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 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 one side surface of the piezoelectric substrate, the interdigital transducer 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 at least 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

Technical Field

[0001] 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

[0002] Surface Acoustic Wave Resonator (SAWR) is a resonant device that uses surface acoustic wave (SAW) to propagate in a crystal. SAW is a mechanical wave that propagates through surface vibrations generated on the surface of a crystal. SAWR uses the special structure and material properties of the crystal to cause the surface acoustic wave to resonate in the crystal. SAWR has broad application prospects in the fields of communications, sensing, navigation, medical treatment, and the Internet of Things. Its high quality factor, low insertion loss, and stability make it an ideal choice for many applications.

[0003] The working principle of SAWR is to use the piezoelectric effect to generate mechanical vibrations, which in turn generate surface acoustic waves on the surface of the crystal and realize a vibration mode of a specific frequency through the resonance phenomenon. In some cases, due to the characteristics of the material or the design of the structure, SAWR may produce transverse mode vibrations. The transverse mode refers to the transverse vibration mode generated in the crystal. Unlike the longitudinal vibration mode of SAWR, the generation of the transverse mode may cause the performance of SAWR to change or become unstable. Therefore, when designing and manufacturing SAWR, it is necessary to pay attention to suppressing the generation of the transverse mode to ensure its stability and performance. Summary of the invention

[0004] 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.

[0005] In a first aspect, the present application provides a temperature compensated surface acoustic wave resonator, comprising:

[0006] Piezoelectric substrate;

[0007] An interdigital transducer is disposed on one side surface of the piezoelectric substrate, the interdigital transducer comprises a plurality of long finger electrodes, the long finger electrodes comprise 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 cross-arranged along the second direction;

[0008] at least one insulating structure, disposed on one side of the long finger electrode;

[0009] at least one first load structure, disposed on a side of the insulating structure away from the long finger electrodes, and an orthographic projection of the first load structure on the piezoelectric substrate at least partially overlaps with an orthographic projection of at least one of the long finger electrodes on the piezoelectric substrate;

[0010] at least one second load structure, disposed on a side of the long finger electrode having the insulating structure, and an orthographic projection of the second load structure on the piezoelectric substrate at least partially overlaps with an orthographic projection of at least one of the long finger electrodes on the piezoelectric substrate;

[0011] The first direction intersects the second direction.

[0012] Preferably, along the second direction, the first long finger electrode includes a first end portion close to a side of the second long finger electrode and a second end portion away from a side of the second long finger electrode;

[0013] At least a portion of the orthographic projection of the second load structure on the piezoelectric substrate overlaps with the orthographic projection of the first end on the piezoelectric substrate; along the second direction, the second long finger electrode includes a third end close to one side of the first long finger electrode and a fourth end away from one side of the first long finger electrode;

[0014] An orthographic projection of at least a portion of the first load structure on the piezoelectric substrate overlaps with an orthographic projection of the third end on the piezoelectric substrate.

[0015] Preferably, the IDT further comprises a bus bar, and the bus bar comprises a first bus bar and a second bus bar;

[0016] 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;

[0017] The second end of the first long finger electrode is connected to the first bus bar;

[0018] The fourth end of the second long finger electrode is connected to the second bus bar.

[0019] Preferably, the first long finger electrode and the second long finger electrode have the same length extending along the second direction.

[0020] Preferably, the widths of the first long finger electrodes and the second long finger electrodes along the first direction are equal.

[0021] Preferably, the temperature-compensated surface acoustic wave resonator further comprises a temperature compensation layer;

[0022] The temperature compensation layer is arranged on a side of the interdigital transducer away from the piezoelectric substrate.

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

[0024] The metal connection thickening layer is arranged on a side of the bus bar away from the piezoelectric substrate.

[0025] 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.

