Resonator, filter and electronic equipment
By placing filler blocks of different materials below the interdigitated electrodes in the resonator, the out-of-band spurious problem caused by the Bragg reflection layer was solved, achieving higher reflection efficiency and signal quality.
Patent Information
- Application Number
- CN202511704925.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-02-24
AI Technical Summary
In resonators, the introduction of Bragg reflector layers leads to additional out-of-band spurious emissions in acoustic resonators of modes such as SH and S0. In particular, when multiple Bragg reflector layers are set, severe out-of-band spurious emissions result in unwanted waveforms.
By placing a filler block of a different material than the high acoustic impedance layer in the high acoustic impedance layer region below the interdigitated electrode, the reflection at this location is reduced or eliminated. By controlling the width and position of the filler block, the probability of out-of-band straying is effectively reduced.
It effectively reduces or eliminates out-of-band spurious emissions, improves the performance of the resonator, reduces the occurrence of unwanted waveforms, and enhances reflection efficiency and signal quality.
Smart Images
Figure CN121567086A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and more specifically, to a resonator, filter, and electronic device. Background Technology
[0002] To suppress the leakage of acoustic energy into the volume, a Bragg reflector is typically incorporated into the resonator. The introduction of the Bragg reflector often introduces additional out-of-band spurious emissions into specific acoustic resonators of modes such as SH and S0. Summary of the Invention
[0003] According to the principle of Bragg reflection, the reflection efficiency increases with the number of reflective layers. Therefore, setting more Bragg reflective layers (e.g., four or more) in pursuit of higher reflection efficiency will lead to more severe out-of-band spurious emissions, resulting in unwanted waveforms.
[0004] Unrestricted by any theory, out-of-band spurs are primarily distributed within the stacked multilayer high acoustic impedance layers, and the resonant region of the out-of-band spurs is located directly below the interdigitated electrodes. (See [link to relevant documentation]). Figure 1 .
[0005] To address this, this application provides a resonator that reduces or eliminates reflections at a high acoustic impedance layer region located below the interdigital electrodes, thereby effectively reducing the probability of out-of-band spurious emissions.
[0006] In a first aspect, embodiments of this application provide a resonator comprising: a substrate layer, a Bragg reflector layer, a piezoelectric thin film layer, and an interdigitated electrode layer. The Bragg reflector layer is stacked on the substrate layer and includes alternating layers of low acoustic impedance (HA) and high acoustic impedance (HI) layers. The piezoelectric thin film layer is stacked on the side of the Bragg reflector layer away from the substrate layer. The interdigitated electrode layer is stacked on the side of the piezoelectric thin film layer away from the Bragg reflector layer and includes multiple interdigitated electrodes. The high acoustic impedance layer has a filler block, which is correspondingly disposed with the interdigitated electrodes. Along the stacking direction Z of the low and high acoustic impedance layers, the projections of the interdigitated electrodes and the projections of the filler block overlap. The thickness of the filler block is the same as the thickness of the high acoustic impedance layer. The material of the filler block is different from the material of the high acoustic impedance layer.
[0007] In the technical solution of this application embodiment, by setting a filler block of a different material than the high acoustic impedance layer in the high acoustic impedance layer region located below the interdigital electrode, the reflection at this location is reduced or eliminated, effectively reducing the probability of out-of-band straying.
[0008] As an alternative implementation, the material of the filler block includes at least one of metallic materials, oxide materials, organic materials, or inorganic materials.
[0009] In the above implementation process, selecting metallic materials, oxide materials, organic materials or inorganic materials as filler materials can effectively reduce or eliminate reflection at this location, thereby effectively reducing the probability of out-of-band straying.
[0010] As an alternative implementation, the filling block is made of the same material as the low acoustic impedance layer.
[0011] In the above implementation process, the material of the filler block is the same as that of the low acoustic impedance layer, which can better reduce or eliminate reflection at this location, thereby further reducing the probability of out-of-band straying.
[0012] As an optional implementation, along the direction X of the interdigitated electrode spacing, the relationship between the width W1 of the filler block and the width W2 of the interdigitated electrode satisfies: W1 / W2 = 0.6~1.4.
