A surface acoustic wave resonator

Abstract

The utility model discloses a surface acoustic wave resonator, include: piezoelectric substrate, interdigital transducer sets up on piezoelectric substrate, and interdigital transducer includes IDT electrode, temperature compensation layer sets up on IDT electrode and piezoelectric substrate, SH wave suppression layer sets up between IDT electrode and temperature compensation layer, the utility model can suppress the influence of SH wave to resonator, widens piezoelectric substrate same cutting angle's scope of application, and promotes the performance of surface acoustic wave resonator.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor device manufacturing, and in particular to a surface acoustic wave resonator. Background Technology

[0002] SAW (Surface Acoustic Wave) resonators are a type of filter device that utilizes the piezoelectric effect and the physical characteristics of surface acoustic wave propagation. They are widely used in radio frequency (RF) front-end filters. With the miniaturization of electronic devices, the integration of multi-mode and multi-frequency functions, and the demands for cost and mass production, the size of filters needs to be further reduced. Currently, using high- and low-acoustic impedance composite metals as electrodes can significantly reduce device size.

[0003] In the TC-SAW (Temperature Compensated SAW) process, different combinations of IDT metal and SiO2, as well as different substrate cutting angles, will result in different amplitudes of Rayleigh waves and SH waves. Under certain conditions, SH waves can severely degrade the performance of surface acoustic wave resonators.

[0004] One common solution is to change the substrate chamfer angle; however, even this may not meet performance requirements. Therefore, how to suppress the influence of SH waves under limited conditions, and thus improve the performance of surface acoustic wave resonators, is another important aspect of resonator design. Utility Model Content

[0005] The purpose of this invention is to provide a surface acoustic wave resonator that can better suppress SH waves, broaden the applicable range of piezoelectric substrates with the same chamfer angle, and improve the performance of the surface acoustic wave resonator.

[0006] To achieve the above objectives, this utility model proposes a surface acoustic wave resonator, comprising:

[0007] piezoelectric substrate;

[0008] An interdigital transducer is disposed on the piezoelectric substrate, and the interdigital transducer includes an IDT electrode;

[0009] A temperature compensation layer is disposed on the IDT electrode and the piezoelectric substrate;

[0010] A SH wave suppression layer is disposed between the IDT electrode and the temperature compensation layer.

[0011] Optionally, the SH wave suppression layer covers the surface of the IDT electrode and the surface of the piezoelectric substrate between the IDT electrodes, and the temperature compensation layer covers the SH wave suppression layer.

[0012] Optionally, the material of the SH wave suppression layer is Si3N4.

[0013] Optionally, the temperature compensation layer covers the surface of the IDT electrode and the surface of the piezoelectric substrate between the IDT electrodes, the SH wave suppression layer is located inside the temperature compensation layer and above the IDT electrode, and a gap is provided between the SH wave suppression layer and the IDT electrode.

[0014] Optionally, the material of the SH wave suppression layer is Si3N4 or a metal.

[0015] Optionally, the gap between the SH wave suppression layer and the IDT electrode is 30nm to 50nm.

[0016] Optionally, the thickness of the SH wave suppression layer is 10nm to 200nm.

[0017] Optionally, the IDT electrode includes a seed layer, a first electrode layer, and a second electrode layer stacked sequentially from bottom to top.

[0018] Optionally, a first electrode protective layer is provided between the first electrode layer and the second electrode layer;

[0019] And / or, a second electrode protective layer is provided on the second electrode layer, and the acoustic impedance of the first electrode layer is greater than the acoustic impedance of the second electrode layer.

[0020] Optionally, the interdigital transducer further includes reflective grids disposed on both sides of the IDT electrode.

[0021] The beneficial effects of this utility model are as follows:

[0022] The surface acoustic wave resonator of this invention, by inserting an SH wave suppression layer between the IDT electrode and the temperature compensation layer, weakens or eliminates the SH wave amplitude, or pushes it to a higher frequency and away from the target passband, thereby suppressing the influence of SH waves on the resonator under limited conditions, widening the applicable range of the same chamfer angle of the piezoelectric substrate, and thus improving the performance of the surface acoustic wave resonator. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1This is a cross-sectional view of a surface acoustic wave resonator according to Embodiment 1 of the present invention.

[0025] Figure 2 This is a diagram of the film structure of a surface acoustic wave resonator according to Embodiment 1 of the present invention.

