Temperature compensation type surface acoustic wave resonator, filter and manufacturing method thereof

Abstract

The invention provides a temperature compensation type surface acoustic wave resonator, a temperature compensation type surface acoustic wave filter and a manufacturing method of the temperature compensation type surface acoustic wave resonator. The surface acoustic wave resonator comprises a piezoelectric substrate, an interdigital transducer, a first load structure, a second load structure and an insulation structure, the interdigital transducer is arranged on the surface of one side of the piezoelectric substrate and comprises a plurality of long-finger electrodes, and the long-finger electrodes comprise a first long-finger electrode and a second long-finger electrode; the first long-finger electrodes and the second long-finger electrodes extend in the second direction, are arranged in a crossed mode and are arranged in the first direction. The insulating structure is arranged on one side of the long finger electrode; the first load structure is arranged on the side, away from the long-finger electrode, of the insulating structure; the second load structure is arranged on the side, provided with the insulation structure, of the long-finger electrode, and the orthographic projection of the first load structure and the orthographic projection of the second load structure on the piezoelectric substrate are partially overlapped with the orthographic projection of at least one long-finger electrode on the piezoelectric substrate. According to the invention, the transverse mode can be suppressed, and the Q value of the surface acoustic wave resonator is improved.

Description

[0001] This application is a divisional application of the invention patent application with application number 202411331745.6 filed on September 24, 2024. Technical Field

[0002] The present application relates to the field of surface acoustic wave technology, and in particular to a temperature-compensated surface acoustic wave resonator, a filter, and a manufacturing method thereof. Background Art

[0003] A surface acoustic wave resonator (SAWR) is a resonant device that utilizes surface acoustic waves (SAWs) propagating through a crystal. SAWs are mechanical waves that propagate through surface vibrations generated on the surface of a crystal. SAWRs utilize the unique structure and material properties of crystals to create resonances within the crystal. SAWRs have broad application prospects in fields such as communications, sensing, navigation, healthcare, and the Internet of Things. Their high quality factor, low insertion loss, and stability make them an ideal choice for many applications.

[0004] The SAWR operates by utilizing the piezoelectric effect to generate mechanical vibrations, which in turn generate surface acoustic waves (SAWs) on the crystal surface. This resonance creates a specific frequency vibration mode. In some cases, due to material properties or structural design, the SAWR may generate transverse modes of vibration. Transverse modes refer to transverse vibration modes generated in the crystal. Unlike the longitudinal vibration modes of the SAWR, the generation of transverse modes can cause SAWR performance variations or instability. Therefore, during the design and manufacture of the SAWR, care must be taken to suppress the generation of transverse modes to ensure stability and performance. Summary of the Invention

[0005] The present application provides a temperature-compensated surface acoustic wave resonator, a filter and a manufacturing method thereof, which are used to solve the problems of increased insertion loss, frequency response distortion, increased bandwidth and cross-coupling that may be caused by lateral parasitic modes.

[0006] In a first aspect, the present application provides a temperature-compensated surface acoustic wave resonator, comprising:

[0007] Piezoelectric substrate;

[0008] An interdigital transducer is provided on a side surface of the piezoelectric substrate, the interdigital transducer comprising a plurality of long finger electrodes, the long finger electrodes comprising a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along a second direction and are arranged along the first direction; the first long finger electrode and the second long finger electrode are arranged crosswise along the second direction; along the second direction, the first long finger electrode comprises a first end proximal to a side of the second long finger electrode and a second end distal to a side of the second long finger electrode; along the second direction, the second long finger electrode comprises a third end proximal to a side of the first long finger electrode and a fourth end distal to a side of the first long finger electrode;

[0009] at least one insulating structure, disposed on one side of the long finger electrode;

[0010] at least one first load structure, disposed on a side of the insulating structure away from the long finger electrodes, wherein an orthographic projection of the at least one first load structure on the piezoelectric substrate overlaps with an orthographic projection of the third end portion of each second long finger electrode on the piezoelectric substrate;

[0011] at least one second load structure, disposed on a side of the long finger electrode having the insulating structure, wherein an orthographic projection of the at least one second load structure on the piezoelectric substrate overlaps with an orthographic projection of a first end portion of each first long finger electrode on the piezoelectric substrate;

[0012] The first direction intersects the second direction.

[0013] Preferably, the orthographic projection of the first load structure on the piezoelectric substrate also overlaps with the orthographic projection of the first long finger electrode between two adjacent third ends on the piezoelectric substrate;

[0014] The orthographic projection of the second load structure on the piezoelectric substrate also overlaps with the orthographic projection of the second long finger electrode between two adjacent first end portions on the piezoelectric substrate.

[0015] Preferably, the orthographic projection of the first load structure on the piezoelectric substrate also overlaps with the orthographic projection of the spacing region between the first long finger electrode and the third end portion on the piezoelectric substrate;

[0016] An orthographic projection of the second load structure on the piezoelectric substrate also overlaps with an orthographic projection of a spacing region between the second long finger electrode and the first end portion on the piezoelectric substrate.

