WO2022193419A1 - Procédé de préparation d'un résonateur acoustique et résonateur acoustique - Google Patents

Procédé de préparation d'un résonateur acoustique et résonateur acoustique Download PDF

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Publication number
WO2022193419A1
WO2022193419A1 PCT/CN2021/092031 CN2021092031W WO2022193419A1 WO 2022193419 A1 WO2022193419 A1 WO 2022193419A1 CN 2021092031 W CN2021092031 W CN 2021092031W WO 2022193419 A1 WO2022193419 A1 WO 2022193419A1
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WIPO (PCT)
Prior art keywords
acoustic
layer
electrode layer
bottom electrode
mirror
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PCT/CN2021/092031
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English (en)
Chinese (zh)
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龚颂斌
吕若辰
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偲百创(深圳)科技有限公司
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Publication of WO2022193419A1 publication Critical patent/WO2022193419A1/fr

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator

Definitions

  • the present application relates to the technical field of resonators, and in particular, to a preparation method of an acoustic resonator and an acoustic resonator.
  • the filter has the function of frequency selection, that is, it allows the signal of the required frequency to pass, and suppresses the signal of the unwanted frequency to pass. It is an extremely important component in the field of microwave communication and is widely used in mobile communication, satellite communication, radar and other microwave communication. communication field. Filters usually consist of multiple resonators interconnected by electrodes.
  • a method for preparing an acoustic resonator comprising the following steps:
  • a piezoelectric substrate comprising lithium niobate and/or lithium tannate
  • An acoustic mirror is formed on the bottom electrode layer;
  • the acoustic mirror includes at least a first acoustic reflection layer and at least a second acoustic reflection layer, and the acoustic impedance of each of the first acoustic reflection layers is smaller than the acoustic impedance of each of the second acoustic reflection layers impedance, the first acoustic reflection layer and the second acoustic reflection layer are alternately stacked, and the first acoustic reflection layer is closest to the bottom electrode layer;
  • the carrier wafer is bonded on the first surface of the acoustic mirror, and the first surface of the acoustic mirror is the side away from the bottom electrode;
  • An upper electrode layer is formed on the second surface of the piezoelectric substrate.
  • the step of bonding the carrier wafer to the first surface of the acoustic mirror includes:
  • An auxiliary layer is deposited on the bonding surface of the carrier wafer.
  • the thickness of each first acoustic reflection layer is gradually increased from the bottom electrode layer to the direction of the carrier wafer; the thickness of each second acoustic reflection layer is from the bottom electrode layer to the direction of the carrier wafer gradually increase.
  • the step of bonding the carrier wafer to the first surface of the acoustic mirror includes:
  • a filling layer is deposited on the piezoelectric substrate to fill the positions where the bottom electrode layer and the acoustic mirror are removed by etching.
  • the step includes:
  • the first sound reflection layer and the second sound reflection filling layer are alternately formed in sequence.
  • the filling layer is made of the same material as each of the first acoustic reflection layers.
  • the forming a bottom electrode on the first surface of the piezoelectric substrate includes: depositing an electrode material on the first surface of the piezoelectric substrate and etching to form the bottom electrode layer;
  • the forming of the acoustic mirror on the bottom electrode layer includes:
  • Step A depositing a low acoustic impedance material to form a first acoustic reflection layer
  • Step B depositing a high acoustic impedance material on the low acoustic impedance material
  • Step C etching the deposited high acoustic impedance material to form a second acoustic reflection layer
  • the method further includes depositing a filling layer on the piezoelectric substrate to fill the bottom electrode where the layers and acoustic mirrors are removed by etching;
  • the low acoustic impedance material includes at least one of silicon dioxide, aluminum, benzocyclobutene, polyimide and spin glass
  • the high acoustic impedance material includes molybdenum, tungsten, titanium, platinum, nitride At least one of aluminum, tungsten oxide, and silicon nitride.
