Surface acoustic wave resonator and surface acoustic wave filter

Abstract

The utility model discloses a surface acoustic wave resonator and a surface acoustic wave filter.The surface acoustic wave resonator comprises a piezoelectric substrate and an interdigital transducer located on the first side of the piezoelectric substrate, and in the plane parallel to the surface acoustic wave resonator, the interdigital transducer comprises a first bus bar and a second bus bar which are oppositely arranged in the first direction; the first interdigital electrode is electrically connected with the first bus bar, the second interdigital electrode is electrically connected with the second bus bar, and the first interdigital electrode and the second interdigital electrode are located between the first bus bar and the second bus bar and are arranged in a staggered mode in the second direction; in the direction perpendicular to the plane where the surface acoustic wave resonator is located, the interdigital transducer comprises a first metal alloy layer and a second metal alloy layer, and the first metal alloy layer and the second metal alloy layer are different, so that the power tolerance of the interdigital transducer is improved, and the power tolerance of the surface acoustic wave resonator is further improved; and the power tolerance requirement when the antenna works in a high-frequency band range can be met.

Description

Technical Field

[0001] The present application relates to the field of radio frequency technology, and in particular, to a surface acoustic wave resonator and a surface acoustic wave filter including the surface acoustic wave resonator. Background Art

[0002] With the rapid development of wireless communication technology, the performance requirements for radio frequency front-end components are increasing day by day. As a key component for radio frequency signal processing, the surface acoustic wave (SAW) filter is widely used in fields such as mobile phones, satellite communications, and radar systems. The SAW filter has become an important tool for frequency screening and signal purification due to its advantages such as miniaturization, high selectivity, and low insertion loss. However, currently, the SAW filter can only be applied in the radio frequency low-frequency band range and is not suitable for operating in the high-frequency band range. Summary of the Utility Model

[0003] To solve the above technical problems, the embodiments of the present application provide a surface acoustic wave resonator and a surface acoustic wave filter including the surface acoustic wave resonator.

[0004] Specifically, the present application provides the following technical solutions:

[0005] A surface acoustic wave resonator includes: a piezoelectric substrate and an interdigital transducer located on the first side of the piezoelectric substrate. In a plane parallel to the plane where the surface acoustic wave resonator is located, the interdigital transducer includes a first bus bar and a second bus bar oppositely arranged in a first direction, a first interdigital electrode electrically connected to the first bus bar, and a second interdigital electrode electrically connected to the second bus bar. The first interdigital electrode and the second interdigital electrode are located between the first bus bar and the second bus bar and are arranged staggeredly in a second direction perpendicular to the first direction.

[0006] Wherein, in a direction perpendicular to the plane where the surface acoustic wave resonator is located, the interdigital transducer includes at least two metal alloy layers, and the at least two metal alloy layers include a first metal alloy layer and a second metal alloy layer, and the first metal alloy layer and the second metal alloy layer are different.

[0007] Optionally, the resistance of the second metal alloy layer is less than that of the first metal alloy layer, or the heat conduction ability of the second metal alloy layer is greater than that of the first metal alloy layer, or the density of the second metal alloy layer is greater than that of the first metal alloy layer.

[0008] Optionally, the first metal alloy layer is an AlCu layer, an AlTi layer, or an AlMo layer; the second metal alloy layer is an AlCu layer, an AlTi layer, or an AlMo layer.

[0009] Optionally, the thickness of the first metal alloy layer is not greater than 350 nm, and the thickness of the second metal alloy layer is not greater than 350 nm.

[0010] Optionally, the interdigital transducer further includes: at least one barrier diffusion layer, and the at least one barrier diffusion layer includes:

[0011] a first barrier diffusion layer located on the side of the first metal alloy layer facing the piezoelectric substrate;

[0012] a second barrier diffusion layer located on the side of the second metal alloy layer away from the piezoelectric substrate;

[0013] a third barrier diffusion layer located between the first metal alloy layer and the second metal alloy layer.

[0014] Optionally, the thickness of the barrier diffusion layer is not less than 10 nm.