[0026] Figure 3a This is a graph showing the admittance curve of the resonator with and without the SH wave suppression layer as a function of frequency and wavelength, in one example of Example 1.

[0027] Figure 3b This is a diagram showing the phase characteristics of the resonator with and without an SH wave suppression layer as a function of frequency and wavelength in one example of Example 1.

[0028] Figure 4a This is a graph showing the impedance of the resonator after inserting an SH wave suppression layer in one example of Example 1, as a function of the product of frequency and wavelength.

[0029] Figure 4b This is a graph showing the phase characteristics of the resonator after inserting an SH wave suppression layer in one example of Embodiment 1, as a function of the product of frequency and wavelength.

[0030] Figure 5a This is a graph showing the admittance curve of the resonator with and without the SH wave suppression layer as a function of frequency and wavelength, in another example of Example 1.

[0031] Figure 5b This is a graph showing the phase characteristics of the resonator with and without an SH wave suppression layer as a function of frequency and wavelength, in another example of Example 1.

[0032] Figure 6a This is another example of Example 1, showing the impedance as a function of the product of frequency and wavelength after inserting an SH wave suppression layer.

[0033] Figure 6b This is a graph showing the phase characteristics as a function of frequency and wavelength after inserting an SH wave suppression layer in another example of Example 1.

[0034] Figure 7a This is a graph showing the impedance of different pitches (width of one electrode finger + gap width between adjacent fingers) as a function of frequency and wavelength under the same insertion conditions, as seen in another example of Example 1.

[0035] Figure 7b This is a characteristic graph of phase versus frequency and wavelength product for different pitches under the same insertion conditions in another example of Example 1.

[0036] Figure 8 This is a cross-sectional view of a surface acoustic wave resonator according to Embodiment 2 of the present invention.

[0037] Figure 9This is a diagram of the film structure of a surface acoustic wave resonator according to Embodiment 2 of the present invention.

[0038] Figure 10a This is a graph showing the admittance curve of an example of Example 2 with and without an SH wave suppression layer (Si3N4) as a function of frequency and wavelength product.

[0039] Figure 10b This is a characteristic graph of the phase versus frequency and wavelength product with or without an SH wave suppression layer (Si3N4) in one example of Example 2.

[0040] Figure 11a This is a graph showing the admittance curve of an example of Example 2 with and without an SH wave suppression layer (W metal layer) as a function of frequency and wavelength product.

[0041] Figure 11b This is a characteristic graph of the phase with or without the SH wave suppression layer (W metal layer) as a function of frequency and wavelength in one example of Example 2.

[0042] Figure 12a This is a graph showing the impedance as a function of frequency and wavelength after inserting a metal W-material SH wave suppression layer in one example of Example 2.

[0043] Figure 12b This is a diagram showing the phase characteristics as a function of frequency and wavelength after inserting a metal W-material SH wave suppression layer in one example of Example 2.

[0044] Figure 13a This is another example of Example 2, showing the admittance curves with and without the SH wave suppression layer (W metal layer) as a function of frequency and wavelength product.

[0045] Figure 13b This is another example of Example 2, showing the phase characteristics of the product of frequency and wavelength with and without the SH wave suppression layer (W metal layer).

[0046] Figure 14a This is another example of Example 2, showing the impedance as a function of frequency and wavelength after inserting an SH wave suppression layer (W metal layer).

[0047] Figure 14b This is another example of Example 2, showing the phase characteristics as a function of frequency and wavelength product after inserting an SH wave suppression layer (W metal layer).

[0048] Figure 15a This is another example of Example 2, showing the impedance of different pitches under the same insertion conditions as the product of frequency and wavelength.

[0049] Figure 15bThis is a characteristic graph of phase versus frequency and wavelength product for different pitches under the same insertion conditions in another example of Example 2. Detailed Implementation

[0050] The following detailed description of a surface acoustic wave resonator according to the present invention, in conjunction with the accompanying drawings and specific embodiments, provides further insight. The advantages and features of the present invention will become clearer from the following description and drawings. However, it should be noted that the concept of the present invention can be implemented in many different forms and is not limited to the specific embodiments described herein. The accompanying drawings are all in a very simplified form and use non-precise proportions, intended only to facilitate and clarify the illustration of the embodiments of the present invention.