[0026] In a third aspect, the present application also provides a method for manufacturing a temperature compensated surface acoustic wave resonator, comprising:

[0027] providing a piezoelectric substrate;

[0028] Fabricating an interdigital transducer on one side surface of the piezoelectric substrate;

[0029] The interdigital transducer comprises a bus bar and a plurality of long finger electrodes, wherein the long finger electrodes comprise 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 a first direction; the first long finger electrode and the second long finger electrode are arranged crosswise along the first direction; the widths of the long finger electrodes along the first direction are equal;

[0030] Making an insulating layer on the surface of the long finger electrode away from the piezoelectric substrate;

[0031] Fabricating a first load structure on a surface of the insulating layer away from the piezoelectric substrate;

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

[0033] 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 layer, the first load structure, the second load structure, the IDT and the piezoelectric substrate;

[0034] Making a metal connection thickening layer on the surface of the bus bar on one side away from the piezoelectric substrate;

[0035] The first direction intersects the second direction.

[0036] In a fourth aspect, the present application also provides a method for manufacturing a temperature compensated surface acoustic wave resonator, comprising:

[0037] providing a piezoelectric substrate;

[0038] 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;

[0039] A first load structure and a second load structure are respectively manufactured 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;

[0040] An insulating layer is formed on a surface of the first load structure away from the piezoelectric substrate; the thickness of the insulating layer is equal to the difference between the depth of the first groove structure and the depth of the second groove structure;

[0041] Fabricating an interdigital transducer on a surface of the piezoelectric substrate on one side close to the first groove structure;

[0042] The interdigital transducer comprises a bus bar and a plurality of long finger electrodes, wherein the long finger electrodes comprise 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 a first direction; the first long finger electrode and the second long finger electrode are arranged crosswise along the first direction; the widths of the long finger electrodes along the first direction are equal;

[0043] 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;

[0044] Making a metal connection thickening layer on the surface of the bus bar on one side away from the piezoelectric substrate;

[0045] The first direction intersects the second direction.

[0046] In a fifth aspect, the present application also provides a method for manufacturing a temperature compensated surface acoustic wave resonator, comprising:

[0047] providing a piezoelectric substrate;

[0048] 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;

[0049] A first load structure and a second load structure are respectively manufactured 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;

[0050] Making an insulating layer on the surface of the first load structure;

[0051] An interdigital transducer is fabricated on a surface of the piezoelectric substrate close to the first groove structure; the interdigital transducer covers at least a portion of the surface of the first load structure and the insulating layer;

[0052] The interdigital transducer comprises a bus bar and a plurality of long finger electrodes, wherein the long finger electrodes comprise 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 a first direction; the first long finger electrode and the second long finger electrode are arranged crosswise along the first direction; the widths of the long finger electrodes along the first direction are equal;

[0053] 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, the insulating layer and the piezoelectric substrate;

[0054] Making a metal connection thickening layer on the surface of the bus bar on one side away from the piezoelectric substrate;

[0055] The first direction intersects the second direction.

[0056] In a sixth aspect, the present application further provides a method for manufacturing a temperature compensated surface acoustic wave resonator, comprising:

[0057] providing a piezoelectric substrate;

[0058] Fabricating a first load structure and a second load structure on one side surface of the piezoelectric substrate;

[0059] Making an insulating layer on a surface of the first load structure away from the piezoelectric substrate;

[0060] 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 layer;

[0061] The interdigital transducer comprises a bus bar and a plurality of long finger electrodes, wherein the long finger electrodes comprise 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 a first direction; the first long finger electrode and the second long finger electrode are arranged crosswise along the first direction; the widths of the long finger electrodes along the first direction are equal;

[0062] 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 layer, the first load structure and at least a portion of the surface of the piezoelectric substrate;

[0063] Making a metal connection thickening layer on the surface of the bus bar on one side away from the piezoelectric substrate;

[0064] The first direction intersects the second direction.

[0065] 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 a side surface of the piezoelectric substrate, the interdigital transducer includes a plurality of long finger electrodes, 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 cross-arranged, 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 a side of the insulating structure away from the long finger electrode; the second load structure is arranged on a 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. The present invention can increase the force of the long finger electrode on the piezoelectric substrate by setting the first load structure and the second load structure, 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 set is smaller than the sound speed of the area where the first load structure and the second load structure are not set, thereby suppressing the lateral mode and improving the Q value of the temperature compensated surface acoustic wave resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] 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 paying any creative work.