[0015] Optionally, it further includes: a temperature compensation layer covering the side of the interdigital transducer away from the piezoelectric substrate.

[0016] Optionally, it further includes: a piezoelectric functional layer located between the piezoelectric substrate and the interdigital transducer, and the piezoelectric functional layer includes at least one functional layer among a temperature compensation layer, a bonding layer, a high acoustic impedance layer, a low acoustic impedance layer, a reflective layer, and a dielectric layer.

[0017] Optionally, it further includes: a passivation layer covering at least the first interdigital electrode, the second interdigital electrode, and the regions between adjacent first interdigital electrodes and between adjacent second interdigital electrodes.

[0018] A surface acoustic wave filter includes:

[0019] a series arm structure and a parallel arm structure connected to the series arm structure, the series arm structure includes at least one series arm, one series arm includes at least one series resonator, the parallel arm structure includes at least one parallel arm, and one parallel arm includes at least one parallel resonator; at least one resonator among the at least one series resonator and the at least one parallel resonator is the resonator described in any one of the above items.

[0020] Optionally, each resonator among the at least one series resonator and the at least one parallel resonator is the resonator described in any one of the above items.

[0021] In the technical solution provided by the embodiment of the present application, in the direction perpendicular to the plane where the surface acoustic wave resonator is located, the interdigital transducer includes at least two metal alloy layers. The at least two metal alloy layers include a first metal alloy layer and a second metal alloy layer. The first metal alloy layer and the second metal alloy layer have high power tolerance, so as to improve the power tolerance of the interdigital transducer, and further improve the power tolerance of the surface acoustic wave resonator, so that it can meet the power tolerance requirements when working in the high-frequency band range. Description of the Drawings

[0022] Combined with the drawings and referring to the following specific embodiments, the above and other features, advantages and aspects of the embodiments of the present disclosure will become more obvious. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic, and the original components and elements are not necessarily drawn to scale.

[0023] Figure 1 Schematic diagram of the requirements for the fusing power of the SAW filter for different radio frequency band ranges;

[0024] Figure 2 and Figure 3 Partial top view of the interdigital electrode before and after the SAW filter works in the high-frequency band range;

[0025] Figure 4 Schematic diagram of the structure of the surface acoustic wave resonator provided by an embodiment of the present application;

[0026] Figure 5 Schematic diagram of the structure of the surface acoustic wave resonator provided by another embodiment of the present application;

[0027] Figure 6 Top view of the surface acoustic wave resonator provided by an embodiment of the present application;

[0028] Figure 7 Top view of the surface acoustic wave resonator provided by another embodiment of the present application;

[0029] Figure 8 Top view of the surface acoustic wave resonator provided by yet another embodiment of the present application;

[0030] Figure 9 Schematic diagram of the structure of the surface acoustic wave resonator provided by yet another embodiment of the present application;

[0031] Figure 10 Schematic diagram of the structure of the surface acoustic wave resonator provided by still another embodiment of the present application;

[0032] Figure 11 Schematic diagram of the structure of the surface acoustic wave resonator provided by yet another embodiment of the present application;

[0033] Figure 12 Schematic diagram of the fusing power of the surface acoustic wave resonator when the metal alloy layer is an AlCu layer, an AlTi layer or an AlMo layer;

[0034] Figure 13 Schematic diagram of the structure of the surface acoustic wave filter provided by an embodiment of the present application. Detailed implementation manners

[0035] The following will clearly and completely describe the embodiments in the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts fall within the scope of protection of the present application.

[0036] Without departing from the spirit or scope of the present application, various modifications and variations can be made in the present application, which will be obvious to those skilled in the art. Therefore, the present application is intended to cover the modifications and variations of the present application that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided by the embodiments of the present application can be combined with each other without conflict.

