A method for manufacturing a temperature-compensated surface acoustic wave resonator

Abstract

The present application provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, including: providing a substrate; manufacturing an interdigital transducer on one side of the substrate; the interdigital transducer includes a bus bar and a plurality of long finger electrodes; manufacturing a first load structure on a side of the long finger electrode away from the substrate; manufacturing a second load structure on a side of the first load structure away from the long finger electrode; etching the second load structure to form at least one hollow area and metal wires around it; manufacturing a temperature compensation layer on a side of the interdigital transducer away from the long finger electrode. By setting the first load structure, the present application can change the propagation speed of the surface acoustic wave, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator. By setting the second load structure including at least one hollow area, the present application increases the heat conduction channel, which can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance of the filter.

Description

Technical Field

[0001] The present application relates to the technical field of surface acoustic wave resonators, and in particular to a method for manufacturing a temperature compensated surface acoustic wave resonator. Background Art

[0002] Surface acoustic wave (SAW) is a mechanical wave that processes electrical signals by propagating on the surface of a crystal. SAW filters use the characteristics of this acoustic wave to achieve signal filtering. However, temperature changes can affect the performance of SAW filters, resulting in frequency drift and unstable performance.

[0003] To solve this problem, the Temperature Compensated Surface Acoustic Wave Filter (TC-SAW) uses special design and technology to maintain stable performance at different temperatures. It usually includes a temperature sensor and compensation circuit to monitor and adjust the operating temperature of the filter to achieve temperature compensation.

[0004] Temperature-compensated surface acoustic wave filters are widely used in wireless communication devices due to their superior temperature stability, such as mobile phones, satellite communications, radars, etc. With the requirement of miniaturization, the reduction in the size of the filter has limited the area of ​​the resonator, and the reduction in size has also reduced the power handling capacity. Therefore, there is an urgent need for a temperature-compensated surface acoustic wave filter that can not only meet the miniaturization requirements of the filter but also improve the power handling capacity. Summary of the invention

[0005] The present application provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, which is used to solve the problem of reduced power handling capability caused by reducing the size of the filter.

[0006] The present application provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0007] Providing a substrate; the substrate is a piezoelectric substrate, and the material used includes lithium niobate or lithium tantalate;

[0008] An interdigital transducer is fabricated on one side surface of the substrate; the interdigital transducer comprises a bus bar and a plurality of long finger electrodes; the long finger electrodes comprise a first long finger electrode and a second long finger electrode arranged crosswise along a first direction; 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 bus bar comprises a first bus bar and a second bus bar arranged opposite to each other along the second direction; the material used for the long finger electrodes comprises any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, aluminum and a combination thereof;

[0009] A first load structure is fabricated on a side of the long finger electrode away from the substrate; an orthographic projection of the first load structure on the substrate at least partially overlaps with an orthographic projection of the long finger electrode on the substrate; a material used for the first load structure includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, and aluminum, and a combination thereof;

[0010] A second load structure is fabricated on a side of the first load structure away from the long finger electrode; the orthographic projection of the second load structure on the substrate at least partially overlaps with the orthographic projection of the long finger electrode on the substrate; the material used for the second load structure includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, aluminum and a combination thereof;

[0011] Etching the second load structure to form at least one hollow area and metal lines around it;

[0012] A temperature compensation layer is formed on a surface of the IDT away from the long finger electrode; the temperature compensation layer covers the first load structure, the second load structure, the IDT and at least a portion of the surface of the substrate; the temperature compensation layer is made of silicon dioxide and silicon nitride;

[0013] The first direction intersects the second direction.

[0014] Preferably, before manufacturing the first load structure on the side of the long finger electrode away from the substrate, the following steps are included: along the first direction, a reflection grating area is manufactured on both sides of the long finger electrode, the reflection grating area includes a plurality of reflection gratings, the reflection gratings extend along the second direction, and the plurality of reflection gratings are arranged along the first direction.

[0015] Preferably, before manufacturing the first load structure on the side of the long finger electrode away from the substrate, the method further comprises the following steps: depositing a first insulating dielectric layer, wherein the first insulating dielectric layer covers the interdigital transducer and at least a portion of the surface of the substrate.

[0016] Preferably, after manufacturing the temperature compensation layer on the surface of the IDT away from the long finger electrode, the following steps are included: performing chemical mechanical polishing (CMP) on the temperature compensation layer to flatten it, remove uneven surface materials, and achieve atomic-level flatness.