[0013] In the above implementation process, the wider the width of the filler block, the more beneficial it is to reduce or eliminate reflection at that location, thereby reducing the probability of out-of-band spurious emissions; the narrower the width of the filler block, the more beneficial it is to the reflection effect of the Bragg reflector layer. By controlling the ratio of the width W1 of the filler block to the width W2 of the interdigitated electrode to 0.6~1.4, it is possible to balance reducing the probability of out-of-band spurious emissions and the reflection effect of the Bragg reflector layer.
[0014] As an optional implementation, W1 / W2 = 0.8~1.2.
[0015] In the above implementation process, by controlling the ratio of the width W1 of the filler block to the width W2 of the interdigitated electrode to be 0.8~1.2, it is possible to better balance reducing the probability of out-of-band straying and the reflection effect of the Bragg reflector.
[0016] As an optional implementation, along the direction X of the interdigitated electrode spacing, the relationship between the distance L between the center line of the filler block and the center line of the interdigitated electrode and the width W2 of the interdigitated electrode satisfies: L / W2≤0.3.
[0017] In the above implementation process, the closer the filler block is to the direct below the interdigital electrode, the better it is to reduce or eliminate reflection at that location, thereby reducing the probability of out-of-band spurious emissions. By controlling the ratio of the distance L between the center line of the filler block and the center line of the interdigital electrode to the width W2 of the interdigital electrode to less than 0.3, the probability of out-of-band spurious emissions can be effectively reduced.
[0018] As an optional implementation, the filling block is made of at least two materials, and each material is stacked along the stacking direction Z of the low acoustic impedance layer and the high acoustic impedance layer.
[0019] In the above implementation process, the use of two materials to form the filler block can effectively reduce or eliminate reflection at that location under certain conditions, thereby reducing the probability of out-of-band straying.
[0020] As an optional implementation, the number of high acoustic impedance layers is at least two; the filling block is disposed on any one of the high acoustic impedance layers.
[0021] In the above implementation process, setting a filler block in any high acoustic impedance layer can improve out-of-band straying to a certain extent.
[0022] As an optional implementation, the number of high acoustic impedance layers is at least two, with the filler block disposed in the high acoustic impedance layer closest to the piezoelectric thin film layer.
[0023] In the above implementation process, placing the filler block in the high acoustic impedance layer closest to the piezoelectric thin film layer can better improve out-of-band straying compared to placing it in other positions.
[0024] As an optional implementation, the number of high acoustic impedance layers is at least two, and all high acoustic impedance layers are provided with filler blocks.
[0025] In the above implementation process, all high acoustic impedance layers are equipped with filler blocks, which can effectively improve out-of-band straying.
[0026] As an alternative implementation, the substrate material includes at least one of silicon, quartz, or polyimide.
[0027] As an alternative implementation, the material of the low acoustic impedance layer includes silicon dioxide.
[0028] As an alternative implementation, the material of the high acoustic impedance layer includes at least one of tungsten, molybdenum, platinum, aluminum nitride, hafnium oxide, or tantalum oxide.
[0029] As an alternative implementation, the material of the piezoelectric thin film layer includes at least one of aluminum nitride, doped aluminum nitride, zinc oxide, lead zirconate titanate, lithium niobate, or lithium tantalate.
[0030] As an alternative implementation, the material of the interdigitated electrode layer includes at least one of Ti, Al, Cu, Au, Pt, Ag, Pd, or Ni.
[0031] Secondly, embodiments of this application provide a filter, which includes the resonator provided in the first aspect.
[0032] Thirdly, embodiments of this application provide an electronic device that includes the filter provided in the second aspect. Attached Figure Description
[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0035] Figure 1 Vibrations at the noise point of resonators with different numbers of Bragg reflectors are provided for implementation of this application, wherein (a) is a resonator with two Bragg reflectors (one low acoustic impedance layer + one high acoustic impedance layer), (b) is a resonator with three Bragg reflectors (two low acoustic impedance layers + one high acoustic impedance layer), (c) is a resonator with four Bragg reflectors (two low acoustic impedance layers + two high acoustic impedance layers), (d) is a resonator with five Bragg reflectors (three low acoustic impedance layers + two high acoustic impedance layers), and (e) is a resonator with six Bragg reflectors (three low acoustic impedance layers + three high acoustic impedance layers).