[0037] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0038] As described in the background art section, currently, SAW filters can only be applied in the radio frequency low-frequency band range and are not suitable for operating in the high-frequency band range. This is because when operating at higher frequencies, SAW filters will exhibit temperature and functional tolerance characteristics different from those in the radio frequency low-frequency band range, such as Figure 1 shown, Figure 1 shows the requirements for the fusing power of SAW filters in different radio frequency band ranges. It can be seen from Figure 1 that compared with the radio frequency low-frequency band, the radio frequency high-frequency band has higher requirements for the fusing power of SAW filters. Among them, the 5G band requires the fusing power of SAW filters to be higher than about 33 dBm. It should be noted that the higher the requirement for the fusing power of SAW filters in the radio frequency band, the higher the requirement for the power tolerance of SAW.

[0039] Such as Figure 2 and Figure 3 shown, Figure 2 and Figure 3 are respectively the partial top views of the interdigital electrodes in the interdigital transducer before and after the SAW filter operates in the high-frequency band range. From Figure 2 andFigure 3 It can be seen that after the SAW filter operates in the high-frequency band range, due to the existence of acoustic and electric migration phenomena, mass transfer will occur in the interdigital electrodes under the action of physical stress generated by acoustic wave transmission, resulting in corrosion and denaturation of the interdigital electrodes, changes in the parameters of the interdigital transducer, a decrease in the performance of the SAW filter, and thus affecting the service life and reliability of the SAW filter in high-frequency devices.

[0040] Therefore, how to improve the power tolerance of SAW in the high-frequency band so that it can operate in the high-frequency band range has become one of the research directions in this field.

[0041] In view of this, an embodiment of the present application provides a surface acoustic wave resonator, as Figures 4 - 6 shown. The surface acoustic wave resonator includes: a piezoelectric substrate 10 and an interdigital transducer located on the first side of the piezoelectric substrate 10. In a plane parallel to the plane where the surface acoustic wave resonator is located, the interdigital transducer includes a first bus bar 110 and a second bus bar 120 oppositely arranged in a first direction, a first interdigital electrode 130 electrically connected to the first bus bar 110, and a second interdigital electrode 140 electrically connected to the second bus bar 120. The first interdigital electrode 130 and the second interdigital electrode 140 are located between the first bus bar 110 and the second bus bar 120 and are staggered in a second direction, where the second direction is perpendicular to the first direction. It should be noted that in this embodiment, in a direction perpendicular to the plane where the surface acoustic wave resonator is located, the interdigital transducer includes at least two metal alloy layers, and the at least two metal alloy layers include a first metal alloy layer 21 and a second metal alloy layer 22, and the first metal alloy layer 21 and the second metal alloy layer 22 are different, so that the interdigital transducer has strong power tolerance, thereby improving the power tolerance of the surface acoustic wave resonator and enabling it to meet the power tolerance requirements when operating in the high-frequency band range.

[0042] Optionally, based on the above embodiments, in an embodiment of the present application, the resistance of the second metal alloy layer is less than that of the first metal alloy layer, thereby reducing the overall resistance of the interdigital transducer, and further reducing the overall resistance of the surface acoustic wave resonator; in another embodiment of the present application, the heat conduction ability of the second metal alloy layer is greater than that of the first metal alloy layer, thereby improving the heat dissipation effect of the interdigital transducer, and further improving the heat dissipation effect of the surface acoustic wave resonator; in yet another embodiment of the present application, the density of the second metal alloy layer is greater than that of the first metal alloy layer, thereby utilizing the mass loading effect to reduce the volume of the interdigital transducer, and further reducing the volume of the surface acoustic wave resonator. In other embodiments of the present application, the first metal alloy layer and the second metal alloy layer may also be different in other parameters, and the present application does not limit this, and it depends on the specific situation.

[0043] Specifically, in an embodiment of the present application, the first metal alloy layer is an AlCu layer, an AlTi layer, or an AlMo layer; the second metal alloy layer is an AlCu layer, an AlTi layer, or an AlMo layer, but the present application does not limit this, and it depends on the specific situation.

[0044] Optionally, based on the above embodiments, in an embodiment of the present application, in the direction perpendicular to the plane where the surface acoustic wave resonator is located, the thickness of the first metal alloy layer is not greater than 350 nm, and can be optionally about 200 nm, such as 160 nm to 240 nm; similarly, in the direction perpendicular to the plane where the surface acoustic wave resonator is located, the thickness of the second metal alloy layer is not greater than 350 nm, and can be optionally about 200 nm, such as 160 nm to 240 nm. The present application does not limit this, and it depends on the specific situation.

