely arranged, and the multiple first suppression blocks and multiple second suppression blocks have the same morphology.

[0018] Optionally, in the same suppression unit, multiple first suppression blocks and multiple second suppression blocks are alternately arranged, and in different suppression units, multiple first suppression blocks and multiple second suppression blocks are oppositely arranged, and the multiple first suppression blocks and multiple second suppression blocks have different morphologies.

[0019] Optionally, the interdigitated electrode further includes a plurality of dummy fingers connected to the bus bar, the plurality of dummy fingers in the same interdigitated electrode are arranged alternately and at intervals with the plurality of electrode fingers, and the plurality of dummy fingers are embedded in the gaps, and there is a preset distance between the plurality of dummy fingers in one interdigitated electrode and the plurality of electrode fingers in another interdigitated electrode.

[0020] Optionally, the material of the inhibition layer includes at least one of a metal material and a high-density dielectric material, the metal material includes at least one of Al, Ti, Cu, Pt and Au, and the high-density dielectric material includes at least one of Ta2O5, HfO2 and BaTiO3.

[0021] The present application also provides a method for manufacturing a resonator with a lateral mode suppression structure, comprising: providing a piezoelectric substrate; forming an electrode layer above the piezoelectric substrate, the electrode layer comprising two interdigital electrodes arranged opposite to each other in a first direction, each of the two interdigital electrodes comprising a bus bar and a plurality of electrode fingers connected to the bus bar, the plurality of electrode fingers in the same interdigital electrode being spaced apart in a second direction, each of the plurality of electrode fingers in one interdigital electrode having a gap with the bus bar in the other interdigital electrode, the second direction being perpendicular to the first direction; forming a passivation layer above the piezoelectric substrate, the passivation layer being embedded between the two interdigital electrodes in the first direction and covering the plurality of electrode fingers in the two interdigital electrodes and the gap; forming an suppression layer above the piezoelectric substrate, the suppression layer comprising two suppression units arranged opposite to each other in the first direction, each of the two suppression units being connected to the bus bar in one interdigital electrode and extending along the first direction to cover the gap and partially overlap with the projection of at least one electrode finger in the other interdigital electrode on the plane where the piezoelectric substrate is located.

[0022] As described above, the resonator with a transverse mode suppression structure of the present application, the additionally provided suppression layer structure realizes the suppression of the transverse mode through the energy limitation effect, and can also improve the quality factor of the resonator, and is applicable to a variety of resonator structures and a wide frequency range, and in the manufacturing process, no special high-resolution process is required, so the structure is simple and the manufacturing process is mature. And after further improvement and optimization of the suppression layer structure, the piston mode effect can be achieved without the need to use a hammer head structure or a selective disassembly method, thereby reducing scattering losses. In addition, the selection of the material of the suppression layer enables the suppression layer to act as a heat sink in addition to the effect of the transverse mode suppression due to its good thermal conductivity, thereby improving the durability and linearity of the resonator, and further improving the working stability and service life of the resonator. The manufacturing method of the resonator with a transverse mode suppression structure of the present application does not require a special high-resolution process to achieve effective improvement of the structural performance of the resonator, the process steps are simple and the cost is low, thereby enabling large-scale production of high-performance resonators. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic diagram showing a partial top view of a resonator.

[0024] FIG. 2 is a schematic diagram showing the longitudinal cross-sectional structure along II′ in FIG. 1 and the corresponding change in the acoustic wave propagation velocity.

[0025] FIG3 is a schematic diagram of a partial top view of the resonator with a lateral mode suppression structure in the first embodiment of the present application.

[0026] FIG4 is a schematic diagram showing the longitudinal cross-sectional structure along the line II-II′ in FIG3 and the corresponding change in the acoustic wave propagation velocity.

[0027] FIG5 is an enlarged schematic diagram of the first local structure in the dotted box in FIG4 .

[0028] FIG6 is a graph showing the effect of the conductivity characteristics of the resonator with the lateral mode suppression structure of the present application on the frequency variation when the suppression unit and the electrode finger overlap with different widths.

[0029] Figure 7 shows a graph showing the effect of the quality factor Q varying with frequency when the suppression unit and the electrode finger partially overlap at different widths for the resonator having a lateral mode suppression structure of the present application.

[0030] FIG8 is a graph showing the effect of the conductivity characteristics of the resonator with the lateral mode suppression structure of the present application on the variation with frequency when the thickness of the suppression unit located above the gap and above the electrode fingers is different.

[0031] FIG9 is a graph showing the effect of the quality factor changing with frequency when the thickness of the portion above the gap and above the electrode fingers in the suppression unit of the resonator with the lateral mode suppression structure of the present application is different.

[0032] FIG10 is a schematic diagram showing the negative linear relationship between the thickness of the passivation layer and the thickness of the suppression layer in the resonator with the lateral mode suppression structure of the present application.

[0033] FIG11 is a graph showing the effect of the quality factor Q of the resonator with the transverse mode suppression structure of the present application on the change of frequency at different passivation layer thicknesses.

[0034] FIG12 is an enlarged schematic diagram of the second local structure in the dotted box in FIG4 .

[0035] FIG13 is an enlarged schematic diagram of the third local structure in the dotted box in FIG4 .

[0036] FIG14 is an enlarged schematic diagram of the fourth local structure in the dotted box in FIG4 .

[0037] FIG15 is a schematic diagram showing a partial longitudinal cross-sectional structure of a resonator with a transverse mode suppression structure according to the present application having dummy fingers.

[0038] FIG. 16 is a schematic diagram showing a top view of the electrode layer structure in the resonator shown in FIG. 15 .

[0039] FIG17 is a schematic diagram of a first partial longitudinal cross-sectional structure of the second embodiment of the present invention when the suppression unit in the resonator with a transverse mode suppression structure is embedded in the passivation layer.

[0040] FIG18 is a schematic diagram of a second partial longitudinal cross-sectional structure of the second embodiment of the present invention when the suppression unit in the resonator with the transverse mode suppression structure is embedded in the passivation layer.

[0041] FIG19 is a schematic diagram of a third partial longitudinal cross-sectional structure of the second embodiment of the present invention when the suppression unit in the resonator with a transverse mode suppression structure is embedded in the passivation layer.

[0042] FIG20 is a schematic diagram of a fourth partial longitudinal cross-sectional structure of the second embodiment of the present invention when the suppression unit in the resonator with the transverse mode suppression structure is embedded in the passivation layer.

[0043] FIG. 21 is a schematic top view of the structure of a resonator with a transverse mode suppression structure according to the present application, wherein the suppression unit has a plurality of through slots in the third embodiment.

