A surface acoustic wave resonator

Abstract

This application discloses a surface acoustic wave (SAW) resonator comprising: a piezoelectric layer, interdigital transducers deposited on the piezoelectric layer, a suppression metal structure, and a connecting metal structure. The interdigital transducers include two opposing busbars and multiple interdigital electrodes disposed between the busbars. The suppression metal structure is disposed near the two ends of each busbar and is connected to the multiple interdigital electrodes via the connecting metal structure. The resonator also includes an isolation layer deposited on the piezoelectric layer, with the suppression metal structure disposed on the isolation layer. This allows for the suppression of transverse modes, preventing interference with the performance of the SAW filter.

Description

Technical Field

[0001] This application relates to the field of surface acoustic wave (SAW) element technology, and in particular to a SAW resonator. Background Technology

[0002] Surface acoustic wave (SAW) resonators, as key components in radio frequency (RF) systems, are widely used in modern communication, sensing, and other electronic devices due to their excellent performance and miniaturization. With the development of communication technology, the performance requirements for SAW resonators are constantly increasing.

[0003] During the operation of a surface acoustic wave (SAW) resonator, due to the anisotropy of the piezoelectric material used as the substrate, undesirable transverse modes are often excited in the aperture direction in addition to the dominant SAW mode. The resonant frequency of the transverse mode is located near the main passband of the SAW resonator. If it is not suppressed, it will lead to a decrease in the quality factor (Q value) of the SAW resonator and the generation of ripples in the passband, thereby severely degrading the device performance.

[0004] Publication number CN118100861A, entitled "A Three-Segment Rhomboid Weighted SAW Resonator for Suppressing Lateral Modes," includes: a piezoelectric substrate and an interdigital transducer disposed on the surface of the piezoelectric substrate; characterized in that the length of the interdigital electrodes within the aperture region of the interdigital transducer varies according to a three-segment rhomboid weighted curve: with the center of the interdigital transducer as the origin, the y-axis along the direction of the interdigitates and the x-axis perpendicular to the direction of the interdigitates, the aperture region is divided into four quadrants; the length of the interdigitates of the two metal electrodes constituting the interdigital transducer decreases along both directions of the x-axis, and the two outermost interdigitates extend at least to the x-axis; if the endpoint of the outermost interdigitate in a certain quadrant is not in that quadrant, then a point is selected on the outermost interdigitate interdigitate that is the endpoint of the interdigitate interdigitate. A point symmetrical about the x-axis is taken as the endpoint of the outermost interdigitated finger in that quadrant. The segment from the endpoint of the outermost interdigitated finger in each quadrant to the x-axis is the first weighted curve. The second weighted curve is the line connecting the endpoint of the outermost interdigitated finger, through the endpoints of each interdigitated finger, to the endpoint of the interdigitated finger in the middle of that quadrant. The third weighted curve is the line connecting the endpoint of the interdigitated finger in the middle of that quadrant, through the endpoints of the remaining interdigitated fingers, to the y-axis vertex of that quadrant. The slope of the second weighted curve is greater than the slope of the third weighted curve. The three weighted curves in each quadrant together form a three-segment diamond weighted structure.

[0005] The publication number is CN120389720A, and the title is "An Interlaced Thickness Type Surface Acoustic Wave Resonator, Filter, and Method for Fabrication Thereof". It includes: a substrate (1), a first electrode finger film layer (2), and a second electrode finger film layer (3). The first electrode finger film layer (2) is disposed on the substrate (1), and a portion of the second electrode finger film layer (3) is disposed on the substrate (1), while the other portion covers the first electrode finger film layer (2), forming an overlapping region (2-3). The first electrode finger film layer (2), the second electrode finger film layer (3), and the overlapping region (2-3) form a grid structure with alternating thicknesses. The grid structure forms different sound velocity regions between the interlaced electrode region and the busbar.

[0006] There is currently no effective solution to the technical problem that the transverse modes in the existing technology are not effectively suppressed, thus affecting the performance of surface acoustic wave resonators. Summary of the Invention

[0007] This disclosure provides a surface acoustic wave resonator to at least solve the technical problem in the prior art where the transverse mode is not effectively suppressed, affecting the performance of the surface acoustic wave resonator.