[0017] Preferably, the IDT further includes a bus bar, and the bus bar includes a first bus bar and a second bus bar;

[0018] The first bus bar and the second bus bar both extend along the second direction and are arranged opposite to each other along the first direction;

[0019] The second end of the first long finger electrode is connected to the first bus bar;

[0020] The fourth end portion of the second long finger electrode is connected to the second bus bar.

[0021] Preferably, the first long finger electrode and the second long finger electrode have the same length extending along the second direction.

[0022] Preferably, the widths of the first long finger electrodes and the second long finger electrodes along the first direction are equal.

[0023] Preferably, the temperature-compensated surface acoustic wave resonator further comprises a temperature compensation layer;

[0024] The temperature compensation layer is arranged on a side of the interdigital transducer away from the piezoelectric substrate.

[0025] Preferably, the temperature-compensated surface acoustic wave resonator further comprises a metal connection thickening layer;

[0026] The metal connection thickening layer is arranged on a side of the bus bar away from the piezoelectric substrate.

[0027] In a second aspect, the present application further provides a temperature-compensated filter, comprising the temperature-compensated surface acoustic wave resonator described in any one of the first aspects.

[0028] In a third aspect, the present application further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0029] providing a piezoelectric substrate;

[0030] Fabricating an interdigital transducer on one side surface of the piezoelectric substrate;

[0031] The interdigital transducer includes a bus bar and a plurality of long finger electrodes, the long finger electrodes including a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along the second direction and are arranged along the first direction; the first long finger electrode and the second long finger electrode are arranged to cross each other along the first direction; the long finger electrodes have equal widths along the first direction;

[0032] Fabricating an insulating structure on a surface of the long finger electrode away from the piezoelectric substrate;

[0033] Fabricating a first load structure on a surface of the insulating structure away from the piezoelectric substrate;

[0034] Fabricating a second load structure on a surface of the long finger electrode away from the piezoelectric substrate;

[0035] A temperature compensation layer is formed on a surface of the IDT away from the piezoelectric substrate, wherein the temperature compensation layer covers at least a portion of the surface of the insulating structure, the first load structure, the second load structure, the IDT, and the piezoelectric substrate;

[0036] Making a metal connection thickening layer on the surface of the bus bar on a side away from the piezoelectric substrate;

[0037] The first direction intersects the second direction.

[0038] In a fourth aspect, the present application further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0039] providing a piezoelectric substrate;

[0040] Etching the piezoelectric substrate to form a first groove structure and a second groove structure; the depth of the first groove structure is greater than the depth of the second groove structure;

[0041] A first load structure and a second load structure are respectively fabricated in the first groove structure and the second groove structure; the thickness of the second load structure is equal to the depth of the second groove structure;

[0042] An insulating structure is formed on a surface of the first load structure away from the piezoelectric substrate; the thickness of the insulating structure is equal to the difference between the depths of the first groove structure and the second groove structure;

[0043] Fabricating an interdigital transducer on a surface of the piezoelectric substrate close to the first groove structure;

[0044] The interdigital transducer includes a bus bar and a plurality of long finger electrodes, the long finger electrodes including a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along the second direction and are arranged along the first direction; the first long finger electrode and the second long finger electrode are arranged to cross each other along the first direction; the long finger electrodes have equal widths along the first direction;

[0045] A temperature compensation layer is formed on a surface of the IDT away from the piezoelectric substrate, wherein the temperature compensation layer covers at least a portion of the surface of the IDT and the piezoelectric substrate;

[0046] Making a metal connection thickening layer on the surface of the bus bar on a side away from the piezoelectric substrate;

[0047] The first direction intersects the second direction.

[0048] In a fifth aspect, the present application further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0049] providing a piezoelectric substrate;

[0050] Etching the piezoelectric substrate to form a first groove structure and a second groove structure; the depth of the first groove structure is equal to the depth of the second groove structure;

[0051] A first load structure and a second load structure are respectively fabricated in the first groove structure and the second groove structure; the thickness of the first load structure is equal to the depth of the first groove structure; the thickness of the second load structure is equal to the depth of the second groove structure;

[0052] Making an insulating structure on the surface of the first load structure;

[0053] An interdigital transducer is fabricated on a surface of the piezoelectric substrate adjacent to the first groove structure; the interdigital transducer covers at least a portion of the surface of the first load structure and the insulating structure;

[0054] The interdigital transducer includes a bus bar and a plurality of long finger electrodes, the long finger electrodes including a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along the second direction and are arranged along the first direction; the first long finger electrode and the second long finger electrode are arranged to cross each other along the first direction; the long finger electrodes have equal widths along the first direction;

[0055] A temperature compensation layer is formed on a surface of the IDT away from the piezoelectric substrate, wherein the temperature compensation layer covers the IDT, the insulating structure and at least a portion of the surface of the piezoelectric substrate;

[0056] Making a metal connection thickening layer on the surface of the bus bar on a side away from the piezoelectric substrate;

[0057] The first direction intersects the second direction.

