Lamb wave resonator including a through hole

Abstract

The present invention discloses a Lamb wave resonator including through-holes, comprising a piezoelectric film layer. The Lamb wave resonator further comprises one or more through-holes arranged in the interdigital electrode region of the piezoelectric film layer. Due to the through-hole structure, the Lamb wave resonator designed in the present invention effectively suppresses parasitic modes of the resonator. The through-holes can suppress or even completely eliminate the parasitic modes of the resonator. The through-holes are universally applicable and are highly effective under various IDT electrode parameters and LiNbO3 film thicknesses. Furthermore, this solution significantly improves the device's design flexibility, compactness, mechanical stability, temperature stability, and power tolerance.

Description

[0001] This application claims priority to a prior application entitled “Lamb wave resonator including through-holes” with patent application number 2023105707041 filed with the State Intellectual Property Office of China on May 19, 2023. The entire text of the prior application is incorporated herein by reference. Technical Field

[0002] The present invention belongs to the technical field of resonators, and in particular, relates to a Lamb wave resonator comprising a through hole. Background Art

[0003] Microwave-band acoustic filters have a long and extensive history of application in mobile communications. With the rapid development of next-generation communication technologies, the demand for more compact filters with higher operating frequency bands and wider bandwidths is rapidly increasing.

[0004] The existing mainstream commercial microwave acoustic filters mainly adopt two technical paths. One is the surface acoustic wave (SAW) filter based on LiNbO3 and LiTaO3 piezoelectric single crystals. The operating frequency of this type of device is limited by the line width of the transducer electrode and is often below 3.5GHz. Further development to higher frequencies will bring about a sharp increase in cost and technical difficulty. The other is the bulk acoustic wave (BAW) filter based on AlN piezoelectric film; the advantage of this type of device is that it is relatively easy to realize filters with frequencies above 3.5GHz. However, due to the low electromechanical coupling coefficient of AlN film, the bandwidth of this type of filter is often not high. Faced with the complex application scenarios of the new generation and future communication technologies, classic SAW and BAW filters are facing many problems.

[0005] In addition to longitudinal BAW modes, the acoustic modes in thin films also include Lamb wave modes and transverse shear wave (SH) modes. Lamb wave modes further include symmetric (S) modes and antisymmetric (A) modes. Acoustic resonators based on these modes (such as A1, S2, A3, and S4 resonators based on LiNbO3 single crystal thin films) are particularly advantageous for realizing high-frequency, large-bandwidth acoustic filters: 1) Only interdigital transducers with micron-scale linewidths are required to achieve acoustic resonances at frequencies of several GHz or even higher; 2) They can have very high electromechanical coupling coefficients, which is conducive to the realization of ultra-wide-bandwidth filters.

[0006] Although Lamb wave resonators can realize high-frequency, ultra-wide-bandwidth filters, they exhibit numerous parasitic modes, making suppression of these modes a challenging problem in resonator design. Existing methods for suppressing these modes either require additional device fabrication steps or impose stringent requirements on electrode design, making it difficult to completely suppress and eliminate them. Summary of the Invention

[0007] In order to solve the above problems, the present invention aims to provide a Lamb wave resonator including a through hole, which introduces a through hole in the interdigital electrode region of the piezoelectric layer film, thereby conveniently and efficiently suppressing or even completely eliminating the parasitic mode.

[0008] To achieve the above objectives, according to one aspect of the present invention, a Lamb wave resonator including through holes is provided, which includes a piezoelectric layer film. The Lamb wave resonator also includes one or more through holes arranged in the interdigital electrode region of the piezoelectric layer film.

[0009] In the context of the present invention, the "interdigitated electrode region" refers to the largest region enclosed by the fingers of the interdigitated electrodes and the first and second bus bar electrodes that are parallel to each other.

[0010] In one embodiment of the present invention, the through holes are arranged in an orderly or disordered manner on the piezoelectric layer film.

[0011] The shape of the through hole is not particularly limited and can be regular or irregular, for example, one or more of a circle, an ellipse, a square, a rectangle, a diamond, a trapezoid, an arc, a ring, a spiral or other regular or irregular polygons.