[0008] According to one aspect of this application, a surface acoustic wave resonator is provided, comprising: a piezoelectric layer, an interdigital transducer deposited on the piezoelectric layer, a suppression metal structure, and a connecting metal structure, wherein the interdigital transducer includes two busbars disposed opposite each other and a plurality of interdigital electrodes disposed between the respective busbars; the suppression metal structure is disposed on the interdigital electrodes near both ends of each busbar, and the suppression metal structure is connected to the plurality of interdigital electrodes through the connecting metal structure; and further comprising: an isolation layer deposited on the piezoelectric layer, and the suppression metal structure is disposed on the isolation layer.

[0009] To address the issue of ineffective suppression of transverse modes, this application provides a surface acoustic wave (SAW) resonator. In the SAW resonator, the interdigital transducer is provided with a suppression metal structure and a connecting metal structure. The suppression metal structure is connected to the interdigital electrodes via the connecting metal structure, and both the suppression metal structure and the connecting metal structure are positioned near the two ends of each busbar of the interdigital electrodes.

[0010] Since the sound velocity of the suppressing metal structure material is typically lower than that of the piezoelectric layer material, a localized low-velocity region can be formed at the ends of the interdigital electrodes, and surface acoustic wave (SAW) energy tends to concentrate in this low-velocity region. Therefore, localized low-velocity regions exist at both ends of the effective aperture region of the interdigital transducer (i.e., the overlapping region of the interdigital electrodes), causing reflection when SAW propagates to the higher-velocity region outside the effective aperture region. This confines the SAW energy within the effective aperture region of the interdigital transducer, preventing energy leakage from the edges of the effective aperture. Consequently, transverse modes can be suppressed. Similarly, the sound velocity of the connecting metal structure is lower than that of the piezoelectric layer material; therefore, the connecting metal structure and the suppressing metal structure can work synergistically to more effectively suppress transverse modes. This solves the technical problem in the prior art where transverse modes are not effectively suppressed, affecting the performance of the SAW resonator.

[0011] Furthermore, in surface acoustic wave (SAW) resonators without a connecting metal structure, a parallel-plate capacitor is formed between the suppression metal structure and the interdigital electrodes, resulting in capacitance. Consequently, the alternating voltage introduced during SAW resonator operation generates an alternating electric field, and the resulting displacement current induces capacitive coupling. This causes the isolation layer between the suppression metal structure and the interdigital electrodes to withstand high voltage, ultimately leading to dielectric breakdown. Consequently, this can damage the interdigital electrodes, affecting the performance of the SAW resonator.

[0012] This application achieves electrical connection between the suppression metal structure and the interdigital electrodes through a connecting metal structure. Therefore, according to the electrostatic equilibrium condition of a conductor, the interdigital electrodes, connecting metal structure, and suppression metal structure form an equipotential body after being connected. That is, the potential difference between the interdigital electrodes and the suppression metal structure is zero. Consequently, the voltage between the interdigital electrodes and the suppression metal structure is zero, and according to the capacitance formula, the capacitance between the interdigital electrodes and the suppression metal structure is also zero. This eliminates capacitive coupling, prevents dielectric breakdown that could damage the interdigital electrodes, and ensures the performance of the surface acoustic wave resonator.

[0013] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this application in conjunction with the accompanying drawings. Attached Figure Description

[0014] The following sections will describe some specific embodiments of this application in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of the structure of a surface acoustic wave resonator according to an embodiment of this application; Figure 2This is a cross-sectional view of a surface acoustic wave resonator according to an embodiment of this application; Figure 3 This is a cross-sectional view of a surface acoustic wave resonator whose width of the metal structure is equal to the width of the interdigitated electrodes, according to an embodiment of this application. Figure 4 This is a cross-sectional view of a surface acoustic wave resonator that suppresses the width of the metal structure being greater than the width of the interdigitated electrodes, according to an embodiment of this application. Figure 5 This is a cross-sectional view of a surface acoustic wave resonator that suppresses the width of the metal structure being smaller than the width of the interdigitated electrodes, according to an embodiment of this application. Figure 6 This is a cross-sectional view of a surface acoustic wave resonator with a continuous strip-shaped connecting metal structure according to an embodiment of this application; Figure 7 This is a cross-sectional view of a surface acoustic wave resonator according to an embodiment of this application, where both the suppression metal structure and the connecting metal structure are continuous strip structures. Figure 8 This is a cross-sectional view of a surface acoustic wave resonator with a continuous strip structure for suppressing metal structures, as described in the embodiments of this application. Figure 9 This is a cross-sectional view of a surface acoustic wave resonator with a suppressed metal structure disposed on a temperature compensation layer according to an embodiment of this application; and Figure 10 This is a comparison chart of the admittance curves of a surface acoustic wave resonator with a suppression metal structure and a surface acoustic wave resonator without a suppression metal structure, according to the embodiments of this application. Detailed Implementation