[0036] Figure 2 A schematic diagram of the resonator provided in the embodiments of this application. Figure 1 .
[0037] Figure 3 A schematic diagram of the resonator provided in the embodiments of this application. Figure 2 .
[0038] Figure 4 The test waveform results of the resonator provided in Comparative Example 1 of this application are shown.
[0039] Figure 5 The test waveform results of the resonator provided in Embodiment 1 of this application are shown.
[0040] Figure 6 The test waveform results of the resonator provided in Embodiment 2 of this application are shown.
[0041] Figure 7 The test waveform results of the resonator provided in Embodiment 3 of this application are shown.
[0042] Figure 8 The test waveform results of the resonator provided in Embodiment 4 of this application are shown.
[0043] Figure 9 The test waveform results of the resonator provided in Embodiment 5 of this application are shown.
[0044] Figure 10The test waveform results of the resonator provided in Embodiment 6 of this application are shown.
[0045] Figure 11 The test waveform results of the resonator provided in Embodiment 7 of this application are shown.
[0046] Figure 12 The test waveform results of the resonator provided in Embodiment 8 of this application are shown.
[0047] Figure 13 The test waveform results of the resonator provided in Embodiment 9 of this application are shown.
[0048] Figure reference numerals: 1-substrate layer; 2-Bracket reflector layer; 21-low acoustic impedance layer; 22-high acoustic impedance layer; 221-filler block; 3-piezoelectric thin film layer; 4-interdigital electrode layer; 41-interdigital electrode. Detailed Implementation
[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0050] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.
[0051] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.
[0052] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Furthermore, in the description of this application, terms such as "comprising" and "including" mean "including but not limited to." In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b or c" or "at least one of a, b and c" can both mean: a, b, c, ab (i.e. a and b), ac, bc, or abc, where a, b, and c can be a single or multiple.
[0053] To suppress the leakage of acoustic energy into the volume, a Bragg reflector is typically incorporated into the resonator. The introduction of the Bragg reflector often introduces additional out-of-band spurious emissions into specific acoustic resonators of modes such as SH and S0.
[0054] According to the principle of Bragg reflection, the reflection efficiency increases with the number of reflective layers. Therefore, setting more Bragg reflective layers (e.g., four or more) in pursuit of higher reflection efficiency will lead to more severe out-of-band spurious emissions, resulting in unwanted waveforms.
[0055] Unrestricted by any theory, out-of-band spurs are primarily distributed within the stacked multilayer high acoustic impedance layers, and the resonant region of the out-of-band spurs is located directly below the interdigitated electrodes. (See [link to relevant documentation]). Figure 1 .
[0056] Based on the above considerations, in order to reduce the probability of out-of-band spurious emissions from the resonator, this application provides a resonator comprising: a substrate layer, a Bragg reflector layer, a piezoelectric thin film layer, and an interdigital electrode layer. The Bragg reflector layer is stacked on the substrate layer and includes alternating layers of low acoustic impedance (HA) and high HA layers. The piezoelectric thin film layer is stacked on the side of the Bragg reflector layer away from the substrate layer. The interdigital electrode layer is stacked on the side of the piezoelectric thin film layer away from the Bragg reflector layer and includes multiple interdigital electrodes. The high HA layer has a filler block, which is correspondingly disposed with the interdigital electrodes. Along the stacking direction Z of the low and high HA layers, the projections of the interdigital electrodes and the filler block overlap. The thickness of the filler block is the same as the thickness of the high HA layer. The material of the filler block is different from the material of the high HA layer.
[0057] This resonator reduces or eliminates reflections at a location with a filler block made of a different material than the high acoustic impedance layer located below the interdigital electrodes, effectively lowering the probability of out-of-band spurious emissions.