[0044] FIG. 22 is a schematic top view of the structure of the third embodiment of the present invention when the suppression unit in the resonator with a transverse mode suppression structure has a through slot.

[0045] FIG23 is a schematic diagram of a first top view structure of a fourth embodiment of the present invention in which the suppression unit in the resonator with a transverse mode suppression structure includes a plurality of suppression blocks.

[0046] FIG24 is a schematic diagram of a second top view structure of a fourth embodiment of the present invention in which the suppression unit in the resonator with a transverse mode suppression structure includes a plurality of suppression blocks.

[0047] FIG. 25 is a schematic diagram of a third top view structure of the fourth embodiment of the present invention when the suppression unit in the resonator with a transverse mode suppression structure includes a plurality of suppression blocks.

[0048] FIG26 is a schematic diagram of a fourth top view structure of the fourth embodiment of the present application when the suppression unit in the resonator with a transverse mode suppression structure includes a plurality of suppression blocks.

[0049] FIG27 is a schematic diagram of a top view of the fifth structure of the fourth embodiment when the suppression unit in the resonator with a transverse mode suppression structure of the present application includes a plurality of suppression blocks.

[0050] FIG28 is a schematic flow chart showing a method for manufacturing a resonator with a lateral mode suppression structure according to the present application.

[0051] Component Reference Numerals 10 Piezoelectric Substrate 20 Electrode Layers 101, 21 Busbar 211 Lower Busbar 212 Upper Busbars 102, 22 Electrode Finger 23 Gap 24 Dummy Finger 30 Passivation Layer 31 Groove 32 Raised Frame 40 Suppression Layer 41 Suppression Unit 411 Blind Groove 412 Through Groove 413 Suppression Block 413a First Suppression Block 413b Second Suppression Block DETAILED DESCRIPTION

[0052] The following describes the embodiments of the present application through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present application from the disclosure herein. The present application may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present application.

[0053] A surface acoustic wave resonator generally includes a substrate made of piezoelectric material and at least two interdigital transducers located on the piezoelectric substrate and composed of multiple pairs of cross-conductive electrode fingers. Please refer to Figures 1 and 2. Figure 1 shows a schematic diagram of a partial top view of the resonator, and Figure 2 shows a schematic diagram of the longitudinal cross-sectional structure along I-I' in Figure 1 and the corresponding change in the acoustic wave propagation speed. The interdigital transducer includes a bus bar 101 and electrode fingers 102. The interdigital transducer converts electrical and acoustic signals through the piezoelectric effect, and the main mode is surface acoustic wave. The surface acoustic wave resonator is a device system composed of two transducers and a piezoelectric substrate, and has a specific frequency response characteristic, and this characteristic can be manipulated by adjusting the material and structure of the transducer and the substrate. The device has the advantages of high stability, small size and high quality factor Q, and is widely used in various acoustic devices. For example, radio frequency filters based on surface acoustic wave resonators are usually used in wireless communication equipment, and exhibit excellent performance by utilizing surface acoustic wave resonators to meet the needs of increasing frequency bands and limiting the radio frequency spectrum.

[0054] During the operation of a surface acoustic wave resonator, the generation of a main mode is usually accompanied by the generation of a transverse mode. The transverse mode propagates in a direction perpendicular to the propagation direction of the main mode. When a piezoelectric resonator or radio frequency filter is composed of multiple surface acoustic wave resonator units, the stray resonance caused by the transverse mode will interfere with and distort the frequency response of the device, resulting in strong noise in the transmitting section and poor insulation and resistance at the receiving end, thereby significantly reducing the overall performance of the radio communication system. At present, in order to reduce the negative impact of the transverse mode during the operation of the resonator, the commonly used method is to suppress the transverse mode. For example, a mass load block or hammer head is set on the interdigital electrode, the shape of the interdigital electrode is adjusted to generate acoustic waves in different directions, and the interdigital electrode structure is adjusted (such as a double-layer interdigital electrode) to obtain a piston mode effect. However, all existing methods have more or less problems. For example, when adjusting the structure, high-resolution technology is usually used, which increases the difficulty and cost of the resonator manufacturing process, or increases the overall volume of the resonator, or the suppression effect of the transverse mode is limited, and it cannot effectively improve the working performance of the resonator and maintain a high Q value.

[0055] Therefore, how to provide a resonator with a lateral mode suppression structure and a manufacturing method thereof to achieve a good suppression effect on the lateral mode generated during the operation of the resonator and improve the quality factor without increasing the process difficulty has become an important technical problem that needs to be urgently solved by technical personnel in this field.

[0056] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solution of this application and facilitating the understanding of those skilled in the art. Therefore, it cannot be considered that the above technical solution is well known to those skilled in the art.

[0057] To address the above-mentioned issues, the present application provides a resonator with a lateral mode suppression structure and a method for manufacturing the same. Please refer to Figures 3 to 27. It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present application. Therefore, the diagrams only show components relevant to the present application and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be varied arbitrarily, and the component layout may also be more complex.

[0058] Example 1

[0059] The present embodiment provides a resonator having a transverse mode suppression structure. Please refer to Figures 3 and 4. Figure 3 shows a schematic diagram of the top view of the resonator, and Figure 4 shows a schematic diagram of the longitudinal cross-sectional structure along II-II' in Figure 3. The resonator includes a piezoelectric substrate 10, an electrode layer 20, a passivation layer 30 and a suppression layer 40.

[0060] Specifically, the electrode layer 20 is located above the piezoelectric substrate 10, and the electrode layer 20 includes two interdigitated electrodes arranged opposite to each other in a first direction (shown in the X direction in FIG3 ), each interdigitated electrode includes a bus bar 21 and a plurality of electrode fingers 22, and the plurality of electrode fingers 22 in the same interdigitated electrode are spaced apart in a second direction (shown in the Y direction in FIG3 ) and are all connected to the bus bar 21, and a gap 23 is provided between the electrode finger 22 in one interdigitated electrode and the bus bar 21 in another interdigitated electrode, and the second direction is perpendicular to the first direction; the passivation layer 30 is located above the piezoelectric substrate 10, and the passivation layer 30 is embedded between the two interdigitated electrodes in the first direction and covers the electrode fingers 22 and the gap 23. ; The inhibition layer 40 is located above the piezoelectric substrate 10, and the inhibition layer 40 includes two inhibition units 41 arranged opposite to each other in the first direction, each inhibition unit 41 is connected to a bus bar 21 and extends along the first direction to cover the gap 23 and partially overlaps with at least one electrode finger 22 located on different sides of the inhibition unit 41, that is, each of the two inhibition units 41 is connected to the bus bar 21 in one interdigitated electrode and extends along the first direction to cover the gap 23, and the projection of the inhibition unit 41 on the plane where the piezoelectric substrate 10 is located partially overlaps with the projection of at least one electrode finger 22 in the other interdigitated electrode on the plane where the piezoelectric substrate 10 is located.