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other. This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0016] To enable those skilled in the art to better understand the present disclosure, the technical solutions of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present disclosure.

[0017] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] Figure 1 This is a schematic diagram of the structure of a surface acoustic wave resonator according to an embodiment of this application. Figure 2 This is a cross-sectional view of a surface acoustic wave resonator according to an embodiment of this application. According to one aspect of this application, a surface acoustic wave resonator 10 is provided, comprising: a piezoelectric layer 100, interdigital transducers 200 deposited on the piezoelectric layer 100, a suppression metal structure 300, and a connecting metal structure 500, wherein the interdigital transducers 200 include two busbars 210 disposed opposite each other and a plurality of interdigital electrodes 220 disposed between the respective busbars 210; the suppression metal structure 300 is disposed on the interdigital electrodes 220 near both ends of each busbar 210, and the suppression metal structure 300 is connected to the plurality of interdigital electrodes 220 through the connecting metal structure 500; and further comprising: an isolation layer 400 deposited on the piezoelectric layer 100, and the suppression metal structure 300 is disposed on the isolation layer 400.

[0020] As described in the background section, surface acoustic wave (SAW) resonators, as key components in radio frequency (RF) systems, are widely used in modern communication, sensing, and other electronic devices due to their excellent performance and miniaturization characteristics. With the development of communication technology, the performance requirements for SAW resonators are constantly increasing. During the operation of an SAW resonator, due to the anisotropy of the piezoelectric material used as the substrate, undesirable transverse modes are often excited in the aperture direction, in addition to the dominant SAW mode. The resonant frequencies of these transverse modes are located near the main passband of the SAW resonator. If not suppressed, this leads to a decrease in the quality factor (Q value) and the generation of ripples in the passband, thereby severely degrading device performance.

[0021] In view of this, this application provides a surface acoustic wave resonator. Specifically, refer to... Figure 1 and Figure 2 As shown, in the surface acoustic wave resonator 10, an interdigital transducer 200 is deposited on the piezoelectric layer 100. The interdigital transducer 200 includes two busbars 210 disposed opposite each other, and a plurality of interdigital electrodes 220 are alternately arranged between the two busbars 210. Furthermore, an isolation layer 400 is deposited on the piezoelectric layer 100.

[0022] Furthermore, the suppression metal structure 300 is disposed on the interdigital electrodes 220 near both ends of each busbar 210. Also, the suppression metal structure 300 is connected to the multiple interdigital electrodes 220 via the connecting metal structure 500.

[0023] Since the sound velocity of the material in the suppression metal structure 300 is typically lower than that of the material in the piezoelectric layer 100, a local low-velocity region can be formed at the ends of the interdigital electrodes 220, and surface acoustic wave (SAW) energy tends to concentrate in the low-velocity region. Therefore, local low-velocity regions exist at both ends of the effective aperture region of the interdigital transducer 200 (i.e., the overlapping region of the interdigital electrodes 220), and reflection occurs when SAW propagates to the higher-velocity region outside the effective aperture region. Thus, SAW energy is confined to the effective aperture region of the interdigital transducer 200, preventing energy leakage from the edges of the effective aperture. This suppresses transverse modes. Similarly, the sound velocity of the connecting metal structure 500 is lower than that of the piezoelectric layer 100, so the connecting metal structure 500 and the suppression metal structure 300 can work synergistically to more effectively suppress transverse modes. This solves the technical problem in the prior art where transverse modes are not effectively suppressed, affecting the performance of the SAW resonator.