[0051] The terms "first," "second," etc., used in the specification and claims are used to distinguish between similar elements and are not necessarily used to describe a particular order or chronological sequence. It should be understood that these terms, used so in this way, can be replaced, for example, to allow the embodiments of the present invention described herein to operate in a different order than that described or shown herein. If a component in one drawing is identical to a component in another drawing, although these components are easily identifiable in all drawings, this specification will not label all identical components in every drawing for the sake of clarity.

[0052] Example 1

[0053] This embodiment provides a surface acoustic wave resonator, including:

[0054] Piezoelectric substrate 1;

[0055] An interdigital transducer is disposed on a piezoelectric substrate 1, and the interdigital transducer includes an IDT electrode 2;

[0056] Temperature compensation layer 3 is disposed on IDT electrode 2 and piezoelectric substrate 1;

[0057] SH wave suppression layer 4 is disposed between IDT electrode 2 and temperature compensation layer 3.

[0058] In this embodiment, the material of the piezoelectric substrate 1 is LiNbO3 or LiTaO3, and the chamfer is not limited; the material of the temperature compensation layer 3 is SiO2.

[0059] like Figure 1As shown, in this embodiment, the SH wave suppression layer 4 covers the surface of the IDT electrode 2 and the surface of the piezoelectric substrate 1 between the IDT electrodes 2, and the temperature compensation layer 3 covers the SH wave suppression layer 4. The material of the SH wave suppression layer 4 is Si3N4; the thickness of the SH wave suppression layer 4 can be selected from 10nm to 200nm. The function of the SH wave suppression layer 4 covering the IDT electrode 2 and the piezoelectric layer is to suppress SH waves to enhance the excitation of Rayleigh waves.

[0060] In this embodiment, the IDT electrode 2 includes a pair of busbars arranged opposite each other, and two sets of IDT fingers arranged alternately between the two busbars;

[0061] like Figure 2 As shown, the film structure of the IDT electrode 2 includes a seed layer 201, a first electrode layer 202, a first electrode protective layer 204, a second electrode layer 203, and a second electrode protective layer 205 stacked sequentially from bottom to top. The acoustic impedance of the first electrode layer 202 is greater than that of the second electrode layer 203.

[0062] The first electrode layer 202 is made of at least one of Pt, W, Mo, Au, Ru, Cu, and alloys with these metals as the main components. Its function is to improve the confinement of acoustic waves within the piezoelectric layer and reduce acoustic wave loss. The second electrode layer 203 is made of materials including, but not limited to, Ag, Al, Cu, or alloys with Al or Cu as the main components. Its function is to reduce ohmic losses and improve the Q value of the electrode. The seed layer 201 ensures high-reliability adhesion between the first electrode layer 202 and the substrate. The seed layer 201 can be made of materials including, but not limited to, Ti, TiN, AlN, Cr, Ni, and Ta. The first electrode protective layer 204 is optional; adding the first electrode protective layer 204 prevents interdiffusion between the first electrode metal and the second electrode metal. The second electrode protective layer 205 protects the second electrode from oxidation in subsequent processes. The materials of both layers include, but are not limited to, Ti, TiN, AlN, Cr, Ni, and Ta.

[0063] In this embodiment, the interdigital transducer also includes a reflective grid disposed on both sides of the IDT electrode 2.

[0064] It should be noted that: in this embodiment, the SH wave suppression layer 4 made of Si3N4 material must suppress the SH wave when the SH wave appears between the resonant frequency and the anti-resonant frequency. This allows the thickness of the SH wave suppression layer 4 to be moderate, minimizing the impact on the resonator TCF. The resonator fabrication in this embodiment does not require alignment or an additional photomask, making the fabrication method simpler. The SiO2 film layer forming the temperature compensation layer 3 can be formed in one step, and the film quality is easier to control. When the Si3N4 covering the IDT electrode 2 is too thick or ineffective, the structure of embodiment 2 should be used.

[0065] In one example, the parameters of each film layer in the resonator structure of this embodiment are as follows:

[0066] Piezoelectric substrate 1: The chamfer is 40°YX (small chamfer, the SH wave is within the resonant and anti-resonant frequencies of the resonator), and the material is LiNbO3;

[0067] Seed layer 201, first electrode protective layer 204, and second electrode protective layer 205: are all Ti films with a thickness of 10 nm;

[0068] First electrode layer 202: Pt film with a thickness of 0.074λ;

[0069] The second electrode layer 203 is a Cu film with a thickness of 0.055λ.