[0058] This resonator can be used, but is not limited to, in electronic devices such as mobile phones, personal digital assistants (PDAs), or smart wearable devices.
[0059] This application provides an electronic device, including but not limited to radio frequency front-ends, filtering and amplification modules, and may also include mobile phones, tablets, smart wearable products (e.g., smartwatches, smart bracelets), virtual reality (VR) devices, augmented reality (AR) devices, drones, etc. Home electronic products include smart door locks, televisions, remote controls, refrigerators, and rechargeable small household appliances (e.g., soymilk makers, robot vacuum cleaners). In-vehicle electronic products include in-vehicle navigation systems and in-vehicle high-density digital video discs (DVDs). Financial terminal products include automated teller machines (ATMs) and self-service terminals. This application does not impose any special limitations on the specific form of the above-mentioned communication devices.
[0060] Electronic devices may include filters and circuit boards. The filter is mounted on the circuit board. Under the control of the circuit board, the filter can convert electrical signals into acoustic signals (sound waves) and back into electrical signals. During the conversion process, the filter can effectively filter out frequencies at specific frequencies or frequencies other than those frequencies in the signal to obtain a signal of a specific frequency or to eliminate a signal after a specific frequency, thereby improving the working performance of the electronic device.
[0061] The filters provided in this application embodiment can be, for example, low-pass acoustic filters, high-pass acoustic filters, band-pass acoustic filters, band-stop acoustic filters, or active acoustic filters.
[0062] In this embodiment, the filter may include multiple acoustic resonators connected in series, or multiple acoustic resonators connected in parallel, or a combination of series and parallel acoustic resonators.
[0063] Acoustic resonators can be classified into bulk acoustic wave (BAW) resonators and surface acoustic wave (SAW) resonators, etc.
[0064] In this filter, at least one acoustic resonator can be a bulk acoustic wave (BAW). The main working principle of a bulk acoustic wave resonator is to use the piezoelectric properties of piezoelectricity to convert the input signal of the radio wave into mechanical energy through input and output transducers, thereby generating reliable oscillation and realizing high-frequency clock output.
[0065] Bulk acoustic wave (BAW) resonators, as one of the filter design units, have advantages over surface acoustic wave (SAW) resonators, such as high frequency, high power capacity, and high Q value. They are considered to replace SAW and dominate 5G and future 6G mobile communication filtering technologies. Based on their structure, BAW resonators can be divided into free-edge beam resonators (FBARs) and solid-mounted resonators (SMRs).
[0066] Free-boundary resonators are characterized by a high quality factor (Q) and a large effective electromechanical coupling coefficient. However, because the electrodes are located beneath air, which is a poor thermal conductor, the heat dissipation of these resonators is very poor. This leads to high temperatures under high power operation, making the resonator susceptible to damage and affecting its power handling capability. Solid-state resonators, on the other hand, use a Bragg radiation layer beneath the electrodes to simulate the reflection of sound waves by the air. This structure allows the heat generated by the resonator to dissipate effectively from the substrate, resulting in excellent power handling capability. The electromechanical coupling coefficient is a key parameter of the resonator, reflecting the conversion efficiency between mechanical and electrical energy. It determines the difference between the series and parallel resonant frequencies of the resonator. When used in filter design, this difference directly determines the filter's bandwidth. Generally, a larger electromechanical coupling coefficient indicates higher resonator conversion efficiency, a larger filter bandwidth, and better performance.
[0067] Besides power handling and electromechanical coupling coefficient, another crucial parameter for resonator performance is the quality factor Q. Factors affecting the quality factor Q include the resonator's stray response. The more effectively the stray response is suppressed, the higher the quality factor Q. The stray response of the resonator can cause ripples within the filter, increasing insertion loss and degrading performance. Therefore, suppressing the resonator's stray response is extremely important. The quality factor Q represents the energy efficiency of the device, that is, the ratio of the total energy received by the device to the energy dissipated within one oscillation cycle. In filter design, both the electromechanical coupling coefficient and the quality factor Q of the resonator constituting the filter are important parameters.