[0017] Preferably, after manufacturing the temperature compensation layer on the surface of the IDT away from the long finger electrodes, the method further comprises the following steps: depositing a second insulating dielectric layer, wherein the second insulating dielectric layer covers the temperature compensation layer.

[0018] Preferably, after the temperature compensation layer is produced on the surface of the side of the interdigital transducer away from the long finger electrode, the following steps are also included: etching the first insulating dielectric layer, the second insulating dielectric layer and the temperature compensation layer to expose the first bus bar and the second bus bar to form a first interdigital through hole and a second interdigital through hole, respectively.

[0019] Preferably, after forming the first interdigitated through hole and the second interdigitated through hole respectively, the following steps are also included: making a first PAD metal layer and a second PAD metal layer, the first PAD metal layer and the second PAD metal layer are connected to the first bus bar and the second bus bar through the first interdigitated through hole and the second interdigitated through hole respectively.

[0020] Preferably, after manufacturing the temperature compensation layer on the surface of the IDT away from the long finger electrodes, the method further comprises the following steps: depositing a passivation layer to protect the first PAD metal layer and the second PAD metal layer.

[0021] Preferably, the shape of the hollow area includes a circle and a polygon.

[0022] Preferably, the maximum size of the hollow area along the first direction is a first size M, and the value range of the first size M is: λ≤M≤2λ; the maximum size of the hollow area along the second direction is a second size N, and the value range of the second size N is: 0.5λ≤N≤λ.

[0023] Preferably, the line width of the metal line is a third dimension Q, and the value range of the third dimension Q is: 0.5λ≤Q≤λ.

[0024] Preferably, the distance between the first load structure and the second load structure along the thickness direction is a first spacing L, and the value range of the first spacing L is: 0≤L≤λ, wherein λ is the wavelength of the surface acoustic wave.

[0025] Preferably, along the first direction, the size of the second load structure is greater than or equal to the size of the effective aperture area; along the second direction, the size of the second load structure is greater than or equal to the size of the effective aperture area.

[0026] Preferably, the first long finger electrode and the second long finger electrode have the same length extending along the second direction.

[0027] Preferably, the process for manufacturing the IDT includes coating, exposure, development, evaporation, and demoulding and peeling (commonly referred to as lift-off in the art).

[0028] The manufacturing method of the temperature-compensated surface acoustic wave resonator provided by the present application includes: providing a substrate; manufacturing an interdigital transducer on one side of the substrate; the interdigital transducer includes a bus bar and a plurality of long finger electrodes; manufacturing a first load structure on the side of the long finger electrode away from the substrate; manufacturing a second load structure on the side of the first load structure away from the long finger electrode; etching the second load structure to form at least one hollow area and metal wires around it; manufacturing a temperature compensation layer on the side of the interdigital transducer away from the long finger electrode. By setting the first load structure, the present application can increase the force of 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 is set is less than the sound speed of the area where the first load structure is not set, thereby suppressing the lateral mode and improving the Q value of the temperature-compensated surface acoustic wave resonator. By setting the second load structure including at least one hollow area, the present application increases the heat conduction channel, which can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1 is a top view of the temperature-compensated surface acoustic wave resonator provided in Example 1 of the present application;

[0031] Figure 2 is a top view of a temperature-compensated surface acoustic wave resonator provided in Example 2 of the present application;

[0032] Figure 3 is a top view of a temperature-compensated surface acoustic wave resonator provided in Embodiment 3 of the present application;

[0033] Figure 4 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 1 ;

[0034] Figure 5 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 2 ;

[0035] Figure 6 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 3 ;

[0036] Figure 7 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 4 ;

[0037] Figure 8 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 5 ;

[0038] Fig. 9 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 6 ;

[0039] Fig.10 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 7 ;

[0040] Fig.11 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 8 ;

[0041] Fig.12 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 9 ;

[0042] Fig.13 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 10 ;

[0043] Fig.14 The cross-sectional view of a resonator manufactured by the method for manufacturing a temperature-compensated surface acoustic wave resonator provided in the second embodiment of the present application Figure 10 one.

