WO2022057466A1 - 薄膜体声波谐振器、其制造方法及滤波器 - Google Patents

薄膜体声波谐振器、其制造方法及滤波器 Download PDF

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Publication number
WO2022057466A1
WO2022057466A1 PCT/CN2021/109531 CN2021109531W WO2022057466A1 WO 2022057466 A1 WO2022057466 A1 WO 2022057466A1 CN 2021109531 W CN2021109531 W CN 2021109531W WO 2022057466 A1 WO2022057466 A1 WO 2022057466A1
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electrode
out structure
forming
annular
electrode lead
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PCT/CN2021/109531
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English (en)
French (fr)
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黄河
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中芯集成电路（宁波）有限公司上海分公司
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Publication of WO2022057466A1 publication Critical patent/WO2022057466A1/zh

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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
    • H03H9/02—Details
    • H03H9/02007—Details of bulk acoustic wave devices
    • H03H9/02015—Characteristics of piezoelectric layers, e.g. cutting angles
    • 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
    • H03H9/02007—Details of bulk acoustic wave devices
    • H03H9/02086—Means for compensation or elimination of undesirable effects
    • H03H9/02118—Means for compensation or elimination of undesirable effects of lateral leakage between adjacent resonators
    • 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
    • H03H9/02007—Details of bulk acoustic wave devices
    • H03H9/02157—Dimensional parameters, e.g. ratio between two dimension parameters, length, width or thickness
    • 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
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H03H9/13—Driving means, e.g. electrodes, coils for networks consisting of piezoelectric or electrostrictive materials
    • 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
    • H03H9/205—Constructional features of resonators consisting of piezoelectric or electrostrictive material having multiple resonators
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
    • H03H9/58—Multiple crystal filters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
    • H03H9/58—Multiple crystal filters
    • H03H9/582—Multiple crystal filters implemented with thin-film techniques
    • H03H9/586—Means for mounting to a substrate, i.e. means constituting the material interface confining the waves to a volume
    • H03H9/588—Membranes
    • 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
    • H03H2003/023—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 the resonators or networks being of the membrane type
    • 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
    • H03H2003/028—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 for obtaining desired values of other parameters
    • 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
    • H03H2009/02165—Tuning
    • H03H2009/02173—Tuning of film bulk acoustic resonators [FBAR]
    • H03H2009/02188—Electrically tuning
    • H03H2009/02196—Electrically tuning operating on the FBAR element, e.g. by direct application of a tuning DC voltage

Definitions

  • the invention relates to the field of semiconductor device manufacturing, in particular to a thin-film bulk acoustic wave resonator, a manufacturing method thereof and a filter.
  • RF front-end modules have gradually become the core components of communication equipment.
  • filters have become the most rapidly growing and most promising components.
  • the performance of the filter is determined by the resonator units that make up the filter.
  • FBARs thin-film bulk acoustic resonators
  • FBARs thin-film bulk acoustic resonators
  • a thin-film bulk acoustic wave resonator includes two thin-film electrodes, and a piezoelectric thin-film layer is arranged between the two thin-film electrodes.
  • the bulk acoustic wave propagating in the thickness direction of the electric film layer is transmitted to the interface between the upper and lower electrodes and the air and is reflected back, and then reflected back and forth inside the film to form an oscillation.
  • Standing wave oscillations are formed when a sound wave propagates in a piezoelectric film layer that is exactly an odd multiple of a half-wavelength.
  • the quality factor (Q) of the cavity-type thin-film bulk acoustic wave resonators produced at present cannot be further improved, so it cannot meet the needs of high-performance radio frequency systems.
  • the purpose of the present invention is to provide a thin film bulk acoustic wave resonator, a method for manufacturing the same and a filter, which can improve the quality factor of the thin film bulk acoustic wave resonator, thereby improving the device performance.
  • the present invention provides a thin film bulk acoustic wave resonator, comprising: a piezoelectric laminated structure, wherein the piezoelectric laminated structure includes a first electrode, a piezoelectric layer and a second electrode stacked sequentially from bottom to top, At least one of the first electrode and the second electrode has an annular groove running through the corresponding electrode; an electrode lead-out structure is arranged on the corresponding electrode provided with the annular groove, and the electrode lead-out structure covers at least part of the annular groove and extends to the invalid resonance area , the electrode lead-out structure includes an annular arched bridge protruding in the direction away from the piezoelectric layer, the inner surface of the arched bridge forms an annular gap, and the annular gap is opposite to the annular groove.
  • the present invention also provides a method for manufacturing a thin film bulk acoustic resonator, comprising: forming a first electrode, a piezoelectric layer and a second electrode, the piezoelectric layer being located between the first electrode and the second electrode forming an annular groove penetrating the corresponding electrode on at least one of the first electrode and the second electrode; forming an electrode lead-out structure with an arch bridge on the electrode having the annular groove, comprising: forming an annular sacrificial protrusion; forming an electrode lead-out structure covering the annular sacrificial protrusion and overlapping the edge of the electrode in the effective resonance area; forming a support layer with a sacrificial layer on the first electrode; removing the sacrificial layer to form a third a cavity; the annular sacrificial protrusion is removed to form an annular space, and the annular space is opposite to the annular groove.
  • the invention also provides a method for manufacturing a thin-film bulk acoustic resonator, comprising: forming a first electrode, a piezoelectric layer and a second electrode, wherein the piezoelectric layer is located between the first electrode and the second electrode; An annular groove penetrating the corresponding electrode is formed on at least one of the second electrodes; an electrode lead-out structure with an arch bridge is formed on the electrode with the annular groove, including: forming an annular sacrificial protrusion; forming a covering annular sacrificial protrusion, An electrode lead-out structure whose edge overlaps the edge of the electrode in the effective resonance area; a support layer with an acoustic mirror is formed on the first electrode; an annular space is formed by removing the annular sacrificial protrusion, and the annular space is opposite to the annular groove.
  • the present invention also provides a filter comprising at least one thin-film bulk acoustic resonator as described above.
  • the beneficial effect of the thin-film bulk acoustic wave resonator of the present invention is that an electrode lead-out structure with an arched bridge structure is arranged on the first electrode and/or the second electrode, the arched bridge forms a ring shape, and the arched bridge and the corresponding electrode are located on the plane.
  • An annular gap is formed on the surface of the electrode, and the area where the arch bridge is located is used to define the boundary of the effective resonance area.
  • the corresponding electrodes are provided with annular grooves to disconnect the corresponding electrodes, and then the disconnected electrodes are connected through the electrode extraction structure.
  • the annular groove can also make the end of the first electrode and/or the second electrode at the boundary of the effective resonance area contact with the gas in the annular gap, so as to achieve the effect of eliminating the boundary clutter of the electrodes in the effective resonance area, thereby improving the The Q value of the resonator.
  • the impedance of the electrode lead-out structure is lower than the impedance of the corresponding electrode, so as to reduce the electrode impedance, make the electrode lead-out structure have better conductivity, and improve the conductivity.
  • the electrode lead-out structure and the corresponding electrode without the electrode lead-out structure or the electrode lead-out structure respectively provided on the first electrode and the second electrode are at least partially staggered from each other in the peripheral area of the arched bridge, which can avoid the occurrence of potential floating.
  • the problem of high-frequency coupling can prevent the formation of parasitic capacitance, which is beneficial to improve the quality factor of the resonator.
  • first electrode and/or the second electrode extend from the effective resonance region to the first substrate on the periphery of the first cavity or the acoustic mirror, which can improve the structural strength of the resonator.
  • the electrode extraction structure also extends from the effective resonance region to the first substrate on the periphery of the first cavity or the acoustic mirror, so as to improve the structural strength of the resonator.
  • the piezoelectric layer is a complete film layer, which can ensure the structural strength of the resonator and improve the yield of the resonator.
  • the piezoelectric layer is provided with a first groove, so that the edge of the piezoelectric layer is exposed to the gas, which can suppress the shear wave loss of the piezoelectric layer.
  • the Q value of the boosting resonator is provided with a first groove, so that the edge of the piezoelectric layer is exposed to the gas, which can suppress the shear wave loss of the piezoelectric layer.
  • the beneficial effects of the method for manufacturing a thin-film bulk acoustic resonator of the present invention are: forming an electrode lead-out structure with an arched bridge structure by forming annular sacrificial protrusions on the corresponding electrodes, and forming annular gaps after removing the annular sacrificial protrusions , in order to define the range of the effective resonance area, and then the corresponding electrodes are etched to form annular grooves running through the corresponding electrodes, which not only facilitates the simplification of the formation process of the electrode lead-out structure, but also separates the electrodes located inside and outside the annular groove.
  • the electrode extraction structure electrically connects the disconnected electrodes, thereby reducing the impedance of the electrodes, and exposing the boundaries of the corresponding electrodes to the annular gap formed by the arch bridge, thereby achieving the effect of eliminating electrode boundary clutter in the effective resonance area.
  • the manufacturing cost can be reduced, and the support can be formed in the subsequent process of forming the support layer, so as to prevent the first electrode, the piezoelectric stack and the second electrode from being stressed. Both are deformed by compression, and can also form support for the piezoelectric laminated structure in the subsequent reverse process, so as to ensure the flatness of the piezoelectric laminated structure.