[0012] In one embodiment of the present invention, the size of the through-hole is 0.20 μm to 100 μm, more preferably 0.2 μm to 1.5 μm, and even more preferably 0.50 to 1.25 μm, for example, 0.50 μm, 0.60 μm, 0.70 μm, 0.75 μm, 0.80 μm, 0.90 μm, 1.00 μm, 1.10 μm, 1.20 μm, 1.25 μm, or any range between any two of the above values or any value within the range.

[0013] In the context of the present invention, the size of a through-hole refers to the maximum distance between two points in the cross-section of the through-hole. For example, if the cross-section of the through-hole is circular, the size of the through-hole is the diameter of the circle; if the cross-section of the through-hole is rectangular, the size of the through-hole is the length of the diagonal of the rectangle; and if the cross-section of the through-hole is elliptical, the size of the through-hole is the length of the major axis of the ellipse.

[0014] In one embodiment of the present invention, the longitudinal distance between two adjacent through holes is 8 to 12 μm, and the lateral distance between two adjacent through holes is 8 to 22 μm.

[0015] In one embodiment of the present invention, the through-holes are periodically or non-periodically arranged in the interdigitated electrode region. "Periodic arrangement" means that the distances between two adjacent through-holes arranged longitudinally and transversely are equal. Periodic arrangement means that the distances between two adjacent through-holes arranged longitudinally are equal, and the distances between two adjacent through-holes arranged transversely are also equal. The distances between two adjacent through-holes arranged longitudinally and two adjacent through-holes arranged transversely may be equal or unequal.

[0016] In one embodiment of the present invention, the through-holes are densely or sparsely arranged in the interdigitated electrode region. "Densely arranged" means that the distance between two adjacent through-holes arranged longitudinally is 0.5 μm to 10 μm, preferably 2 μm to 10 μm, and more preferably 5 μm to 8 μm. "Sparsely arranged" means that the distance between two adjacent through-holes arranged longitudinally is 10.0 μm or greater.

[0017] The present invention has no particular limitation on the number of through holes, as long as the number is greater than one.

[0018] In one embodiment of the present invention, the number of the through holes may be 1-4000, preferably 1-2000, more preferably 1-1000, further preferably 1-200, for example 1-100.

[0019] In one embodiment of the present invention, the Lamb wave resonator further comprises an optional temperature compensation layer.

[0020] In one embodiment of the present invention, the through hole penetrates the piezoelectric layer in a thickness direction and extends downward to penetrate or not penetrate the temperature compensation layer.

[0021] In one embodiment of the present invention, the temperature compensation layer is located above, below, or between the piezoelectric layer film.

[0022] In one embodiment of the present invention, the Lamb wave resonator further comprises an optional fixed substrate layer.

[0023] In one embodiment of the present invention, the through-hole extends downward in the thickness direction of the piezoelectric layer film or does not penetrate the fixed base layer.

[0024] In one embodiment of the present invention, the fixed substrate layer is located below the piezoelectric film layer.

[0025] Preferably, the fixing base layer is at least one layer, preferably at least two layers.

[0026] Preferably, the material of the fixed base layer is the same or different, and is independently selected from at least one of Pt, Al2O3, W, Mo, BCB, Si, SiC, SiO2, and diamond.

[0027] The present invention has no particular limitation on the thickness of the temperature compensation layer, which may be, for example, 0 μm to 100 μm, wherein a thickness of 0 means that no temperature compensation layer exists.

[0028] The present invention has no particular limitation on the material of the temperature compensation layer, and the material may be, for example, one or more of SiO2, GeO2, and Si2OF6.

[0029] In one embodiment of the present invention, the material of the piezoelectric layer film is selected from one or more of LiNbO3, LiTaO3, AlN, AlScN, ZnO, PbZrTiO3, etc., preferably LiNbO3, LiTaO3, AlN, AlScN, and more preferably LiNbO3 and LiTaO3.

[0030] In a preferred embodiment of the present invention, the piezoelectric layer film is a LiNbO3 single crystal film, and the LiNbO3 single crystal film includes a suspended LiNbO3 single crystal film portion and a non-suspended LiNbO3 single crystal film portion, and interdigitated electrodes are provided on the suspended LiNbO3 single crystal film portion; the through holes are arranged on the surface of the suspended LiNbO3 single crystal film and are located between the interdigitated electrode regions.