[0044] Explanation of symbols:

[0045] 1. Substrate; 2. Interdigital transducer; 21. Long finger electrode; 211. First long finger electrode; 212. Second long finger electrode; 22. Bus bar; 221. First bus bar; 222. Second bus bar; 3. First load structure; 4. Second load structure; 41. Hollow area; 42. Metal wire; 5. Reflective grid area; 6. Temperature compensation layer; 7. First insulating dielectric layer; 8. Second insulating dielectric layer; 91. First interdigital through hole; 92. Second interdigital through hole; 101. First PAD metal layer; 102. Second PAD metal layer; 11. Passivation layer; L. First spacing; M. First size; N. Second size; Q. Third size; X. First direction; Y. Second direction. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] The present application provides a method for manufacturing a temperature-compensated surface acoustic wave resonator, comprising:

[0049] like Figure 4 As shown, a substrate 1 is provided; the substrate 1 is a piezoelectric substrate 1, and the material used includes lithium niobate or lithium tantalate;

[0050] like Figure 5 As shown, an IDT 2 is fabricated on one side surface of the substrate 1; the IDT 2 comprises a bus bar 22 and a plurality of long finger electrodes 21; the long finger electrodes 21 comprise a first long finger electrode 211 and a second long finger electrode 212 arranged crosswise along a first direction X; the first long finger electrode 211 and the second long finger electrode 212 both extend along a second direction Y and are arranged along the first direction X; the bus bar 22 comprises a first bus bar 221 and a second bus bar 222 arranged opposite to each other along the second direction Y; the material used for the long finger electrodes 21 comprises any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, and aluminum, and a combination thereof;

[0051] Preferably, along the first direction X, a reflection grating region 5 is formed on both sides of the long finger electrode 21, and the reflection grating region 5 includes a plurality of reflection gratings, the reflection gratings extend along the second direction Y, and the plurality of reflection gratings are arranged along the first direction X. The reflection gratings can be used to reflect surface acoustic waves to prevent surface acoustic waves from leaking, and adding reflection gratings can enhance the selectivity of the filter, expand the bandwidth of the filter, reduce the size of the filter, and improve the stability of the filter;

[0052] like Figure 6As shown, preferably, a first insulating dielectric layer 7 is deposited, and the first insulating dielectric layer 7 covers the IDT 2 and at least a portion of the surface of the substrate 1. The first insulating dielectric layer 7 is made of insulating material, and illustratively, the first insulating dielectric layer 7 can be made of silicon nitride, aluminum nitride, gallium nitride, or amorphous silicon. The first insulating dielectric layer 7 plays an insulating role and is used to protect the IDT 2 and prevent the IDT 2 from being oxidized;

[0053] like Figure 7 As shown, a first load structure 3 is made on a side of the long finger electrode 21 away from the substrate 1; the orthographic projection of the first load structure 3 on the substrate 1 at least partially overlaps with the orthographic projection of the long finger electrode 21 on the substrate 1; the material used for the first load structure 3 includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, and aluminum, and a combination thereof; by setting the first load structure 3, the present application can increase the force of the long finger electrode 21 on the piezoelectric substrate 1, 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 is set is less than the sound speed of the area where the first load structure 3 is not set, thereby suppressing the lateral mode and improving the Q value of the temperature compensated surface acoustic wave resonator;

[0054] like Figure 8 As shown, a second load structure 4 is fabricated on a side of the first load structure 3 away from the long finger electrode 21; the orthographic projection of the second load structure 4 on the substrate 1 at least partially overlaps with the orthographic projection of the long finger electrode 21 on the substrate 1; the material used for the second load structure 4 includes any one of titanium, chromium, silver, copper, molybdenum, platinum, tungsten, aluminum and a combination thereof;

[0055] like Fig. 9 As shown, the second load structure 4 is etched to form at least one hollow area 41 and a metal wire 42 around it; the present application increases the heat conduction channel by providing the second load structure 4 including at least one hollow area 41, and can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter;

[0056] like Fig.10As shown, a temperature compensation layer 6 is made on the surface of the side of the interdigital transducer 2 away from the long finger electrode 21; the temperature compensation layer 6 covers the first load structure 3, the second load structure 4, the interdigital transducer 2 and at least a portion of the surface of the substrate 1; illustratively, the material of the temperature compensation layer 6 can be silicon dioxide or 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;

[0057] Preferably, the temperature compensation layer 6 is flattened by CMP to remove uneven surface materials, achieve atomic-level flatness, improve the performance and reliability of the filter, and improve the manufacturing yield;