[0058] In a sixth aspect, the present application further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0059] providing a piezoelectric substrate;

[0060] Fabricating a first load structure and a second load structure on one side surface of the piezoelectric substrate;

[0061] Fabricating an insulating structure on a surface of the first load structure away from the piezoelectric substrate;

[0062] An interdigital transducer is fabricated on a surface of the piezoelectric substrate close to the first load structure; the interdigital transducer covers at least a portion of the surface of the first load structure, the second load structure, and the insulating structure;

[0063] The interdigital transducer includes a bus bar and a plurality of long finger electrodes, the long finger electrodes including a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along the second direction and are arranged along the first direction; the first long finger electrode and the second long finger electrode are arranged to cross each other along the first direction; the long finger electrodes have equal widths along the first direction;

[0064] A temperature compensation layer is formed on a surface of the IDT away from the piezoelectric substrate, wherein the temperature compensation layer covers the IDT, the insulating structure, the first load structure and at least a portion of the surface of the piezoelectric substrate;

[0065] Making a metal connection thickening layer on the surface of the bus bar on a side away from the piezoelectric substrate;

[0066] The first direction intersects the second direction.

[0067] The embodiments of the present invention provide a temperature-compensated surface acoustic wave resonator, a filter, and a manufacturing method thereof, wherein the temperature-compensated surface acoustic wave resonator includes a piezoelectric substrate, an interdigital transducer, a first load structure, a second load structure, and an insulating structure; the interdigital transducer is arranged on one side surface of the piezoelectric substrate, the interdigital transducer includes a plurality of long finger electrodes, and the long finger electrodes include a first long finger electrode and a second long finger electrode; the first long finger electrode and the second long finger electrode both extend along the second direction and are arranged crosswise, and are arranged along the first direction; the insulating structure is arranged on one side of the long finger electrode; the first load structure is arranged on the side of the insulating structure away from the long finger electrode; the second load structure is arranged on the side of the long finger electrode having the insulating structure, and the orthographic projections of the first load structure and the second load structure on the piezoelectric substrate at least partially overlap with the orthographic projection of at least one long finger electrode on the piezoelectric substrate. By providing a first load structure and a second load structure, the present invention can increase the force exerted by the long finger electrode on the piezoelectric substrate, thereby changing the propagation speed of the surface acoustic wave, so that the sound speed of the surface acoustic wave in the area where the first load structure and the second load structure are provided is lower than the sound speed of the surface acoustic wave in the area where the first load structure and the second load structure are not provided, thereby suppressing the transverse mode and improving the Q value of the temperature-compensated surface acoustic wave resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0069] Figure 1 is a cross-sectional view of a temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0070] Figure 2 is a cross-sectional view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0071] Figure 3 is a cross-sectional view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0072] Figure 4 is a cross-sectional view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0073] Figure 5 is a top view of a temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0074] Figure 6 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0075] Figure 7 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0076] Figure 8 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0077] Figure 9 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0078] Figure 10 This is a diagram showing test results of the temperature-compensated surface acoustic wave resonator provided by an embodiment of the present invention and a temperature-compensated surface acoustic wave resonator in the prior art. DETAILED DESCRIPTION

[0079] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0080] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments described herein can be practiced in an order other than that shown or described herein.

[0081] like Figures 1 to 9 As shown, the temperature-compensated surface acoustic wave resonator provided in the embodiment of the present application includes: a piezoelectric substrate 1, an interdigital transducer 2, at least one first load structure 3, at least one second load structure 4 and at least one insulating structure 5.

[0082] Illustratively, the material of the piezoelectric substrate 1 may be lithium niobate or lithium tantalate.

[0083] The interdigital transducer 2 is arranged on one side surface of the piezoelectric substrate 1, and the interdigital transducer 2 includes a plurality of long finger electrodes 21, and the long finger electrodes 21 include a first long finger electrode 211 and a second long finger electrode 212; the first long finger electrode 211 and the second long finger electrode 212 both extend along the second direction Y and are arranged along the first direction X to form a comb-like structure respectively; the first long finger electrode 211 and the second long finger electrode 212 are arranged crosswise along the second direction Y; illustratively, the material of the long finger electrodes 21 can be copper, aluminum, titanium, tungsten or silver; the first direction X intersects with the second direction Y.

[0084] The insulating structure 5 is provided on one side of the long finger electrode 21; it can be understood that, if Figure 1 As shown, the insulating structure 5 can also be provided on the side of the long finger electrode 21 away from the piezoelectric substrate 1; Figures 2 to 4 As shown, the insulating structure 5 can also be arranged on the side of the long finger electrode 21 close to the piezoelectric substrate 1; the setting of the insulating structure 5 can effectively isolate the adjacent long finger electrodes 21 to prevent short circuit or interference between the adjacent long finger electrodes 21.

[0085] like Figures 1 to 9As shown, the first load structure 3 is arranged on the side of the insulating structure 5 away from the long finger electrode 21, and the orthographic projection of the first load structure 3 on the piezoelectric substrate 1 is at least partially overlapped with the orthographic projection of at least one of the long finger electrodes 21 on the piezoelectric substrate 1; it can be understood that, as Figures 2 to 4 As shown, the first load structure 3 can be provided on a side surface of the long finger electrode 21 close to the piezoelectric substrate 1; Figure 1 As shown, the first load structure 3 may also be provided on a surface of the long finger electrode 21 away from the piezoelectric substrate 1. For example, the material of the first load structure 3 may be different from that of the long finger electrode 21, and the first load structure 3 may be made of a metal material or a metal oxide material.