[0068] Figure 2 and Figure 3 For a schematic diagram of the resonator provided in the embodiments of this application, please refer to... Figure 2 and Figure 3 This application provides a resonator comprising: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 is provided with a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the projections of the filler block 221 overlap. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0069] The material of the substrate layer 1 can be selected from at least one of silicon, quartz or polyimide.
[0070] The material of the low acoustic impedance layer 21 can be selected from silicon dioxide. Since the positive temperature coefficient of silicon dioxide can reduce the device's TCF, silicon dioxide is commonly used as the material for the low acoustic impedance layer 21. The material of the high acoustic impedance layer 22 can be selected from at least one of tungsten, molybdenum, platinum, aluminum nitride, hafnium oxide, or tantalum oxide. The high acoustic impedance layer 22 and the low acoustic impedance layer 21 in the same layer can be composed of a single material or multiple different materials.
[0071] To meet the different electromechanical coupling coefficients required, different piezoelectric thin film layer 3 materials and their Euler angle tangents can be selected. The piezoelectric thin film layer 3 material can be selected from at least one of aluminum nitride, doped aluminum nitride, zinc oxide, lead zirconate titanate, lithium niobate, or lithium tantalate. It is important to note that different piezoelectric thin film layer 3 materials have different anisotropic characteristics, and even for the same piezoelectric thin film layer 3 material, different Euler angle tangents result in different anisotropic characteristics. Therefore, to suppress the transverse modes of the resonator, the piezoelectric thin film layer 3 is designed based on the material's anisotropic characteristics in the horizontal direction.
[0072] The material of the interdigitated electrode layer 4 includes at least one of Ti, Al, Cu, Au, Pt, Ag, Pd, or Ni. For example, it can be at least one pure metal selected from Ti, Al, Cu, Au, Pt, Ag, Pd, or Ni, or an alloy formed from at least one of Ti, Al, Cu, Au, Pt, Ag, Pd, or Ni. The interdigitated electrode layer 4 can be a single layer of interdigitated electrodes 41, i.e., a single layer of metal, or it can be formed by stacking and combining different metals.
[0073] Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the overlapping area between the projection of the interdigitated electrode 41 and the projection of the filler block 221 refers to: Figure 2 and Figure 3 Taking the resonator shown as an example, the filler block 221 is located directly below the interdigital electrode 41.
[0074] The resonator reduces or eliminates reflections at the high acoustic impedance layer 22 region located below the interdigital electrode 41 by setting a filler block 221 of a different material than the high acoustic impedance layer 22, thereby effectively reducing the probability of out-of-band spurious emissions.
[0075] In some embodiments, the material of the filler block 221 includes at least one of metallic materials, oxide materials, organic materials, or inorganic materials. Selecting metallic materials, oxide materials, organic materials, or inorganic materials as the material of the filler block 221 can better reduce or eliminate reflection at that location, thereby effectively reducing the probability of out-of-band straying.
[0076] For example, metallic materials can be tungsten, molybdenum, etc. Oxide materials can be silicon oxide, tantalum oxide, hafnium oxide, etc. Inorganic materials can be silicon carbide, silicon nitride, etc.
[0077] In some embodiments, the filler block 221 is made of the same material as the low acoustic impedance layer 21. The fact that the filler block 221 and the low acoustic impedance layer 21 are made of the same material allows for better reduction or elimination of reflection at that location, thereby further reducing the probability of out-of-band straying. For example, when the low acoustic impedance layer 21 is made of SiO2, the filler block 221 is also made of SiO2.
[0078] In some embodiments, along the direction X in which the interdigitated electrodes 41 are spaced apart, the relationship between the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 satisfies: W1 / W2 = 0.6~1.4.
[0079] The wider the filler block 221, the better it is for reducing or eliminating reflection at that location, thereby reducing the probability of out-of-band spurious emissions; the narrower the filler block 221, the better it is for the reflection effect of the Bragg reflector layer 2. By controlling the ratio of the width W1 of the filler block 221 to the width W2 of the interdigitated electrode 41 to 0.6~1.4, it is possible to balance reducing the probability of out-of-band spurious emissions with the reflection effect of the Bragg reflector layer 2.