[0061] Specifically, the resonator structure of this embodiment adds a suppression layer 40 on the basis of the conventional resonator structure, so that the suppression layer 40 is connected to the bus bar 21 and extends to above the gap 23 and above the edge area of ​​the electrode finger 22 (including two situations when the suppression unit 41 just extends to the edge of the electrode finger 22 and further extends to above the electrode finger 22). That is, the suppression layer 40 can be regarded as an extended structure of the bus bar 21. As can be seen from the sound velocity change diagram in Figure 4, the propagation speed of sound in the area where the suppression unit 41 overlaps with the electrode finger 22 is significantly lower than the propagation speed of sound in the main area of ​​the electrode finger 22 (the area not covered by the suppression layer 40); and, compared with the distribution trend of the surface acoustic wave propagation speed in the conventional resonator structure, when the propagation speed of the sound wave in the electrode finger 22 area is the same (that is, V in Figure 2 1a Compared with V in Figure 4 1b When the gap 23 is equal to the speed of sound wave propagation, the speed of sound wave propagation in the gap 23 is relatively reduced (ie, V 2b Smaller than V in Figure 2 2a ), after analysis, it is believed that the above-mentioned reason for the acoustic wave propagation velocity is that the suppression layer 40, based on the acoustic interaction and phase shift effect with the surface acoustic wave, causes the transverse stray mode with a propagation direction perpendicular to the propagation direction of the surface acoustic wave to exhibit non-uniform acoustic impedance interaction in the edge area of ​​the electrode finger 22 (i.e., the partially overlapping area) and the gap 23 area. This introduces a large amount of acoustic stray energy into the passivation layer 30 through the phase shift effect, thereby suppressing the interference caused by the transverse mode on the resonator performance. In addition, by improving and optimizing the suppression structure, it is also possible to introduce a piston mode effect on the basic structure to further enhance the operating performance of the resonator (see below for details).

[0062] As an example, the material of the piezoelectric substrate 10 includes but is not limited to 128Y-cut lithium niobate (LN) material.

[0063] As an example, refer to FIG5 , which shows an enlarged schematic diagram of the first partial structure in the dashed box in FIG4 . Vertically (as shown in the Z direction in FIG5 ), the height of the busbar 21 is greater than the height of the electrode fingers 22, and the passivation layer 30 is embedded in the area between the two busbars 21. In other embodiments, the passivation layer 30 may be partially embedded in the area where the busbar 21 is located but not completely cover the busbar 21. In actual applications, the structure of the passivation layer may be modified based on actual needs. The phrase "the height of the busbar 21 is greater than the height of the electrode fingers 22" can be interpreted as the busbar 21 including a lower busbar 211 that is vertically aligned with the electrode fingers 22 and an upper busbar 212 located above the lower busbar 211. Furthermore, the material of the upper busbar 212 may be the same as or different from the material of the lower busbar 211. In this embodiment, the material of the upper busbar 212 is different from that of the lower busbar 211, and in the vertical direction, the thickness of the upper busbar 212 is greater than the thickness of the lower busbar 211, that is, the busbar 21 is a stacked structure, which can achieve the characteristics of low-speed and lossy (high damping) regions. In this case, the structure of the suppression layer 40 is first optimized to achieve the optimal piston mode effect, and then the gap 23 area is adjusted to achieve complete stray suppression. It should be noted that although the upper busbar 212 and the lower busbar 211 are not distinguished in the subsequent drawings, it does not mean that the materials of the upper busbar 212 and the lower busbar 211 are the same material.

[0064] As an example, the material of the passivation layer 30 includes at least one of SiO2, SiN or other dielectric materials with positive thermal velocity characteristics. In this embodiment, the material of the passivation layer is SiO2. The setting of the suppression layer 40 can, on the one hand, play the role of electrical insulation between the suppression layer 40 and the electrode fingers 22, and on the other hand, can serve as an acoustic guide layer to allow surface acoustic waves to propagate in the passivation layer 30 and reduce lateral energy diffusion during the operation of the resonator. In addition, the side of the passivation layer 30 facing away from the piezoelectric substrate 10 maintains a flat surface (which can be achieved by flattening after the production is completed), thereby reducing unnecessary scattering losses generated when the suppression layer 40 is formed thereon, thereby improving the working performance of the resonator. In this embodiment, the material of the passivation layer 30 is SiO2, and the thickness of the passivation layer 30 in the vertical direction is 1 μm.

[0065] As an example, the material of the electrode layer 20 includes one or more metal materials such as Al, Ti, Cu, Pt, and Au. In this embodiment, the material of the electrode layer 20 is Cu.

[0066] As an example, the material of the inhibition layer 40 includes at least one of a metal material and a high-density dielectric material, the metal material includes at least one of Al, Ti, Cu, Pt and Au, and the high-density dielectric material includes at least one of Ta2O5, HfO2 and BaTiO3 (the above three high-density dielectric materials have a high density, and the relative density is greater than 6.0 g / cm 3 ). The selection of the above materials to form the suppression layer 40 can bring about a certain mass loading effect (phase shift effect) to realize the piston mode, thereby reducing the speed of the transverse mode and improving the performance of the resonator. The material of the suppression layer 40 is preferably a metal material to simultaneously realize the heat sink function. Furthermore, the material of the suppression layer 40 can be the same as or different from the material of the electrode layer 20. In this embodiment, the material of the suppression layer 40 is the same as the material of the upper bus bar 21.

[0067] Specifically, in this embodiment, the suppression layer 40 is made of a metal material, so that on the one hand, the suppression layer 40 is connected to the bus bar 21 to improve the electric field distribution in the gap 23 area (based on the electrostatic effect generated by the electrical interaction between the suppression layer 40 and the edge of the electrode finger 22), and the electrical effect presented by the potential linearization of the electric field in this area is used to reduce the high-order nonlinearity and distortion of the signal transmission, and based on the acoustic interaction and phase shift effect between the suppression layer 40 and the surface acoustic wave, the lateral stray mode is suppressed to improve the working performance of the resonator. On the other hand, the material properties of the suppression layer 40 enable it to have good thermal conductivity, so that it can act as a heat sink, thereby further improving the durability and linearity of the resonator, thereby improving the working stability and service life of the resonator without the need for an additional heater structure to avoid increasing the overall volume of the resonator. Of course, in other embodiments, one or more of the high-density dielectric materials mentioned above can also be used as the constituent material of the suppression layer 40, which can also achieve the effect of suppressing the lateral stray mode to improve the working performance of the resonator. The material of the suppression layer 40 is preferably a metal material to simultaneously realize the heat sink function. During application, the material of the suppression layer 40 is reasonably selected based on actual needs.