  • forming the upper electrode layer on the second surface of the piezoelectric substrate includes:
  • a second electrode layer is deposited on the patterned first electrode layer, and the thickness of the second electrode layer is greater than that of the first electrode layer.
  • the method further includes: depositing a passivation layer on the first electrode layer.
  • an acoustic resonator comprising:
  • an acoustic mirror comprising at least one first acoustic reflection layer and at least one second acoustic reflection layer, and the acoustic impedance of each of the first acoustic reflection layers is smaller than the acoustic impedance of each of the second acoustic reflection layers;
  • a bottom electrode layer located on the acoustic mirror, a first acoustic reflection layer of the acoustic mirror is closer to the bottom electrode layer than all the second acoustic reflection layers;
  • a piezoelectric substrate located on the side of the bottom electrode layer away from the acoustic mirror, the piezoelectric layer comprising lithium niobate and/or lithium tantalate;
  • the upper electrode layer is located on the side of the piezoelectric substrate away from the bottom electrode layer.
  • the preparation method of the above-mentioned acoustic resonator provides a piezoelectric substrate comprising one of lithium niobate and lithium tantalate, and deposits a first acoustic reflection layer on the bottom electrode layer, by selecting a specific direction of the piezoelectric substrate,
  • the acoustic resonator prepared by the above-mentioned preparation method of the acoustic resonator can be excited into a shear vibration mode in the thickness direction, because the acoustic resonator adopts a more superior shear vibration mode in the thickness direction and selects niobic acid that can support the vibration mode.
  • Lithium or lithium tannate material therefore, this acoustic resonator can support high electromechanical coupling at frequencies above 3GHz.
  • FIG. 1 is a flowchart of a method for preparing an acoustic resonator provided in the first embodiment
  • FIG. 2 is a schematic cross-sectional structural diagram of a structure obtained in S102 in a method for preparing an acoustic resonator provided in an embodiment
  • FIG. 3 is a schematic cross-sectional structural diagram of a structure obtained in S104 in a method for preparing an acoustic resonator provided in an embodiment
  • FIG. 4 is a schematic cross-sectional structural diagram of a structure obtained in S106 in a method for preparing an acoustic resonator provided in an embodiment
  • FIG. 5 is a schematic cross-sectional structural diagram of a structure obtained in S108 in a method for preparing an acoustic resonator provided in an embodiment
  • FIG. 6 is a schematic cross-sectional structural diagram of a structure obtained in S110 in a method for preparing an acoustic resonator provided in an embodiment
  • FIG. 8 is a schematic cross-sectional structural diagram of the structure obtained in S702 in the technical process of “forming an upper electrode layer on the second surface of the piezoelectric substrate” provided in an embodiment
  • FIG. 9 is a schematic cross-sectional structure diagram of the structure obtained in S704 in the technical process of “forming an upper electrode layer on the second surface of the piezoelectric substrate” provided in an embodiment
  • FIG. 10 is a schematic cross-sectional structural diagram of the structure obtained in S706 in the technical process of “forming an upper electrode layer on the second surface of the piezoelectric substrate” provided in an embodiment
  • FIG. 11 is a schematic cross-sectional structural diagram of a structure obtained by a technical process of “depositing a passivation layer on the first electrode layer” provided in an embodiment
  • FIG. 12 is a schematic cross-sectional structural diagram of a structure obtained by the technical process of “forming three first acoustic reflection layers and two second acoustic reflection layers” provided in an embodiment;
  • FIG. 13 is a flowchart of a technical process before S108 in a method for manufacturing an acoustic resonator provided in an embodiment
  • 14a is a schematic cross-sectional structure diagram of the structure obtained in S1302 in the technical process before S108 in the method for manufacturing an acoustic resonator provided in the second embodiment;
  • 14b is a schematic cross-sectional structure diagram of the structure obtained in S1302 in the technical process before S108 in the method for manufacturing an acoustic resonator provided in the third embodiment;
  • 14c is a schematic cross-sectional structure diagram of the structure obtained in S1302 in the technical process before S108 in the method for manufacturing an acoustic resonator provided in the fourth embodiment;
  • 16 is a schematic cross-sectional structural diagram of a structure obtained by a technical process between S104 and S108 in a method for manufacturing an acoustic resonator provided in an embodiment
  • 17 is a flowchart of a method for manufacturing an acoustic resonator provided in the fifth embodiment
  • FIG. 19 is a schematic cross-sectional structure diagram of an acoustic resonator provided in an embodiment.