[0024] Furthermore, in surface acoustic wave (SAW) resonators without a connecting metal structure, a parallel-plate capacitor is formed between the suppression metal structure and the interdigital electrodes, resulting in capacitance. Consequently, the alternating voltage introduced during SAW resonator operation generates an alternating electric field, and the resulting displacement current induces capacitive coupling. This causes the isolation layer between the suppression metal structure and the interdigital electrodes to withstand high voltage, ultimately leading to dielectric breakdown. Consequently, this can damage the interdigital electrodes, affecting the performance of the SAW resonator.

[0025] This application achieves electrical connection between the suppression metal structure 300 and the interdigital electrode 220 through the connecting metal structure 500. Therefore, according to the electrostatic equilibrium condition of a conductor, the interdigital electrode 220, the connecting metal structure 500, and the suppression metal structure 300 form an equipotential body after being connected. That is, the potential difference between the interdigital electrode 220 and the suppression metal structure 300 is zero. Consequently, the voltage between the interdigital electrode 220 and the suppression metal structure 300 is zero, and according to the capacitance formula, the capacitance between the interdigital electrode 220 and the suppression metal structure 300 is also zero. Furthermore, capacitive coupling can be eliminated, preventing dielectric breakdown that could damage the interdigital transducer 210 and ensuring the performance of the surface acoustic wave resonator.

[0026] Furthermore, since the upper surface of the isolation layer 400 is lower than the upper surface of the connecting metal structure 500, the electromechanical coupling coefficient will decrease; conversely, if the upper surface of the isolation layer 400 is higher than the upper surface of the connecting metal structure 500, the electromechanical coupling coefficient will increase, both affecting the performance of the surface acoustic wave resonator 10. Therefore, in this application, the upper surface of the connecting metal structure 500 is flush with the upper surface of the isolation layer 400. This avoids affecting the performance of the surface acoustic wave resonator 10.

[0027] Preferably, the material of the suppressing metal structure 300 can be, for example, one of copper, aluminum and iron, and the material of the connecting metal structure 500 can be, for example, one of copper, aluminum and iron.

[0028] More preferably, the suppressing metal structure 300 can be, for example, a composite metal layer consisting of multiple metal layers, and the connecting metal structure 500 can be, for example, a composite metal layer consisting of multiple metal layers.

[0029] Optionally, the suppression metal structure 300 spans multiple interdigital electrodes 220, and in a first direction, the suppression metal structure 300 is disposed at the extension ends and extension roots of the multiple interdigital electrodes 220, wherein the first direction corresponds to the extension direction of the interdigital electrodes 220; and in the first direction, the width of the suppression metal structure 300 is greater than the width of the connecting metal structure 500.

[0030] Specifically, refer to Figure 1 and Figure 2As shown, the suppression metal structure 300 spans the multiple interdigital electrodes 220 of the interdigital transducer 200. Furthermore, in a first direction corresponding to the extension direction of the interdigital electrodes 220, the suppression metal structure 300 is disposed at the extension ends of the multiple interdigital electrodes 220.

[0031] Furthermore, in the first direction, the width of the connecting metal structure 500 is smaller than the width of the suppressing metal structure 300, and the width of the suppressing metal structure 300 is much smaller than the width of the interdigitated electrode 220. That is, a gap is formed between the suppressing metal structure 300 and the connecting metal structure 500 as... Figure 2 The L-shaped structure shown is illustrated.

[0032] Therefore, the suppression metal structure 300 and the connecting metal structure 500 can act as acoustic reflection boundaries, preventing surface acoustic waves from propagating to the edges of the extended ends of the multiple interdigital electrodes 220. Furthermore, this suppresses the transverse modes of the surface acoustic wave resonator 10, ensuring the performance of the surface acoustic wave resonator 10.

[0033] Optionally, in the second direction, the suppression metal structure 300 is an intermittent block structure, wherein the second direction corresponds to the cross-sectional direction of the interdigitated electrode 220.

[0034] Specifically, Figure 3 A cross-sectional view of a surface acoustic wave resonator according to an embodiment of this application, wherein the width of the metal structure is equal to the width of the interdigitated electrodes, is shown. (Reference) Figure 1 and Figure 3 As shown, in the second direction corresponding to the cross-sectional direction of the interdigital electrode 220, the suppression metal structure 300 is an intermittent block structure corresponding to the plurality of interdigital electrodes 220. That is, the suppression metal structure 300 is a plurality of metal blocks corresponding to the plurality of interdigital electrodes 220 respectively.