[0086] like Figures 1 to 9 As shown, the second load structure 4 is disposed on the side of the long finger electrode 21 having the insulating structure 5, and the orthographic projection of the second load structure 4 on the piezoelectric substrate 1 at least partially overlaps with the orthographic projection of at least one of the long finger electrodes 21 on the piezoelectric substrate 1. It is understood that the second load structure 4 can be disposed on the side of the long finger electrode 21 close to the piezoelectric substrate 1, or on the side of the long finger electrode 21 away from the piezoelectric substrate 1. Exemplarily, the material of the second load structure 4 can be different from that of the long finger electrode 21, and the second load structure 4 can be made of a metal material or a metal oxide material.

[0087] It should be noted that the embodiment of the present invention does not limit the number, area, or shape of the first load structures 3 and the second load structures 4. This not only enhances the suppression of transverse modes, but also allows for diversified configuration of the temperature-compensated surface acoustic wave filter. For ease of illustration, the embodiment of the present invention sets the first load structures 3 and the second load structures 4 to be rectangular. Exemplarily, the shapes of the first load structures 3 and the second load structures 4 may also be circular, trapezoidal, regularly shaped polygons, or irregularly shaped polygons. The embodiment of the present invention does not specifically limit the shapes of the first load structures 3 and the second load structures 4.

[0088] By providing the first load structure 3 and the second load structure 4, the force exerted by the long finger electrode 21 on the piezoelectric substrate 1 can be increased, thereby changing the propagation speed of the surface acoustic wave, so that the sound speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are provided is smaller than the sound speed of the area where the first load structure 3 and the second load structure 4 are not provided, thereby suppressing the transverse mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0089] Preferably, along the second direction Y, the first long finger electrode 211 includes a first end close to the second long finger electrode 212 and a second end away from the second long finger electrode 212; along the second direction Y, the second long finger electrode 212 includes a third end close to the first long finger electrode 211 and a fourth end away from the first long finger electrode 211;

[0090] like Figures 5 to 9 As shown, at least a portion of the orthographic projection of the second load structure 4 on the piezoelectric substrate 1 overlaps with the orthographic projection of the first end portion on the piezoelectric substrate 1; and at least a portion of the orthographic projection of the first load structure 3 on the piezoelectric substrate 1 overlaps with the orthographic projection of the third end portion on the piezoelectric substrate 1. It is understood that the minimum overlapping area between the orthographic projection of the first load structure 3 on the piezoelectric substrate 1 and the orthographic projection of the first elongated finger electrode 211 on the piezoelectric substrate 1 is the area of ​​the first end portion. Similarly, the minimum overlapping area between the orthographic projection of the second load structure 4 on the piezoelectric substrate 1 and the orthographic projection of the second elongated finger electrode 212 on the piezoelectric substrate 1 is the area of ​​the third end portion. The configuration of the first load structure 3 and the second load structure 4 is simple, flexible, and has a large degree of configuration freedom.

[0091] In such Figure 5 In the embodiment shown, the orthographic projection of the first load structure 3 on the piezoelectric substrate 1 is equal to the orthographic projection of the first long finger electrode 211 on the piezoelectric substrate 1, and the orthographic projection of the second load structure 4 on the piezoelectric substrate 1 is equal to the orthographic projection of the second long finger electrode 212 on the piezoelectric substrate 1, that is, the first load structure 3, the second load structure 4 and the first end and the third end have the same area and shape. Figures 6 to 9 In the embodiment shown, the orthographic projection of the first load structure 3 on the piezoelectric substrate 1 is larger than the orthographic projection of the first long finger electrode 211 on the piezoelectric substrate 1, and the orthographic projection of the second load structure 4 on the piezoelectric substrate 1 is larger than the orthographic projection of the second long finger electrode 212 on the piezoelectric substrate 1. It can be understood that, as Figures 5 to 9 The illustrated embodiments are merely some of the embodiments of the present invention and are not intended to limit the present invention.

[0092] Preferably, the IDT 2 further includes a bus bar 22, and the bus bar 22 includes a first bus bar 221 and a second bus bar 222; the bus bar 22 is capable of receiving an AC signal, and when an AC signal of a certain frequency is applied to the bus bar 22, a surface acoustic wave can be generated in the temperature-compensated surface acoustic wave resonator;

[0093] The first bus bar 221 and the second bus bar 222 both extend along the second direction Y and are arranged opposite to each other along the first direction X;

[0094] The second end of the first long finger electrode 211 is connected to the first bus bar 221;

[0095] The fourth end of the second long finger electrode 212 is connected to the second bus bar 222 .

[0096] Preferably, the first long finger electrodes 211 and the second long finger electrodes 212 have the same length extending along the second direction Y. This simplifies the arrangement and enhances the suppression of the lateral mode.

[0097] Preferably, the widths of the first long finger electrodes 211 and the second long finger electrodes 212 along the first direction X are equal. This simplifies the arrangement and enhances the suppression of the lateral mode.