[0045] It should be noted that under certain conditions, when the operating frequency band of the surface acoustic wave resonator is relatively low and the total thickness of the interdigital electrodes is relatively large in the direction perpendicular to the plane where the surface acoustic wave resonator is located (for example, in the direction perpendicular to the plane where the surface acoustic wave resonator is located, the total thickness of at least two metal alloy layers in the interdigital transducer is 400 nm), the interdigital transducer may also include more metal alloy layers, and the present application does not limit this, and it depends on the specific situation.

[0046] It should also be noted that if the interdigital transducer further includes a third metal alloy layer, the third metal alloy layer may be the same as the first metal alloy layer, or the same as the second metal alloy layer, or different from both the first metal alloy layer and the second metal alloy layer, and the present application does not limit this, and it depends on the specific situation.

[0047] Based on any of the above embodiments, in an embodiment of the present application, the interdigital transducer further includes: at least one barrier diffusion layer. Continuing as Figure 4 and Figure 5 shown, the at least one barrier diffusion layer includes: a first barrier diffusion layer 31 located on the side of the first metal alloy layer 21 facing the piezoelectric substrate 10, a second barrier diffusion layer 32 located on the side of the second metal alloy layer 22 away from the piezoelectric substrate 10, and a third impedance diffusion layer 33 located between the first metal alloy layer 21 and the second metal alloy layer 22. Optionally, in an embodiment of the present application, the first barrier diffusion layer 31 is located between the piezoelectric substrate 10 and the first metal alloy layer 21. The material of the first barrier diffusion layer 31 is different from any of the constituent materials of the first metal alloy layer 21, and the diffusion coefficient of any metal component in the first metal alloy layer 21 in the first barrier diffusion layer 31 is different from the self-diffusion coefficient of this metal, so that the first barrier diffusion layer 31 can increase the adhesion between the piezoelectric substrate 10 and the first metal alloy layer 21. At the same time, it can also reduce the atomic diffusion between the piezoelectric substrate 10 and the first metal alloy layer 21 to a certain extent, thereby improving the performance of the surface acoustic wave resonator. Similarly, the material of the second barrier diffusion layer 32 is different from any of the constituent materials of the second metal alloy layer 22, and the diffusion coefficient of any metal component in the second metal alloy layer 22 in the second barrier diffusion layer 32 is different from the self-diffusion coefficient of this metal, so that the second barrier diffusion layer 32 can increase the adhesion between the second metal alloy layer 22 and other film layers located on the side of the second metal alloy layer 22 away from the piezoelectric substrate 10, and reduce the atomic diffusion between the second metal alloy layer 22 and other film layers located on the side of the second metal alloy layer 21 away from the piezoelectric substrate 10. The material of the third barrier diffusion layer 33 is different from any of the constituent materials of the first metal alloy layer 21 and different from any of the constituent materials of the second metal alloy layer 22. The diffusion coefficient of any metal component in the first metal alloy layer 21 in the third barrier diffusion layer 33 is different from the self-diffusion coefficient of this metal, and the diffusion coefficient of any metal component in the second metal alloy layer 22 in the third barrier diffusion layer 33 is different from the self-diffusion coefficient of this metal, so that the third barrier diffusion layer 33 can increase the adhesion between the first metal alloy layer 21 and the second metal alloy layer 22, and reduce the atomic diffusion between the first metal alloy layer 21 and the second metal alloy layer 22.

[0048] Optionally, in an embodiment of the present application, the materials of the first diffusion barrier layer, the second diffusion barrier layer, and the third diffusion barrier layer are the same to simplify the process complexity of the surface acoustic wave resonator. However, the present application does not limit this, and it depends on the specific situation.