[0058] like Fig.11 As shown, preferably, a second insulating dielectric layer 8 is deposited, and the second insulating dielectric layer 8 covers the temperature compensation layer 6. The second insulating dielectric layer 8 is made of insulating material. For example, the first insulating dielectric layer 7 can use silicon nitride, aluminum nitride, gallium nitride, or amorphous silicon. The second insulating dielectric layer 8 plays an insulating role and is used to prevent the first load structure 3 from being oxidized;

[0059] like Fig.12 As shown, preferably, the first insulating dielectric layer 7, the second insulating dielectric layer 8 and the temperature compensation layer 6 are etched to expose the first bus bar 221 and the second bus bar 222, and form a first interdigital through hole 91 and a second interdigital through hole 92 respectively;

[0060] like Fig.13 As shown, preferably, a first PAD metal layer 101 and a second PAD metal layer 102 are manufactured, and the first PAD metal layer 101 and the second PAD metal layer 102 are connected to the first bus bar 221 and the second bus bar 222 through the first interdigital through hole 91 and the second interdigital through hole 92, respectively. The first PAD metal layer 101 and the second PAD metal layer 102 are used for electrical connection. Exemplarily, the first PAD metal layer 101 and the second PAD metal layer 102 can be made of at least one of titanium, chromium, aluminum, copper, nickel, silver, and gold;

[0061] like Fig.14 As shown, preferably, a passivation layer 11 is deposited to protect the first PAD metal layer 101 and the second PAD metal layer 102. Exemplarily, the passivation layer 11 may be made of insulating materials with high density such as silicon nitride or aluminum nitride that can isolate oxygen and air;

[0062] The first direction X and the second direction Y intersect.

[0063] Preferably, the shape of the hollow area 41 includes a circle and a polygon. Figure 1 As shown, in the first embodiment, the second load structure 4 is surrounded by a closed rectangle, and a hollow area 41 is formed inside the rectangle. The routing of the hollow area 41 intersects with the multiple long finger electrodes 21 of the interdigital transducer 2, and is neither perpendicular nor parallel, and the shape of the hollow area 41 is divided into a triangle and a rhombus. Among them, the part where the hollow area 41 is connected to the edge of the rectangle is cut by the edge of the rectangle to form a triangle. Figure 2 As shown, in the second embodiment, the routing of the hollow area 41 is parallel or perpendicular to the multiple long finger electrodes 21 of the interdigital transducer 2, and the hollow area 41 is divided into multiple rectangular hollow areas 41. Figure 3 As shown, in the third embodiment, the routing of the hollow area 41 is divided into a plurality of sub-rectangles along the width direction, and the configuration inside each sub-rectangle is a bent shape, dividing the sub-rectangle into a plurality of triangular hollow areas 41. Exemplarily, the shape of the hollow area 41 can also be a circle, an ellipse, a regular polygon or an irregular polygon. It is understandable that, as Figures 1 to 3 The embodiments shown are only some of the embodiments shown in the present invention, and are not intended to limit the present invention. It should be noted that the embodiments of the present invention do not limit the number, area, and shape of the hollow regions 41, which can enhance the power handling capability of the filter on the one hand, and can diversify the settings of the temperature-compensated surface acoustic wave filter on the other hand.

[0064] Preferably, the maximum size of the hollow area 41 along the first direction X is a first size M, and the value range of the first size M is: λ≤M≤2λ; the maximum size of the hollow area 41 along the second direction Y is a second size N, and the value range of the second size N is: 0.5λ≤N≤λ. This setting increases the heat conduction channel, can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0065] Preferably, the width of the metal wire 42 is a third dimension Q, and the value range of the third dimension Q is: 0.5λ≤Q≤λ. This configuration increases the heat conduction channel, and can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance of the filter.

[0066] Preferably, the distance between the first load structure 3 and the second load structure 4 along the thickness direction is a first spacing L, and the value range of the first spacing L is: 0≤L≤λ, wherein λ is the wavelength of the surface acoustic wave.

[0067] Preferably, along the first direction X, the size of the second load structure 4 is greater than or equal to the size of the effective aperture area; along the second direction Y, the size of the second load structure 4 is greater than or equal to the size of the effective aperture area. This arrangement increases the heat conduction channel, and can improve the heat dissipation capacity of the resonator under the premise of miniaturization, thereby improving the power resistance capacity of the filter.

[0068] Preferably, the first long finger electrode 211 and the second long finger electrode 212 have the same length extending along the second direction Y. This simplifies the arrangement so that the overall structure has symmetry and consistency, and is easy to design and maintain. It can also further enhance the suppression of lateral modes.