  • the piezoelectric layer is formed on a flat electrode or a carrier substrate, so that the upper surface and the lower surface of the piezoelectric layer are flat, so as to ensure that the piezoelectric layer has a good lattice orientation and improve the pressure of the piezoelectric layer. electrical characteristics, thereby improving the performance of the resonator.
  • the beneficial effect of the filter of the present invention is that the filter is formed by connecting the above-mentioned thin-film bulk acoustic wave resonators, so as to ensure that the filter has good structural stability, and the electrode impedance of the resonator is low, which can improve the performance of the filter. Conductivity, improve the accuracy of filtering.
  • Fig. 1 shows a schematic structural diagram of the thin film bulk acoustic resonator according to the first embodiment of the present invention
  • Fig. 2 shows the structural schematic diagram of the thin film bulk acoustic wave resonator according to the second embodiment of the present invention
  • Fig. 3 shows the third embodiment of the present invention.
  • Figures 4 to 7 show schematic structural diagrams corresponding to different steps of the manufacturing method of the thin-film bulk acoustic resonator according to Embodiment 4 of the present invention
  • Figures 8 to 10 show the implementation of the present invention.
  • FIG. 14 is a schematic structural diagram of a thin film bulk acoustic wave resonator manufactured according to the manufacturing method of the thin film bulk acoustic resonator in Example 5;
  • FIGS. 15-21 are manufactured according to the manufacturing method of the thin film bulk acoustic wave resonator in Example 6.
  • FIG. 22 is a schematic structural diagram of the thin film bulk acoustic resonator manufactured according to the manufacturing method of the thin film bulk acoustic resonator in Example 7;
  • FIG. 23 is the manufacturing method of the thin film bulk acoustic wave resonator according to the embodiment 8 Schematic diagram of the fabricated thin-film bulk acoustic wave resonator.
  • first substrate 11, base; 12, support layer; 121, first cavity; 121', sacrificial layer; 21, first electrode; 22, piezoelectric layer; 23, second electrode; 24, annular groove; 25, first groove; 3, electrode lead-out structure; 31, arch bridge; 32, annular gap; 32', annular sacrificial protrusion; 4, carrier substrate; 5, second Substrate; 51. Acoustic mirror.
  • Embodiment 1 provides a thin-film bulk acoustic resonator.
  • FIG. 1 is a schematic cross-sectional structure diagram of a thin-film bulk acoustic resonator provided in Embodiment 1 of the present invention. Please refer to FIG. 1.
  • the thin-film bulk acoustic resonator includes: a piezoelectric Laminated structure 2.
  • the piezoelectric laminated structure 2 includes a first electrode 21, a piezoelectric layer 22 and a second electrode 23 that are stacked sequentially from bottom to top.
  • At least one of the first electrode 21 and the second electrode 23 has a corresponding The annular groove 24 of the electrode; the electrode lead-out structure 3 is provided on the corresponding electrode provided with the annular groove 24, and the electrode lead-out structure 3 covers at least part of the annular groove 24 and extends to the invalid resonance area.
  • An annular arch bridge 31 protruding in the direction of the electrical layer 22 , the inner surface of the arch bridge 31 encloses an annular gap 32 , and the annular gap 32 is opposite to the annular groove 24 .
  • the area enclosed by the annular space 32 is an effective resonance area, and the area outside the effective resonance area is an ineffective resonance area.
  • the boundary of the effective resonance area is defined by the annular space 32 to effectively prevent transverse wave leakage.
  • the above-mentioned corresponding electrodes are electrodes provided with the annular groove 24 , that is, when the first electrode 21 is provided with the annular groove 24 , the first electrode 21 is an electrode corresponding to the annular groove 24 , and the first electrode 21 is an electrode corresponding to the annular groove 24 .
  • 21 corresponds to the electrode lead-out structure 3 provided thereon; when the second electrode 23 is provided with an annular groove 24, the second electrode 23 is an electrode corresponding to the annular groove 24, and the second electrode 23 is connected to the electrode lead-out structure provided thereon 3 accordingly.
  • the structure of the thin film bulk acoustic wave resonator will be described in detail below by taking the arrangement of the annular groove 24 on the first electrode 21 and the formation of the electrode lead-out structure 3 on the first electrode 21 as an example.
  • the piezoelectric laminated structure 3 is formed on the first substrate 1 having the first cavity 121 .
  • the piezoelectric laminated structure 3 includes a first electrode 21 , a piezoelectric layer 22 and a second electrode 23 that are stacked in sequence.
  • the first electrode The material of 21 and the second electrode 23 can be any suitable conductive material or semiconductor material that is well known in the art, wherein the conductive material can be a metal material with conductive properties, for example, made of molybdenum (Mo), aluminum (Al) , Copper (Cu), Tungsten (W), Tantalum (Ta), Platinum (Pt), Ruthenium (Ru), Rhodium (Rh), Iridium (Ir), Chromium (Cr), Titanium (Ti), Gold (Au) , osmium (Os), rhenium (Re), palladium (Pd) and other metals or a stack formed by the above metals, and the semiconductor material is Si, Ge, SiGe, SiC, SiGeC
  • the piezoelectric layer 22 can be made of aluminum nitride (AlN), zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO 3 ), quartz (Quartz), potassium niobate (KNbO 3 ) or Piezoelectric materials having a wurtzite crystal structure, such as lithium tantalate (LiTaO 3 ), and combinations thereof.
  • the piezoelectric layer 22 may further include rare earth metals such as at least one of scandium (Sc), erbium (Er), yttrium (Y) and lanthanum (La). .
  • the piezoelectric layer 22 may further include transition metals such as zirconium (Zr), titanium (Ti), manganese (Mn), and hafnium (Hf). at least one.
  • transition metals such as zirconium (Zr), titanium (Ti), manganese (Mn), and hafnium (Hf). at least one.
  • the periphery of the first electrode 21 and/or the second electrode 23 extends to the first substrate 1 on the periphery of the first cavity 121 to improve the structural strength of the resonator.
  • the resonator structure has better strength.
  • the periphery of the first electrode 21 is the outer edge of the overall structure
  • the periphery of the second electrode 23 is the outer edge of the overall structure. In this embodiment, the entire periphery of the first electrode 21 and/or the second electrode 23 extends to the first substrate 1 at the periphery of the first cavity 121 .
  • parts of the first electrode 21 and/or the second electrode 23 extend around the first substrate 1 on the periphery of the first cavity 121 . At this time, in order to ensure the structural strength of the resonator, parts of the first electrode 21 and/or the second electrode 23 extend to The electrodes on the first substrate 1 around the first cavity 121 are symmetrically distributed to ensure support strength.
  • the impedance of the electrode extraction structure 3 is lower than the impedance of the first electrode 21
  • the annular groove 24 is a closed annular groove.
  • the first electrode 21 is completely isolated at the annular groove 24 through the annular groove 24, and the disconnected first electrode 21 is electrically connected through the electrode lead-out structure 3 whose impedance is lower than that of the first electrode 21, thereby reducing the first electrode 21.
  • Impedance of electrode 21 .
  • the material of the electrode extraction structure 3 may be a metal material, and the metal material includes one or more of gold, silver, tungsten, platinum, aluminum, copper, titanium, tin, and nickel.
  • the electrode lead-out structure 3 and the second electrode 23 respectively have a first portion extending outside the effective resonance region, and the first portion serves as an electrode connection terminal for electrical connection with the outside.
  • the periphery of the electrode extraction structure 3 and the second electrode 23 extends to the first substrate 1 on the periphery of the first cavity 121 .
  • the periphery of the first electrode 21 may or may not extend to the first cavity.
  • the first electrode 21 and the electrode extraction structure 3 together form a support to improve resonance. the structural strength of the device.
  • the projections of the electrode lead-out structure 3 and the corresponding electrodes without the electrode lead-out structure 3 on the surface of the piezoelectric layer 22 are at least partially staggered from each other, that is, the electrode lead-out structure 3 and the second electrode at the periphery of the effective resonance area are at least partially staggered.
  • the projections of 23 on the surface of the piezoelectric layer 22 do not overlap at least in part, so as to avoid the problem of high-frequency coupling caused by potential floating, and prevent the formation of parasitic capacitance, thereby improving the quality factor of the resonator.
  • the annular gap 32 is opposite to the annular groove 24, so that the edge of the first electrode 21 at the boundary of the effective resonance region is exposed in the annular gap 32, thereby reducing the sound wave leaking from the end of the first electrode 21 energy, thereby improving the quality factor of the resonator.
  • the relative arrangement of the annular gap 32 and the annular groove 24 can be referred to as the above-mentioned relative arrangement of the annular groove 24 and the first groove 25 , which will not be repeated here.
  • the annular gap 32 is a closed annular shape, so as to define the boundary of the effective resonance area, so as to effectively eliminate the clutter at the boundary of the effective resonance area.
  • the arched bridge 31 surrounds the entire periphery of the first electrode 21 so that the annular space 32 can form a closed ring shape, and the electrode lead-out structure 3 further includes a connecting arched bridge 31 and extending to the periphery of the first cavity 121 .
  • the lap part, the lap part surrounds part or all of the outer circumference of the corresponding electrode, and the part of the lap part extends to the outer edge of the first substrate 1 around the periphery of the first cavity 121, or, the whole circumference of the lap part extends to the outer edge of the first substrate 1 at the periphery of the first cavity 121, so as to facilitate electrical connection with the outside.