[0035] Therefore, the above structure can reduce the sound velocity at the extension ends of each interdigital electrode 220. That is, a local low sound velocity region is formed at the extension ends of the interdigital electrodes 220. As a result, the sound field distribution between each interdigital electrode 220 can be matched more accurately. As a result, energy leakage to the edge of the effective aperture can be reduced, and transverse modes can be suppressed more effectively. Furthermore, it is possible to avoid affecting the performance of the surface acoustic wave resonator 10.

[0036] Optionally, in the second direction, the width of the suppression metal structure 300 is equal to the width of the interdigitated electrode 220.

[0037] Specifically, refer to Figure 3 As shown, in the second direction corresponding to the cross-sectional direction of the interdigital electrode 220, the width of the discontinuous block structure suppression metal structure 300 is equal to the width of the interdigital electrode 220.

[0038] Optionally, in the second direction, the width of the suppression metal structure 300 is greater than the width of the interdigitated electrode 220.

[0039] Specifically, Figure 4 A cross-sectional view of a surface acoustic wave resonator according to an embodiment of this application is shown, which suppresses surface acoustic wave resonators where the width of the metal structure is greater than the width of the interdigitated electrodes. (Reference) Figure 4 As shown, in the second direction corresponding to the cross-sectional direction of the interdigital electrode 220, the width of the discontinuous block structure suppression metal structure 300 is greater than the width of the interdigital electrode 220.

[0040] Optionally, in the second direction, the width of the suppression metal structure 300 is smaller than the width of the interdigitated electrode 220.

[0041] Specifically, Figure 5 A cross-sectional view of a surface acoustic wave resonator according to an embodiment of this application, which suppresses surface acoustic wave resonators where the width of the metal structure is smaller than the width of the interdigitated electrodes, is shown. (Reference) Figure 5 As shown, in the second direction corresponding to the cross-sectional direction of the interdigital electrode 220, the width of the intermittent block structure suppression metal structure 300 is smaller than the width of the interdigital electrode 220.

[0042] Optionally, the connecting metal structure 500 is an intermittent block structure corresponding to each of the suppressing metal structures 300.

[0043] Specifically, refer to Figure 3 As shown, the connecting metal structure 500 is an intermittent block structure corresponding to each of the suppression metal structures 300. That is, the connecting metal structure 500 is only disposed below each of the suppression metal structures 300.

[0044] Therefore, the connecting metal structure 500 and the suppressing metal structure 300 can work synergistically in the local area above the corresponding interdigital electrode 220 to form a local low-velocity region. This prevents surface acoustic wave energy leakage, suppresses the transverse mode of the surface acoustic wave resonator 10, and avoids the performance of the surface acoustic wave resonator 10 being affected by the ineffective suppression of the transverse mode.

[0045] Optionally, the connecting metal structure 500 is a continuous strip structure corresponding to the suppressing metal structure 300.

[0046] Specifically, Figure 6 A cross-sectional view of a surface acoustic wave resonator with a continuous strip-shaped connecting metal structure according to an embodiment of this application is shown. (Reference) Figure 6 As shown, the connecting metal structure 500 is a continuous strip structure corresponding to the suppressing metal structure 300.

[0047] Therefore, the continuous strip-shaped connecting metal structure 500 forms a continuous and uniform acoustic reflection boundary in the second direction. This prevents surface acoustic wave energy leakage and suppresses the transverse modes of the surface acoustic wave resonator 10. Furthermore, it avoids the performance of the surface acoustic wave resonator 10 being affected by the ineffective suppression of transverse modes.

[0048] Optionally, in the second direction, the suppressing metal structure 300 is a continuous strip structure; and the connecting metal structure 500 is a continuous strip structure corresponding to the suppressing metal structure 300.

[0049] also, Figure 7 A cross-sectional view of a surface acoustic wave resonator with a continuous strip structure for suppressing the metal structure and connecting the metal structure according to an embodiment of this application is shown. (Reference) Figure 7 As shown, the connecting metal structure 500 is a continuous strip structure corresponding to the suppressing metal structure 300, and the suppressing metal structure 300 is a continuous strip structure.