  • first doping type becomes the second doping type
  • second doping type can be the first doping type
  • the first doping type and the second doping type are different doping types, for example,
  • the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.
  • Spatial relational terms such as “under”, “below”, “below”, “under”, “above”, “above”, etc., in This may be used to describe the relationship of one element or feature to other elements or features shown in the figures. It should be understood that in addition to the orientation shown in the figures, the spatially relative terms encompass different orientations of the device in use and operation. For example, if the device in the figures is turned over, elements or features described as “below” or “beneath” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary terms “below” and “under” can encompass both an orientation of above and below. In addition, the device may also be otherwise oriented (eg, rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.
  • Embodiments of the invention are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention, such that variations in the shapes shown may be contemplated due, for example, to manufacturing techniques and/or tolerances. Accordingly, embodiments of the present invention should not be limited to the particular shapes of the regions shown herein, but include shape deviations due, for example, to manufacturing techniques. For example, an implanted region shown as a rectangle typically has rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface over which the implantation proceeds. Thus, the regions shown in the figures are schematic in nature and their shapes do not represent the actual shape of a region of a device and do not limit the scope of the invention.
  • the present invention provides a preparation method of an acoustic resonator, comprising the following steps:
  • S102 Provide a piezoelectric substrate, where the piezoelectric substrate includes lithium niobate and/or lithium tantalate.
  • a piezoelectric substrate 202 is provided.
  • the piezoelectric substrate 202 may include lithium niobate and/or lithium tantalate.
  • the thickness of the piezoelectric substrate is achieved by grinding and polishing the piezoelectric substrate to achieve a desired thickness.
  • the present application does not limit the thickness of the piezoelectric substrate, and the thickness of the piezoelectric substrate can be set as required.
  • the thickness of the piezoelectric substrate is less than 1 micron.
  • the surface roughness of the piezoelectric substrate can be reduced by polishing treatment, and a bright and flat surface of the piezoelectric substrate can be obtained, which facilitates the formation of a subsequent layer structure.
  • a bottom electrode layer 302 is formed on the first surface of the piezoelectric substrate 202 .
  • the bottom electrode layer 302 may be a single-layer structure or a multi-layer structure.
  • the bottom electrode layer 302 may include one or more of molybdenum, tungsten, ruthenium, platinum, titanium, aluminum, aluminum copper, aluminum silicon copper, and chromium.
  • S106 forming an acoustic mirror on the bottom electrode layer; the acoustic mirror includes at least one first acoustic reflection layer and at least one second acoustic reflection layer, and the acoustic impedance of each first acoustic reflection layer is smaller than the acoustic impedance of each second acoustic reflection layer, The first acoustic reflection layers and the second acoustic reflection layers are alternately stacked, and the one closest to the bottom electrode layer is the first acoustic reflection layer.
  • an acoustic mirror 402 is formed on the bottom electrode layer 302 .
  • the acoustic mirror 402 includes at least one first acoustic reflection layer and at least one second acoustic reflection layer, the acoustic impedance of each first acoustic reflection layer is smaller than the acoustic impedance of each second acoustic reflection layer, the first acoustic reflection layer and the second acoustic reflection layer
  • the two acoustic reflection layers are alternately stacked and the one closest to the bottom electrode layer 302 is the first acoustic reflection layer.
  • the acoustic mirror 402 includes two first acoustic reflection layers (a first acoustic reflection layer 404 and a first acoustic reflection layer 406 ) and a second acoustic reflection layer (Second acoustic reflection layer 408).