  • the overlapping portion may be a planar structure laid on the corresponding electrodes; or, the overlapping portion may be a plurality of strip-shaped structures, and the overlapping portions are symmetrically distributed on the corresponding electrodes, so as to improve the structural strength of the resonator.
  • the effective resonance region is an irregular polygon, and any two sides of the polygon are not parallel.
  • the effective resonance region may also be a circle or an ellipse, or an irregular pattern formed by arcs and straight lines.
  • a first groove 25 is provided in the piezoelectric layer 22, the first groove 25 penetrates the piezoelectric layer 22, and the first groove 25 is opposite to the annular groove 24, so that the first groove 25, the annular groove 24 and the annular groove
  • the gap 32 is connected, so that the end face of the piezoelectric layer 22 and the gas in the annular gap 32 form a reflection interface, thereby effectively suppressing the sound wave leakage in the piezoelectric layer 22, avoiding parasitic resonance, and improving the quality factor of the resonator.
  • the relative relationship between the first groove 25 and the annular groove 24 may refer to the relative relationship between the annular groove 24 and the annular gap 32 , and details are not described herein again.
  • the first groove 25 is a closed annular shape, and the piezoelectric layer 22 around the annular gap 32 and the piezoelectric layer 22 around the annular gap 32 are isolated from each other; The piezoelectric layer 32 on the inner periphery is isolated from the piezoelectric layer on the periphery of the annular gap 32 by the discontinuity.
  • the first groove 25 is a closed annular shape, the effect of suppressing sound wave leakage is better.
  • the first groove 25 is a closed ring, and the piezoelectric layer 22 in the effective resonance area and the piezoelectric layer 22 outside the effective resonance area are isolated from each other; or, the first groove 25 is an intermittent ring, The piezoelectric layer 22 in the effective resonant region and the piezoelectric layer 22 outside the effective resonant region are isolated from each other at the discontinuity and connected to each other at the discontinuity. It can be understood that when the first groove 25 is a closed ring and penetrates through the piezoelectric layer 22, the effect of suppressing the sound wave leakage is better.
  • the piezoelectric laminated structure 2 is disposed on the first substrate 1 having the first cavity 121 , and the piezoelectric laminated structure 2 covers the first cavity 121 .
  • the first substrate includes a base 11 and a support layer 12
  • the support layer 12 and the piezoelectric laminated structure 3 are sequentially stacked on the base 11
  • the first cavity 121 is disposed in the support layer 12 .
  • the support layer 12 may be combined with the substrate 11 by means of a bonding layer or deposition.
  • the material of the bonding layer includes silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride or ethyl silicate.
  • the bonding layer can also use adhesives such as light-curing materials or heat-curing materials, such as adhesive film (Die Attach Film, DAF) or dry film (Dry Film), etc.
  • the deposition method can be chemical vapor deposition or physical vapor deposition.
  • the material of the substrate 11 may be at least one of the following materials: silicon (Si), germanium (Ge), silicon germanium (SiGe), silicon carbon (SiC), silicon germanium carbon (SiGeC), indium arsenide (InAs), Gallium Arsenide (GaAs), Indium Phosphide (InP) or other III/V compound semiconductors.
  • the material of the support layer 12 can be any suitable dielectric material, including but not limited to one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride and other materials.
  • the first cavity 121 penetrates a part of the support layer 12 , that is, the first cavity 121 extends to a part of the thickness of the support layer 12 , so that the first cavity 121 exposes the support layer 12 . In other embodiments, the first cavity 121 completely penetrates the support layer 12 , so that the first cavity 121 exposes the substrate 11 .
  • the first cavity 121 may be formed by a sacrificial layer process or by etching. In an alternative solution, when the supporting layer 12 is exposed at the bottom of the first cavity 121, it is formed by a sacrificial layer process, and the specific forming method will be described in the following method embodiments.
  • the first cavity 121 When the first cavity 121 penetrates through the support layer 12 , the first cavity 121 may be formed by etching the support layer 12 or by forming a sacrificial layer.
  • the cross-sectional shape of the first cavity 121 may be a rectangle, but in other embodiments of the present invention, the cross-sectional shape of the first cavity 121 may also be a circle, an ellipse, or a shape other than a rectangle Polygons such as pentagons, hexagons, etc.
  • the first substrate 1 includes a semiconductor substrate, the material of which can be referred to as the material of the base 11 , which will not be repeated here.
  • the first cavity 121 is formed in the first substrate 1 by etching the first liner. A first cavity 121 that does not penetrate the first substrate 1 is formed on the surface of the bottom 1 adjacent to the first electrode 21 , and the first substrate 1 forming the first cavity 121 is bonded to the first electrode 21 .
  • the piezoelectric stack structure 2 is provided on a second substrate with an acoustic mirror.
  • the acoustic mirror is such as a Bragg reflection structure, and the Bragg reflection structure is a common knowledge in the art, and will not be described in detail here.
  • the annular groove is only provided on the second electrode 23, and the electrode lead-out structure is formed on the second electrode 23.
  • the structure please refer to the above-mentioned arrangement of the annular groove 24 on the first electrode 21 and the electrode lead-out structure. The structure of structure 3 will not be repeated here.
  • Embodiment 2 provides a thin film bulk acoustic resonator.
  • FIG. 2 is a schematic cross-sectional structure diagram of the thin film bulk acoustic wave resonator according to Embodiment 2 of the present invention.
  • the difference between this embodiment and Embodiment 1 is that the piezoelectric The layer 22 is provided with a first groove 25.
  • the piezoelectric layer 22 in the second embodiment is a complete film layer, specifically: the piezoelectric layer 22 is a complete film layer, covering the first cavity 121 and extending to the first cavity. on the first substrate 1 outside the cavity 121 .
  • the piezoelectric layer 22 is complete without etching, which can ensure the structural strength of the resonator and improve the yield of the resonator.
  • Other structural features of the thin-film bulk acoustic wave resonator in this embodiment are the same as those in Embodiment 1, and will not be repeated here.
  • Embodiment 3 provides a thin-film bulk acoustic resonator.
  • FIG. 3 is a schematic cross-sectional structure diagram of the thin-film bulk acoustic resonator according to Embodiment 3 of the present invention.
  • the difference between this embodiment and Embodiment 1 is that the electrodes in Embodiment 1 lead out
  • the structure 3 is only provided on the first electrode 21 or the second electrode 23 , and the electrode extraction structure in Embodiment 3 is provided on the first electrode 21 and the second electrode 23 .
  • the electrodes in Embodiment 1 lead out The structure 3 is only provided on the first electrode 21 or the second electrode 23 , and the electrode extraction structure in Embodiment 3 is provided on the first electrode 21 and the second electrode 23 .
  • both the first electrode 21 and the second electrode 24 are provided with an electrode lead-out structure 3 , and the electrode lead-out structure provided on the first electrode 21 and the electrode lead-out structure provided on the second electrode 23 respectively have extending to The second part outside the effective resonance area is used as the electrode connection terminal.
  • the electrode lead-out structure 3 disposed on the first electrode 21 and the electrode lead-out structure 3 disposed on the second electrode 23 are at least partially staggered from each other on the periphery of the annular gap 32, that is, on the periphery of the annular gap 32, and disposed on the first
  • the projections of the electrode lead-out structure 3 on the electrode 21 and the electrode lead-out structure 3 disposed on the second electrode 23 on the surface of the piezoelectric layer 22 do not overlap at least partially, so as to avoid the high frequency coupling problem caused by the existence of potential floating, and prevent the formation of
  • the parasitic capacitance is beneficial to improve the quality factor of the resonator.
  • the electrode lead-out structure 3 disposed on the first electrode 21 and the electrode lead-out structure 3 disposed on the second electrode 23 extend from the effective resonance region to the first cavity 121 periphery.
  • the peripheries of the first electrode 21 and the second electrode 23 both extend to the first substrate 1 on the periphery of the first cavity 21, so that the first electrode 21 and the electrode lead-out structure disposed thereon,
  • the second electrode 23 and the electrode lead-out structure disposed on the second electrode 23 together form a support, thereby improving the structural strength of the resonator.
  • annular space 32 encloses an effective resonance area, in order to avoid the effective resonance area enclosed by the annular space 32 formed by the arched bridge structure 31 disposed on the first electrode 21 and the effective resonance area disposed on the second electrode 23
  • the effective resonance area enclosed by the annular gap 32 formed by the arched bridge structure 31 is staggered, and the arched bridge structure 31 located on the first electrode 21 and the arched bridge structure located on the second electrode 23 need to be arranged oppositely, that is, to set
  • the projections of the arched bridge structure 31 on the second electrode 23 and the arched bridge structure 31 provided on the first electrode 21 on the surface of the piezoelectric layer 22 completely overlap.
  • the overlapping parts on the first substrate 1 extending to the periphery of the first cavity 121 play the role of connection and support, the overlapping parts respectively located on the two electrodes may overlap the projections on the surface of the piezoelectric layer 22 or not.
  • the structure of the overlapping portion can be referred to in Embodiment 1, which will not be repeated here.
  • the piezoelectric layer 22 is provided with a first trench 25 penetrating the piezoelectric layer 22.