[0080] For example, along the direction X in which the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 can be 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3 or 1.4, etc., or it can be any value in the range of 0.6 to 1.4.
[0081] In some embodiments, W1 / W2 = 0.8 to 1.2. By controlling the ratio of the width W1 of the filler block 221 to the width W2 of the interdigitated electrode 41 to be 0.8 to 1.2, it is possible to better balance reducing the probability of out-of-band spurious emissions and improving the reflection effect of the Bragg reflector layer 2.
[0082] In some embodiments, along the direction X in which the interdigitated electrodes 41 are spaced apart, the relationship between the distance L between the center line of the filler block 221 and the center line of the interdigitated electrode 41 and the width W2 of the interdigitated electrode 41 satisfies: L / W2 ≤ 0.3. The closer the filler block 221 is to the direct below the interdigitated electrode 41, the better it is to reduce or eliminate reflection at that location, thereby reducing the probability of out-of-band spurious emissions. By controlling the ratio of the distance L between the center line of the filler block 221 and the center line of the interdigitated electrode 41 to the width W2 of the interdigitated electrode 41 to be less than 0.3, the probability of out-of-band spurious emissions can be effectively reduced.
[0083] For example, along the direction X in which the interdigitated electrodes 41 are distributed, the ratio of the distance L between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 can be 0, 0.05, 0.1, 0.15, 0.2, 0.25 or 0.3, etc., or it can be any value in the range of ≤0.3.
[0084] In some embodiments, the filler block 221 is made of at least two materials, which are stacked along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22. Using two materials to form the filler block 221 can better reduce or eliminate reflection at that location under certain conditions, thereby reducing the probability of out-of-band straying.
[0085] In some embodiments, the number of high acoustic impedance layers 22 is at least one; the filler block 221 is disposed on any one of the high acoustic impedance layers 22. Disposing of the filler block 221 on any one of the high acoustic impedance layers 22 can improve out-of-band spurious emissions to some extent. For example, when the Bragg reflector layer 2 of the resonator has six layers (three low acoustic impedance layers 21 + three high acoustic impedance layers 22), the filler block 221 can be disposed on the high acoustic impedance layer 22 closest to the piezoelectric thin film layer 3, or on the high acoustic impedance layer 22 furthest from the piezoelectric thin film layer 3, or on a high acoustic impedance layer 22 located in the middle.
[0086] In some embodiments, the number of high acoustic impedance layers 22 is at least two, and the filler block 221 is disposed in the high acoustic impedance layer 22 closest to the piezoelectric thin film layer 3. Disposing the filler block 221 in the high acoustic impedance layer 22 closest to the piezoelectric thin film layer 3 can better improve out-of-band spurious emissions compared to disposing it in other locations. For example, when the Bragg reflector layer 2 of the resonator has six layers (three low acoustic impedance layers 21 + three high acoustic impedance layers 22), the filler block 221 can be disposed in the high acoustic impedance layer 22 closest to the piezoelectric thin film layer 3.
[0087] In some embodiments, the number of high acoustic impedance layers 22 is at least two, and all high acoustic impedance layers 22 are provided with filler blocks 221. Providing filler blocks 221 to all high acoustic impedance layers 22 can effectively improve out-of-band spurious emissions. For example, when the Bragg reflector layer 2 of the resonator has five layers (three low acoustic impedance layers 21 + two high acoustic impedance layers 22), both high acoustic impedance layers 22 are provided with filler blocks 221.
[0088] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.
[0089] Example 1 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0090] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of two layers (one low acoustic impedance layer 21 and one high acoustic impedance layer 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; All high acoustic impedance layers 22 are provided with filler blocks 221, and the thickness of the filler blocks 221 is the same as that of the high acoustic impedance layers 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The material of filler block 221 is silicon dioxide.
[0091] Example 2 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0092] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of two layers (one low acoustic impedance layer 21 and one high acoustic impedance layer 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; All high acoustic impedance layers 22 are provided with filler blocks 221, and the thickness of the filler blocks 221 is the same as that of the high acoustic impedance layers 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The material of filler block 221 is hafnium oxide.