[0098] Preferably, the temperature-compensated surface acoustic wave resonator further includes a temperature compensation layer 6; the temperature compensation layer 6 is arranged on the side of the interdigital transducer 2 away from the piezoelectric substrate 1. Exemplarily, the material of the temperature compensation layer 6 can be silicon dioxide or silicon nitride or a silicon-containing dielectric film such as silicon nitride. The provision of the temperature compensation layer 6 can prevent temperature changes from affecting the resonant frequency of the temperature-compensated surface acoustic wave resonator, thereby improving the temperature stability and reliability of the resonator. It should be noted that in order to enable the resonator to have better temperature stability, a material with a positive temperature coefficient can be used to compensate for the adverse effects of the piezoelectric material. This temperature-compensated surface acoustic wave resonator can reduce the adverse effects of temperature drift.

[0099] Preferably, the temperature-compensated surface acoustic wave resonator further includes a metal connection thickening layer 7; the metal connection thickening layer 7 is disposed on the side of the busbar 22 away from the piezoelectric substrate 1. Exemplarily, the material of the metal connection thickening layer 7 may be titanium, aluminum, copper, gold, or silver. The provision of the metal connection thickening layer 7 can dissipate heat, reduce electrical losses, and improve the quality factor of the resonator.

[0100] Based on the same inventive concept, an embodiment of the present invention further provides a temperature-compensated filter, including the temperature-compensated surface acoustic wave resonator in the above embodiment. Therefore, the filter provided by the embodiment of the present invention also has the beneficial effects described in the above embodiment, which will not be repeated here.

[0101] like Figure 1 As shown, based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0102] Providing a piezoelectric substrate 1;

[0103] An interdigital transducer 2 is fabricated on one side surface of the piezoelectric substrate 1;

[0104] The IDT 2 includes a bus bar 22 and a plurality of long finger electrodes 21. The long finger electrodes 21 include a first long finger electrode 211 and a second long finger electrode 212. The first long finger electrode 211 and the second long finger electrode 212 both extend along the second direction Y and are arranged along the first direction X. The first long finger electrode 211 and the second long finger electrode 212 are arranged to intersect along the first direction X. The long finger electrodes 21 have equal widths along the first direction X.

[0105] An insulating structure 5 is formed on the surface of the long finger electrode 21 away from the piezoelectric substrate 1;

[0106] A first load structure 3 is fabricated on a surface of the insulating structure 5 that is away from the piezoelectric substrate 1;

[0107] A second load structure 4 is fabricated on a surface of the long finger electrode 21 away from the piezoelectric substrate 1 ;

[0108] A temperature compensation layer 6 is formed on a surface of the IDT 2 away from the piezoelectric substrate 1, wherein the temperature compensation layer 6 covers at least a portion of the surface of the insulating structure 5, the first load structure 3, the second load structure 4, the IDT 2 and the piezoelectric substrate 1;

[0109] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 away from the piezoelectric substrate 1;

[0110] The first direction X and the second direction Y intersect.

[0111] The fabrication method described in this embodiment can be used to fabricate the temperature-compensated surface acoustic wave resonator described in the above embodiment. By providing the first load structure 3 and the second load structure 4, the fabrication method can increase the force exerted by the long-finger electrodes 21 on the piezoelectric substrate 1, thereby changing the propagation speed of the surface acoustic wave. This makes the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are provided lower than the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are not provided, thereby suppressing the transverse mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0112] like Figure 2 As shown, based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0113] Providing a piezoelectric substrate 1;

[0114] Etching the piezoelectric substrate 1 to form a first groove structure and a second groove structure; the depth of the first groove structure is greater than the depth of the second groove structure;

[0115] A first load structure 3 and a second load structure 4 are respectively fabricated in the first groove structure and the second groove structure; the thickness of the second load structure 4 is equal to the depth of the second groove structure;

[0116] An insulating structure 5 is formed on a surface of the first load structure 3 away from the piezoelectric substrate 1; the thickness of the insulating structure 5 is equal to the difference between the depths of the first groove structure and the second groove structure;

[0117] An interdigital transducer 2 is fabricated on a surface of the piezoelectric substrate 1 on one side close to the first groove structure;

[0118] The IDT 2 includes a bus bar 22 and a plurality of long finger electrodes 21. The long finger electrodes 21 include a first long finger electrode 211 and a second long finger electrode 212. The first long finger electrode 211 and the second long finger electrode 212 both extend along the second direction Y and are arranged along the first direction X. The first long finger electrode 211 and the second long finger electrode 212 are arranged to intersect along the first direction X. The long finger electrodes 21 have equal widths along the first direction X.

[0119] A temperature compensation layer 6 is formed on a surface of the IDT 2 away from the piezoelectric substrate 1, wherein the temperature compensation layer 6 covers at least a portion of the surface of the IDT 2 and the piezoelectric substrate 1;

[0120] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 away from the piezoelectric substrate 1;

[0121] The first direction X and the second direction Y intersect.