  • the piezoelectric layer 22 may not be etched to form the first trench 25, which is complete film. Refer to Embodiment 1 for the benefits of providing the first grooves 25, and refer to Embodiment 2 for the benefits of not providing the first grooves 25, which will not be repeated here.
  • Other structural features of the thin-film bulk acoustic wave resonator in this embodiment are the same as those in Embodiment 1, and will not be repeated here.
  • Embodiment 4 provides a method for manufacturing a thin-film bulk acoustic resonator, and the method for manufacturing a thin-film bulk acoustic resonator includes: S01: forming a first electrode, a piezoelectric layer, and a second electrode, and the piezoelectric layer is located on the first electrode and the second electrode.
  • S02 forming an annular groove penetrating the corresponding electrode on at least one of the first electrode and the second electrode;
  • S04 forming a support layer with a sacrificial layer on the first electrode;
  • S05 removing the sacrificial layer to form The first cavity; the annular sacrificial protrusion is removed to form an annular space, and the annular space is opposite to the annular groove.
  • Step S0N does not represent a sequential order.
  • FIG. 4 to FIG. 7 are the manufacturing of a thin film bulk acoustic resonator according to this embodiment.
  • the manufacturing method of the thin film bulk acoustic wave resonator provided in this embodiment is described in detail with reference to FIGS. 4 to 7 .
  • the method for forming the first electrode 21 , the piezoelectric layer 22 and the second electrode 24 includes: providing a carrier substrate 4 ; forming the second electrode 23 , The piezoelectric layer 22 is formed and the first electrode 21 is formed; after the supporting layer 12 is formed on the first electrode 21 , the carrier substrate 4 is removed. Specifically, after forming the first electrode, an electrode lead-out structure is formed on the first electrode. Specifically: referring to FIG.
  • a carrier substrate 4 is provided, and the carrier substrate 4 may be a semiconductor material, such as silicon (Si), germanium (Ge), silicon germanium (SiGe), silicon carbon (SiC), silicon germanium carbon (SiGeC) , Indium Arsenide (InAs), Gallium Arsenide (GaAs), Indium Phosphide (InP) or other III/V compound semiconductors.
  • the second electrode 23, the piezoelectric layer 22, and the first electrode 21 are sequentially formed on the carrier substrate 4, wherein the first electrode 21 and the second electrode 23 can be formed by a physical vapor deposition process and etching, and the first electrode 21 .
  • the material of the second electrode 24 refers to Example 1.
  • the peripheries of the first electrode 21 and/or the second electrode 23 extend to the support layer 12 on the periphery of the first cavity formed subsequently, and the beneficial effects thereof refer to Embodiment 1.
  • the piezoelectric layer 22 can be deposited and formed by any suitable method known to those skilled in the art, such as chemical vapor deposition, physical vapor deposition, or atomic layer deposition.
  • the material of the piezoelectric layer 22 refer to Embodiment 1.
  • the upper surface and the lower surface of the piezoelectric layer 22 are both flat, so as to ensure that the piezoelectric layer 22 has a good lattice orientation and improve the piezoelectric layer 22. piezoelectric properties, thereby improving the overall performance of the resonator.
  • the first electrode 21 is etched to form an annular trench 24 .
  • the piezoelectric layer 22 may also be etched to form a first trench 25 penetrating the piezoelectric layer 22 , and a first trench 25 is formed on the piezoelectric layer 22
  • the beneficial effects of the grooves 25 are referred to in the above-mentioned Embodiment 1, and are not repeated here. It should be noted that the area surrounded by the subsequently formed annular sacrificial protrusions is an effective resonance area.
  • the first groove 25 is a closed ring, and the piezoelectric layer 22 in the effective resonance area and the piezoelectric layer 22 outside the effective resonance area are isolated from each other; or, the first groove 25 is an intermittent ring, The piezoelectric layer 22 in the effective resonance area is isolated from the piezoelectric layer 22 outside the effective resonance area by the discontinuity, and the piezoelectric layer 22 in the effective resonance area is connected with the piezoelectric layer 22 outside the effective resonance area by the discontinuity. .
  • this step can be omitted.
  • a first sacrificial material is deposited on the first electrode 21, the first sacrificial material fills the annular trench and the first trench and covers part of the first electrode 21 located in the peripheral region of the annular trench, the first sacrificial material includes Phosphosilicate glass, low temperature silica, borophosphosilicate glass, germanium, amorphous carbon, polyimide or photoresist.
  • the first sacrificial material on the first electrode 21 is patterned to form an annular sacrificial protrusion 32', which is a continuous structure, enclosing a closed ring, and defining the effective resonance area of the resonator through the ring boundary border.
  • forming an electrode lead-out structure 3 covering the annular sacrificial protrusion 32 ′ and overlapping the edge of the electrode in the effective resonance region on the first electrode 21 includes: depositing a conductive material on the first electrode 21 to form The electrode lead-out structure 3 covers the first electrode 21 and the annular sacrificial protrusion 32' disposed on the first electrode 21, and extends to the support layer 12 on the periphery of the first cavity; or, on the first electrode A conductive material is deposited on 21 to cover the annular sacrificial protrusion 32' disposed on the first electrode 21; the conductive material is etched, and the conductive material located in the area surrounded by the annular sacrificial protrusion 32' is removed to form an electrode lead-out structure 3 , the formed electrode lead-out structure 3 covers part of the first electrode 21 around the annular groove and extends to the support layer 12 around the first cavity.
  • the electrode lead-out structure 3 only needs to be used to connect the first electrode 21 disconnected by the annular groove and extend to the supporting layer on the periphery of the subsequently formed first cavity for electrical connection with the outside.
  • the structure of the formed electrode extraction structure 3 and its beneficial effects are not repeated here with reference to Embodiment 1.
  • the electrode lead-out structure 3 on the first electrode 21 When forming the electrode lead-out structure 3 on the first electrode 21, it also includes patterning the electrode lead-out structure, so that the electrode lead-out structure 3 and the second electrode formed subsequently are at least partially staggered from each other at the periphery of the effective resonance area.
  • the specific structure and beneficial effects Referring to Embodiment 1, details are not repeated here.
  • the structure of the formed electrode extraction structure 3 and its positional relationship with the first electrode 21 are also referred to in Embodiment 1, and are not repeated here.
  • the annular sacrificial protrusion 32' will be removed to form an annular gap, the annular gap is a closed annular structure, and the annular gap is opposite to the annular groove.
  • the electrode lead-out structure 3 is not formed on the first electrode 21, this step can be omitted.
  • a support layer having a sacrificial layer 121' is formed on the first electrode 21. Specifically: forming a sacrificial layer 121' on the first electrode 21, covering part of the electrode lead-out structure 3 and its corresponding part of the first electrode 21; forming a support layer 12, covering the outer periphery of the sacrificial layer 121' and the sacrificial layer 121'; removing The sacrificial layer 121' forms a first cavity.
  • the sacrificial layer 121 ′ covers at least the arch bridge 31 structure of the electrode lead-out structure 3, so that the effective resonance area is formed above the first cavity, so as to facilitate the reflection of longitudinal waves in the effective resonance area and improve the utilization rate of acoustic waves.
  • the support layer 12 covers the sacrificial layer 121', the electrode lead-out structure 3 and the first electrode 21 located on the outer periphery of the sacrificial layer 121'.
  • the material of the sacrificial layer 121' refer to the first sacrificial material described above, which will not be repeated here. It should be noted that when the electrode lead-out structure 3 is not formed on the first electrode 21, the sacrificial layer 121' only covers part of the first electrode 21.
  • the method for removing the sacrificial layer 121' includes: forming a first release hole on the support layer 12 to expose the sacrificial layer 121', and removing the sacrificial layer 121' through the first release hole.
  • a corresponding removal method is adopted in the process of removing the sacrificial layer 121'.
  • the chemical method is as follows: at a temperature of 250 degrees Celsius, oxygen chemically reacts with the sacrificial layer material through the air, and the generated gaseous substances are volatilized.
  • the silicon oxide is removed by reaction to form a first cavity 121, and the shape of the first cavity 121 is the same as that of the sacrificial layer 121'.
  • the sacrificial layer 121' can also be removed together with the subsequent removal of the annular sacrificial protrusion 32'.
  • the substrate 11 may also be formed on the supporting layer 12 , and reference may be made to Embodiment 1 for the combination of the supporting layer 12 and the substrate 11 .
  • the carrier substrate is removed, and the above structure is turned over.
  • the carrier substrate may be removed by a grinding process or a wet etching process, or an isolation layer may be formed on the carrier substrate before the second electrode 23 is formed, and the carrier substrate may be peeled off by removing the isolation layer.
  • the material of the isolation layer includes, but is not limited to, at least one of silicon dioxide, silicon nitride, aluminum oxide, and aluminum nitride, or thermal expansion tape.
  • the annular sacrificial protrusion 32 ′ is removed to form an annular space 32 , which is opposite to the annular groove 24 .
  • a second release hole penetrating the second electrode 23 to expose the first sacrificial material in the first trench 25 and the annular trench 24 is formed on the second electrode 23 , and the annular sacrificial protrusion is removed through the second release hole.
  • the method for removing the annular sacrificial protrusion may refer to the method for removing the sacrificial layer, which will not be repeated here.