[0031] Preferably, the tangent direction of the piezoelectric layer film includes all tangent directions of the piezoelectric layer film, such as Z-cut, Y-cut or 128°-Y-cut.

[0032] The thickness of the piezoelectric layer film is not particularly limited, and may be, for example, 50-5000 nm, preferably 300-900 nm.

[0033] In one embodiment of the present invention, the interdigitated electrodes are a periodic structure or a weighted electrode structure.

[0034] In one embodiment of the present invention, the periodic direction of the interdigitated electrodes is any direction within a partial region of the suspended LiNbO 3 single crystal thin film.

[0035] The interdigital electrodes include N groups of first fingers and N-1 groups of second fingers that are sequentially spaced apart, where N is an integer greater than or equal to 2. Preferably, the through hole is disposed in the middle of the interdigital electrodes and is located at any position to the left or right between the N groups of first fingers and the N groups of second fingers.

[0036] In one embodiment of the present invention, the interdigitated electrode includes a first bus bar electrode and a second bus bar electrode parallel to each other; the first bus bar electrode is connected to the input end, and the second bus bar electrode is grounded; the first bus bar electrode is provided with multiple groups of first fingers; the second bus bar electrode is provided with multiple groups of second fingers, and the multiple groups of first fingers and the multiple groups of second fingers are arranged in sequence at intervals.

[0037] In one embodiment of the present invention, the first bus bar electrode is connected to N groups of first fingers; and the second bus bar electrode is connected to N-1 groups of second fingers.

[0038] The width of the interdigital electrodes may be 0.1 μm to 20 μm, preferably 0.5 μm to 10 μm, the spacing may be 2 μm to 100 μm, and the thickness may be 5 nm to 1000 nm, preferably 10 nm to 600 nm.

[0039] The length of the overlap between the first finger and the second finger is the aperture of the interdigital electrode. The aperture of the interdigital electrode can be 5 μm to 800 μm, preferably 20 μm to 500 μm, and more preferably 70 μm to 100 μm, such as 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, or any range between any two of the above points or any value within the range.

[0040] In one embodiment of the present invention, the material of the interdigitated electrodes and the materials of the first bus bar electrode and the second bus bar electrode can be any material with conductive properties, for example, one or more selected from graphene, topological semimetal, Al, Au, Pt, Cr, W, Mo, Ni, Fe and Ti.

[0041] In one embodiment of the present invention, the Lamb wave resonator further includes a release window provided in the piezoelectric layer film, wherein the release window is distributed on the lower side of the first bus bar electrode and the upper side of the second bus bar electrode.

[0042] The present invention has no particular limitation on the shape of the release windows. For example, the release windows may be rectangular in cross section and hollow in shape, with four release windows located below the first busbar electrode and three release windows located above the second busbar electrode.

[0043] Beneficial effects of the present invention:

[0044] 1) Suppressing parasitic modes: When the resonator is working, it is necessary to apply voltage to the electrode structure. Due to the excellent piezoelectric properties of the piezoelectric film (such as LiNbO3 single crystal film), the electric load causes the piezoelectric film covering the bottom of the electrode to generate mechanical stress, resulting in acoustic wave reflection at the edge of the electrode. The acoustic wave reflection at the edge of the electrode is a potential cause of the emergence of high-order lateral parasitic modes. The present invention introduces subwavelength-sized through-holes between the interdigitated electrodes on the surface of the piezoelectric layer film. Due to the air gap between the interdigitated electrodes and the huge acoustic impedance mismatch between the air and the piezoelectric film, the acoustic wave reflection generated at the edge of the electrode is suppressed, thereby conveniently, efficiently and thoroughly suppressing the high-order lateral parasitic modes with almost no effect on the main mode.