[0122] The fabrication method described in this embodiment can be used to fabricate the temperature-compensated surface acoustic wave resonator described in the above embodiment. By providing the first load structure 3 and the second load structure 4, the fabrication method can increase the force exerted by the long-finger electrodes 21 on the piezoelectric substrate 1, thereby changing the propagation speed of the surface acoustic wave. This makes the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are provided lower than the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are not provided, thereby suppressing the transverse mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0123] like Figure 3As shown, based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0124] Providing a piezoelectric substrate 1;

[0125] Etching the piezoelectric substrate 1 to form a first groove structure and a second groove structure; the depth of the first groove structure is equal to the depth of the second groove structure;

[0126] A first load structure 3 and a second load structure 4 are respectively fabricated in the first groove structure and the second groove structure; the thickness of the first load structure 3 is equal to the depth of the first groove structure; the thickness of the second load structure 4 is equal to the depth of the second groove structure;

[0127] Making an insulating structure 5 on the surface of the first load structure 3;

[0128] An interdigital transducer 2 is fabricated on a surface of the piezoelectric substrate 1 close to the first groove structure; the interdigital transducer 2 covers at least a portion of the surface of the first load structure 3 and the insulating structure 5;

[0129] The IDT 2 includes a bus bar 22 and a plurality of long finger electrodes 21. The long finger electrodes 21 include a first long finger electrode 211 and a second long finger electrode 212. The first long finger electrode 211 and the second long finger electrode 212 both extend along the second direction Y and are arranged along the first direction X. The first long finger electrode 211 and the second long finger electrode 212 are arranged to intersect along the first direction X. The long finger electrodes 21 have equal widths along the first direction X.

[0130] A temperature compensation layer 6 is formed on a surface of the IDT 2 away from the piezoelectric substrate 1, wherein the temperature compensation layer 6 covers the IDT 2, the insulating structure 5 and at least a portion of the surface of the piezoelectric substrate 1;

[0131] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 away from the piezoelectric substrate 1;

[0132] The first direction X and the second direction Y intersect.

[0133] The fabrication method described in this embodiment can be used to fabricate the temperature-compensated surface acoustic wave resonator described in the above embodiment. By providing the first load structure 3 and the second load structure 4, the fabrication method can increase the force exerted by the long-finger electrodes 21 on the piezoelectric substrate 1, thereby changing the propagation speed of the surface acoustic wave. This makes the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are provided lower than the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are not provided, thereby suppressing the transverse mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0134] like Figure 4 As shown, based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0135] Providing a piezoelectric substrate 1;

[0136] A first load structure 3 and a second load structure 4 are fabricated on one side surface of the piezoelectric substrate 1;

[0137] An insulating structure 5 is formed on a surface of the first load structure 3 away from the piezoelectric substrate 1;

[0138] An interdigital transducer 2 is fabricated on a surface of the piezoelectric substrate 1 close to the first load structure 3; the interdigital transducer 2 covers at least a portion of the surface of the first load structure 3, the second load structure 4 and the insulating structure 5;

[0139] The IDT 2 includes a bus bar 22 and a plurality of long finger electrodes 21. The long finger electrodes 21 include a first long finger electrode 211 and a second long finger electrode 212. The first long finger electrode 211 and the second long finger electrode 212 both extend along the second direction Y and are arranged along the first direction X. The first long finger electrode 211 and the second long finger electrode 212 are arranged to intersect along the first direction X. The long finger electrodes 21 have equal widths along the first direction X.

[0140] A temperature compensation layer 6 is formed on a surface of the IDT 2 away from the piezoelectric substrate 1, wherein the temperature compensation layer 6 covers the IDT 2, the insulating structure 5, the first load structure 3 and at least a portion of the surface of the piezoelectric substrate 1;

[0141] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 away from the piezoelectric substrate 1;

[0142] The first direction X and the second direction Y intersect.

[0143] The fabrication method described in this embodiment can be used to fabricate the temperature-compensated surface acoustic wave resonator described in the above embodiment. By providing the first load structure 3 and the second load structure 4, the fabrication method can increase the force exerted by the long-finger electrodes 21 on the piezoelectric substrate 1, thereby changing the propagation speed of the surface acoustic wave. This makes the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are provided lower than the speed of the surface acoustic wave in the area where the first load structure 3 and the second load structure 4 are not provided, thereby suppressing the transverse mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0144] Figure 10 The test results of the temperature-compensated surface acoustic wave resonator provided by the embodiment of the present invention and the temperature-compensated surface acoustic wave resonator in the prior art are shown in FIG. Figure 10 , Figure 10 The horizontal axis represents the frequency, Figure 10 The vertical axis in the figure represents the admittance. The red curve represents the admittance curve of the temperature-compensated surface acoustic wave resonator in the prior art, and the blue curve represents the admittance curve of the temperature-compensated surface acoustic wave resonator provided in this embodiment. The left peak of the red and blue curves is the resonance point, and the right peak is the anti-resonance point. Figure 10 It can be seen from the figure that the admittance curve of the temperature-compensated surface acoustic wave resonator provided by the prior art has obvious transverse mode noise between the resonance point and the antiresonance point, while the admittance curve obtained by using the temperature-compensated surface acoustic wave resonator provided by this embodiment is very smooth between the resonance point and the antiresonance point, and the transverse mode suppression effect is obvious.