  • the electrode extraction structure 3 when the first electrode 21 is not provided with the electrode extraction structure 3, the electrode extraction structure 3 needs to be formed on the second electrode 23, and the process of forming the electrode extraction structure 3 on the second electrode is omitted, and Embodiment 4 is omitted.
  • the annular groove 24 and the electrode lead-out structure 3 on the first electrode 21 and after the second electrode 23 is formed the annular groove and the electrode lead-out structure are formed on the second electrode 23.
  • the formation process can be referred to in The process of forming the electrode extraction structure 3 on the first electrode 21 will not be repeated here.
  • the first trench 25 may be formed when the annular trench 24 penetrating the second electrode 23 is formed, or may be formed after the piezoelectric layer 22 is formed and before the second electrode 23 is formed.
  • the sacrificial layer material needs to be filled in the first trench 25 now, so that the upper surface of the first trench 25 is kept flat with the surface of the piezoelectric layer 22, and then the first trench 25 is formed. Two electrodes 23 .
  • the method for forming the first electrode 21 , the piezoelectric layer 22 and the second electrode 23 further includes: providing a carrier substrate 4 ; and forming the first electrode 21 on the carrier substrate 4 ; After the supporting layer 12 is formed on the first electrode 21, the carrier substrate 4 is removed; then the piezoelectric layer 22 and the second electrode 23 are formed on the first electrode 21 in turn; the electrode lead-out structure 3 is formed on the first electrode 21; Forming the electrode lead-out structure 3 on the first electrode 21 includes: forming the electrode lead-out structure 3 on the first electrode 21 after forming the first electrode 21 and before forming the support layer 12 . Specifically, referring to FIG.
  • a carrier substrate 4 is provided, and the first electrode 21 is formed on the carrier substrate 4 .
  • the annular groove 24 may be formed after the carrier substrate 4 is subsequently removed and before the piezoelectric layer 22 is formed.
  • the annular trench 24 may be formed by etching after the first electrode 21 is formed and before the electrode lead-out structure 3 is formed.
  • the electrode lead-out structure 3 and the support layer 12 having the first cavity are formed on the first electrode 21 , and the specific steps can be referred to as described in Embodiment 4, wherein the annular sacrificial protrusion 32 ′ fills the annular groove and The first electrode 21 covers the peripheral region of the annular trench.
  • the carrier substrate is removed, the above structure is turned over, and then the piezoelectric layer 22 and the second electrode 23 are sequentially deposited on the first electrode 21 .
  • the piezoelectric layer 22 is etched to form a groove penetrating the piezoelectric layer 22 and the first electrode 21, wherein the part penetrating the first electrode 21 is an annular groove,
  • the part passing through the piezoelectric layer 22 is the first groove, and the annular groove and the projection of the first groove on the surface of the piezoelectric layer 22 completely overlap; flush; and then form a second electrode 23 on the piezoelectric layer 22 .
  • the first electrode 21 is etched to form an annular trench penetrating the first electrode 21 ; the annular trench is filled with sacrificial material so that the upper surface of the annular trench is in contact with the first electrode 21 The surface is flush; then the piezoelectric layer 22 is formed on the first electrode 21, and the piezoelectric layer 22 is etched to form a first trench penetrating the piezoelectric layer 22; the sacrificial material is filled in the first trench to make the upper surface It is flush with the upper surface of the piezoelectric layer 22; and then a second electrode 23 is formed on the piezoelectric layer 22, and the first groove is opposite to the annular groove.
  • the second electrode 23 is formed, the sacrificial material and the annular sacrificial protrusion are removed, and the removal method thereof is referred to in Embodiment 4, which will not be repeated here.
  • the electrode lead-out structure is not formed on the first electrode 21
  • the electrode lead-out structure 3 is formed on the second electrode 23 , and the formation steps can refer to the above steps and Embodiment 4, and are not repeated here.
  • the method for forming the first electrode 21 , the piezoelectric layer 22 and the second electrode 23 further includes: providing a carrier substrate 4 ; and sequentially forming the piezoelectric layers on the carrier substrate 4 22.
  • Forming the electrode lead-out structure 3 on the first electrode 21 includes: forming the electrode lead-out structure 3 on the first electrode 21 after forming the first electrode 21 and before forming the support layer 12 .
  • FIG. 11-13 the method for forming the first electrode 21 , the piezoelectric layer 22 and the second electrode 23 further includes: providing a carrier substrate 4 ; and sequentially forming the piezoelectric layers on the carrier substrate 4 22.
  • a carrier substrate 4 is provided, a piezoelectric layer 22 is formed on the carrier substrate 4 , a first electrode 21 is formed on the piezoelectric layer 22 , the first electrode 21 and the piezoelectric layer 22 are etched to form The groove penetrating the first electrode 21 and the piezoelectric layer 22 , wherein the part penetrating the first electrode 21 is the annular groove 24 , and the part penetrating the piezoelectric layer 22 is the first groove 25 .
  • the etching of the annular trench 24 and the first trench 25 may be performed simultaneously or in steps to the piezoelectric layer 22 and the first electrode 21 before the subsequent formation of the second electrode 23 .
  • an electrode lead-out structure 3 and a support layer 12 having a first cavity are formed on the first electrode 21 , and the specific steps can be referred to as described in Embodiment 4, which will not be repeated here.
  • the annular sacrificial protrusion 32' forming the arch bridge structure of the electrode lead-out structure 3 fills the annular groove and the first groove, and covers part of the first electrode 21 in the peripheral region of the annular groove.
  • the carrier substrate is removed, and the above-mentioned structure is turned over to deposit the second electrode 23 on the piezoelectric layer 22 . It should be noted that, after the second electrode 23 is formed, the annular sacrificial protrusion also needs to be removed.
  • the electrode lead-out structure is not formed on the first electrode 21
  • the electrode lead-out structure 3 is formed on the second electrode 23 , and the formation steps can refer to the above steps and Embodiment 4, and are not repeated here.
  • Embodiment 5 provides a method for manufacturing a thin-film bulk acoustic resonator.
  • FIG. 14 is a schematic structural diagram of a thin-film bulk acoustic resonator manufactured according to the method for manufacturing a thin-film bulk acoustic resonator in this embodiment. The difference is that the piezoelectric layer 22 in Embodiment 4 is formed with a first trench 25, and the piezoelectric layer 22 in this embodiment is a complete film layer, and the etching of the piezoelectric layer 22 in the above-mentioned Embodiment 4 is omitted For this step, the remaining steps refer to Example 4 above.
  • the beneficial effect of the piezoelectric layer 22 being a complete film layer reference may be made to the above-mentioned Embodiment 2, which will not be repeated here.
  • Embodiment 6 provides a method for manufacturing a thin-film bulk acoustic resonator.
  • FIGS. 15-21 are schematic structural diagrams of a thin-film bulk acoustic resonator manufactured according to the method for manufacturing a thin-film bulk acoustic resonator in this embodiment. The difference between 4 and 4 is that in Embodiment 4, one of the first electrode 21 and the second electrode 23 is provided with an electrode extraction structure 3 , and in this embodiment, both the first electrode 21 and the second electrode 24 are provided with an electrode extraction structure 4 .
  • the second electrode 23, the piezoelectric layer 22, and the first electrode 21 are sequentially formed on the carrier substrate 4;
  • the first sacrificial material when the first sacrificial material is deposited on the first electrode 21 to form an annular sacrificial protrusion, the first sacrificial material fills the trench and covers the first electrode 21 in the peripheral region of the trench, and then forms a covering annular shape on the first electrode 21 .
  • Sacrificial raised electrode extraction structure 3 refer to FIG. 16 .
  • the support layer 12 having the first cavity 121 is formed on the first electrode 21 by means of a sacrificial layer, the carrier substrate 4 is removed, and the above structure is turned over.
  • Another annular sacrificial bump is formed on the second electrode 21 , the annular sacrificial bump is connected to the annular sacrificial bump and covers part of the surface of the second electrode 23 , and then an electrode covering the annular sacrificial bump is formed on the second electrode 23
  • the sacrificial material is removed.
  • the specific formation process of the above steps and the remaining steps of the thin-film bulk acoustic wave resonator refer to the above-mentioned Embodiment 4, and will not be repeated here.
  • forming the electrode lead-out structure 3 on the first electrode 21 also includes patterning the electrode lead-out structure
  • forming the electrode lead-out structure 3 on the second electrode 23 also includes patterning the electrode lead-out structure, so that the electrode lead-out structure formed on the first electrode 23 also includes patterning.
  • the electrode lead-out structure 3 on the electrode 21 and the electrode lead-out structure 3 formed on the second electrode 23 are at least partially offset from each other at the periphery of the annular gap, that is, at the periphery of the annular gap, the electrode lead-out structure 3 formed on the first electrode 21 and
  • the projection of the electrode lead-out structure 3 formed on the second electrode 23 on the surface of the piezoelectric layer 22 does not overlap at least in part, so as to avoid the problem of high-frequency coupling caused by the existence of potential floating, prevent the formation of parasitic capacitance, and help improve the quality of the resonator factor.
  • the electrode lead-out structure 3 formed on the first electrode 21 and the electrode lead-out structure 3 formed on the second electrode 23 are completely offset from each other at the periphery of the annular gap, the problem of high frequency coupling can be better avoided.