[0068] As an example, when the spacing between two adjacent electrode fingers 22 in the same interdigitated electrode is λ (λ as shown in FIG3 ), the width of the partial overlap between the suppression unit 41 and the electrode finger 22 along the first direction (shown as w in FIG5 ) is 0 to 1.0λ, including but not limited to 0, 0.3λ, 0.5λ, 0.8λ or 1.0λ. The area where the suppression unit 41 partially overlaps with the electrode finger 22 is very important for achieving the piston mode effect and lateral suppression. In this area, the propagation speed of the surface acoustic wave is significantly reduced compared to the main area of ​​the electrode finger 22, thereby achieving the piston mode effect. It should be noted that the propagation speed of the surface acoustic wave in the gap 23 area will also be reduced, but the effect on lateral suppression is small, and the propagation speed of the surface acoustic wave in the busbar area is very low. Therefore, the adverse effects of the thin suppression layer 40 can be ignored.

[0069] Please refer to Figure 6, which shows a graph showing how the resonator's conductance changes with frequency when the partial overlap widths of the suppression unit and electrode fingers are different. When the partial overlap width is less than 0 (e.g., -0.1λ), this means that the suppression unit 41 does not extend above the electrode fingers 22 (i.e., the suppression unit 41 and electrode fingers 22 do not partially overlap in the first direction). When the partial overlap width is greater than 0 (e.g., 0.1λ), this means that the suppression unit 41 extends above the electrode fingers 22 (i.e., the suppression unit 41 and electrode fingers 22 partially overlap in the first direction). While keeping other parameters constant, a comparison of the conductivity characteristics of resonators with varying widths of partial overlap between the suppression unit 41 and the electrode fingers 22 reveals that the resonator's transverse modes are suppressed to varying degrees at these widths. When the suppression unit 41 partially overlaps the electrode fingers 22, the transverse mode suppression effect is significantly greater (compared to when the suppression unit 41 extends only partially above the gap 23). The effect is particularly pronounced when the partial overlap between the suppression unit 41 and the electrode fingers 22 is 0.2λ. At this point, the transverse mode is almost completely suppressed in the frequency range of 860MHz to 880MHz, effectively improving the resonator's operating performance. It should be noted that although Figure 5 does not compare the data curves for partial overlaps greater than 0.8λ, in reality, a certain degree of transverse mode suppression is also achieved when the partial overlap is greater than 0.8λ.

[0070] In addition, please refer to FIG7 , which shows a graph of the effect of the resonator's quality factor Q on frequency when the partial overlap widths of the suppression unit and the electrode fingers vary (Fr and Fa in FIG7 correspond to the resonant frequency and antiresonant frequency of the resonator, respectively). FIG7 shows that the resonator's quality factor Q does not change significantly due to changes in the width of the partial overlap between the suppression unit 41 and the electrode fingers 22 (i.e., the partial overlap between the suppression unit 41 and the electrode fingers 22 does not affect the resonator's quality factor Q). It should be noted that when the width of the partial overlap is small, the suppression unit 41 is primarily located above the gap 23, and the electrostatic interaction between it and the periodically arranged electrode fingers 22 is small. In this case, the effect of this electrostatic interaction on the resonator's performance is negligible. However, as the width of the partial overlap increases, the electrostatic interaction between the suppression unit 41 and the periodically arranged electrode fingers 22 also increases, and the impact on the resonator's operation becomes increasingly prominent. Therefore, the width of the partial overlap between the suppression unit 41 and the electrode fingers 22 is strictly limited to the aforementioned range, and is preferably between 0.1λ and 0.5λ (inclusive). In addition, the arrangement of the suppression unit 41 plays a transition buffering role on the propagation speed of the sound wave, so as to ensure the working stability of the resonator.

[0071] As an example, the vertical thickness range (h in Figure 5) of the portion of the suppression unit 41 located above the gap 23 and above the electrode finger 22 is 1 to 100 nm (when the thickness of the suppression unit 41 is equal everywhere, the thickness range of the portion of the suppression unit 41 located above the bus bar 21 is also 1 to 100 nm), which includes but is not limited to 1 nm, 25 nm, 40 nm, 75 nm or 100 nm.

[0072] Please refer to Figure 8, which shows a curve diagram of the effect of the conductivity characteristics of the resonator changing with frequency when the thickness of the suppression unit is located above the gap and above the electrode finger is different. When other parameters remain consistent (such as keeping the width of the partial overlap between the suppression unit 41 and the electrode finger 22 unchanged at 0.2λ), after comparing the conductivity characteristics of the resonators with different above-mentioned thicknesses, it is found that: the transverse mode of the resonator is suppressed to varying degrees at different above-mentioned thicknesses, and when the above-mentioned thickness is in the range of 20nm to 60nm, the transverse mode suppression effect is relatively good, and when the above-mentioned thickness is 40nm, the transverse mode generated during the operation of the resonator is completely suppressed (as shown by the arrows in Figure 8).

[0073] In addition, please refer to Figure 9, which shows a curve diagram of the effect of the quality factor Q of the resonator changing with frequency when the thickness of the suppression unit located above the gap and above the electrode fingers is different. After a simultaneous analysis of the quality factor Q of the resonator, it can be seen that: as the above-mentioned thickness increases, the acoustic impact phenomenon generated in the corresponding suppression layer 41 is intensified, resulting in a downward trend in the quality factor Q of the resonator. When the above-mentioned thickness is 1nm, since the very thin suppression layer 41 does not generate acoustic impact, the quality factor Q remains relatively high. When the above-mentioned thickness is relatively thick (for example, ≥100nm), the acoustic impact generated by the suppression layer 41 is quite high, resulting in a significant downward trend in the quality factor Q. As can be seen from Figure 9, when the above-mentioned thickness is 40nm, the reduction in the quality factor Q of the resonator is negligible, and the quality factor Q even performs better in the low-frequency region (for example, ≤840MHz).