[0093] Example 3 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0094] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of two layers (one low acoustic impedance layer 21 and one high acoustic impedance layer 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; All high acoustic impedance layers 22 are provided with filler blocks 221, and the thickness of the filler blocks 221 is the same as that of the high acoustic impedance layers 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The material of filler block 221 is tungsten.
[0095] Example 4 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0096] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of two layers (one low acoustic impedance layer 21 and one high acoustic impedance layer 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; All high acoustic impedance layers 22 are provided with filler blocks 221, and the thickness of the filler blocks 221 is the same as that of the high acoustic impedance layers 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The material of filler block 221 is molybdenum.
[0097] Example 5 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0098] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of two layers (one low acoustic impedance layer 21 and one high acoustic impedance layer 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; All high acoustic impedance layers 22 are provided with filler blocks 221, and the thickness of the filler blocks 221 is the same as that of the high acoustic impedance layers 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The filler block 221 is made of tantalum oxide and tungsten. The two materials are stacked together along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, and the thicknesses are the same.
[0099] Example 6 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0100] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of two layers (one low acoustic impedance layer 21 and one high acoustic impedance layer 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; All high acoustic impedance layers 22 are provided with filler blocks 221, and the thickness of the filler blocks 221 is the same as that of the high acoustic impedance layers 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The filler block 221 is made of silicon oxide and tungsten. The two materials are stacked together along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, and the thicknesses are the same.
[0101] Example 7 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0102] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of 4 layers (2 low acoustic impedance layers 21 + 2 high acoustic impedance layers 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; All high acoustic impedance layers 22 are provided with filler blocks 221, and the thickness of the filler blocks 221 is the same as that of the high acoustic impedance layers 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The material of filler block 221 is tungsten.
[0103] Example 8 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0104] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of 4 layers (2 low acoustic impedance layers 21 + 2 high acoustic impedance layers 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; Only the high acoustic impedance layer 22 closest to the piezoelectric thin film layer 3 has a filling block 221, and the thickness of the filling block 221 is the same as that of the high acoustic impedance layer 22. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The material of filler block 221 is tungsten.
[0105] Example 9 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0106] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of 4 layers (2 low acoustic impedance layers 21 + 2 high acoustic impedance layers 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm; The thickness of the filler block 221 is the same as that of the high acoustic impedance layer 22; Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio W1 / W2 of the width W1 of the filling block 221 and the width W2 of the interdigitated electrodes 41 is 1. Along the direction X where the interdigitated electrodes 41 are spaced apart, the ratio L / W2 of the distance between the center line of the filling block 221 and the center line of the interdigitated electrodes 41 to the width W2 of the interdigitated electrodes 41 is 0. The material of filler block 221 is tungsten.
[0107] Comparative Example 1 A resonator includes: a substrate layer 1, a Bragg reflector layer 2, a piezoelectric thin film layer 3, and an interdigitated electrode layer 4. The Bragg reflector layer 2 is stacked on the substrate layer 1 and includes alternating layers of low acoustic impedance layer 21 and high acoustic impedance layer 22. The piezoelectric thin film layer 3 is stacked on the side of the Bragg reflector layer 2 away from the substrate layer 1. The interdigitated electrode layer 4 is stacked on the side of the piezoelectric thin film layer 3 away from the Bragg reflector layer 2 and includes a plurality of interdigitated electrodes 41. The high acoustic impedance layer 22 has a filler block 221. Along the stacking direction Z of the low acoustic impedance layer 21 and the high acoustic impedance layer 22, the projections of the interdigitated electrodes 41 and the filler block 221 have an overlapping area. The thickness of the filler block 221 is the same as the thickness of the high acoustic impedance layer 22. The material of the filler block 221 is different from the material of the high acoustic impedance layer 22.