  • the arch bridge 31 of the electrode lead-out structure 3 formed on the first electrode 21 and the arch bridge 31 of the electrode lead-out structure 3 formed on the second electrode 23 The structures are arranged oppositely, that is, the projection of the arched bridge 31 structure formed on the first electrode 21 and the arched bridge 31 structure formed on the second electrode 23 on the surface of the piezoelectric layer 22 overlap each other, so that the The effective resonance area enclosed by the annular gap is the same area.
  • the electrode lead-out structure 3 disposed on the first electrode 21 and the electrode lead-out structure 3 disposed on the second electrode 23 respectively have a second portion extending outside the effective resonance area as an electrode connection terminal.
  • the steps of the above-mentioned Embodiment 4 are performed, and the second electrode 23 is etched before removing the annular sacrificial bump on the first electrode 21 after the substrate is removed. , forming an annular groove penetrating the second electrode 23 , referring to FIG. 18 .
  • An annular sacrificial protrusion is formed on the second electrode 23 , covering the first sacrificial material and partially covering the second electrode 23 , and an electrode lead-out structure 3 covering the annular sacrificial protrusion is formed on the second electrode 23 , referring to FIG. 19 .
  • the first sacrificial material and the annular sacrificial bump are removed.
  • Embodiment 4 For the specific formation process corresponding to the above steps, refer to Embodiment 4, which will not be repeated here.
  • the remaining steps of the thin film bulk acoustic wave resonator refer to the above-mentioned Embodiment 4, and are not repeated here.
  • a second electrode 23 , a piezoelectric layer 22 , and a first electrode 21 are formed in sequence on the carrier substrate 4 ; an electrode lead-out structure is formed on the first electrode 21 , see Figure 20.
  • the support layer 12 having the first cavity 121 is formed by means of a sacrificial layer; the carrier substrate 4 is removed, and the above structure is turned over.
  • Embodiment 4 For the specific formation process of the above steps, refer to Embodiment 4, which will not be repeated here.
  • Embodiment 7 provides a method for manufacturing a thin-film bulk acoustic resonator.
  • FIG. 22 is a schematic structural diagram of a thin-film bulk acoustic resonator manufactured according to the method for manufacturing a thin-film bulk acoustic resonator in this embodiment. The difference is that the piezoelectric layer 22 in the embodiment 6 is formed with the first groove 25, and the piezoelectric layer 22 in this embodiment is not etched to form the first groove 25, which is a complete film layer, and the above embodiment is omitted.
  • the step of etching the piezoelectric layer 22 in step 6 refer to the above-mentioned embodiment 6 for other steps.
  • the beneficial effect of the piezoelectric layer 22 being a complete film layer reference may be made to the above-mentioned Embodiment 2, which will not be repeated here.
  • the first electrode 21 and the second electrode 23 are both provided with the electrode lead-out structure 3, and the relative relationship between the two is referred to in Embodiment 1, and is not repeated here.
  • Embodiment 8 of the present invention provides a method for manufacturing a thin-film bulk acoustic resonator.
  • FIG. 23 is a schematic structural diagram of a thin-film bulk acoustic resonator manufactured according to the method for manufacturing a thin-film bulk acoustic resonator in this embodiment.
  • the first cavity 121 is formed in the support layer 12, while in this embodiment, the acoustic mirror is formed in the support layer 12, which specifically includes: S01: forming a first electrode, a piezoelectric layer and a second electrode, and the piezoelectric layer is located between the first electrode and the second electrode; S02: forming an annular groove penetrating the corresponding electrode on at least one of the first electrode and the second electrode ; S03: forming an electrode lead-out structure with an arched bridge on an electrode with an annular groove, including: forming an annular sacrificial bump; forming an electrode lead-out structure covering the annular sacrificial bump on the corresponding electrode; S04: on the first electrode A support layer with an acoustic mirror is formed thereon; S05 : removing the annular sacrificial protrusion to form an annular gap, and the area enclosed by the annular gap is an effective resonance area.
  • the method for forming the support layer 12 with the acoustic reflection mirror 51 on the first electrode 21 includes: sequentially forming a plurality of alternately stacked high and low acoustic impedance reflection film layers on the first electrode 21 to reflect The film layer covers part of the first electrode 21 or covers part of the first electrode 21 and the electrode lead-out structure 21 located on the first electrode 21 .