[0074] Furthermore, after analyzing the performance of resonators having the suppression layer 41 and the passivation layer 30 with different thicknesses, the following rules were summarized: In order to achieve a better lateral mode suppression effect, it is necessary to ensure that the thickness of the passivation layer 30 is negatively linearly correlated with the above-mentioned thickness of the suppression layer 40 (as shown in Figure 10). Therefore, in actual application, if the thickness of the passivation layer 30 is relatively thin, the thickness of the suppression layer 40 is increased accordingly, and when the thickness of the passivation layer 40 is relatively thick, the thickness of the suppression layer 40 is reduced accordingly. For example, when the passivation layer 30 is relatively thick (for example, about 1450nm), the suppression layer 40 has a relatively low thickness (for example, about 20nm) to have a better suppression effect. Please refer to Figure 11, which shows a graph of the effect of the resonator's quality factor Q on frequency at different passivation layer thicknesses (it should be noted that Figures 10 and 11 are data collected when the width of the partial overlap between the suppression unit 41 and the electrode finger 22 is 0.2λ). The resonator's quality factor Q does not significantly decrease due to the different thicknesses of the passivation layer 30. When the passivation layer 30 is thicker (≥1250nm), the corresponding curve in Figure 11 shows an increase in spurious signals. This is because the width of the suppression unit 41 above the gap 23 and above the electrode finger 22 is not properly adjusted. Therefore, when designing the resonator structure, the thickness of the suppression layer 40 (especially the thickness of the portion of the suppression unit 41 above the gap 23 and above the electrode finger 22), the width range of the partial overlap between the suppression unit 41 and the electrode finger 22, and the corresponding thickness of the passivation layer 30 are optimized simultaneously to ensure better performance of the resonator.

[0075] As an example, referring to Figures 5 and 12 to 14, the suppression unit 41 is connected to the side of the busbar 21 away from the piezoelectric substrate 10 and extends above the passivation layer 30. That is, in this embodiment, the suppression unit 41 includes a portion located above the busbar 21 in addition to the portion located above the gap 23 and the electrode fingers 22.

[0076] Further, as shown in Figures 5 and 13, in the vertical direction, the thickness of the portion of the suppression unit 41 located above the bus bar 21 is equal to the thickness of the portion of the suppression unit 41 located above the passivation layer 30, or, as shown in Figure 12, in the vertical direction, the thickness of the portion of the suppression unit 41 located above the bus bar 21 (shown as h2 in Figure 12) is greater than the thickness of the portion of the suppression unit 41 located above the passivation layer 30 (that is, the portion of the suppression unit 41 located above the gap 23 and above the electrode finger 22) (shown as h1 in Figure 12).

[0077] As an example, as shown in FIG14 , the suppression unit 41 is further vertically embedded in the passivation layer 30, and the portion of the suppression unit 41 vertically embedded in the passivation layer 30 is located above the gap 23. The above-mentioned structure can be easily formed by etching an opening in the fabricated passivation layer 30 and then filling the opening with the material of the suppression layer 40. That is, an additional structure is filled above the gap 23, so that the structure serves as an energy limit, thereby improving the quality factor Q, durability, and linearity of the resonator. In addition, the portion of the suppression unit 41 vertically extending into the passivation layer 30 is located near the electrode finger 22, which can also act as a dummy finger to reduce scattered energy loss, thereby further improving the performance of the resonator.

[0078] As an example, as shown in FIG13 , the passivation layer 30 has a groove 31, the vertical projection of which is located between the vertical projections of the two suppression units 41, and the portion of the passivation layer 30 surrounding the groove 31 forms a raised frame 32. In actual manufacturing, the above structure can be achieved by patterning the passivation layer 30 (or even the suppression layer 40). The provision of the raised frame 32 can impose a certain degree of restriction on the acoustic wave propagation velocity in the area corresponding to the gap 23 and the edge area of ​​the electrode finger 22, thereby suppressing the lateral mode. Correspondingly, the provision of the groove 31 can relatively increase the acoustic wave propagation velocity in the portion of the electrode finger 22 located below the groove 31, thereby specifically improving the performance of the resonator.

[0079] As an example, refer to Figures 15 and 16. Figure 15 shows a schematic diagram of a partial longitudinal cross-section of a resonator having dummy fingers, and Figure 16 shows a schematic diagram of a top-down view of the electrode layer in the resonator shown in Figure 15. The interdigitated electrodes further include a plurality of dummy fingers 24 connected to a bus bar 21. The dummy fingers 24 in the same interdigitated electrode are arranged alternately and spaced apart from the electrode fingers 22, and the dummy fingers 24 are embedded in the gaps 23. A predetermined distance exists between the dummy fingers 24 in one interdigitated electrode and the electrode fingers 22 in the other interdigitated electrode (i.e., the dummy fingers 24 are located in the gaps 23, and the ends of the dummy fingers 24 facing away from the bus bar 21 maintain a predetermined distance from the electrode fingers 22 in the other interdigitated electrode). The arrangement of the dummy fingers 24 can achieve a better energy confinement effect. Furthermore, the width, thickness, and material of the dummy fingers 24 are preferably consistent with the corresponding parameters of the electrode fingers 22, so that the dummy fingers 24 and the electrode fingers 22 can be simultaneously manufactured in a single process step during the manufacturing process.

[0080] As an example, the resonator includes at least one of a temperature compensated surface acoustic wave resonator (TC-SAW), a piezoelectric on insulator-surface acoustic wave resonator (POI-SAW), a solid-mounted resonator (SMR), a transversely excited bulk acoustic wave resonator (XBAR), a longitudinally coupled bulk acoustic wave resonator (YBAR) and a film bulk acoustic wave resonator (FBAR).

[0081] In the resonator with a transverse mode suppression structure of this embodiment, the additionally provided suppression layer structure achieves the suppression of the transverse mode through the energy limiting effect, while also being able to improve the quality factor of the resonator, and is applicable to a variety of resonator structures and a wide frequency range, and during the manufacturing process, no special high-resolution process is required, so the structure is simple and the manufacturing process is mature. After further improvement and optimization of the suppression layer structure, the piston mode effect can be achieved without using a hammer head structure or a selective disassembly method to reduce scattering losses. In addition, the selection of the material of the suppression layer allows the suppression layer to act as a heat sink in addition to the transverse mode suppression effect due to its good thermal conductivity, thereby improving the durability and linearity of the resonator, and further improving the working stability and service life of the resonator. In addition, adding multiple pseudo-finger structures to the interdigitated electrode structure does not increase the overall volume of the resonator, so that it can better limit the energy during the operation of the resonator while also improving the volume utilization rate, thereby further improving the working performance of the resonator.