[0070] SH wave suppression layer 4: Si3N4 film, film thickness 30nm;

[0071] SH wave suppression layer type 4: IDT surface coverage;

[0072] Temperature compensation layer 3: SiO2 film with a thickness of 0.34λ (λ is the wavelength of SH wave).

[0073] Figure 3a This is a graph showing the admittance curve of the resonator with and without the SH wave suppression layer 4 (Si3N4) as a function of frequency and wavelength. Figure 3b This is a graph showing the phase characteristics of the resonator with and without the SH suppression layer 4 as a function of frequency and wavelength (dashed line represents the resonator without SH suppression layer 4, solid line represents the resonator with SH suppression layer 4). Figure 3a and Figure 3b It can be seen that without the SH wave suppression layer 4, the SH wave amplitude is large near the sound speed of 2900m / s. After adding the SH wave suppression layer 4 (Si3N4), the SH wave is suppressed. Figure 4a The impedance of the resonator after inserting the SH wave suppression layer 4 is a characteristic graph of the product of frequency and wavelength. Figure 4b The characteristic graph of phase versus frequency and wavelength product after inserting SH wave suppression layer 4 into the resonator, from... Figure 4a and Figure 4b It can be seen that after inserting the SH wave suppression layer 4 (Si3N4), the phase of the higher-order modes also meets the requirement of <-25°.

[0074] In another example, the parameters of each film layer in the resonator structure of this embodiment are as follows:

[0075] Piezoelectric substrate 1: The chamfer angle is 150°YX (large chamfer angle, SH wave is within the resonant and anti-resonant frequencies of the resonator), and the material is LiNbO3.

[0076] Seed layer 201, first electrode protective layer 204, and second electrode protective layer 205: are all Ti films with a thickness of 10 nm;

[0077] The first electrode layer 202 is a W film with a thickness of 0.105λ.

[0078] The second electrode layer 203 is an Al film with a thickness of 0.03λ.

[0079] SH wave suppression layer 4: Si3N4 film, film thickness 165nm;

[0080] SH wave suppression layer type 4: IDT surface coverage;

[0081] Temperature compensation layer 3: SiO2 film with a thickness of 0.34λ.

[0082] Figure 5a The figure shows the admittance curve of the resonator with and without SH wave suppression layer 4 as a function of frequency and wavelength. Figure 5b The diagram shows the phase characteristics of the resonator with and without the SH wave suppression layer 4 as a function of frequency and wavelength (dashed line represents the resonator without SH wave suppression layer 4, solid line represents the resonator with SH wave suppression layer 4). It can be seen that without the SH wave suppression layer 4 (Si3N4), the SH wave amplitude is very large near the sound speed of 3000m / s. With the addition of the SH wave suppression layer 4 (Si3N4), the SH wave is suppressed. Figure 6a The graph shows the impedance as a function of frequency and wavelength after inserting the SH wave suppression layer 4. Figure 6b This is a graph showing the phase characteristics as a function of frequency and wavelength after inserting the SH wave suppression layer 4. From... Figure 6a and Figure 6b It can be seen that after inserting the SH wave suppression layer 4 (Si3N4), the phase of the higher-order modes also meets the requirement of <-25°. Figure 7a This is a graph showing the impedance characteristics of different pitches (width of one electrode finger + gap width between adjacent fingers) as a function of frequency and wavelength under the same insertion conditions. Figure 7b This is a graph showing the phase characteristics as a function of the product of frequency and wavelength for different pitches under the same insertion conditions. From... Figure 7a and Figure 7b It can be seen that the proposed method shows good consistency in effectiveness near a single passband. To achieve suppression across multiple passbands, local trimming techniques are needed for thinning.

[0083] Example 2

[0084] This embodiment provides another surface acoustic wave resonator, including:

[0085] Piezoelectric substrate 1;

[0086] An interdigital transducer is disposed on a piezoelectric substrate 1, and the interdigital transducer includes an IDT electrode 2;

[0087] Temperature compensation layer 3 is disposed on IDT electrode 2 and piezoelectric substrate 1;

[0088] SH wave suppression layer 4 is disposed between IDT electrode 2 and temperature compensation layer 3.