  • the second substrate 5 may also be formed on the support layer 12 .
  • Embodiment 9 of the present invention provides a filter, including at least one thin-film bulk acoustic resonator as described above.
  • a filter is formed by connecting the above-mentioned thin film bulk acoustic wave resonators to ensure that the filter has good structural stability, and because the electrode impedance of the resonator is low, the conductivity of the filter can be improved, and the filtering accuracy can be improved.

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Abstract

本发明涉及一种薄膜体声波谐振器、其制造方法及滤波器，其中，薄膜体声波谐振器包括：压电叠层结构，压电叠层结构包括依次从下至上叠置的第一电极、压电层和第二电极，第一电极、第二电极至少其中之一具有贯穿相应电极的环形沟槽；在设有环形沟槽的相应电极上设置电极引出结构，电极引出结构遮盖至少部分环形沟槽并延伸至无效谐振区，电极引出结构包括向远离压电层方向凸起的环形拱形桥，拱形桥的内表面围成环形空隙，环形空隙与环形沟槽相对。本发明通过电极引出结构的环形空隙所在区域界定有效区的边界，并通过环形沟槽使有效区边界处相应电极的端部与空隙的气体接触，从而达到消除有效区的电极的边界杂波的效果，进而提升谐振器的Q值。

Description

薄膜体声波谐振器、其制造方法及滤波器 技术领域
本发明涉及半导体器件制造领域，尤其涉及一种薄膜体声波谐振器、其制造方法及滤波器。
 背景技术
自模拟射频通讯技术在上世纪90代初被开发以来，射频前端模块已经逐渐成为通讯设备的核心组件。在所有射频前端模块中，滤波器已成为增长势头最猛、发展前景最大的部件。随着无线通讯技术的高速发展，5G通讯协议日渐成熟，市场对射频滤波器的各方面性能也提出了更为严格的标准。滤波器的性能由组成滤波器的谐振器单元决定。在现有的滤波器中，薄膜体声波谐振器(FBAR)因其体积小、插入损耗低、带外抑制大、品质因数高、工作频率高、功率容量大以及抗静电冲击能力良好等特点，成为最适合5G应用的滤波器之一。
通常，薄膜体声波谐振器包括两个薄膜电极，并且两个薄膜电极之间设有压电薄膜层，其工作原理为利用压电薄膜层在交变电场下产生振动，该振动激励出沿压电薄膜层厚度方向传播的体声波，此声波传至上下电极与空气交界面被反射回来，进而在薄膜内部来回反射，形成震荡。当声波在压电薄膜层中传播正好是半波长的奇数倍时，形成驻波震荡。
 技术问题
但是，目前制作出的空腔型薄膜体声波谐振器，其品质因子（Q）无法进一步提高，因此无法满足高性能的射频系统的需求。
 技术解决方案
本发明的目的在于提供一种薄膜体声波谐振器、其制造方法及滤波器，能够提高薄膜体声波谐振器的品质因子，进而提高器件性能。
为了实现上述目的，本发明提供了一种薄膜体声波谐振器，包括：压电叠层结构，压电叠层结构包括依次从下至上叠置的第一电极、压电层和第二电极，第一电极、第二电极至少其中之一具有贯穿相应电极的环形沟槽；在设有环形沟槽的相应电极上设置电极引出结构，电极引出结构遮盖至少部分环形沟槽并延伸至无效谐振区，电极引出结构包括向远离压电层方向凸起的环形拱形桥，拱形桥的内表面围成环形空隙，环形空隙与环形沟槽相对。
本发明还提供了一种薄膜体声波谐振器的制造方法，包括：形成第一电极、压电层和第二电极，所述压电层位于所述第一电极和所述第二电极之间；在所述第一电极、所述第二电极至少其中之一上形成贯穿相应电极的环形沟槽；在具有所述环形沟槽的电极上形成具有拱形桥的电极引出结构，包括：形成环形牺牲凸起；形成覆盖所述环形牺牲凸起、边缘搭接在有效谐振区电极边缘上的电极引出结构；所述第一电极上形成具有牺牲层的支撑层；去除所述牺牲层形成第一空腔；去除所述环形牺牲凸起形成环形空隙，所述环形空隙和所述环形沟槽相对。
本发明还提供了一种薄膜体声波谐振器的制造方法，包括：形成第一电极、压电层和第二电极，压电层位于第一电极和第二电极之间；在第一电极、第二电极至少其中之一上形成贯穿相应电极的环形沟槽；在具有环形沟槽的电极上形成具有拱形桥的电极引出结构，包括：形成环形牺牲凸起；形成覆盖环形牺牲凸起、边缘搭接在有效谐振区电极边缘上的电极引出结构；在第一电极上形成具有声反射镜的支撑层；去除环形牺牲凸起形成环形空隙，所述环形空隙和所述环形沟槽相对。
本发明还提供了一种滤波器，包括至少一个如上所述的薄膜体声波谐振器。
 有益效果
本发明的薄膜体声波谐振器的有益效果在于：在第一电极和/或第二电极上设置具有拱形桥结构的电极引出结构，拱形桥围成环形，拱形桥与相应电极所在平面的表面形成环形空隙，用拱形桥所在的区域界定有效谐振区的边界，相应电极上设有环形沟槽，以将相应电极断开，再通过电极引出结构将被断开的电极连接起来，此外，环形沟槽还可以使有效谐振区边界处的第一电极和/或第二电极的端部与环形空隙的气体接触，从而达到消除有效谐振区内电极的边界杂波的效果，进而提升谐振器的Q值。
进一步地，电极引出结构的阻抗低于相应电极的阻抗，以降低电极阻抗，使电极引出结构具有较好的导电性，提高导电率。
进一步地，电极引出结构与未设有电极引出结构的相应电极或分别设于第一电极、第二电极上的电极引出结构在拱形桥外围区域至少部分相互错开，可以避免由于电位浮空产生的高频耦合问题，防止形成寄生电容，有利于提高谐振器品质因数。
进一步地，第一电极和/或第二电极从有效谐振区延伸至第一空腔或声反射镜外围的第一衬底上，可以提高谐振器的结构强度，另外，形成于相应电极上的电极引出结构也从有效谐振区延伸至第一空腔或声反射镜外围的第一衬底上，以提高谐振器的结构强度。
进一步地，压电层为完整的膜层，可以保障谐振器的结构强度，提高谐振器的成品率。
进一步地，压电层中设有第一沟槽，使压电层的边缘暴露在气体中，能够抑制压电层的横波损失，当第一沟槽全部位于环形空隙范围内时，可以更好的提升谐振器的Q值。
本发明的薄膜体声波谐振器的制造方法的有益效果在于：通过在相应电极上形成环形牺牲凸起的方式形成具有拱形桥结构电极引出结构，并在去除环形牺牲凸起后，形成环形空隙，以界定有效谐振区的范围，再通过刻蚀相应电极形成贯穿相应电极的环形沟槽，既便于简化电极引出结构的形成工艺，又可以将位于环形沟槽内、外的电极分离，并通过电极引出结构将被断开的电极电连，从而降低电极的阻抗，并使相应电极的边界暴露于拱形桥形成的环形空隙中，从而达到消除有效谐振区的电极边界杂波的效果。
进一步地，通过采用牺牲层的方式形成第一空腔，可以减少制造成本，能够在后续形成支撑层的过程中对其形成支撑，避免第一电极、压电叠层和第二电极受力不均被压变形，还能够在后续反面工艺过程中对压电叠层结构形成支撑，保证压电叠层结构的平整性。
进一步地，将压电层形成在平整的电极或承载衬底上，使得压电层的上表面和下表面均为平面，保证压电层具有较好的晶格取向，提高压电层的压电特性，进而提高谐振器的性能。
本发明的滤波器的有益效果在于：通过上述薄膜体声波谐振器连接形成滤波器，以确保该滤波器具有较好的结构稳定性，且由于谐振器的电极阻抗较低，可以提高滤波器的导电率，提高滤波的准确性。
 附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1示出了本发明实施例1的薄膜体声波谐振器的结构示意图；图2示出了本发明实施例2的薄膜体声波谐振器的结构示意图；图3示出了本发明实施例3的薄膜体声波谐振器的结构示意图；图4至图7示出了本发明实施例4的薄膜体声波谐振器的制造方法不同步骤对应的结构示意图；图8至图10示出了本发明实施例4中形成的薄膜体声波谐振器的另一制造方法不同步骤对应的结构示意图；图11至图13示出了本发明实施例4中形成的薄膜体声波谐振器的另一制造方法不同步骤对应的结构示意图；图14为根据实施例5薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图；图15-21为根据实施例6薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图；图22为根据实施例7薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图；图23为根据实施例8薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图。
附图标记说明：1、第一衬底；11、基底；12、支撑层；121、第一空腔；121’、牺牲层；21、第一电极；22、压电层；23、第二电极；24、环形沟槽；25、第一沟槽；3、电极引出结构；31、拱形桥；32、环形空隙；32’、环形牺牲凸起；4、承载衬底；5、第二衬底；51、声反射镜。
 本发明的实施方式
以下结合附图和具体实施例对本发明的薄膜体声波谐振器及其制作方法作进一步详细说明。根据下面的说明和附图，本发明的优点和特征将更清楚，然而，需说明的是，本发明技术方案的构思可按照多种不同的形式实施，并不局限于在此阐述的特定实施例。附图均采用非常简化的形式且均使用非精准的比例，仅用以方便、明晰地辅助说明本发明实施例的目的。
在说明书和权利要求书中的术语“第一”“第二”等用于在类似要素之间进行区分，且未必是用于描述特定次序或时间顺序。要理解，在适当情况下，如此使用的这些术语可替换，例如可使得本文所述的本发明实施例能够以不同于本文所述的或所示的其他顺序来操作。类似的，如果本文所述的方法包括一系列步骤，且本文所呈现的这些步骤的顺序并非必须是可执行这些步骤的唯一顺序，且一些所述的步骤可被省略和/或一些本文未描述的其他步骤可被添加到该方法。若某附图中的构件与其他附图中的构件相同，虽然在所有附图中都可轻易辨认出这些构件，但为了使附图的说明更为清楚，本说明书不会将所有相同构件的标号标于每一图中。
实施例 1