  • the first acoustic reflection layer 404 is disposed on the bottom electrode layer 302
  • the second acoustic reflection layer 408 is disposed on the first acoustic reflection layer 404
  • the first acoustic reflection layer 406 is disposed on the second acoustic reflection layer 408 .
  • the acoustic impedances of the first acoustic reflection layer 404 and the second acoustic reflection layer 406 are both smaller than the acoustic impedance of the second acoustic reflection layer 408 .
  • the above-mentioned acoustic mirror can also take other forms, and is not limited to the forms already mentioned in the above-mentioned embodiments.
  • the number of layers of the acoustic mirror can be set as required.
  • the number of layers of the acoustic mirror may be 2-7 layers.
  • S108 Bond the carrier wafer on the first surface of the acoustic mirror, where the first surface of the acoustic mirror is the side away from the bottom electrode.
  • a carrier wafer 504 is bonded to the first surface of the acoustic mirror 402 .
  • the first surface of the acoustic mirror is the side away from the bottom electrode.
  • the first surface of the acoustic mirror 402 is the upper surface of the first reflection layer 404 .
  • the first surface of the acoustic mirror 402 and the bonding surface of the carrier wafer 404 are bonded into one body.
  • the carrier wafer may include one or more of silicon, sapphire, and quartz.
  • the second surface of the piezoelectric substrate 202 is subjected to grinding treatment, so that the thickness of the piezoelectric substrate 202 is reduced to reach a desired thickness.
  • the thickness of the piezoelectric substrate after grinding is less than 1 micrometer.
  • an upper electrode layer 602 is formed on the second surface of the piezoelectric substrate 202 .
  • the conductive layer is formed on the piezoelectric substrate by sputtering technology, etc., and then the upper electrode layer is formed by patterning.
  • FIG. 7 shows an exemplary technical process of “forming an upper electrode layer on the second surface of a piezoelectric substrate” provided by an embodiment of the present application.
  • the technical process may include The following steps:
  • a first electrode layer 802 is deposited on the second surface of the piezoelectric substrate 202 .
  • the first electrode layer is a metal material.
  • the first electrode layer includes at least one of aluminum, titanium, chromium, molybdenum, tungsten, copper, aluminum silicon copper alloy (AlSiCu) or any other alloy of these materials.
  • S706 depositing a second electrode layer on the patterned first electrode layer, where the thickness of the second electrode layer is greater than that of the first electrode layer.
  • a second electrode layer 1002 is deposited on the patterned first electrode layer 902 , and the thickness of the second electrode layer 1002 is greater than that of the first electrode layer 902 .
  • the second electrode layer 1002 is deposited and patterned to direct the signal from the acoustic resonator to the pad.
  • the second electrode layer 1002 includes at least one of aluminum, titanium, chromium, molybdenum, tungsten, copper, aluminum silicon copper alloy (AlSiCu), or any other alloy of these materials.
  • the structure formed by depositing and patterning the second electrode layer 1002 further includes the tops of the bus bar regions connected to all the interdigitated electrodes.
  • the method may further include: depositing a passivation layer on the first electrode layer.
  • a passivation layer 1102 is deposited on the first electrode layer 902 .
  • the passivation layer 1102 may include one of silicon dioxide and silicon nitride.
  • a passivation layer 1102 is deposited on the first electrode layer 902, and the passivation layer 1102 is patterned to provide passivation and temperature compensation for the acoustic resonator.
  • the preparation method of the above-mentioned acoustic resonator provides a piezoelectric substrate comprising one of lithium niobate and lithium tantalate, and deposits a first acoustic reflection layer on the bottom electrode layer, by selecting a specific direction of the piezoelectric substrate,
  • the acoustic resonator prepared by the above-mentioned preparation method of the acoustic resonator can be excited into a shear vibration mode in the thickness direction, because the acoustic resonator adopts a more superior shear vibration mode in the thickness direction and selects niobic acid that can support the vibration mode.