[0089] like Figure 8 As shown, in this embodiment, the temperature compensation layer 3 covers the surface of the IDT electrode 2 and the surface of the piezoelectric substrate 1 between the IDT electrodes 2. The SH wave suppression layer 4 is located inside the temperature compensation layer 3 and above the IDT electrode 2, and a gap is provided between the SH wave suppression layer 4 and the IDT electrode 2. The gap distance between the SH wave suppression layer 4 and the IDT electrode 2 is preferably 30nm to 50nm.

[0090] In this embodiment, the material of the SH wave suppression layer 4 is Si3N4 or a metal. The thickness of the SH wave suppression layer 4 can be selected from 10nm to 200nm. When the material of the SH wave suppression layer 4 is a metal, the metal is generally selected to be the same material as the first electrode layer 202. The function of the SH wave suppression layer 4 (Si3N4 or a metal) inserted into the temperature compensation layer 3 is to suppress SH waves in order to enhance the excitation of Rayleigh waves.

[0091] like Figure 9 As shown, in this embodiment, the IDT electrode 2 includes a seed layer 201, a first electrode layer 202, a first electrode protection layer 204 (optional), a second electrode layer 203, and a second electrode protection layer 205 stacked sequentially from bottom to top.

[0092] The materials of each film layer in the piezoelectric substrate 1, temperature compensation layer 3, and IDT electrode 2 are as described in Example 1 and will not be repeated here.

[0093] In this embodiment, the interdigital transducer also includes a reflective grid disposed on both sides of the IDT electrode 2.

[0094] It should be noted that this embodiment uses a metal layer inserted into the temperature compensation layer 3 as the SH wave suppression layer 4, which can additionally suppress SH waves to the left of the resonant frequency of the resonator. If the SH wave suppression layer 4 inserted into the temperature compensation layer 3 (SiO2) is Si3N4, no additional photomask is needed; if the inserted SH wave suppression layer 4 is metal, an additional photomask is required to ensure electrical isolation between IDTs. The SiO2 film forming the temperature compensation layer 3 requires two growths. Similarly, if the Si3N4 inserted into the SiO2 is too thick or ineffective, a metal material is required. In this embodiment, the distance between the SH wave suppression layer 4 in the temperature compensation layer 3 (SiO2) and the IDT electrode 2 (finger strip or busbar) is 30nm to 50nm. When the frequency band difference is large, the thickness of the inserted SH wave suppression layer 4 needs to be fine-tuned using trimming technology, which will require an additional photomask.

[0095] In one example, the parameters of each film layer in the resonator structure of this embodiment are as follows:

[0096] Piezoelectric substrate 1: The chamfer is 150°YX (large chamfer, SH wave is within the resonant and anti-resonant frequencies of the resonator), and the material is LiNbO3;

[0097] Seed layer 201, first electrode protective layer 204, and second electrode protective layer 205: are all Ti films with a thickness of 10 nm;

[0098] The first electrode layer 202 is a W film with a thickness of 0.105λ.

[0099] The second electrode layer 203 is an Al film with a thickness of 0.03λ.

[0100] SH wave suppression layer 4: W film, 80nm thick or Si3N4 film, 413nm thick;

[0101] SH wave suppression layer type 4: inserted in the middle of temperature compensation layer 3 (SiO2);

[0102] Temperature compensation layer 3: SiO2 film, with a film thickness of 0.34λ;

[0103] The distance between the surface layer of IDT electrode 2 and SH wave suppression layer 4 is 50nm.

[0104] Figure 10a This is a graph showing the admittance curves with and without the SH wave suppression layer 4 (Si3N4) as a function of frequency and wavelength. Figure 10b The diagram shows the phase characteristics of the product of frequency and wavelength with and without the SH wave suppression layer 4 (Si3N4). Figure 11a This is a graph showing the admittance curves with and without the SH wave suppression layer 4 (W metal layer) as a function of frequency and wavelength. Figure 11bThe diagram shows the phase characteristics of the product of frequency and wavelength with and without the SH wave suppression layer 4 (W metal layer). It can be seen that since both Si3N4 and W can achieve the same effect, the thickness of Si3N4 is very thick, which affects the TCF, while the thickness of W metal layer is only 1 / 5. Figure 12a 12b shows the impedance characteristics as a function of frequency and wavelength after inserting the SH wave suppression layer 4 made of metal W.