[0145] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A temperature-compensated surface acoustic wave resonator, characterized in that: include: Piezoelectric substrate (1); An interdigital transducer (2) is provided on a side surface of the piezoelectric substrate (1), the interdigital transducer (2) comprising a plurality of long finger electrodes (21), the long finger electrodes (21) comprising a first long finger electrode (211) and a second long finger electrode (212); the first long finger electrode (211) and the second long finger electrode (212) both extend along a second direction (Y) and are arranged along a first direction (X); the first long finger electrode (211) and the second long finger electrode (212) are arranged crosswise along the second direction (Y); along the second direction (Y), the first long finger electrode (211) comprises a first end close to the second long finger electrode (212) and a second end away from the second long finger electrode (212); along the second direction (Y), the second long finger electrode (212) comprises a third end close to the first long finger electrode (211) and a fourth end away from the first long finger electrode (211); at least one insulating structure (5) disposed on one side of the long finger electrode (21); At least one first load structure (3) is arranged on a side of the insulating structure (5) away from the long finger electrode (21), and the orthographic projection of the at least one first load structure (3) on the piezoelectric substrate (1) overlaps with the orthographic projection of the third end of each second long finger electrode (212) on the piezoelectric substrate (1); At least one second load structure (4) is provided on a side of the long finger electrode (21) having the insulating structure (5), and an orthographic projection of the at least one second load structure (4) on the piezoelectric substrate (1) overlaps with an orthographic projection of a first end portion of each first long finger electrode (211) on the piezoelectric substrate (1); The first direction (X) intersects the second direction (Y).

2. The temperature-compensated surface acoustic wave resonator according to claim 1, wherein The orthographic projection of the first load structure (3) on the piezoelectric substrate (1) also overlaps with the orthographic projection of the first long finger electrode (211) between two adjacent third end portions on the piezoelectric substrate (1); The orthographic projection of the second load structure (4) on the piezoelectric substrate (1) also overlaps with the orthographic projection of the second long finger electrode (212) between two adjacent first end portions on the piezoelectric substrate (1).

3. The temperature-compensated surface acoustic wave resonator according to claim 2, wherein: The orthographic projection of the first load structure (3) on the piezoelectric substrate (1) also overlaps with the orthographic projection of the spacing region between the first long finger electrode (211) and the third end on the piezoelectric substrate (1); The orthographic projection of the second load structure (4) on the piezoelectric substrate (1) also overlaps with the orthographic projection of the spacing region between the second long-finger electrode (212) and the first end portion on the piezoelectric substrate (1).

4. The temperature-compensated surface acoustic wave resonator according to claim 1, wherein The interdigital transducer (2) further includes a bus bar (22), wherein the bus bar (22) includes a first bus bar (221) and a second bus bar (222); The first bus bar (221) and the second bus bar (222) both extend along the second direction (Y) and are arranged opposite to each other along the first direction (X); The second end of the first long finger electrode (211) is connected to the first bus bar (221); The fourth end of the second long finger electrode (212) is connected to the second bus bar (222).

5. The temperature-compensated surface acoustic wave resonator according to claim 1, wherein The first long finger electrode (211) and the second long finger electrode (212) have the same length when extended along the second direction (Y).

6. The temperature-compensated surface acoustic wave resonator according to claim 1, wherein: The first long finger electrode (211) and the second long finger electrode (212) have the same width along the first direction (X).

7. The temperature-compensated surface acoustic wave resonator according to claim 1, wherein: Also includes a temperature compensation layer (6); The temperature compensation layer (6) is arranged on a side of the interdigital transducer (2) away from the piezoelectric substrate (1).

8. The temperature-compensated surface acoustic wave resonator according to claim 4, wherein: Also includes a metal connection thickening layer (7); The metal connection thickening layer (7) is arranged on a side of the bus bar (22) away from the piezoelectric substrate (1).

9. A temperature compensation filter, characterized in that: The temperature-compensated surface acoustic wave resonator comprises the temperature-compensated surface acoustic wave resonator according to any one of claims 1 to 8.

10. A method for manufacturing a temperature-compensated surface acoustic wave resonator, characterized in that: include: Providing a piezoelectric substrate (1); An interdigital transducer (2) is fabricated on one side surface of the piezoelectric substrate (1); The interdigital transducer (2) comprises a bus bar (22) and a plurality of long finger electrodes (21), wherein the long finger electrodes (21) comprise a first long finger electrode (211) and a second long finger electrode (212); the first long finger electrode (211) and the second long finger electrode (212) both extend along a second direction (Y) and are arranged along a first direction (X); the first long finger electrode (211) and the second long finger electrode (212) are arranged to cross each other along the first direction (X); the widths of the long finger electrodes (21) along the first direction (X) are equal; An insulating structure (5) is fabricated on a surface of the long finger electrode (21) that is away from the piezoelectric substrate (1); A first load structure (3) is fabricated on a surface of the insulating structure (5) that is away from the piezoelectric substrate (1); A second load structure (4) is fabricated on a surface of the long finger electrode (21) that is away from the piezoelectric substrate (1); A temperature compensation layer (6) is formed on a surface of the interdigital transducer (2) away from the piezoelectric substrate (1), wherein the temperature compensation layer (6) covers at least a portion of the surface of the insulating structure (5), the first load structure (3), the second load structure (4), the interdigital transducer (2), and the piezoelectric substrate (1); A metal connection thickening layer (7) is formed on the surface of the bus bar (22) away from the piezoelectric substrate (1); The first direction (X) intersects the second direction (Y).