[0049] It should be noted that in other embodiments of the present application, if the interdigital transducer further includes more metal alloy layers, such as including M metal alloy layers where M is greater than 2, the interdigital transducer further includes more diffusion barrier layers, such as including N diffusion barrier layers where N = M + 1. Among them, the first diffusion barrier layer is located between the first metal alloy layer and the piezoelectric substrate, the second diffusion barrier layer is located on the side of the M metal alloy layers away from the piezoelectric substrate, and the other impedance diffusion layers are located between adjacent metal alloy layers. It should also be noted that in this embodiment, the material of any diffusion barrier layer is different from any constituent material of the metal alloy layer in contact with it, and the diffusion coefficient of any metal constituent of any diffusion barrier layer for the metal alloy layer in contact with it is different from the self-diffusion coefficient of this metal.

[0050] Optionally, in an embodiment of the present application, the materials of the diffusion barrier layers are the same to simplify the process complexity of the surface acoustic wave resonator. However, the present application does not limit this, and it depends on the specific situation.

[0051] Specifically, in an embodiment of the present application, the thickness of the diffusion barrier layer is not less than 10 nm to ensure that the diffusion barrier layer can achieve the effect of blocking diffusion and reduce the atomic diffusion of the film layers on both sides of the diffusion barrier layer. Optionally, the thickness of the diffusion barrier layer is about 20 nm to reduce the impact of the diffusion barrier layer on the performance of the interdigital transducer while ensuring the effect of reducing atomic diffusion by the diffusion barrier layer. However, the present application does not limit this, and it depends on the specific situation.

[0052] Optionally, based on the above embodiments, in an embodiment of the present application, the material of the diffusion barrier layer can be at least one of Ti, Ta, Cr, and Pd. Optionally, the material of the diffusion barrier layer can be Ti, Ta, Cr, or Pd, preferably Ti. However, the present application does not limit this, and it depends on the specific situation.

[0053] Based on any of the above embodiments, in an embodiment of the present application, such as Figure 7As shown, the interdigital transducer further includes a first dummy finger electrode 150 electrically connected to the first bus bar 110, and a second dummy finger electrode 160 electrically connected to the second bus bar 120. Among them, the first dummy finger electrode 150 and the second interdigital electrode 140 are in the same row, and the second dummy finger electrode 160 and the first interdigital electrode 130 are in the same row. By means of the sound velocity mutation boundary in the regions where the first dummy finger electrode 150 and the second dummy finger electrode 160 are located, the transverse mode is reflected, thereby avoiding the formation of resonance conditions and enabling better resonator performance.

[0054] Based on any of the above embodiments, in an embodiment of the present application, as Figure 8 shown, the surface acoustic wave resonator further includes: a first reflection grating structure 170 and a second reflection grating structure 180 that are relatively located on both sides of the interdigital transducer in the second direction, where the second direction is perpendicular to the extension direction of the first interdigital electrode or the second interdigital electrode. It should be noted that in this embodiment, the first reflection grating structure 170 and the second reflection grating structure 180 are used to reflect sound waves, thereby helping to form better resonance in the main resonance region and further improving the transmission performance of the resonator.

[0055] Optionally, in an embodiment of the present application, the materials of the first reflection grating structure and the second reflection grating structure are the same as the manufacturing materials of the first metal alloy layer or the second alloy layer in the interdigital transducer, so that the first reflection grating structure and the second reflection grating structure can be manufactured simultaneously with the at least two metal alloy layers, simplifying the manufacturing process of the surface acoustic wave resonator.

[0056] Specifically, in an embodiment of the present application, the first reflection grating structure and the second reflection grating structure include multiple component film layers, and the component film layers correspond one by one to the metal alloy layers in the interdigital transducer, and the manufacturing materials of the component film layers are the same as those of the corresponding metal alloy layers, so that the first reflection grating structure and the second reflection grating structure can be manufactured simultaneously with the metal alloy layers, simplifying the manufacturing process of the surface acoustic wave resonator.

[0057] Based on any of the above embodiments, in an embodiment of the present application, in the direction perpendicular to the plane where the surface acoustic wave resonator is located, the cross-sectional view of the interdigital transducer is trapezoidal, as shown in Figure 4 and Figure 5 shown, but the present application does not limit this. In other embodiments of the present application, in the direction perpendicular to the plane where the surface acoustic wave resonator is located, the cross-sectional view of the interdigital transducer can also be other shapes, such as rectangular or other shapes, depending on the specific situation.