[0105] In another example, the parameters of each film layer in the resonator structure of this embodiment are as follows:

[0106] Piezoelectric substrate 1: The chamfer is 128°YX (a common chamfer, where the SH wave is outside the resonant and anti-resonant frequencies of the resonator), and the material is LiNbO3;

[0107] Seed layer 201, first electrode protective layer 204, and second electrode protective layer 205: are all Ti films with a thickness of 10 nm;

[0108] The first electrode layer 202 is a W film with a thickness of 0.105λ.

[0109] The second electrode layer 203 is an Al film with a thickness of 0.03λ.

[0110] SH wave suppression layer 4: W film, film thickness 110nm;

[0111] SH wave suppression layer type 4: inserted in the middle of temperature compensation layer 3 (SiO2);

[0112] Temperature compensation layer 3: SiO2 film, with a film thickness of 0.34λ;

[0113] The distance between the surface layer of IDT electrode 2 and SH wave suppression layer 4 is 50nm.

[0114] Figure 13a This is a graph showing the admittance curves with and without the SH wave suppression layer 4 (W metal layer) as a function of frequency and wavelength. Figure 13b The diagram shows the phase characteristics of the product of frequency and wavelength with and without the SH wave suppression layer 4 (W metal layer). It can be seen that the SH wave appears to the left of the resonant frequency and is relatively close. After inserting the W metal layer into SiO2, it can be pushed to a higher frequency (the diagram shows the anti-resonant frequency point) and weakened. Figure 14a The graph shows the impedance as a function of frequency and wavelength after inserting the SH wave suppression layer 4 (W metal layer). Figure 14b This is a graph showing the phase characteristics as a function of frequency and wavelength after inserting the SH wave suppression layer 4 (W metal layer). Figure 15a This is a graph showing the impedance of different pitches as a function of the product of frequency and wavelength under the same insertion conditions. Figure 15b The graphs show the phase characteristics of different pitches under the same insertion conditions, as a function of the product of frequency and wavelength. It can be seen that the given methods show good consistency in performance near the multi-passband.

[0115] It should be noted that the various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for structural embodiments, since they are basically similar to method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments.

[0116] The above description is only a description of the preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A surface acoustic wave resonator, characterized in that, include: piezoelectric substrate; An interdigital transducer is disposed on the piezoelectric substrate, and the interdigital transducer includes an IDT electrode; A temperature compensation layer is disposed on the IDT electrode and the piezoelectric substrate; A SH wave suppression layer is disposed between the IDT electrode and the temperature compensation layer.

2. The surface acoustic wave resonator according to claim 1, characterized in that, The SH wave suppression layer covers the surface of the IDT electrode and the surface of the piezoelectric substrate between the IDT electrodes, and the temperature compensation layer covers the SH wave suppression layer.

3. The surface acoustic wave resonator according to claim 2, characterized in that, The material of the SH wave suppression layer is Si3N4.

4. The surface acoustic wave resonator according to claim 1, characterized in that, The temperature compensation layer covers the surface of the IDT electrode and the surface of the piezoelectric substrate between the IDT electrodes. The SH wave suppression layer is located inside the temperature compensation layer and above the IDT electrode, and there is a gap between the SH wave suppression layer and the IDT electrode.

5. The surface acoustic wave resonator according to claim 4, characterized in that, The material of the SH wave suppression layer is Si3N4 or metal.

6. The surface acoustic wave resonator according to claim 4, characterized in that, The gap between the SH wave suppression layer and the IDT electrode is 30nm to 50nm.

7. The surface acoustic wave resonator according to any one of claims 1-6, characterized in that, The thickness of the SH wave suppression layer is 10nm to 200nm.

8. The surface acoustic wave resonator according to any one of claims 1-6, characterized in that, The IDT electrode comprises a seed layer, a first electrode layer, and a second electrode layer stacked sequentially from bottom to top.

9. The surface acoustic wave resonator according to claim 8, characterized in that, A first electrode protective layer is provided between the first electrode layer and the second electrode layer; And / or, a second electrode protective layer is provided on the second electrode layer, and the acoustic impedance of the first electrode layer is greater than the acoustic impedance of the second electrode layer.

10. The surface acoustic wave resonator according to claim 1, characterized in that, The interdigital transducer also includes a reflective grid disposed on both sides of the IDT electrode.

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