  • Lithium or lithium tannate material therefore, this acoustic resonator can support high electromechanical coupling at frequencies above 3GHz.
  • the above embodiments describe the setting of the number of layers of the acoustic mirror. Different thicknesses of the layers of the acoustic mirror will also affect the performance of the acoustic resonator. In order to further improve the performance of the acoustic resonator, the following embodiments will briefly describe the setting of the thicknesses of the first acoustic reflection layer and the second acoustic reflection layer of the acoustic resonator.
  • the thickness of each first acoustic reflection layer is equal, and the thickness of each second acoustic reflection layer is equal;
  • the thickness of the second acoustic reflective layer gradually decreases from the bottom electrode layer to the direction of the carrier wafer; optionally, the thicknesses of the first acoustic reflective layer closest to the bottom electrode layer and the first acoustic reflective layer closest to the base are greater than those in the middle.
  • the thickness of the first acoustic reflection layer of the layer, the thickness of the second acoustic reflection layer closest to the bottom electrode layer and the thickness of the second acoustic reflection layer closest to the base electrode are greater than the thickness of the second acoustic reflection layer of the intermediate layer.
  • each first acoustic reflection layer and each second acoustic reflection layer of the above acoustic mirror may also adopt other forms, which are not limited to the forms already mentioned in the above embodiments.
  • the embodiments of the present application do not limit the thickness relationship between the first acoustic reflection layer and the second acoustic reflection layer.
  • the thickness relationship between the first acoustic reflection layer and the second acoustic reflection layer may be set according to the materials of the first acoustic reflection layer and the second acoustic reflection layer.
  • the thickness of the first acoustic reflection layer of the acoustic mirror provided by the above embodiment gradually increases from the bottom electrode layer to the direction of the carrier wafer; the thickness of each second acoustic reflection layer is determined by the bottom electrode layer. Gradually increase in the direction of the carrier wafer.
  • the acoustic mirror provided by the above embodiment can achieve the maximum quality factor under the same conditions.
  • an exemplary technical process of "forming an acoustic mirror on a bottom electrode layer” includes: forming three layers of a first acoustic reflection layer and two layers of a second acoustic mirror reflective layer.
  • a second sound reflection layer 1204 is formed on the first sound reflection layer 1202
  • a first sound reflection layer 1206 is formed on the second sound reflection layer 1204
  • a first sound reflection layer 1206 is formed on the first sound reflection layer 1206
  • the second acoustic reflection layer 1208 , and the first acoustic reflection layer 1210 is formed on the second acoustic reflection layer 1208 .
  • the first surface of the acoustic mirror 1200 provided in this embodiment is the opposite surface of the contact surface of the first acoustic reflection layer 1210 and the second acoustic reflection layer 1208 , which is beneficial to realize the bonding of the acoustic mirror 1200 and the carrier wafer.
  • an exemplary method for preparing an acoustic resonator is provided. Before the step of "bonding the first surface of the acoustic mirror to the carrier wafer" in the above embodiment, further The following technical processes can be included:
  • An auxiliary layer is deposited on the bonding surface of the carrier wafer.
  • an auxiliary layer is deposited on the first surface of the acoustic mirror and/or the bonding surface of the carrier wafer.
  • the auxiliary layer provided in the above embodiment may be a silicon dioxide layer.
  • Depositing an auxiliary layer on the first surface of the acoustic mirror and/or the bonding surface of the carrier wafer can improve the growth quality and simplify the handling of subsequent layers. It should be noted that the present application does not limit the thickness and material of the auxiliary layer, as long as the auxiliary layer can achieve the function of improving the growth quality of the subsequent layer and simplifying the processing of the subsequent layer.
  • an electrical structure needs to be arranged on the acoustic resonator, then the following embodiments will provide a method for preparing an acoustic resonator, so as to prepare an acoustic resonator that is beneficial to the arrangement of the electrical structure.