[0067] Figure 1 is a cross-sectional view of a temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0068] Figure 2 is a cross-sectional view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0069] Figure 3 is a cross-sectional view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0070] Figure 4 is a cross-sectional view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0071] Figure 5is a top view of a temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0072] Figure 6 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0073] Figure 7 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0074] Figure 8 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0075] Fig. 9 is a top view of another temperature-compensated surface acoustic wave resonator provided in an embodiment of the present application;

[0076] Fig.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 the temperature compensated surface acoustic wave resonator in the prior art. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0078] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0079] 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.

[0080] Exemplarily, the material of the piezoelectric substrate 1 may be lithium niobate or lithium tantalate.

[0081] 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 cross-arranged 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.

[0082] The insulating structure 5 is disposed on one side of the long finger electrode 21; it can be understood that Figure 1 As shown, the insulating structure 5 may also be arranged on a 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 the adjacent long finger electrodes 21 from short circuiting or interference.

[0083] like Figures 1 to 9 As shown, the 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 first load structure 3 on the piezoelectric substrate 1 overlaps at least partially with the orthographic projection of at least one of the long finger electrodes 21 on the piezoelectric substrate 1; it can be understood that Figures 2 to 4 As shown, the first load structure 3 can be arranged 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 disposed on a surface of the long finger electrode 21 away from the piezoelectric substrate 1. Exemplarily, 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 metal material or metal oxide material.

[0084] like Figures 1 to 9As shown, the second load structure 4 is arranged 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 can be understood that the second load structure 4 can be arranged on the side surface of the long finger electrode 21 close to the piezoelectric substrate 1, and can also be arranged on the side surface 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 the material of the long finger electrode 21, and the second load structure 4 can be made of metal material or metal oxide material.

[0085] It should be noted that the embodiment of the present invention does not limit the number, area and shape of the first load structure 3 and the second load structure 4, so that on the one hand, the suppression of the lateral mode can be enhanced, and on the other hand, the temperature compensation type surface acoustic wave filter can be diversified. For the convenience of illustration, the embodiment of the present invention sets the shape of the first load structure 3 and the second load structure 4 to be rectangular. Exemplarily, the shape of the first load structure 3 and the second load structure 4 can also be circular, trapezoidal, regularly shaped polygons or irregular polygons, etc. The embodiment of the present invention does not specifically limit the shape of the first load structure 3 and the second load structure 4.

[0086] By setting the first load structure 3 and the second load structure 4, the force of 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 set is smaller than the sound speed of the area where the first load structure 3 and the second load structure 4 are not set, thereby suppressing the lateral mode and improving the Q value of the temperature compensated surface acoustic wave resonator.

[0087] 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;

[0088] like Figures 5 to 9As shown, at least part of the orthographic projection of the second load structure 4 on the piezoelectric substrate 1 overlaps with the orthographic projection of the first end on the piezoelectric substrate 1; at least part of the orthographic projection of the first load structure 3 on the piezoelectric substrate 1 overlaps with the orthographic projection of the third end on the piezoelectric substrate 1. It can be understood that the minimum overlapping area of ​​the orthographic projection of the first load structure 3 on the piezoelectric substrate 1 and the orthographic projection of the first long finger electrode 211 on the piezoelectric substrate 1 is the area of ​​the first end. Similarly, the minimum overlapping area of ​​the orthographic projection of the second load structure 4 on the piezoelectric substrate 1 and the orthographic projection of the second long finger electrode 212 on the piezoelectric substrate 1 is the area of ​​the third end. The first load structure 3 and the second load structure 4 are simple to set and have a large degree of freedom and are flexible to set.

[0089] 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 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.

[0090] Preferably, the IDT 2 further comprises a bus bar 22, and the bus bar 22 comprises 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;

[0091] 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;

[0092] The second end of the first long finger electrode 211 is connected to the first bus bar 221;

[0093] The fourth end of the second long finger electrode 212 is connected to the second bus bar 222 .