[0045] 2) Design Requirements and Difficulty of Degraded Resonators: Existing Lamb wave resonators must be dimensioned within stringent limits to minimize parasitic modes. In existing Lamb wave resonators, parasitic modes are significantly dependent on the electrode spacing and duty cycle. When the electrode spacing is very small, high-order parasitic modes are almost inevitable. When the electrode spacing is very large, parasitic modes can be partially suppressed. Given the structure of existing Lamb wave resonators, release windows are often located outside the interdigitated electrodes. During the device release process, whether wet or dry etching, the substrate material must be etched from the outside inward through the release windows. Excessive electrode spacing increases the device area. This significantly increases the backside etching (release) process time and processing difficulty for resonators with a large number of electrode pairs. Furthermore, the release process is isotropic, and while etching from the outside inward, it also etches the substrate in the opposite direction, resulting in an excessively large floating area that impacts device layout. A resonator with an excessively large floating area not only affects device stability but also hinders the design of miniaturized acoustic filters. If the electrode width is reduced to less than 1μm, parasitic modes can be suppressed through smaller electrode spacing or a suitable electrode duty cycle, but the requirements for the photolithography process increase significantly. To more thoroughly suppress parasitic modes, the thickness of the interdigitated electrodes must also be within a very small range.

[0046] The through-hole structure of the present invention is applicable to any electrode structure. Regardless of whether the electrode spacing is small or large, the through-holes effectively suppress parasitic modes without adding additional device preparation steps. This reduces the requirements for various resonator design parameters, eliminating the need for stringent limits. Under various resonator design parameters (including different interdigital electrode apertures, different electrode duty cycles, and different LiNbO3 film thicknesses), all resonators with through-holes are more likely to exhibit an admittance response free of parasitic modes. This design is versatile and has wide adaptability.

[0047] 3) The through-hole can be used as a release window to reduce the ineffective suspension area of the piezoelectric film and improve the stability and compactness of the device: the through-hole is used as a release window, so that the peripheral release window can be reduced or even no peripheral release window is required. In the release process of resonator preparation, corrosive gas (or liquid) can corrode the substrate material from the inside to the outside and from the outside to the inside at the same time through the through-hole structure, greatly shortening the corrosion time. This reduces the time and cost of device preparation and greatly reduces the ineffective suspension area of the piezoelectric film. The reduction of the ineffective suspension area of the piezoelectric film is of great value. It is beneficial to the mechanical stability and compactness of the resonator, and at the same time, it allows the heat generated during the operation of the resonator to be conducted to the substrate material more quickly, which is beneficial to the temperature stability and power tolerance of the resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 (a) is a top view of the Lamb wave resonator in Example 1; Figure 1 (b) is a side view of the Lamb wave resonator in Example 1;

[0049] Figure 2 is the admittance diagram of the Lamb wave resonator with different aperture diameters in Example 1;

[0050] Figure 3 is the admittance diagram of the Lamb wave resonator with different electrode structures in Example 2;

[0051] Figure 4 is the admittance diagram of the Lamb wave resonator with different piezoelectric film thicknesses in Example 3;

[0052] Figure 5 1 is the admittance diagram of the Lamb wave resonator with different through-hole arrangements in Example 4;

[0053] Figure 6 is the admittance diagram of the Lamb wave resonator in Example 5 in which the piezoelectric material is changed to LiTaO3 thin film;

[0054] Figure 7 This is the admittance diagram of the Lamb wave resonator in Example 7 in which the electrode material is changed to Al.

[0055] Figure 8 The admittance spectrum of the LiNbO3 Lamb wave resonator in Example 8 when the through holes are circular, square, elliptical, triangular, and rectangular. DETAILED DESCRIPTION

[0056] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0058] Example 1

[0059] like Figure 1 As shown, the LiNbO3 Lamb wave resonator comprises a LiNbO3 single crystal thin film. The LiNbO3 single crystal thin film comprises a suspended LiNbO3 single crystal thin film portion 9 and an unsuspended LiNbO3 single crystal thin film portion 10. The film is Z-cut and 300 nm thick. The suspended LiNbO3 single crystal thin film 9 is provided with interdigital electrodes, through-holes 8, and a release window 11.

[0060] The interdigitated electrode layer includes parallel first and second busbar electrodes 5 and 4, each with a width of 5 μm. The first busbar electrode 5 is connected to the input terminal, while the second busbar electrode 4 is grounded. The first busbar electrode 5 is provided with N groups (N is 3) of first fingers 6, and the second busbar electrode 4 is provided with N-1 groups of second fingers 7. The N groups of first fingers 6 and the N-1 groups of second fingers 7 are spaced apart in sequence. The spacing between a first finger 6 and an adjacent second finger 7 is 1, with the spacing 1 being 8 μm. The width 2 of a first finger or a second finger is 2 μm.