[0058] Based on any of the above embodiments, in an embodiment of the present application, the surface acoustic wave resonator is a common surface acoustic wave resonator, and the piezoelectric substrate is a piezoelectric material. The piezoelectric material generally refers to a piezoelectric single crystal or polycrystalline material that forms the piezoelectric substrate of a SAW device, such as quartz, lithium niobate (LiNbO3), and lithium tantalate (LiTaO3). These materials not only have piezoelectricity but also can support the propagation of acoustic waves on the material surface.

[0059] In another embodiment of the present application, the surface acoustic wave resonator is a temperature-compensated surface acoustic wave resonator (TC-SAW, Temperature-compensation). In this embodiment, as Figure 9 shown, the surface acoustic wave resonator further includes: a temperature compensation layer 40 covering the side of the interdigital transducer away from the piezoelectric substrate 10. Optionally, the temperature compensation layer 40 is a silicon dioxide layer, but the present application does not make a limitation, and it depends on the specific situation. It should be noted that the main function of the temperature compensation layer is to improve the frequency temperature coefficient and enhance the stability of the surface acoustic wave resonator at different temperatures.

[0060] In yet another embodiment of the present application, the surface acoustic wave resonator is a thin-film surface acoustic wave resonator (TF-SAW, Thin-Film). In this embodiment, the piezoelectric substrate uses a substrate with a piezoelectric thin film. It should be noted that fabricating the piezoelectric substrate using thin-film technology can achieve better resonator performance and help miniaturize SAW devices (such as surface acoustic wave resonators).

[0061] Optionally, in an embodiment of the present application, as Figure 10 shown, the surface acoustic wave resonator further includes: a piezoelectric functional layer 50 located between the piezoelectric substrate 10 and the interdigital transducer. The piezoelectric functional layer 50 includes at least one functional layer among a temperature compensation layer, a bonding layer, a high acoustic impedance layer, a low acoustic impedance layer, a reflective layer, and a dielectric layer.

[0062] It should be noted that the main function of the bonding layer in a SAW device is to achieve physical and electrical connections between different materials. It is usually used to bond the piezoelectric substrate to other components (such as a packaging housing or a sensing element) to provide a stable mechanical bonding interface. In addition, the bonding layer helps protect the sensitive elements inside the SAW device from the external environment and ensures the effective transmission of electrical signals.

[0063] The high acoustic impedance layer is used to control the propagation speed and attenuation rate of acoustic waves within the SAW device. This layer is typically made of materials with a relatively high acoustic impedance, which can effectively reduce the energy loss of acoustic waves during propagation, thereby improving the sensitivity and selectivity of the SAW device. Additionally, by optimizing the material and structure of the high acoustic impedance layer, better performance of the SAW device can be achieved in high-frequency applications.

[0064] Corresponding to the high acoustic impedance layer, the low acoustic impedance layer is mainly composed of materials with a relatively low acoustic impedance. The introduction of this layer aims to enhance the acoustic wave absorption ability of the SAW device. Especially when it is necessary to suppress unnecessary acoustic wave reflection and scattering, the low acoustic impedance layer helps to improve the rejection ratio and bandwidth characteristics of the SAW device, making it work more effectively and stably in specific application scenarios.

[0065] The basic function of the reflection layer is to reflect acoustic waves of certain frequencies. In a SAW resonator, the reflection layer is used to enhance the feedback of specific frequency signals, thereby improving the Q factor (quality factor) of the SAW device. This not only improves the frequency selectivity of the SAW device but also significantly enhances its applicability and efficiency in wireless communication systems.

[0066] The dielectric layer mainly serves as an electrical insulation layer to prevent electrical short circuits and protect sensitive components within the device. In some cases, the dielectric layer can also act as a surface treatment layer to protect the SAW device from the erosion of the external environment, such as the effects of humidity and chemical substances. Additionally, the material and thickness of the dielectric layer can be optimized to adjust its influence on the characteristics of acoustic wave propagation, further enhancing the overall device performance.