[0050] Thus, the connecting metal structure 500 and the suppressing metal structure 300 can work together to form a continuous and uniform acoustic reflection boundary at the edge of the effective aperture region of the interdigital transducer 200, confining the surface acoustic wave energy within the effective aperture region and preventing the excitation of transverse modes in the surface acoustic wave resonator 10. Furthermore, this avoids performance degradation of the surface acoustic wave resonator 10.

[0051] Optionally, in the second direction, the suppressing metal structure 300 is a continuous strip structure; and the connecting metal structure 500 is an intermittent block structure corresponding to the suppressing metal structure 300.

[0052] Specifically, Figure 8 A cross-sectional view is shown of a surface acoustic wave resonator according to an embodiment of this application, wherein the connecting metal structure 500 is a discontinuous block structure and the connecting metal structure is a continuous strip structure. (Reference) Figure 8 As shown, in the second direction corresponding to the cross-sectional direction of the interdigitated electrode 220, the suppression metal structure 300 is a continuous metal strip, and the connecting metal structure 500 is an intermittent block structure corresponding to the suppression metal structure 300.

[0053] Therefore, the continuous strip-shaped suppression metal structure 300 forms a continuous and uniform acoustic reflection boundary in the second direction. This prevents surface acoustic wave energy leakage and suppresses the transverse modes of the surface acoustic wave resonator 10. Furthermore, it avoids the performance of the surface acoustic wave resonator 10 being affected by the ineffective suppression of transverse modes.

[0054] Optionally, it also includes: a reflective grid 600 disposed on both sides of the interdigital transducer 200, and the reflective grid 600 includes a plurality of reflective electrodes 610, wherein the plurality of reflective electrodes 610 are connected to the suppression metal structure 300 through the connecting metal structure 500, and the arrangement positions of the suppression metal structure 300 and the connecting metal structure 500 correspond to the extension ends of the interdigital electrodes 220.

[0055] Specifically, refer to Figure 1 and Figure 3 As shown, in the surface acoustic wave resonator 10, reflection gratings 600 are provided on both sides of the interdigital transducer 200. The reflection grating 600 includes multiple reflection electrodes 610.

[0056] Furthermore, multiple reflective electrodes 610 are connected to the suppression metal structure 300 via a connecting metal structure 500. The positions of the suppression metal structure 300 and the connecting metal structure 500 on the reflective electrodes 610 correspond to the extension ends of the interdigital electrodes 220.

[0057] Therefore, the suppression metal structure 300 and the connecting metal structure 500 can form a local low-velocity region in the reflector grating 600 area. Consequently, within the effective width corresponding to the effective aperture region of the reflector grating 600 and the interdigital transducer 200, the surface acoustic wave energy can be confined laterally, suppressing the propagation of surface acoustic waves to the edges on both sides of the reflector grating 600. Thus, the excitation of transverse modes in the surface acoustic wave resonator 10 can be avoided. Furthermore, it is possible to avoid affecting the performance of the surface acoustic wave resonator 10.

[0058] Furthermore, by connecting the suppression metal structure 300 and the reflective electrode 610 through the connecting metal structure 500, capacitance can be eliminated, avoiding dielectric breakdown caused by capacitive coupling. This prevents damage to the reflective electrode 610 and ensures the performance of the surface acoustic wave resonator 10.

[0059] Optionally, it also includes a temperature compensation layer 700, wherein the temperature compensation layer 700 is deposited on the isolation layer 400 and the connecting metal structure 500, and covers the suppression metal structure 300.

[0060] Specifically, refer to Figure 3 As shown, in the surface acoustic wave resonator 10, a temperature compensation layer 700 is deposited on the isolation layer 400 and the connecting metal structure 500. Furthermore, the temperature compensation layer 700 covers the suppression metal structure 300. Therefore, it can provide temperature compensation and improve the temperature stability of the surface acoustic wave resonator 10.

[0061] Preferably, the piezoelectric layer 100 is made of lithium niobate (LiNbO3, LN), the insulating layer 400 is made of silicon nitride, and the temperature compensation layer 700 is made of silicon oxide.