[0061] The overlapping length of the first finger 6 and the second finger 7 is equal to the aperture 3 of the interdigital electrode, which is 90 μm. The interdigital electrode is made of Au and has a thickness of 50 nm (i.e., the thickness of the first finger 6 and the second finger 7 between the first bus bar electrode 5 and the second bus bar electrode 4, including the thickness of the first bus bar electrode 5 and the second bus bar electrode 4 themselves). Figure 1 13 represents the periodic direction of the interdigital electrodes.

[0062] Through-holes 8 are located between the surface of the unsuspended LiNbO3 single crystal thin film portion 10 and the interdigitated electrodes. These through-holes are circular and have a diameter ranging from 0 to 1.25 μm. The vertical spacing between two adjacent through-holes is marked as 14, with a vertical spacing of 10 μm, and the number of through-holes in each longitudinal arrangement is 9. The horizontal spacing between two adjacent through-holes is marked as 15, with a horizontal spacing of 20 μm, and the number of through-holes in each transverse arrangement is 6. The total number of through-holes is 54, and they are periodically arranged on the surface of the unsuspended LiNbO3 single crystal thin film portion 10.

[0063] See also Figure 1 As shown in (a), the release windows 11 are all rectangular and hollow in cross section, with four release windows located below the first bus bar electrode 5 and three release windows located above the second bus bar electrode 4. The silicon dioxide 16 has a thickness of 0 μm.

[0064] In order to verify the suppression of the parasitic mode of the resonator by the through hole, we calculated the admittance spectrum of the resonator with and without the through hole through 3D full model finite element simulation. Figure 2 shown.

[0065] Figure 2 a to 2f show the admittance spectra of the LiNbO3-based Lamb wave resonator when the through-hole diameter is 0μm (i.e., no through-hole), 0.25μm, 0.50μm, 0.75μm, 1.00μm, and 1.25μm, respectively.

[0066] In the absence of through-holes ( Figure 2 a), the admittance spectrum of the LiNbO3 Lamb wave resonator has obvious parasitic modes. When the through hole diameter is small, such as 0.25μm ( Figure 2 b), this parasitic mode is suppressed to a certain extent, but still exists. As the through-aperture diameter increases, such as 0.50μm ( Figure 2 c), this parasitic mode is almost completely suppressed. When the diameter of the through hole continues to increase, such as 0.75μm ( Figure 2 d) and 1.00 μm ( Figure 2 e), this parasitic mode is in a suppressed state. When the through-aperture diameter is further increased, such as 1.25μm ( Figure 2 f), the parasitic mode appears again, but it is still greatly suppressed compared to the case without through-holes. In the above case, the admittance of the LiNbO3 Jilan wave resonator and the frequency of the main mode are almost completely unchanged.

[0067] Example 2

[0068] The through hole proposed in the present invention has good applicability to different interdigital electrode designs.

[0069] To verify this, the admittance spectrum of the LiNbO3 Lamb wave resonator with different interdigital electrode design parameters under the same through hole (hole diameter 1.0μm) is calculated, as shown in Figure 2. Figure 3 The Lamb wave resonator used in this embodiment is the same as that used in embodiment 1, with the only difference being changes in the duty cycle and the aperture of the interdigital electrodes.

[0070] Figure 3 a to Figure 3 c shows the admittance spectra of the resonator at different duty cycles (0.15, 0.20, 0.25). Figure 3 Figures 3d to 3f show the admittance spectra of the resonators with different interdigital electrode apertures (80μm, 100μm, and 110μm), respectively. It can be seen that when the same through-hole is placed in all Lamb wave resonators, the parasitic mode to the right of the antiresonance peak is well suppressed.

[0071] Example 3

[0072] The through-holes proposed in the present invention are also very applicable to LiNbO3 single crystal films of different thicknesses.

[0073] To verify this, the resonator with a through hole diameter of 1.0 μm in Example 1 was used as an example to calculate the admittance spectrum of the resonator under the change of the thickness of the LiNbO3 single crystal film. Figure 4 shown.