[0082] Example 2

[0083] This embodiment provides a resonator with a lateral mode suppression structure. This embodiment differs from the first embodiment in that, whereas the suppression unit in the first embodiment is connected to the side of the busbar facing away from the piezoelectric substrate and extends above the passivation layer, the suppression unit in this embodiment is connected to the side of the busbar and embedded in the passivation layer in the first direction. Referring to Figures 17 to 20 , the resonator includes a piezoelectric substrate 10, an electrode layer 20, a passivation layer 30 (see Figure 4 in conjunction with the structure), and a suppression layer 40 (see Figure 4 in conjunction with the structure).

[0084] As an example, the suppression unit 41 is connected to the side of the busbar 21 and embedded in the passivation layer 30 in the first direction, that is, the suppression unit 41 is only located above the gap 23 and above the electrode finger 22, and does not include the portion located above the busbar 21. In this embodiment, the suppression unit 41 is embedded in the passivation layer 30. Compared with the solution in which the suppression unit 41 is located above the passivation layer 30 (i.e., the solution described in Example 1), the portion of the suppression unit 41 embedded in the passivation layer 30 can provide better stray mode suppression. However, when adopting the structure of the embedded suppression unit 41, it is necessary to comprehensively consider the impact of the thickness design of the passivation layer 30 and the thickness design of the suppression layer 40 on the performance of the resonator. For example, when the suppression unit 41 is completely embedded in the passivation layer 30, the suppression layer 40 needs to have a relatively small thickness while ensuring good lateral mode suppression. Otherwise, the overall thickness of the passivation layer 30 is relatively high, which will cause unnecessary loss to the working performance of the resonator.

[0085] Furthermore, vertically, the thickness of the portion of the suppression unit 41 located above the gap 23 is less than the thickness of the portion of the suppression unit 41 located above the electrode fingers 22 (as shown in FIG19 , h12 > h11). Alternatively, vertically, the thickness of the portion of the suppression unit 41 located above the gap 23 is equal to the thickness of the portion of the suppression unit 41 located above the electrode fingers 22 (as shown in FIG17 and FIG18 ). Thickening the portion of the suppression unit 41 located above the electrode fingers 22 (compare FIG18 and FIG19 ) can further improve the lateral mode suppression and energy confinement effects, but this also increases additional process steps or costs. Therefore, the choice should be made based on actual needs during application.

[0086] The resonator with a lateral mode suppression structure of this embodiment, based on the resonator structure of the first embodiment, flexibly sets the positional relationship between the suppression unit and the passivation layer, thereby specifically adjusting the performance parameters of the resonator to meet the needs of multiple application scenarios.

[0087] It should be understood that the vertical direction mentioned above refers to the direction from the piezoelectric substrate 10 to the inhibition layer 40 or the direction from the inhibition layer 40 to the piezoelectric substrate 10, and the vertical direction (i.e., the Z direction in Figure 5) is perpendicular to both the first direction (i.e., the X direction in Figures 3 and 5) and the second direction (i.e., the Y direction in Figure 3).

[0088] Example 3

[0089] This embodiment provides a resonator with a lateral mode suppression structure. This embodiment differs from the first and second embodiments in that the suppression unit in the resonators described in the first and second embodiments does not have blind slots or through slots, while the suppression unit in this embodiment does have blind slots or through slots. Referring to Figures 20 to 22 , the resonator includes a piezoelectric substrate 10, an electrode layer 20, a passivation layer 30 (see Figure 4 in conjunction with the structure), and a suppression layer 40 (see Figure 4 in conjunction with the structure).

[0090] As an example, referring to Figures 20 to 22, the portion of the suppression unit 41 located above the gap 23 has at least one blind groove 411 and / or at least one through groove 412. The blind groove 411 opens from a side of the suppression unit 41 toward the piezoelectric substrate 10 and / or a side away from the piezoelectric substrate 10 and extends vertically. The through groove 412 opens from a side of the suppression unit 41 away from the piezoelectric substrate 10 and exposes at least a portion of at least one electrode finger 22.

[0091] As shown in Figure 20, the portion of the suppression unit 41 located above the gap 23 has two blind slots 411. These two blind slots 411 are spaced apart in the first direction and open from different sides of the suppression unit 41. The provision of the blind slots 411 can be achieved through detailed design of the structure of the portion of the suppression unit 41 located above the gap 23 (or even the portion located above the electrode fingers 22) to specifically alter the local structure's effects on lateral suppression and energy confinement, thereby adaptively adjusting the resonator's performance parameters.

[0092] As shown in Figure 21, the portion of suppression unit 41 located above gap 23 has multiple through-slots 412 spaced apart in the second direction, each of which exposes at least a portion of electrode finger 22. After suppression layer 40 is fabricated, patterning is performed to achieve the aforementioned structure. This structure not only controls the acoustic wave propagation velocity at the edges of electrode fingers 22, but also controls the acoustic wave propagation velocity in gap 23, thereby reducing scattering losses and limiting energy leakage, thereby improving resonator performance.

[0093] As shown in Figure 22, the part of the suppression unit 41 located above the gap 23 has a through groove 412, which occupies nearly half of the area of ​​the suppression unit 41 above the gap 23 and is triangular in shape. The setting of the through groove 412 makes the suppression unit 41 toe-cut, so that the energy transmitted through the interdigital electrodes is concentrated in the electrode finger 22 area to reduce energy loss, thereby further improving the resonator performance.

[0094] The resonator with a transverse mode suppression structure of this embodiment is based on the resonator structures of the first and second embodiments, and the structure of the suppression unit is diversified to further improve the working performance of the resonator.

[0095] Example 4

[0096] This embodiment provides a resonator with a lateral mode suppression structure. This embodiment differs from the first and second embodiments in that the suppression unit in the resonators of the first and second embodiments, located above the gap and electrode fingers, is a monolithic structure. In contrast, the suppression unit in this embodiment, located above the gap and electrode fingers, comprises multiple discrete suppression blocks. Referring to Figures 23 to 27 , this resonator includes a piezoelectric substrate 10, an electrode layer 20, a passivation layer 30 (see Figure 4 in conjunction with this), and a suppression layer 40 (see Figure 4 in conjunction with this).

[0097] As an example, the portion of the suppression unit 41 located above the gap 23 and the electrode fingers 22 includes a plurality of suppression blocks 413 spaced apart in the second direction, and the projection of at least one suppression block 413 on the plane where the piezoelectric substrate 10 is located partially overlaps with the projection of the electrode finger 22 located on a different side of the suppression block 413 on the plane where the piezoelectric substrate 10 is located. That is, the projection of at least one suppression block 413 in the suppression unit 41 connected to the bus bar 21 in one interdigitated electrode on the plane where the piezoelectric substrate 10 is located partially overlaps with the projection of the electrode finger 22 in another interdigitated electrode on the plane where the piezoelectric substrate 10 is located.