[0094] Preferably, the first long finger electrode 211 and the second long finger electrode 212 have the same length extending along the second direction Y, which simplifies the arrangement and enhances the suppression of the lateral mode.

[0095] Preferably, the widths of the first long finger electrodes 211 and the second long finger electrodes 212 along the first direction X are equal, which simplifies the arrangement and enhances the suppression of the lateral mode.

[0096] Preferably, the temperature compensated surface acoustic wave resonator further comprises 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 silicon-containing dielectric films such as silicon nitride. The provision of the temperature compensation layer 6 can avoid the influence of temperature changes on the resonant frequency of the temperature compensated surface acoustic wave resonator, and improve 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.

[0097] Preferably, the temperature-compensated surface acoustic wave resonator further comprises a metal connection thickening layer 7; the metal connection thickening layer 7 is arranged on the side of the bus bar 22 away from the piezoelectric substrate 1. Exemplarily, the material of the metal connection thickening layer 7 can be titanium, aluminum, copper, gold or silver. The arrangement of the metal connection thickening layer 7 can play a role in heat dissipation, and at the same time can reduce electrical loss and improve the quality factor of the resonator.

[0098] 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.

[0099] 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:

[0100] Providing a piezoelectric substrate 1;

[0101] An interdigital transducer 2 is fabricated on one side surface of the piezoelectric substrate 1;

[0102] The interdigital transducer 2 includes a bus bar 22 and a plurality of long finger electrodes 21, wherein 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 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 first direction X; the widths of the long finger electrodes 21 along the first direction X are equal;

[0103] An insulating layer 5 is formed on the surface of the long finger electrode 21 which is away from the piezoelectric substrate 1;

[0104] A first load structure 3 is fabricated on a surface of the insulating layer 5 which is away from the piezoelectric substrate 1;

[0105] A second load structure 4 is fabricated on a surface of the long finger electrode 21 which is away from the piezoelectric substrate 1;

[0106] 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 layer 5, the first load structure 3, the second load structure 4, the IDT 2 and the piezoelectric substrate 1;

[0107] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 which is away from the piezoelectric substrate 1;

[0108] The first direction X and the second direction Y intersect.

[0109] The manufacturing method described in this embodiment can be used to manufacture the temperature-compensated surface acoustic wave resonator described in the above embodiment. The manufacturing method can increase the force of the long finger electrode 21 on the piezoelectric substrate 1 by setting the first load structure 3 and the second load structure 4, 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 set is smaller than the sound speed of the area where the first load structure 3 and the second load structure 4 are not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0110] 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:

[0111] Providing a piezoelectric substrate 1;

[0112] Etching the piezoelectric substrate 1 to form a first groove structure 11 and a second groove structure 12; the depth of the first groove structure 11 is greater than the depth of the second groove structure 12;

[0113] A first load structure 3 and a second load structure 4 are respectively manufactured in the first groove structure 11 and the second groove structure 12; the thickness of the second load structure 4 is equal to the depth of the second groove structure 12;

[0114] An insulating layer 5 is formed on the surface of the first load structure 3 which is away from the piezoelectric substrate 1; the thickness of the insulating layer 5 is equal to the difference between the depth of the first groove structure 11 and the depth of the second groove structure 12;

[0115] An interdigital transducer 2 is fabricated on a surface of the piezoelectric substrate 1 on one side close to the first groove structure 11;

[0116] The interdigital transducer 2 includes a bus bar 22 and a plurality of long finger electrodes 21, wherein 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 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 first direction X; the widths of the long finger electrodes 21 along the first direction X are equal;

[0117] A temperature compensation layer 6 is formed on a surface of the IDT 2 which is away from the piezoelectric substrate 1, and the temperature compensation layer 6 covers at least a portion of the surface of the IDT 2 and the piezoelectric substrate 1;

[0118] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 which is away from the piezoelectric substrate 1;

[0119] The first direction X and the second direction Y intersect.