[0074] It can be seen that in the process of reducing the thickness of the LiNbO3 single crystal film from 300nm to 250nm, no parasitic modes appeared in the admittance spectrum of the resonator; at the same time, its resonant frequency increased almost linearly.

[0075] Example 4

[0076] This embodiment is the same as embodiment 1, except that:

[0077] The diameter of the through-hole is 1.0 μm. The distance between two adjacent through-holes in the first longitudinal row is 10 μm, and the number of through-holes in the longitudinal direction is 9. The distance between two adjacent through-holes in the second longitudinal row is 10 μm, and the number of through-holes in the longitudinal direction is 8. Through-holes with different longitudinal numbers are arranged periodically in the transverse direction, and the distance between two adjacent through-holes is 20 μm. The total number of through-holes is 51. Figure 5 It can be seen that when the through holes in the resonator are arranged in gaps, the parasitic mode on the right side of the antiresonance peak is also well suppressed.

[0078] Example 5

[0079] Based on Example 1, the piezoelectric layer is changed to a LiTaO3 film with a thickness of 500nm. The parameters of the interdigital electrodes are the same as those in Example 1. The diameter of the through-holes is 0.75μm, the longitudinal spacing is 5μm, and the number of through-holes in each longitudinal arrangement is 18; the transverse spacing is 20μm, and the number of through-holes in each transverse arrangement is 6. The total number of through-holes is 108. Figure 6 It can be seen that for the piezoelectric layer of LiTaO3 thin film, the through-hole structure has a certain inhibitory effect on the parasitic mode of the resonator.

[0080] Example 6

[0081] Taking the resonator with a through-hole diameter of 1.0 μm in Example 1 as an example, a fixed substrate is set below the LiNbO3 single crystal thin film. The fixed substrate is composed of SiO2, metal tungsten (W), and Si from top to bottom. The thicknesses of SiO2, metal tungsten (W), and Si are 300 nm, 500 nm, 400 nm, 300 nm, and 525 μm, respectively.

[0082] Example 7

[0083] Other parameters refer to the resonator with a through hole diameter of 1.0 μm in Example 1.

[0084] The interdigital electrode material was changed to Al with a thickness of 100 nm. The first busbar electrode 5 was provided with 20 groups of first fingers 6, and the second busbar electrode 4 was provided with 19 groups of second fingers 7. N groups of first fingers 6 and N-1 groups of second fingers 7 were arranged in sequence. The spacing between a first finger 6 and an adjacent second finger 7 was 1, with spacing 1 being 15 μm. The width 2 of a first finger or a second finger was 5 μm. Through-holes 8 were provided between the surface of the suspended LiNbO3 single crystal thin film 10 and the interdigital electrodes. The through-holes were circular and had a diameter of 1 μm. The longitudinal spacing between adjacent through-holes was 10 μm, with 9 through-holes per longitudinal arrangement. The lateral spacing between adjacent through-holes was 40 μm, with 40 through-holes per transverse arrangement. The total number of through-holes was 360. Figure 7 The admittance spectrum of the resonator with and without through-holes is shown. It can be seen that by changing the electrode material to Al, the through-hole structure can effectively suppress the parasitic mode of the resonator.

[0085] Example 8

[0086] The other parameters of this embodiment are the same as those of embodiment 1, except that:

[0087] The through-hole shapes were changed to circle, square, rectangle, equilateral triangle and ellipse. The side length of the square was 1 μm; the side length of the equilateral triangle was 1 μm; the length of the rectangle was 2 μm and the width was 1 μm; the major axis of the ellipse was 2 μm and the minor axis was 1 μm.

[0088] Figure 8 a to 8f show the admittance spectra of the LiNbO3 Lamb wave resonator with no through-hole, circular, square, elliptical, triangular and rectangular through-holes, respectively. Figure 8 It can be seen from the figure that through-holes of different shapes have a certain inhibitory effect on the parasitic mode, and this inhibitory effect is most obvious when the through-hole is circular.

[0089] The various technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the description of this specification.