[0067] Based on any of the above embodiments, in an embodiment of the present application, as Figure 11 shown, it further includes: a passivation layer 60 that at least covers the first interdigital electrode, the second interdigital electrode, and the regions between adjacent first interdigital electrodes and between adjacent second interdigital electrodes to protect the functional region of the surface acoustic wave resonator. Specifically, in an embodiment of the present application, the passivation layer 60 covers the side of the interdigital transducer away from the piezoelectric substrate 10. Optionally, the passivation layer 60 can also extend to cover the first reflection grating structure and the second reflection grating structure, etc. For example, the projection of the passivation layer on the plane where the piezoelectric substrate is located coincides with the piezoelectric substrate, but the present application does not make any limitations in this regard and it depends on the specific situation.

[0068] As Figure 12 shown, Figure 12 shows the schematic diagram of the fusing power of the surface acoustic wave resonator when the metal alloy layer is an AlCu layer, an AlTi layer, or an AlMo layer. Among them, the vertical coordinate represents the fusing power, and the horizontal coordinate represents the average result of multiple tests. From Figure 12It can be seen that in the surface acoustic wave resonator provided by the embodiments of the present application, when the first metal alloy layer and the second metal alloy layer adopt any one of the AlCu layer, the AlTi layer or the AlMo layer, the fusing power of the surface acoustic wave resonator can reach 33.5 or more, which can meet the requirements of the 5G frequency band for the fusing power of the surface acoustic wave resonator, and thus can meet the requirements of the 5G frequency band for the power tolerance of the surface acoustic wave resonator.

[0069] Correspondingly, the embodiments of the present application further provide a surface acoustic wave filter, as Figure 13 shown, the surface acoustic wave filter includes: a series arm structure 200 and a parallel arm structure 300 connected to the series arm structure 200, wherein the series arm structure 200 includes at least one series arm, and one series arm includes at least one series resonator, and the parallel arm structure 300 includes at least one parallel arm, and one parallel arm includes at least one parallel resonator. It should be noted that in this embodiment, at least one of the at least one series resonator and the at least one parallel resonator is the resonator provided by any of the above embodiments, so as to improve the power tolerance of the surface acoustic wave filter when applied to high-frequency signals.

[0070] Specifically, in an embodiment of the present application, continuing as Figure 13 shown, the series arm structure 200 includes a first series arm 201, a second series arm 202 and a third series arm 203, wherein the first series arm 201 includes a series resonator R s1 , the second series arm 202 includes series resonators R s2 and R s3 , and the third series arm 203 includes series resonators R s4 and R s5 ; the parallel arm structure 300 includes a first parallel arm 301 and a second parallel arm 302, wherein the first parallel arm 301 includes parallel resonators R p1 and R p2 , and the second parallel arm 302 includes a parallel resonator R p3 . In other embodiments of the present application, the series arm structure and the parallel arm structure may also adopt other structures, and the present application does not limit this, and it depends on the specific situation.

[0071] Optionally, each resonator in the surface acoustic wave filter is the surface acoustic wave resonator provided by any of the above embodiments, so as to simplify the manufacturing process of the surface acoustic wave filter, but the present application does not limit this, and it depends on the specific situation.

[0072] Based on any of the above embodiments, in an embodiment of the present application, at least one series arm in the series arm structure further includes at least one first passive device, and at least one shunt arm in the shunt arm structure further includes at least one second passive device (such as Figure 13 the second shunt arm 302 described in

[0073] In summary, in the surface acoustic wave resonator provided by the embodiments of the present application and the surface acoustic wave filter including the surface acoustic wave resonator, in a direction perpendicular to the plane where the surface acoustic wave resonator is located, the interdigital transducer includes at least two metal alloy layers, and the at least two metal alloy layers include a first metal alloy layer and a second metal alloy layer. The first metal alloy layer and the second metal alloy layer have high power tolerance, thereby improving the power tolerance of the interdigital transducer, and further improving the power tolerance of the surface acoustic wave resonator and the surface acoustic wave filter, so that it can meet the power tolerance requirements when operating in a high-frequency band range.