  • the method for preparing an acoustic resonator provided by the above embodiment may further include:
  • the bottom electrode layer and the acoustic mirror are etched at the same time, so that all layer structures included in the bottom electrode layer and the acoustic mirror have similar lateral dimensions (the etched bottom electrode layer 1402 and the acoustic mirror 1404 are shown in FIG. 14a . ) to simplify the etching operation.
  • the structure formed after etching the bottom electrode layer and the second acoustic reflection layer is: the lateral size of each etched second acoustic reflection layer gradually increases from the bottom electrode layer to the direction of the carrier wafer (etching).
  • the bottom electrode layer 1406 and the second acoustic reflection layer 1408 are shown in FIG.
  • each etched second acoustic reflection layer gradually decreases from the bottom electrode layer to the direction of the carrier wafer (etched
  • the back bottom electrode layer 1410 and the second acoustic reflection layer 1412 are shown in Figure 14c).
  • the bottom electrode layer and the etched region of the acoustic mirror are formed through the above step S1302, and a filling layer is deposited in the region.
  • a filling layer is deposited in the region. It should be noted that the material included in the filling layer should be compatible with the process flow, that is, the material included in the filling layer will not react with other structures of the acoustic resonator, resulting in changes in the properties of other structures.
  • the auxiliary layer material provided by the above embodiments is beneficial to the setting of the electrical structure. Further, depositing a filling layer in the etched area improves the flatness of the acoustic resonator.
  • FIG. 15 shows an exemplary method for fabricating an acoustic resonator provided by an embodiment of the present application, after the step of “forming a bottom electrode layer on the first surface of the piezoelectric sinker” in the above-mentioned embodiment , before the step of "bonding the carrier wafer on the first surface of the acoustic mirror", the following technical process may also be included:
  • the present application does not limit the etching position and etching area of the bottom electrode layer, which can be limited as required, as long as the bottom electrode layer formed by etching does not affect the performance of the acoustic resonator.
  • a bottom electrode filling layer 1602 is formed by depositing a filling material at the position where the bottom electrode layer is removed by etching. It should be noted that the filling material should be compatible with the process flow, ie the filling material does not react with other structures of the acoustic resonator, resulting in changes in the properties of the other structures.
  • a first acoustic reflection layer 1604 is formed by depositing a low acoustic impedance material on the bottom electrode filling layer 1602 .
  • the low acoustic impedance material may include at least one of silicon dioxide, aluminum, benzocyclobutene (BCB), polyimide (polyimide) and spin on glass.
  • S1508 Deposit a high acoustic impedance material on the first acoustic reflection layer to form a second acoustic reflection layer.
  • the high acoustic impedance material may include at least one of molybdenum, tungsten, titanium, platinum, aluminum nitride, tungsten oxide and silicon nitride.
  • the present application does not limit the etching position and etching area of the second acoustic reflection layer, which can be defined as required, as long as the bottom second acoustic reflection layer formed by etching does not affect the performance of the acoustic resonator.
  • S1512 Deposit a filling material at the position where the second acoustic reflection layer is removed by etching to form a second acoustic reflection filling layer.
  • S1514 Form the first sound reflection layer and the second sound reflection filling layer alternately in sequence.
  • the acoustic resonator 1600 forms two layers of the first acoustic reflection layer (the first acoustic reflection layer 1604 and the first acoustic reflection layer 1608 ) and two layers of the second acoustic reflection filling layer (the second acoustic reflection layer Filling layer 1606 and second acoustic reflecting filling layer 1610).
  • the embodiments of the present application do not limit the number of the first acoustic reflection layers and the second acoustic reflection filling layers, as long as the first acoustic reflection layers and the second acoustic reflection filling layers are stacked in sequence.
  • the bottom electrode is etched and filled, and then the low acoustic resistance material is deposited to form the first acoustic reflection layer, and the second acoustic reflection layer is etched and filled, and then the low acoustic resistance is deposited.