Claims

1. A Lamb wave resonator comprising a through hole, comprising a piezoelectric layer film, characterized in that: The Lamb wave resonator further comprises a plurality of through holes (8) arranged in the interdigital electrode region of the piezoelectric layer film; the through holes are arranged periodically or non-periodically; and the size of the through holes (8) is 0.50-1.25 μm.

2. The Lamb wave resonator according to claim 1, wherein The through holes (8) are of regular or irregular shape and are arranged in an orderly or disordered manner on the piezoelectric layer film.

3. The Lamb wave resonator according to claim 1, wherein The shape of the through hole (8) is one or more of a circle, an ellipse, a square, a rectangle, a rhombus, a trapezoid, an arc, a ring, a spiral or other regular or irregular polygons.

4. The Lamb wave resonator according to claim 1, wherein The sizes of the through holes (8) are 0.50 μm, 0.60 μm, 0.70 μm, 0.75 μm, 0.80 μm, 0.90 μm, 1.00 μm, 1.10 μm, 1.20 μm, and 1.25 μm.

5. The Lamb wave resonator according to claim 1, wherein: The number of the through holes (8) is 9-4000.

6. The Lamb wave resonator according to claim 5, characterized in that The number of the through holes (8) is 9-2000.

7. The Lamb wave resonator according to claim 6, characterized in that The number of the through holes (8) is 9-1000.

8. The Lamb wave resonator according to claim 7, characterized in that The number of the through holes (8) is 9-200.

9. The Lamb wave resonator according to claim 8, characterized in that The number of the through holes (8) is 9-100.

10. The Lamb wave resonator according to claim 1, wherein: The longitudinal spacing between two adjacent through holes (8) is 8-12 μm, and the lateral spacing is 8-22 μm.

11. The Lamb wave resonator according to claim 1, wherein: The through holes (8) are densely arranged or sparsely arranged in the interdigital electrode area.

12. The Lamb wave resonator according to claim 11, characterized in that The distance between two adjacent through holes (8) arranged longitudinally is 0.5 μm-10 μm or the distance between two adjacent through holes arranged longitudinally is greater than 10.5 μm.

13. The Lamb wave resonator according to claim 12, wherein: The distance between two adjacent through holes (8) arranged longitudinally is 2 μm-10 μm.

14. The Lamb wave resonator according to claim 13, wherein: The distance between two adjacent through holes (8) arranged longitudinally is 5 μm-8 μm.

15. The Lamb wave resonator according to claim 1, wherein It also includes an optional temperature compensation layer (16); the through hole penetrates the piezoelectric layer in the thickness direction of the film and extends downward to penetrate or not penetrate the temperature compensation layer (16).

16. The Lamb wave resonator according to claim 15, characterized in that The temperature compensation layer (16) is located above, below or between the piezoelectric layer film.

17. The Lamb wave resonator according to claim 15, characterized in that The material of the temperature compensation layer (16) is selected from one or more of SiO2, GeO2 and Si2OF6.

18. The Lamb wave resonator according to claim 1, wherein The Lamb wave resonator further includes an optional fixed base layer; the through hole penetrates the piezoelectric layer in the thickness direction and extends downward to penetrate or not penetrate the fixed base layer.

19. The Lamb wave resonator according to claim 18, wherein: The fixed base layer is located below the piezoelectric layer film.

20. The Lamb wave resonator according to claim 18, wherein The fixing base layer is at least one layer.

21. The Lamb wave resonator according to claim 18, wherein The fixing base layer has at least two layers.

22. The Lamb wave resonator according to claim 18, wherein The material of the fixed base layer is the same or different, and is independently selected from at least one of Pt, Al2O3, W, Mo, BCB, Si, SiC, SiO2, and diamond.

23. The Lamb wave resonator according to claim 1, wherein The material of the piezoelectric layer film is selected from one or more of LiNbO3, LiTaO3, AlN, AlScN, ZnO, and PbZrTiO3.

24. The Lamb wave resonator according to claim 23, wherein: The material of the piezoelectric layer film is one or both of LiNbO3 and LiTaO3.