[0120] The manufacturing method described in this embodiment can be used to manufacture the temperature-compensated surface acoustic wave resonator described in the above embodiment. The manufacturing method can increase the force of the long finger electrode 21 on the piezoelectric substrate 1 by setting the first load structure 3 and the second load structure 4, 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 set is smaller than the sound speed of the area where the first load structure 3 and the second load structure 4 are not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0121] like Figure 3 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:

[0122] Providing a piezoelectric substrate 1;

[0123] Etching the piezoelectric substrate 1 to form a first groove structure 11 and a second groove structure 12; the depth of the first groove structure 11 is equal to the depth of the second groove structure 12;

[0124] A first load structure 3 and a second load structure 4 are respectively manufactured in the first groove structure 11 and the second groove structure 12; the thickness of the first load structure 3 is equal to the depth of the first groove structure 11; the thickness of the second load structure 4 is equal to the depth of the second groove structure 12;

[0125] Making an insulating layer 5 on the surface of the first load structure 3;

[0126] An IDT 2 is fabricated on a surface of the piezoelectric substrate 1 close to the first groove structure 11; the IDT 2 covers at least a portion of the surface of the first load structure 3 and the insulating layer 5;

[0127] The interdigital transducer 2 includes a bus bar 22 and a plurality of long finger electrodes 21, wherein 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 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 first direction X; the widths of the long finger electrodes 21 along the first direction X are equal;

[0128] A temperature compensation layer 6 is formed on a surface of the IDT 2 which is away from the piezoelectric substrate 1, and the temperature compensation layer 6 covers at least a part of the surface of the IDT 2, the insulating layer 5 and the piezoelectric substrate 1;

[0129] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 which is away from the piezoelectric substrate 1;

[0130] The first direction X and the second direction Y intersect.

[0131] The manufacturing method described in this embodiment can be used to manufacture the temperature-compensated surface acoustic wave resonator described in the above embodiment. The manufacturing method can increase the force of the long finger electrode 21 on the piezoelectric substrate 1 by setting the first load structure 3 and the second load structure 4, 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 set is smaller than the sound speed of the area where the first load structure 3 and the second load structure 4 are not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0132] like Figure 4As 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:

[0133] Providing a piezoelectric substrate 1;

[0134] A first load structure 3 and a second load structure 4 are fabricated on one side surface of the piezoelectric substrate 1;

[0135] An insulating layer 5 is formed on a surface of the first load structure 3 on a side away from the piezoelectric substrate 1;

[0136] An IDT 2 is fabricated on a surface of the piezoelectric substrate 1 close to the first load structure 3; the IDT 2 covers at least a portion of the surface of the first load structure 3, the second load structure 4 and the insulating layer 5;

[0137] The interdigital transducer 2 includes a bus bar 22 and a plurality of long finger electrodes 21, wherein 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 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 first direction X; the widths of the long finger electrodes 21 along the first direction X are equal;

[0138] 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, the insulating layer 5, the first load structure 3 and the piezoelectric substrate 1;

[0139] A metal connection thickening layer 7 is formed on the surface of the bus bar 22 which is away from the piezoelectric substrate 1;

[0140] The first direction X and the second direction Y intersect.

[0141] The manufacturing method described in this embodiment can be used to manufacture the temperature-compensated surface acoustic wave resonator described in the above embodiment. The manufacturing method can increase the force of the long finger electrode 21 on the piezoelectric substrate 1 by setting the first load structure 3 and the second load structure 4, 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 set is smaller than the sound speed of the area where the first load structure 3 and the second load structure 4 are not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator.

[0142] Fig.10The 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. Fig.10 , Fig.10 The horizontal axis in represents the frequency, Fig.10 The ordinate 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 peaks in the red and blue curves are the resonance points, and the right peaks are the anti-resonance points. Fig.10 It can be seen that the admittance curve of the temperature compensated surface acoustic wave resonator provided by the prior art has obvious lateral mode noise between the resonance point and the anti-resonance 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 anti-resonance point, and the lateral mode suppression effect is obvious.