  • the first sound reflection layer is formed by using the resistive material, and the preparation is simple.
  • the acoustic resonator prepared by using the method for preparing an acoustic resonator provided in the above embodiments has a higher flatness.
  • FIG. 17 shows a method for preparing an acoustic resonator provided by an embodiment of the present application.
  • the method for preparing an acoustic resonator may include:
  • S1702 Provide a piezoelectric substrate.
  • the piezoelectric substrate includes lithium niobate and/or lithium tantalate.
  • S1704 Deposit an electrode material on the first surface of the piezoelectric substrate and etch to form a bottom electrode layer.
  • the electrode material may include one or more of molybdenum, tungsten, ruthenium, platinum, titanium, aluminum, aluminum copper, aluminum silicon copper, and chromium.
  • S1706 Deposit a low acoustic impedance material to form a first acoustic reflection layer.
  • S1710 Etch the deposited high acoustic impedance material to form a second acoustic reflection layer.
  • S1712 Repeat S1706-S1710 until the required number of layers of the first acoustic reflection layer and the second acoustic reflection layer are formed.
  • the first surface of the acoustic mirror can be the first surface of the acoustic mirror.
  • the surface of the acoustic reflection layer may also be the surface of the second acoustic reflection layer. It should be noted that the first sound reflection layer and the second sound reflection layer can be set as required.
  • the low acoustic impedance material may include at least one of silicon dioxide, aluminum, benzocyclobutene (BCB), polyimide (polyimide), and spin on glass, which may be
  • the high acoustic impedance material may include at least one of molybdenum, tungsten, titanium, platinum, aluminum nitride, tungsten oxide, and silicon nitride.
  • the first surface of the acoustic mirror is the side away from the bottom electrode.
  • S1718 Thinning the piezoelectric substrate to form a piezoelectric thin film.
  • FIG. 18 shows a method for preparing an acoustic resonator provided by an embodiment of the present application.
  • the method for preparing an acoustic resonator may include:
  • S102 Provide a piezoelectric substrate, where the piezoelectric substrate includes lithium niobate and/or lithium tantalate.
  • S1508 Deposit a high acoustic impedance material on the first acoustic reflection layer to form a second acoustic reflection layer.
  • S1514 Form the first sound reflection layer and the second sound reflection filling layer alternately in sequence.
  • the first surface of the acoustic mirror is the side away from the bottom electrode.
  • S1718 Thinning the piezoelectric substrate to form a piezoelectric thin film.
  • 1 , 7 , 13 , 15 and 17-18 may include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but These steps or stages may be performed at different times, and the order of execution of these steps or stages is not necessarily sequential, but may be performed alternately or alternately with other steps or at least a portion of the steps or stages in the other steps.
  • an embodiment of the present application further provides an acoustic resonator, including: an acoustic mirror 402 , a bottom electrode layer 302 , a piezoelectric substrate 202 , and an upper electrode layer 602 .
  • the acoustic mirror 402 includes at least one first acoustic reflection layer and at least one second acoustic reflection layer, and the acoustic impedance of each first acoustic reflection layer is smaller than the acoustic impedance of each second acoustic reflection layer.
  • the acoustic mirror 402 includes a first acoustic reflection layer 404 , a second acoustic reflection layer 408 and a first acoustic reflection layer 406 .
  • the bottom electrode layer 302 is located on the acoustic mirror 402, and one of the first acoustic reflection layers of the acoustic mirror 402 is closer to the bottom electrode layer 302 than all the second acoustic reflection layers.
  • the first acoustic reflection layer 404 is closer to the bottom electrode layer than the second acoustic reflection layer 408 .
  • the piezoelectric substrate 202 is located on the bottom electrode layer 302 .
  • the piezoelectric substrate 202 includes lithium niobate and/or lithium tantalate.
  • the upper electrode layer 602 is located on the piezoelectric substrate 202 .