[0098] As an example, as shown in Figures 23 and 24, the dimensions (length, width and thickness) of each suppression block 413 are the same, and the suppression blocks 413 in the same suppression unit 41 are aligned, or, as shown in Figures 25 and 26, the dimensions of the suppression blocks 413 are different, but multiple suppression blocks 413 are symmetrically distributed about the central axis of the resonator in the first direction, and as shown in Figure 26, two suppression units 41 are symmetrically distributed about the central axis of the resonator in the second direction, for example, the length of the suppression block 413 is inversely proportional to the distance of the suppression block 413 close to the center position.

[0099] As an example, as shown in Figures 23 to 25, the multiple suppression blocks 413 include multiple first suppression blocks 413a, which extend in the first direction through the gap 23 and overlap with the projections of the electrode fingers 22 on different sides of the first suppression block 413a on the plane where the piezoelectric substrate 10 is located. That is, the projection of the first suppression block 413a in the suppression unit 41 connected to the bus bar 21 in one interdigitated electrode on the plane where the piezoelectric substrate 10 is located partially overlaps with the projection of the electrode fingers 22 in the other interdigitated electrode on the plane where the piezoelectric substrate 10 is located.

[0100] As an example, as shown in Figures 24 and 25, the multiple suppression blocks 413 also include multiple second suppression blocks 413b, and the second suppression blocks 413b extend in the first direction above the electrode fingers 22 located on the same side as the second suppression blocks 413b. That is, the second suppression block 413b in the suppression unit 41 connected to the bus bar 21 in one interdigitated electrode extends in the first direction above the electrode fingers 22 in the one interdigitated electrode. The multiple first suppression blocks 413a and the multiple second suppression blocks 413b in the same suppression unit 41 are alternately arranged, and the first suppression block 413a in one suppression unit 41 is arranged opposite to the second suppression block 413b in another suppression unit 41. The first suppression block 413a and the second suppression block 413b have the same morphology (as shown in Figure 24), or the first suppression block 413a and the second suppression block 413b (as shown in Figure 25) have different morphologies.

[0101] As an example, each of the multiple suppression blocks 413 is connected to each other at one end close to the bus bar 21. For example, as shown in Figure 27, each of the multiple suppression blocks 413 is connected at one end close to the bus bar 21 through two partial suppression units 41 similar to right triangles, that is, each suppression block 413 is connected to the bus bar 21 through a partial suppression unit 41; as shown in Figure 24, each of the multiple suppression blocks 413 is independent of each other at one end close to the bus bar 21, that is, each suppression block 413 is in direct contact with the bus bar 21.

[0102] The resonator with a transverse mode suppression structure of this embodiment is based on the resonator structures described in the first and second embodiments, and the structure of the suppression unit is diversified to further improve the working performance of the resonator.

[0103] Example 5

[0104] The present application also provides a method for manufacturing a resonator having a transverse mode suppression structure. The method is used to manufacture the resonator structures described in Examples 1 to 4 and other suitable resonator structures. As shown in FIG28 , the method includes the following steps:

[0105] Step S110, providing a piezoelectric substrate;

[0106] Step S120, forming an electrode layer on the piezoelectric substrate, the electrode layer including two interdigital electrodes arranged opposite to each other in a first direction, each of the two interdigital electrodes including a bus bar and a plurality of electrode fingers connected to the bus bar, the plurality of electrode fingers in the same interdigital electrode being spaced apart in a second direction, each of the plurality of electrode fingers in one interdigital electrode having a gap with the bus bar in another interdigital electrode, and the second direction being perpendicular to the first direction;

[0107] Step S130 , forming a passivation layer on the piezoelectric substrate, wherein the passivation layer is embedded between the two interdigital electrodes in a first direction and covers a plurality of electrode fingers and gaps in the two interdigital electrodes;

[0108] Step S140, forming an inhibition layer above the piezoelectric substrate, the inhibition layer including two inhibition units arranged opposite to each other in a first direction, each of the two inhibition units being connected to a bus bar in one interdigitated electrode and extending along the first direction to cover the gap and partially overlap with a projection of at least one electrode finger in the other interdigitated electrode on the plane where the piezoelectric substrate is located.

[0109] The method for manufacturing a resonator with a transverse mode suppression structure in this embodiment can effectively improve the structural performance of the resonator without requiring special high-resolution processes. The process steps are simple and the cost is low, thereby enabling large-scale production of high-performance resonators.

[0110] In summary, in the resonator with a transverse mode suppression structure of the present application, the additionally provided suppression layer structure achieves the suppression of the transverse mode through the energy limiting effect, while also being able to improve the quality factor of the resonator, and is applicable to a variety of resonator structures and a wide frequency range, and during the manufacturing process, no special high-resolution process is required, so the structure is simple and the manufacturing process is mature. And after further improvement and optimization of the suppression layer structure, the piston mode effect can be achieved without the need to use a hammer head structure or a selective disassembly method to reduce scattering losses. In addition, the selection of the material of the suppression layer allows the suppression layer to act as a heat sink in addition to the transverse mode suppression effect due to its good thermal conductivity, thereby improving the durability and linearity of the resonator, and further improving the working stability and service life of the resonator. The manufacturing method of the resonator with a transverse mode suppression structure of the present application does not require a special high-resolution process to achieve effective improvement of the resonator structure performance, the process steps are simple and the cost is low, thereby enabling large-scale production of high-performance resonators. Therefore, the present application effectively overcomes the various shortcomings in the related art and has a high industrial utilization value.

[0111] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A resonator with a transverse mode suppression structure, characterized in that, Comprising: A piezoelectric substrate; An electrode layer located above the piezoelectric substrate. The electrode layer includes two interdigital electrodes oppositely arranged in a first direction. Each of the two interdigital electrodes includes a bus bar and a plurality of electrode fingers connected to the bus bar. The plurality of electrode fingers in the same interdigital electrode are spaced apart in a second direction perpendicular to the first direction. There is a gap between each electrode finger in the plurality of electrode fingers of one interdigital electrode and the bus bar of the other interdigital electrode; A passivation layer located above the piezoelectric substrate. The passivation layer is embedded between the two interdigital electrodes in the first direction and covers the plurality of electrode fingers and the gap in the two interdigital electrodes; A suppression layer located above the piezoelectric substrate. The suppression layer includes two suppression units oppositely arranged in the first direction. Each of the two suppression units is connected to the bus bar of one interdigital electrode and extends along the first direction to cover the gap and partially overlap with at least one electrode finger of the other interdigital electrode in the projection on the plane where the piezoelectric substrate is located.