[0069] Preferably, the process for manufacturing the IDT 2 includes coating, exposure, development, evaporation, and demoulding.

[0070] 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 method for manufacturing a temperature-compensated surface acoustic wave resonator, characterized in that: include: providing a substrate; An interdigital transducer is fabricated on one side surface of the substrate; the interdigital transducer comprises a bus bar and a plurality of long finger electrodes; the long finger electrodes comprise a first long finger electrode and a second long finger electrode arranged crosswise along a first direction; 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 bus bar comprises a first bus bar and a second bus bar arranged opposite to each other along the second direction; A first load structure is fabricated on a side of the long finger electrode away from the substrate; an orthographic projection of the first load structure on the substrate at least partially overlaps with an orthographic projection of the long finger electrode on the substrate; A second load structure is fabricated on a side of the first load structure away from the long finger electrode; an orthographic projection of the second load structure on the substrate at least partially overlaps with an orthographic projection of the long finger electrode on the substrate; Etching the second load structure to form at least one hollow region and metal wires around it, so as to increase the heat conduction channel of the temperature-compensated surface acoustic wave resonator; A temperature compensation layer is formed on a surface of the IDT away from the long finger electrode; the temperature compensation layer covers the first load structure, the second load structure, the IDT and at least a portion of the surface of the substrate; The first direction intersects the second direction.

2. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Before manufacturing the first load structure on the side of the long finger electrode away from the substrate, the following steps are included: Along the first direction, a reflection grating region is formed on both sides of the long finger electrode, the reflection grating region includes a plurality of reflection gratings, the reflection gratings extend along the second direction, and the plurality of reflection gratings are arranged along the first direction.

3. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Before manufacturing the first load structure on the side of the long finger electrode away from the substrate, the method further includes the following steps: A first insulating dielectric layer is deposited, wherein the first insulating dielectric layer covers the IDT and at least a portion of the surface of the substrate.

4. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: After the temperature compensation layer is formed on the surface of the interdigital transducer away from the long finger electrode, the following steps are included: The temperature compensation layer is flattened by CMP to remove uneven surface materials and achieve atomic-level flatness.

5. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 3, characterized in that: After the temperature compensation layer is formed on the surface of the IDT away from the long finger electrode, the following steps are also included: A second insulating dielectric layer is deposited, wherein the second insulating dielectric layer covers the temperature compensation layer.

6. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 5, characterized in that: After the temperature compensation layer is formed on the surface of the IDT away from the long finger electrode, the following steps are also included: The first insulating dielectric layer, the second insulating dielectric layer and the temperature compensation layer are etched to expose the first bus bar and the second bus bar, and to form a first interdigital through hole and a second interdigital through hole, respectively.

7. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 6, characterized in that: After the first interdigital through hole and the second interdigital through hole are formed respectively, the following steps are also included: A first PAD metal layer and a second PAD metal layer are manufactured, wherein the first PAD metal layer and the second PAD metal layer are connected to the first bus bar and the second bus bar through the first interdigital through-holes and the second interdigital through-holes, respectively.

8. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 7, characterized in that: After the temperature compensation layer is formed on the surface of the IDT away from the long finger electrode, the following steps are also included: A passivation layer is deposited to protect the first PAD metal layer and the second PAD metal layer.

9. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The shape of the hollow area includes a circle and a polygon.

10. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The maximum size of the hollow area along the first direction is a first size M, and the value range of the first size M is: λ≤M≤2λ; the maximum size of the hollow area along the second direction is a second size N, and the value range of the second size N is: 0.5λ≤N≤λ, where λ is the wavelength of the surface acoustic wave.

11. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The line width of the metal line is a third dimension Q, and the value range of the third dimension Q is: 0.5λ≤Q≤λ, wherein λ is the wavelength of the surface acoustic wave.

12. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The distance between the first load structure and the second load structure along the thickness direction is a first spacing L, and the value range of the first spacing L is: 0≤L≤λ, where λ is the wavelength of the surface acoustic wave.

13. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: Along the first direction, the size of the second load structure is greater than or equal to the size of the effective aperture area; along the second direction, the size of the second load structure is greater than or equal to the size of the effective aperture area.

14. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The first long finger electrode and the second long finger electrode have the same length extending along the second direction.

15. The method for manufacturing a temperature-compensated surface acoustic wave resonator according to claim 1, characterized in that: The process for making the interdigital transducer includes gluing, exposure, development, evaporation, and demoulding and peeling.

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