25. The Lamb wave resonator according to claim 1, wherein The piezoelectric layer film is a LiNbO3 single crystal film, and the LiNbO3 single crystal film includes a suspended LiNbO3 single crystal film portion (9) and a non-suspended LiNbO3 single crystal film portion (10). Interdigital electrodes are provided on the suspended LiNbO3 single crystal film portion (9), and the through holes (8) are arranged between the interdigital electrodes on the surface of the suspended LiNbO3 single crystal film portion (9).

26. The Lamb wave resonator according to claim 1, wherein The tangential direction of the piezoelectric layer film includes all tangential directions of the film.

27. The Lamb wave resonator according to claim 26, wherein: The tangent direction of the piezoelectric layer film is Z-cut, Y-cut or 128°-Y-cut.

28. The Lamb wave resonator according to claim 1, wherein The thickness of the piezoelectric layer film is 50-5000 nm.

29. The Lamb wave resonator according to claim 28, characterized in that The thickness of the piezoelectric layer film is 300-900 nm.

30. The Lamb wave resonator according to claim 1, wherein The interdigitated electrodes include a first bus bar electrode (5) and a second bus bar electrode (4) that are parallel to each other; the first bus bar electrode (5) is connected to an input terminal, and the second bus bar electrode (4) is grounded; a plurality of groups of first fingers (6) are provided on the first bus bar electrode (5); a plurality of groups of second fingers (7) are provided on the second bus bar electrode (4), and the plurality of groups of first fingers (6) and the plurality of groups of second fingers (4) are sequentially arranged at intervals.

31. The Lamb wave resonator according to claim 30, characterized in that The number of groups of the first fingers (6) is N, the number of groups of the second fingers (7) is N-1, and N is an integer greater than or equal to 2.

32. The Lamb wave resonator according to claim 31, characterized in that Preferably, the first bus bar electrode (5) is connected to N groups of first fingers (6); and the second bus bar electrode (4) is connected to N-1 groups of second fingers (7).

33. The Lamb wave resonator according to claim 32, characterized in that The through hole (8) is arranged in the middle of the interdigitated electrodes and is located at any position on the left or right between the N groups of first fingers (6) and the N groups of second fingers (7).

34. The Lamb wave resonator according to claim 30, wherein The interdigital electrodes are a periodic structure or a weighted electrode structure; the periodic direction of the interdigital electrodes is any direction within the suspended film region.

35. The Lamb wave resonator according to claim 30, wherein The interdigital electrodes have a width of 0.1 μm to 20 μm, a spacing of 2 μm to 100 μm, and a thickness of 5 nm to 1000 nm.

36. The Lamb wave resonator according to claim 35, characterized in that The width of the interdigital electrodes is 0.5 μm to 10 μm.

37. The Lamb wave resonator according to claim 35, characterized in that The thickness of the interdigital electrodes is 10 nm to 600 nm.

38. The Lamb wave resonator according to claim 34, wherein: The pore size of the interdigital electrodes is 5 μm to 800 μm.

39. The Lamb wave resonator according to claim 38, wherein The pore size of the interdigital electrodes is 20 μm to 500 μm.

40. The Lamb wave resonator according to claim 39, wherein The pore size of the interdigital electrodes is 70 μm to 100 μm.

41. The Lamb wave resonator according to claim 40, characterized in that The pore size of the interdigital electrodes is, for example, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, or any range between any two of the above points or any point within the range.

42. The Lamb wave resonator according to claim 30, wherein The material of the interdigital electrodes, and the material of the first busbar electrode (5) and the second busbar electrode (4) are all materials with conductive properties.

43. The Lamb wave resonator according to claim 42, characterized in that The material of the interdigital electrodes, and the material of the first busbar electrode (5) and the second busbar electrode (4) are selected from one or more of graphene, topological semimetal, Al, Au, Pt, Cr, W, Mo, Ni, Fe and Ti.

44. The Lamb wave resonator according to claim 1, wherein It also includes a release window (11) arranged on the surface of the piezoelectric layer film, wherein the release window (11) is distributed on the lower side of the first bus bar electrode (5) and the upper side of the second bus bar electrode (4).

45. The Lamb wave resonator according to claim 44, characterized in that The release window (11) has a rectangular cross-section and is hollow. Four release windows are distributed on the lower side of the first busbar electrode (5), and three release windows are distributed on the upper side of the second busbar electrode (4).

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