[0143] 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 arranged 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); 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 an orthographic projection of the first load structure (3) on the piezoelectric substrate (1) at least partially overlaps with an orthographic projection of at least one of the long finger electrodes (21) on the piezoelectric substrate (1); at least one second load structure (4) is arranged on a side of the long finger electrode (21) having the insulating structure (5), and an orthographic projection of the second load structure (4) on the piezoelectric substrate (1) at least partially overlaps with an orthographic projection of at least one of the long finger electrodes (21) on the piezoelectric substrate (1); The first direction (X) intersects with the second direction (Y).

2. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Along the second direction (Y), the first long finger electrode (211) comprises a first end portion close to a side of the second long finger electrode (212) and a second end portion away from a side of the second long finger electrode (212); The orthographic projection of at least part of the second load structure (4) on the piezoelectric substrate (1) overlaps with the orthographic projection of the first end on the piezoelectric substrate (1); 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); An orthographic projection of at least part of the first load structure (3) on the piezoelectric substrate (1) overlaps with an orthographic projection of the third end on the piezoelectric substrate (1).

3. The temperature-compensated surface acoustic wave resonator according to claim 2, characterized in that: The interdigital transducer (2) further comprises a bus bar (22), wherein the bus bar (22) comprises 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).

4. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The first long finger electrode (211) and the second long finger electrode (212) have the same length extending along the second direction (Y).

5. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The widths of the first long finger electrode (211) and the second long finger electrode (212) along the first direction (X) are equal.

6. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: 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).

7. The temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: It 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).

8. A temperature compensation filter, characterized in that: The invention comprises the temperature-compensated surface acoustic wave resonator according to any one of claims 1 to 7.

9. 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 crosswise along the first direction (X); the widths of the long finger electrodes (21) along the first direction (X) are equal; An insulating layer (5) is formed on the surface of the long finger electrode (21) which is away from the piezoelectric substrate (1); A first load structure (3) is fabricated on a surface of the insulating layer (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 layer (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) on the side away from the piezoelectric substrate (1); The first direction (X) intersects with the second direction (Y).

10. 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 (11) and a second groove structure (12); the depth of the first groove structure (11) is greater than the depth of the second groove structure (12); A first load structure (3) and a second load structure (4) are respectively manufactured in the first groove structure (11) and the second groove structure (12); the thickness of the second load structure (4) is equal to the depth of the second groove structure (12); An insulating layer (5) is formed on a surface of the first load structure (3) that is away from the piezoelectric substrate (1); the thickness of the insulating layer (5) is equal to the difference between the depth of the first groove structure (11) and the depth of the second groove structure (12); An interdigital transducer (2) is fabricated on a surface of the piezoelectric substrate (1) on one side close to the first groove structure (11); 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 crosswise 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) that is 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) on the side away from the piezoelectric substrate (1); The first direction (X) intersects with 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 (11) and a second groove structure (12); the depth of the first groove structure (11) is equal to the depth of the second groove structure (12); A first load structure (3) and a second load structure (4) are respectively manufactured in the first groove structure (11) and the second groove structure (12); the thickness of the first load structure (3) is equal to the depth of the first groove structure (11); and the thickness of the second load structure (4) is equal to the depth of the second groove structure (12); Producing an insulating layer (5) on the surface of the first load structure (3); An interdigital transducer (2) is fabricated on a surface of the piezoelectric substrate (1) close to the first groove structure (11); the interdigital transducer (2) covers at least a portion of the surface of the first load structure (3) and the insulating layer (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 crosswise 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) that is 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 layer (5) and the piezoelectric substrate (1); A metal connection thickening layer (7) is formed on the surface of the bus bar (22) on the side away from the piezoelectric substrate (1); The first direction (X) intersects with 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); A first load structure (3) and a second load structure (4) are fabricated on one side surface of the piezoelectric substrate (1); An insulating layer (5) is formed 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 layer (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 crosswise 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 layer (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) on the side away from the piezoelectric substrate (1); The first direction (X) intersects with the second direction (Y).

Images