  • the acoustic resonator provided by the embodiments of the present application includes an acoustic mirror, a bottom electrode layer, a piezoelectric substrate, and an upper electrode layer in sequence, wherein the piezoelectric substrate includes lithium niobate and/or lithium tantalate, and the first acoustic reflection The layer is located above the bottom electrode layer.
  • the acoustic resonator can be excited to the thickness shear vibration mode, since the acoustic resonator adopts the more superior thickness shear vibration mode and selects the Lithium niobate or lithium tantalate materials that support this vibrational mode, therefore, this acoustic resonator can support high electromechanical coupling at frequencies above 3GHz.
  • the acoustic resonator provided by the above embodiments may use a single crystal material to reduce the attenuation of sound waves and improve the quality factor of the acoustic resonator.
  • Acoustic resonators capable of supporting high electromechanical coupling and high quality factor at frequencies above 3 GHz are obtained.

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  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)

Abstract

La présente invention concerne un procédé de préparation d'un résonateur acoustique, et un résonateur acoustique. Le procédé de préparation d'un résonateur acoustique comprend : la fourniture d'un substrat piézoélectrique comprenant l'un parmi le niobate de lithium et le tantalate de lithium, et le dépôt d'une première couche de réflexion acoustique sur une couche d'électrode inférieure. Au moyen de la sélection d'une direction spécifique du substrat piézoélectrique, un résonateur acoustique préparé en utilisant le procédé de préparation pour un résonateur acoustique peut être excité pour être dans un mode de vibration en cisaillement dans la direction de l'épaisseur. Dans le résonateur acoustique, le mode de vibration en cisaillement dans la direction de l'épaisseur supérieure est utilisé, et un matériau de niobate de lithium ou de tantalate de lithium qui peut supporter le mode de vibration est sélectionné, de telle sorte que le résonateur acoustique peut supporter un couplage électromécanique élevé à une fréquence qui n'est pas inférieure à 3 GHz.
PCT/CN2021/092031 2021-03-15 2021-05-07 Procédé de préparation d'un résonateur acoustique et résonateur acoustique WO2022193419A1 (fr)

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Application Number Priority Date Filing Date Title
CN202110275987.8A CN114285389A (zh) 2021-03-15 2021-03-15 声学谐振器的制备方法和声学谐振器
CN202110275987.8 2021-03-15

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WO2022193419A1 true WO2022193419A1 (fr) 2022-09-22

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130038408A1 (en) * 2011-02-28 2013-02-14 Avago Technologies General Ip (Singapore) Pte.Ltd. Bulk acoustic wave resonator device comprising an acoustic reflector and a bridge
CN103283147A (zh) * 2010-12-24 2013-09-04 株式会社村田制作所 弹性波装置及其制造方法
CN110224680A (zh) * 2019-05-13 2019-09-10 电子科技大学 一种固态反射型体声波谐振器及其制备方法
CN111245387A (zh) * 2020-02-14 2020-06-05 杭州见闻录科技有限公司 一种固态装配谐振器的结构及制作工艺
CN111919383A (zh) * 2018-03-28 2020-11-10 Rf360欧洲有限责任公司 体声波谐振器设备及其制造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103283147A (zh) * 2010-12-24 2013-09-04 株式会社村田制作所 弹性波装置及其制造方法
US20130038408A1 (en) * 2011-02-28 2013-02-14 Avago Technologies General Ip (Singapore) Pte.Ltd. Bulk acoustic wave resonator device comprising an acoustic reflector and a bridge
CN111919383A (zh) * 2018-03-28 2020-11-10 Rf360欧洲有限责任公司 体声波谐振器设备及其制造方法
CN110224680A (zh) * 2019-05-13 2019-09-10 电子科技大学 一种固态反射型体声波谐振器及其制备方法
CN111245387A (zh) * 2020-02-14 2020-06-05 杭州见闻录科技有限公司 一种固态装配谐振器的结构及制作工艺

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