[0108] The substrate layer 1 is made of silicon. The Bragg reflector layer 2 consists of two layers (one low acoustic impedance layer 21 and one high acoustic impedance layer 22). The material of the low acoustic impedance layer 21 is silicon dioxide with a single layer thickness of 600 nm, and the material of the high acoustic impedance layer 22 is tantalum oxide with a single layer thickness of 600 nm. The piezoelectric thin film layer 3 is made of lithium tantalate, has an Euler angle of Y42, and a thickness of 600 nm; The interdigitated electrode 41 in the interdigitated electrode layer 4 is an Al electrode with a thickness of 180 nm.
[0109] The resonators provided in Examples 1 to 9 and Comparative Example 1 were tested, and the results are as follows: Figures 4 to 13 As shown. By Figures 4 to 13 It can be seen that filling with materials with higher acoustic impedance (such as metal) is more effective. Filling can effectively reduce stray resonances around the main resonance.
[0110] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A resonator, characterized in that, The resonator includes: Substrate layer; A Bragg reflector layer, wherein the Bragg reflector layer is stacked on the substrate layer, and the Bragg reflector layer includes alternating layers of low acoustic impedance and high acoustic impedance; A piezoelectric thin film layer is stacked on the side of the Bragg reflective layer away from the substrate layer; An interdigitated electrode layer is stacked on the side of the piezoelectric thin film layer away from the Bragg reflector layer, and the interdigitated electrode layer includes a plurality of interdigitated electrodes; The high acoustic impedance layer is provided with a filler block, which is correspondingly disposed with the interdigitated electrode. Along the stacking direction Z of the low acoustic impedance layer and the high acoustic impedance layer, the projection of the interdigitated electrode and the projection of the filler block have an overlapping area. The thickness of the filler block is the same as the thickness of the high acoustic impedance layer. The material of the filler block is different from the material of the high acoustic impedance layer.
2. The resonator according to claim 1, characterized in that, The material of the filler block includes at least one of metallic materials, oxide materials, organic materials, or inorganic materials.
3. The resonator according to claim 1 or 2, characterized in that, The filling block is made of the same material as the low acoustic impedance layer.
4. The resonator according to claim 1, characterized in that, Along the direction X of the interdigitated electrode spacing, the relationship between the width W1 of the filling block and the width W2 of the interdigitated electrode satisfies: W1 / W2 = 0.6~1.
4.
5. The resonator according to claim 4, characterized in that, W1 / W2 = 0.8~1.
2.
6. The resonator according to claim 1, characterized in that, Along the direction X of the interdigitated electrode spacing, the relationship between the distance L between the center line of the filler block and the center line of the interdigitated electrode and the width W2 of the interdigitated electrode satisfies: L / W2≤0.
3.
7. The resonator according to claim 1, characterized in that, The filling block is made of at least two materials, and each material is stacked along the stacking direction Z of the low acoustic impedance layer and the high acoustic impedance layer.
8. The resonator according to claim 1, characterized in that, The number of high acoustic impedance layers is at least two; the filling block is disposed on any one of the high acoustic impedance layers.
9. The resonator according to claim 8, characterized in that, The number of high acoustic impedance layers is at least two, and the filler block is disposed on the high acoustic impedance layer closest to the piezoelectric thin film layer.
10. The resonator according to claim 1, characterized in that, The number of high acoustic impedance layers is at least two, and all of the high acoustic impedance layers are provided with the filling block.
11. The resonator according to claim 1, characterized in that, The substrate layer is made of at least one of silicon, quartz, or polyimide; and / or The material of the low acoustic impedance layer includes silicon dioxide; and / or The material of the high acoustic impedance layer includes at least one of tungsten, molybdenum, platinum, aluminum nitride, hafnium oxide, or tantalum oxide; and / or The material of the piezoelectric thin film layer includes at least one of aluminum nitride, doped aluminum nitride, zinc oxide, lead zirconate titanate, lithium niobate, or lithium tantalate; and / or The material of the interdigitated electrode layer includes at least one of Ti, Al, Cu, Au, Pt, Ag, Pd, or Ni.
12. A filter, characterized in that, The filter includes the resonator according to any one of claims 1 to 11.
13. An electronic device, characterized in that, The electronic device includes the filter as described in claim 12.