[0062] Optionally, the suppression metal structure 300 is disposed on the temperature compensation layer 700.

[0063] Specifically, Figure 9 A cross-sectional view of a surface acoustic wave resonator with a suppression metal structure disposed on a temperature compensation layer according to an embodiment of this application is shown. (Reference) Figure 9 As shown, the suppression metal structure 300 is disposed on the temperature compensation layer 700, and the passivation layer 800 covers the suppression metal structure 300 and the temperature compensation layer 700. Furthermore, the suppression metal structure 300 is connected to the interdigitated electrode 220 through the connecting metal structure 500.

[0064] Therefore, the suppression metal structure 300 and the connecting metal structure 500 can act as acoustic reflection boundaries, preventing surface acoustic waves from propagating to the edges of the extended ends of the multiple interdigital electrodes 220. Furthermore, this suppresses the transverse modes of the surface acoustic wave resonator 10, ensuring the performance of the surface acoustic wave resonator 10.

[0065] Furthermore, by connecting the suppression metal structure 300 and the interdigital electrode 220 through the connecting metal structure 500, capacitance can be eliminated, avoiding dielectric breakdown caused by capacitive coupling. This prevents damage to the interdigital electrode 211 and ensures the performance of the surface acoustic wave resonator 10.

[0066] Optionally, it also includes a passivation layer 800 deposited on the temperature compensation layer 700.

[0067] Specifically, refer to Figure 3 As shown, a passivation layer 800 is deposited on the temperature compensation layer 700. Thus, the passivation layer 800 can protect the surface acoustic wave resonator 10, avoid the influence of the external environment, and improve the reliability of the surface acoustic wave resonator 10.

[0068] Optionally, it also includes: a metal trace area 900, wherein the metal trace area 900 is disposed on the outer periphery of the interdigital transducer 200 and the reflective grid 600; and an isolation layer 400 having a first opening 410 for exposing the metal trace area 900, a temperature compensation layer 700 having a second opening 710, and a passivation layer 800 having a third opening 810, wherein the third opening 810 communicates with the first opening 410 through the second opening 710.

[0069] Specifically, refer to Figure 1 and Figure 3As shown, in the surface acoustic wave resonator 10, a metal trace region 900 is provided on the outer periphery of the interdigital transducer 200 and the reflector grating 600. Furthermore, at a position corresponding to the metal trace region 900, the isolation layer 400 has a first opening 410 for exposing a portion of the metal trace region 900, the temperature compensation layer 700 has a second opening 710 communicating with the first opening 410, and the passivation layer 800 has a third opening 810 communicating with the second opening 710.

[0070] Thus, the first opening 410, the second opening 710, and the third opening 810 serve as windows for the surface acoustic wave resonator 10 to connect with the outside world, enabling the surface acoustic wave resonator 10 to achieve conductive connection with the outside world.

[0071] Figure 10 The diagram shows a comparison of the admittance curves of the surface acoustic wave resonator with and without the suppression metal structure according to this embodiment.

[0072] refer to Figure 10 As shown, the admittance curve of the surface acoustic wave resonator 10 with the suppression metal structure 300 proposed in this application is smooth, while the admittance curve of the surface acoustic wave resonator without the suppression metal structure has multiple stray responses. Specifically, the admittance curve of the surface acoustic wave resonator 10 with the suppression metal structure 300 in this application is... Figure 10 The solid line in the graph corresponds to the admittance curve of the surface acoustic wave resonator without a metal suppression structure. Figure 10 The dotted lines in the text correspond to this.

[0073] In other words, the smoothness of the admittance curve of the surface acoustic wave resonator 10 of this application is significantly better than that of the surface acoustic wave resonator without a suppression metal structure. This demonstrates that, compared to the surface acoustic wave resonator without a suppression metal structure, the surface acoustic wave resonator 10 in this embodiment can significantly suppress transverse mode clutter and significantly improve the performance of the surface acoustic wave resonator 10.

[0074] Furthermore, it is worth noting that the suppression metal structure 300 in this application can be, for example, granular, discontinuous, or continuous. No limitation is imposed here.