11. A method for manufacturing a temperature-compensated surface acoustic wave resonator, characterized in that: include: Providing a piezoelectric substrate (1); Etching the piezoelectric substrate (1) to form a first groove structure and a second groove structure; The depth of the first groove structure is greater than the depth of the second groove structure; A first load structure (3) and a second load structure (4) are respectively manufactured in the first groove structure and the second groove structure; the thickness of the second load structure (4) is equal to the depth of the second groove structure; An insulating structure (5) is fabricated on a surface of the first load structure (3) that is away from the piezoelectric substrate (1); the thickness of the insulating structure (5) is equal to the difference between the depths of the first groove structure and the second groove structure; An interdigital transducer (2) is fabricated on a surface of the piezoelectric substrate (1) on one side close to the first groove structure; The interdigital transducer (2) comprises a bus bar (22) and a plurality of long finger electrodes (21), wherein the long finger electrodes (21) comprise a first long finger electrode (211) and a second long finger electrode (212); the first long finger electrode (211) and the second long finger electrode (212) both extend along a second direction (Y) and are arranged along a first direction (X); the first long finger electrode (211) and the second long finger electrode (212) are arranged to cross each other along the first direction (X); the widths of the long finger electrodes (21) along the first direction (X) are equal; A temperature compensation layer (6) is formed on a surface of the interdigital transducer (2) away from the piezoelectric substrate (1), wherein the temperature compensation layer (6) covers at least a portion of the surface of the interdigital transducer (2) and the piezoelectric substrate (1); A metal connection thickening layer (7) is formed on the surface of the bus bar (22) away from the piezoelectric substrate (1); The first direction (X) intersects the second direction (Y).

12. A method for manufacturing a temperature-compensated surface acoustic wave resonator, characterized in that: include: Providing a piezoelectric substrate (1); Etching the piezoelectric substrate (1) to form a first groove structure and a second groove structure; The depth of the first groove structure is equal to the depth of the second groove structure; A first load structure (3) and a second load structure (4) are respectively manufactured in the first groove structure and the second groove structure; the thickness of the first load structure (3) is equal to the depth of the first groove structure; the thickness of the second load structure (4) is equal to the depth of the second groove structure; Producing an insulating structure (5) on the surface of the first load structure (3); An interdigital transducer (2) is fabricated on a surface of the piezoelectric substrate (1) on one side close to the first groove structure; the interdigital transducer (2) covers at least a portion of the surface of the first load structure (3) and the insulating structure (5); The interdigital transducer (2) comprises a bus bar (22) and a plurality of long finger electrodes (21), wherein the long finger electrodes (21) comprise a first long finger electrode (211) and a second long finger electrode (212); the first long finger electrode (211) and the second long finger electrode (212) both extend along a second direction (Y) and are arranged along a first direction (X); the first long finger electrode (211) and the second long finger electrode (212) are arranged to cross each other along the first direction (X); the widths of the long finger electrodes (21) along the first direction (X) are equal; A temperature compensation layer (6) is formed on a surface of the interdigital transducer (2) away from the piezoelectric substrate (1), wherein the temperature compensation layer (6) covers at least a portion of the surface of the interdigital transducer (2), the insulating structure (5), and the piezoelectric substrate (1); A metal connection thickening layer (7) is formed on the surface of the bus bar (22) away from the piezoelectric substrate (1); The first direction (X) intersects the second direction (Y).

13. A method for manufacturing a temperature-compensated surface acoustic wave resonator, characterized in that: include: Providing a piezoelectric substrate (1); A first load structure (3) and a second load structure (4) are fabricated on one side surface of the piezoelectric substrate (1); An insulating structure (5) is fabricated on a surface of the first load structure (3) that is away from the piezoelectric substrate (1); An interdigital transducer (2) is fabricated on a surface of the piezoelectric substrate (1) close to the first load structure (3); the interdigital transducer (2) covers at least a portion of the surface of the first load structure (3), the second load structure (4), and the insulating structure (5); The interdigital transducer (2) comprises a bus bar (22) and a plurality of long finger electrodes (21), wherein the long finger electrodes (21) comprise a first long finger electrode (211) and a second long finger electrode (212); the first long finger electrode (211) and the second long finger electrode (212) both extend along a second direction (Y) and are arranged along a first direction (X); the first long finger electrode (211) and the second long finger electrode (212) are arranged to cross each other along the first direction (X); the widths of the long finger electrodes (21) along the first direction (X) are equal; A temperature compensation layer (6) is formed on a surface of the interdigital transducer (2) away from the piezoelectric substrate (1), wherein the temperature compensation layer (6) covers at least a portion of the surface of the interdigital transducer (2), the insulating structure (5), the first load structure (3), and the piezoelectric substrate (1); A metal connection thickening layer (7) is formed on the surface of the bus bar (22) away from the piezoelectric substrate (1); The first direction (X) intersects the second direction (Y).

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