[0074] In this specification, the various embodiments are described in a progressive, or parallel, or a combination of progressive and parallel manners. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0075] It should be noted that in the description of the present application, it should be understood that the descriptions of the drawings and the embodiments are illustrative rather than restrictive. It should also be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that an article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such article or device. Without further limitation, an element defined by the phrase "including a..." does not exclude the existence of additional identical elements in the article or device including the above elements.

[0076] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surface acoustic wave resonator, characterized in that: include: A piezoelectric substrate and an interdigital transducer located on a first side of the piezoelectric substrate, wherein the interdigital transducer comprises a first bus bar and a second bus bar arranged opposite to each other in a first direction, a first interdigital electrode electrically connected to the first bus bar, and a second interdigital electrode electrically connected to the second bus bar, wherein the first interdigital electrode and the second interdigital electrode are located between the first bus bar and the second bus bar and are arranged alternately in a second direction, and the second direction is perpendicular to the first direction; Wherein, in a direction perpendicular to the plane where the surface acoustic wave resonator is located, the interdigital transducer includes at least two metal alloy layers, the at least two metal alloy layers include a first metal alloy layer and a second metal alloy layer, and the first metal alloy layer and the second metal alloy layer are different.

2. The surface acoustic wave resonator according to claim 1, characterized in that: The resistance of the second metal alloy layer is lower than that of the first metal alloy layer, or the thermal conductivity of the second metal alloy layer is higher than that of the first metal alloy layer, or the density of the second metal alloy layer is higher than that of the first metal alloy layer.

3. The surface acoustic wave resonator according to claim 1, characterized in that: The first metal alloy layer is an AlCu layer, an AlTi layer or an AlMo layer; the second metal alloy layer is an AlCu layer, an AlTi layer or an AlMo layer.

4. The surface acoustic wave resonator according to claim 1, characterized in that: The thickness of the first metal alloy layer is not greater than 350 nm, and the thickness of the second metal alloy layer is not greater than 350 nm.

5. The surface acoustic wave resonator according to claim 1, characterized in that: The interdigital transducer further comprises: at least one barrier diffusion layer, wherein the at least one barrier diffusion layer comprises: a first barrier diffusion layer located on a side of the first metal alloy layer facing the piezoelectric substrate; a second barrier diffusion layer located on a side of the second metal alloy layer away from the piezoelectric substrate; A third diffusion barrier layer is located between the first metal alloy layer and the second metal alloy layer.

6. The surface acoustic wave resonator according to claim 5, characterized in that: The thickness of the diffusion barrier layer is not less than 10 nm.

7. The surface acoustic wave resonator according to claim 1, characterized in that: Also includes: A temperature compensation layer covers a side of the IDT away from the piezoelectric substrate.

8. The surface acoustic wave resonator according to claim 1, characterized in that: Also includes: The piezoelectric functional layer is located between the piezoelectric substrate and the interdigital transducer, and the piezoelectric functional layer includes at least one functional layer selected from the group consisting of a temperature compensation layer, a bonding layer, a high acoustic resistance layer, a low acoustic resistance layer, a reflective layer and a dielectric layer.

9. The surface acoustic wave resonator according to claim 1, characterized in that: Also includes: A passivation layer at least covers the first interdigital electrodes, the second interdigital electrodes, and regions between adjacent first interdigital electrodes and regions between adjacent second interdigital electrodes.

10. A surface acoustic wave filter, characterized in that: include: A series arm structure and a parallel arm structure connected to the series arm structure, the series arm structure includes at least one series arm, one of the series arms includes at least one series resonator, the parallel arm structure includes at least one parallel arm, one of the parallel arms includes at least one parallel resonator; at least one of the at least one series resonator and the at least one parallel resonator is the resonator described in any one of claims 1 to 9.

11. The surface acoustic wave filter according to claim 10, characterized in that: Each resonator in the at least one series resonator and the at least one parallel resonator is a resonator as described in any one of claims 1 to 9.

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