[0075] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0076] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0077] In the description of this disclosure, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this disclosure and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this disclosure; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0078] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A surface acoustic wave resonator (10), characterized in that, include: The piezoelectric layer (100), the interdigitated transducer (200) deposited on the piezoelectric layer (100), the suppression metal structure (300), and the connecting metal structure (500), wherein The interdigital transducer (200) includes two busbars (210) arranged opposite each other and a plurality of interdigital electrodes (220) arranged between each busbar (210). The suppression metal structure (300) is disposed on the interdigital electrodes (220) near both ends of each busbar (210), and the suppression metal structure (300) is connected to the plurality of interdigital electrodes (220) through the connecting metal structure (500). as well as It also includes an isolation layer (400) deposited on the piezoelectric layer (100), and the suppression metal structure (300) is disposed on the isolation layer (400).

2. The surface acoustic wave resonator (10) according to claim 1, characterized in that, The suppression metal structure (300) spans the plurality of interdigitated electrodes (220), and In a first direction, the suppression metal structure (300) is disposed at the end of the extension end and the root of the extension end of the plurality of interdigital electrodes (220), wherein the first direction corresponds to the extension direction of the interdigital electrodes (220); as well as In the first direction, the width of the suppressing metal structure (300) is greater than the width of the connecting metal structure (500).

3. The surface acoustic wave resonator (10) according to claim 2, characterized in that, In the second direction, the suppression metal structure (300) is an intermittent block structure, wherein the second direction corresponds to the cross-sectional direction of the interdigitated electrode (220).

4. The surface acoustic wave resonator (10) according to claim 3, characterized in that, In the second direction, the width of the suppression metal structure (300) is equal to the width of the interdigitated electrode (220).

5. The surface acoustic wave resonator (10) according to claim 3, characterized in that, In the second direction, the width of the suppression metal structure (300) is greater than the width of the interdigitated electrode (220).

6. The surface acoustic wave resonator (10) according to claim 3, characterized in that, In the second direction, the width of the suppression metal structure (300) is smaller than the width of the interdigitated electrode (220).

7. The surface acoustic wave resonator (10) according to claim 3, characterized in that, The connecting metal structure (500) is an intermittent block structure corresponding to each of the suppressing metal structures (300).

8. The surface acoustic wave resonator (10) according to claim 2, characterized in that, The connecting metal structure (500) is a continuous strip structure corresponding to the suppressing metal structure (300).

9. The surface acoustic wave resonator (10) according to claim 2, characterized in that, In the second direction, the suppressing metal structure (300) is a continuous strip structure; and The connecting metal structure (500) is a continuous strip structure corresponding to the suppressing metal structure (300).

10. The surface acoustic wave resonator (10) according to claim 2, characterized in that, In the second direction, the suppressing metal structure (300) is a continuous strip structure; and The connecting metal structure (500) is an intermittent block structure corresponding to each of the suppressing metal structures (300).

11. The surface acoustic wave resonator (10) according to claim 1, characterized in that, Also includes: Reflective gratings (600) are disposed on both sides of the interdigital transducer (200), and the reflective gratings (600) include a plurality of reflective electrodes (610), wherein The plurality of reflective electrodes (610) are connected to the suppression metal structure (300) through the connecting metal structure (500), and the arrangement positions of the suppression metal structure (300) and the connecting metal structure (500) correspond to the extension ends of the interdigital electrodes (220).

12. The surface acoustic wave resonator (10) according to claim 11, characterized in that, Also includes: A temperature compensation layer (700) is deposited on the isolation layer (400) and covers the suppression metal structure (300).

13. The surface acoustic wave resonator (10) according to claim 12, characterized in that, The suppression metal structure (300) is disposed on the temperature compensation layer (700).

14. The surface acoustic wave resonator (10) according to claim 12, characterized in that, Also includes: A passivation layer (800) is deposited on the temperature compensation layer (700).

15. The surface acoustic wave resonator (10) according to claim 14, characterized in that, Also includes: Metal trace area (900), wherein the metal trace area (900) is disposed on the outer periphery of the interdigital transducer (200) and the reflective grating (600); and The isolation layer (400) has a first opening (410) for exposing the metal trace area (900), the temperature compensation layer (700) has a second opening (710), and the passivation layer (800) has a third opening (810), wherein the third opening (810) communicates with the first opening (410) through the second opening (710).

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