2. The resonator with a lateral mode suppression structure according to claim 1, characterized in that: When the distance between two adjacent electrode fingers in the same interdigital electrode is λ, the range of the width in the first direction where the projection of the suppression unit on the plane where the piezoelectric substrate is located partially overlaps with the projection of the at least one electrode finger of the other interdigital electrode on the plane where the piezoelectric substrate is located is 0 to 1.0λ.

3. The resonator with a lateral mode suppression structure according to claim 1 or 2, characterized in that: The range of the thickness in the vertical direction of the part of the suppression unit located above the gap and above the at least one electrode finger of the other interdigital electrode is 1 to 100 nm, and the vertical direction is perpendicular to both the first direction and the second direction.

4. The resonator with a lateral mode suppression structure according to any one of claims 1 to 3, characterized in that: The suppression unit is connected to the side of the bus bar of the one interdigital electrode away from the piezoelectric substrate and extends above the passivation layer.

5. The resonator with a lateral mode suppression structure according to claim 4, characterized in that: In the vertical direction, the thickness of the part of the suppression unit located above the bus bar of the one interdigital electrode is greater than or equal to the thickness of the part of the suppression unit located above the passivation layer.

6. The resonator with a lateral mode suppression structure according to claim 4 or 5, characterized in that: The suppression unit is also embedded in the passivation layer in the vertical direction, and the part of the suppression unit embedded in the passivation layer in the vertical direction is located above the gap.

7. The resonator with a lateral mode suppression structure according to any one of claims 1 to 3, characterized in that: The suppression unit is connected to the side of the bus bar of the one interdigital electrode and is embedded in the passivation layer in the first direction.

8. The resonator with a lateral mode suppression structure according to any one of claims 1 to 7, characterized in that: The part of the suppression unit located above the gap has at least one blind groove, and each of the at least one blind groove opens from the side of the suppression unit facing the piezoelectric substrate and / or the side facing away from the piezoelectric substrate and extends in the vertical direction.

9. The resonator with a lateral mode suppression structure according to any one of claims 1 to 8, characterized in that: The part of the suppression unit located above the gap has at least one through groove, and each of the at least one through groove opens from the side of the suppression unit facing away from the piezoelectric substrate, and the at least one through groove exposes at least a part of at least one electrode finger of the one interdigital electrode.

10. The resonator with a lateral mode suppression structure according to any one of claims 1 to 9, characterized in that: The passivation layer has a groove, and a projection of the groove on a plane where the piezoelectric substrate is located is located between projections of the two suppression units on the plane where the piezoelectric substrate is located. A part of the passivation layer surrounding the groove constitutes a raised frame.

11. The resonator with a lateral mode suppression structure according to any one of claims 1 to 10, characterized in that: A part of the suppression unit located above the gap and above at least one electrode finger in the other interdigital electrode includes a plurality of suppression blocks spaced apart in a second direction. A projection of at least one suppression block in the plurality of suppression blocks on the plane where the piezoelectric substrate is located partially overlaps a projection of at least one electrode finger in the other interdigital electrode on the plane where the piezoelectric substrate is located.

12. The resonator with a lateral mode suppression structure according to claim 11, characterized in that: The plurality of suppression blocks includes a plurality of first suppression blocks. The plurality of first suppression blocks extends above the gap in a first direction and partially overlaps a projection of at least one electrode finger in the other interdigital electrode on the plane where the piezoelectric substrate is located.

13. The resonator with a lateral mode suppression structure according to claim 12, wherein: The plurality of suppression blocks further includes a plurality of second suppression blocks. The plurality of second suppression blocks extends above electrode fingers in one interdigital electrode in the first direction.

14. The resonator with a lateral mode suppression structure according to claim 13, wherein: In the same suppression unit, the plurality of first suppression blocks and the plurality of second suppression blocks are alternately arranged, and in different suppression units, the plurality of first suppression blocks and the plurality of second suppression blocks are oppositely arranged, and the plurality of first suppression blocks and the plurality of second suppression blocks have the same morphology.

15. The resonator with a lateral mode suppression structure according to claim 13, characterized in that: In the same suppression unit, the plurality of first suppression blocks and the plurality of second suppression blocks are alternately arranged, and in different suppression units, the plurality of first suppression blocks and the plurality of second suppression blocks are oppositely arranged, and the plurality of first suppression blocks and the plurality of second suppression blocks have different morphologies.

16. The resonator with a lateral mode suppression structure according to any one of claims 1 to 15, characterized in that: The interdigital electrode further includes a plurality of dummy fingers connected to the bus bar. The plurality of dummy fingers in the same interdigital electrode are alternately and spacedly arranged with the plurality of electrode fingers, and the plurality of dummy fingers are embedded in the gap. A preset distance exists between the plurality of dummy fingers in one interdigital electrode and the plurality of electrode fingers in the other interdigital electrode.

17. The resonator with a lateral mode suppression structure according to any one of claims 1 to 16, characterized in that: The material of the suppression layer includes at least one of a metal material and a high-density dielectric material. The metal material includes at least one of Al, Ti, Cu, Pt, and Au. The high-density dielectric material includes at least one of Ta2O5, HfO2, and BaTiO3.

18. A method for manufacturing a resonator with a lateral mode suppression structure, characterized in that, Comprising: Providing a piezoelectric substrate; Forming an electrode layer above the piezoelectric substrate. The electrode layer includes two interdigital electrodes oppositely arranged in a first direction. Each interdigital electrode in the two interdigital electrodes includes a bus bar and a plurality of electrode fingers connected to the bus bar. The plurality of electrode fingers in the same interdigital electrode are spaced apart in a second direction. A gap exists between each electrode finger in the plurality of electrode fingers in one interdigital electrode and the bus bar in the other interdigital electrode. The second direction is perpendicular to the first direction; Forming a passivation layer above the piezoelectric substrate. The passivation layer is embedded between the two interdigital electrodes in the first direction and covers the plurality of electrode fingers and the gap in the two interdigital electrodes; A suppression layer is formed above the piezoelectric substrate. The suppression layer includes two suppression units oppositely arranged in the first direction. Each of the two suppression units is connected to the bus bar in one of the interdigital electrodes and extends along the first direction to cover the gap and partially overlap at least one electrode finger in the other interdigital electrode in the projection on the plane where the piezoelectric substrate is located.

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