实施例1提供了一种薄膜体声波谐振器，图1为本发明实施例1提供的一种薄膜体声波谐振器的剖面结构示意图，请参考图1，该薄膜体声波谐振器包括：压电叠层结构2，压电叠层结构2包括依次从下至上叠置的第一电极21、压电层22和第二电极23，第一电极21、第二电极23至少其中之一具有贯穿相应电极的环形沟槽24；在设有环形沟槽24的相应电极上设置电极引出结构3，电极引出结构3遮盖至少部分环形沟槽24并延伸至无效谐振区，电极引出结构3包括向远离压电层22方向凸起的环形拱形桥31，拱形桥31的内表面围成环形空隙32，环形空隙32与环形沟槽24相对。需要说明的是，环形空隙32围成的区域为有效谐振区，有效谐振区以外的区域为无效谐振区，通过环形空隙32界定有效谐振区的边界，以有效防止横波泄露。需要说明的是，上述相应电极为设置有环形沟槽24的电极，即当第一电极21设有环形沟槽24时，第一电极21为与环形沟槽24相应的电极，且第一电极21与其上设置的电极引出结构3相应；当第二电极23设有环形沟槽24时，第二电极23为与环形沟槽24相应的电极，且第二电极23与其上设置的电极引出结构3相应。下文以在第一电极21上设置环形沟槽24、并在第一电极21上形成电极引出结构3为例，对该薄膜体声波谐振器的结构做具体说明。
压电叠层结构3形成于具有第一空腔121的第一衬底上1，压电叠层结构3包括依次层叠的第一电极21、压电层22和第二电极23，第一电极21和第二电极23的材料可以使用本领域技术任意熟知的任意合适的导电材料或半导体材料，其中，导电材料可以为具有导电性能的金属材料，例如，由钼（Mo）、铝（Al）、铜（Cu）、钨（W）、钽（Ta）、铂（Pt）、钌（Ru）、铑（Rh）、铱（Ir）、铬（Cr）、钛（Ti）、金(Au)、锇(Os)、铼(Re)、钯(Pd)等金属中一种制成或由上述金属形成的叠层制成，所述半导体材料例如是Si、Ge、SiGe、SiC、SiGeC等。压电层22的材料可以使用氮化铝(AlN)、氧化锌(ZnO)、锆钛酸铅(PZT)、铌酸锂(LiNbO 3)、石英(Quartz)、铌酸钾(KNbO 3)或钽酸锂(LiTaO 3)等具有纤锌矿型结晶结构的压电材料及它们的组合。当压电层22材料为氮化铝(AlN)时，压电层22还可包括稀土金属，例如钪(Sc)、铒(Er)、钇(Y)和镧(La)中的至少一种。此外，当压电层22的材料为氮化铝(AlN)时，压电层22还可包括过渡金属，例如锆(Zr)、钛(Ti)、锰(Mn)和铪(Hf)中的至少一种。
第一电极21和/或第二电极23的四周延伸至第一空腔121外围的第一衬底1上，以提高谐振器的结构强度，当第一电极21和第二电极23的四周均延伸至第一空腔121外围的第一衬底1上时，谐振器结构强度较佳。需要说明的是，第一电极21的四周为其整体结构的外边缘，第二电极23的四周为其整体结构的外边缘。在本实施例中，第一电极21和/或第二电极23的全部四周延伸至第一空腔121外围的第一衬底1上。在其他实施例中，第一电极21和/或第二电极23的部分四周延伸至第一空腔121外围的第一衬底1上，此时，为保证谐振器的结构强度，部分延伸至第一空腔121外围第一衬底1上的电极对称分布，以确保支撑强度。
在本实施例中，电极引出结构3的阻抗低于第一电极21的阻抗，环形沟槽24为封闭的环形沟槽。通过环形沟槽24将第一电极21在环形沟槽24处完全隔断开，再通过阻抗低于第一电极21的电极引出结构3将被断开的第一电极21电连，从而降低第一电极21的阻抗。电极引出结构3的材料可以为金属材料，金属材料包括金、银、钨、铂、铝、铜、钛、锡、镍中的一种或多种。
具体地，电极引出结构3和第二电极23分别具有延伸至有效谐振区外的第一部分，第一部分作为电极连接端以与外部电连。具体而言，电极引出结构3和第二电极23的四周延伸至第一空腔121外围的第一衬底1上，此时，第一电极21的四周可以延伸或不延伸至第一空腔121外围的第一衬底1上，当第一电极21的四周可以延伸至第一空腔121外围的第一衬底1上时，第一电极21和电极引出结构3共同形成支撑以提高谐振器的结构强度。
另外，在环形空隙32外围，电极引出结构3与未设有电极引出结构3的相应电极在压电层22表面的投影至少部分相互错开，即有效谐振区外围的电极引出结构3与第二电极23在压电层22表面的投影至少部分不重叠，以避免由于电位浮空产生的高频耦合问题，防止形成寄生电容，进而提高谐振器品质因数。当位于有环形空隙32外围的电极引出结构3和第二电极23在压电层22表面的投影完全错开时，可以较好的避免高频耦合问题。
在本实施例中，环形空隙32与环形沟槽24相对，以使有效谐振区边界处的第一电极21的边缘被暴露于环形空隙32中，从而减少从第一电极21端部泄露的声波能量，进而提高谐振器的品质因数。应当注意，环形空隙32与环形沟槽24相对可参照上述环形沟槽24与第一沟槽25相对设置，此处不再赘述。
环形空隙32为封闭的环形，以便于界定有效谐振区的边界，从而有效消除有效谐振区边界的杂波。需要说明的是，拱形桥31环绕第一电极21的全部外周，以便于环形空隙32围成封闭的环形，电极引出结构3还包括连接拱形桥31并延伸至第一空腔121外围的搭接部，搭接部环绕相应电极的部分外周或全部外周，搭接部的部分四周延伸至第一空腔121外围的第一衬底1的外边缘，或，搭接部的全部四周延伸至第一空腔121外围的第一衬底1的外边缘，从而便于与外部电连。另外，搭接部可以为面状结构，铺设于相应电极上；或，搭接部为多个条状结构，多个搭接部对称分布于相应电极上，以便于提高谐振器的结构强度。
在本实施例中，有效谐振区为不规则的多边形，多边形的任意两边不平行。在其他实施例中，有效谐振区也可以是圆形或者椭圆形或者由弧线和直线构成的不规则图形。
压电层22中设置第一沟槽25，第一沟槽25贯穿压电层22，且第一沟槽25与环形沟槽24相对，以使第一沟槽25、环形沟槽24和环形空隙32连通，从而使压电层22的端面与环形空隙32内的气体形成反射界面，进而有效抑制压电层22中的声波泄露，并避免发生寄生谐振，提高谐振器的品质因数。需要说明的是，第一沟槽25与环形沟槽24相对关系可参照环形沟槽24与环形空隙32相对关系，此处不再赘述。当第一沟槽25在压电层22表面的投影全部位于环形沟槽24在压电层22表面的投影以及环形空隙32在压电层22表面的投影范围内时，抑制声波效果较好。另外，第一沟槽25为封闭的环形，环形空隙32内围的压电层22和环形空隙32外围的压电层22相互隔离；或者，第一沟槽25为间断的环形，环形空隙32内围的压电层32通过间断处与环形空隙32外围的压电层相互隔离。当第一沟槽25为封闭的环形时，抑制声波泄露效果较好。
在本实施例中，第一沟槽25为封闭的环形，有效谐振区内的压电层22和有效谐振区外的压电层22相互隔离；或，第一沟槽25为间断的环形，有效谐振区内的压电层22与有效谐振区外的压电层22在其间断处相互隔离、在非间断处相互连接。可以理解，当第一沟槽25为封闭的环形，并且贯穿压电层22，抑制声波泄露的效果较好。
在本实施例中，在具有第一空腔121的第一衬底1上设置压电叠层结构2，压电叠层结构2遮盖第一空腔121。具体地，第一衬底包括基底11和支撑层12，支撑层12和压电叠层结构3依次层叠于基底11上，第一空腔121设置于支撑层12中。需要说明的是，支撑层12可以通过键合层或沉积的方式与基底11结合。键合层的材料包括氧化硅、氮化硅、氮氧化硅、碳氮化硅或硅酸乙酯。此外，键合层还可以采用光固化材料或热固化材料等黏结剂，例如粘片膜（Die Attach Film，DAF）或干膜（Dry Film）等。沉积的方式可以化学气相沉积或物理气相沉积。基底11的材料可以为以下所提到的材料中的至少一种：硅(Si)、锗(Ge)、锗硅(SiGe)、碳硅(SiC)、碳锗硅(SiGeC)、砷化铟(InAs)、砷化镓(GaAs)、磷化铟(InP)或者其它III/V化合物半导体。支撑层12的材料可以是任意适合的介电材料，包括但不限于氧化硅、氮化硅、氮氧化硅、碳氮化硅等材料中的一种。
在本实施例中，第一空腔121贯穿部分支撑层12，即第一空腔121延伸至支撑层12的部分厚度，使第一空腔121暴露支撑层12。在其他实施例中，第一空腔121完全贯穿支撑层12，使第一空腔121暴露基底11。第一空腔121可以通过牺牲层工艺形成，也可以通过刻蚀的方式形成。可选方案中，当第一空腔121的底部暴露的是支撑层12时，通过牺牲层工艺形成，具体形成方法将在后面的方法实施例中描述。当第一空腔121贯穿支撑层12时，第一空腔121可以通过刻蚀支撑层12或形成牺牲层的方式形成。在本实施例中，第一空腔121的截面形状为可以为矩形，但在本发明的其他实施例中，第一空腔121的截面形状还可以是圆形、椭圆形或是矩形以外的多边形，例如五边形、六边形等。
在其他实施例中，第一衬底1包括半导体衬底，其材料可以参照基底11材料，此处不再赘述，第一空腔121形成于第一衬底1中，通过刻蚀第一衬底1临近于第一电极21的表面形成不贯穿第一衬底1的第一空腔121，将形成第一空腔121的第一衬底1键合于第一电极21上。
在其他实施例中，在具有声反射镜的第二衬底上设置压电叠层结构2。声反射镜如布拉格反射结构，布拉格反射结构为本领域的公知常识，此处不再详述。
在其他实施例中，仅在第二电极23上设置环形沟槽，并在第二电极23上形成电极引出结构，其结构具体参照上文在第一电极21上设置环形沟槽24和电极引出结构3的结构，此处不再赘述。
实施例 2
实施例2提供了一种薄膜体声波谐振器，图2为本发明实施例2的薄膜体声波谐振器的剖面结构示意图，本实施例与实施例1的区别在于，实施例1中的压电层22设有第一沟槽25，实施例2中的压电层22为完整的膜层，具体为：压电层22为完整的膜层，遮盖第一空腔121且延伸至第一空腔121外的第一衬底1上。压电层22完整，不经过刻蚀，可以保证谐振器的结构强度，提高谐振器的成品率。本实施例薄膜体声波谐振器的其它结构特征与实施例1相同，此处不再赘述。
实施例 3
实施例3提供了一种薄膜体声波谐振器，图3为本发明实施例3的薄膜体声波谐振器的剖面结构示意图，本实施例与实施例1的区别在于，实施例1中的电极引出结构3仅设置于第一电极21或第二电极23上，实施例3中的电极引出结构设置于第一电极21和第二电极23上。具体为：
在本实施例中，第一电极21和第二电极24均设有电极引出结构3，设置于第一电极21上的电极引出结构和设置于第二电极23上的电极引出结构分别具有延伸至有效谐振区外的第二部分，第二部分作为电极连接端。另外，设置于第一电极21上的电极引出结构3和设置于第二电极23上的电极引出结构3至少部分在环形空隙32的外围相互错开，即在环形空隙32的外围，设置于第一电极21上的电极引出结构3和设置于第二电极23上的电极引出结构3在压电层22表面的投影至少部分不重叠，以避免由于存在电位浮空产生的高频耦合问题，防止形成寄生电容，有利于提高谐振器品质因数。
为了确保谐振器具有较好的结构强度，设置于第一电极21上的电极引出结构3和设置于第二电极23上的电极引出结构3从有效谐振区延伸至第一空腔121外围的第一衬底1上，第一电极21和第二电极23的四周均延伸至第一空腔21外围的第一衬底1上，以使第一电极21及设置于其上的电极引出结构、第二电极23及设置于其上的电极引出结构共同形成支撑，从而提高谐振器的结构强度。需要说明的是，由于环形空隙32围成有效谐振区，因此为避免设置于第一电极21上的拱形桥结构31形成的环形空隙32围成的有效谐振区与设置于第二电极23上的拱形桥结构31形成的环形空隙32围成的有效谐振区错开，需使位于第一电极21上的拱形桥结构31与位于第二电极23上的拱形桥结构相对设置，即设置于第二电极23上的拱形桥结构31与设置于第一电极21上的拱形桥结构31在压电层22表面的投影完全重叠。另外，由于延伸至第一空腔121外围的第一衬底1上的搭接部起连接、支撑作用，因此分别位于两电极上的搭接部可以在压电层22表面的投影重叠或不重叠，搭接部的结构可参照实施例1，此处不再赘述。
在本实施例中，压电层22中设有贯穿压电层22的第一沟槽25，在另一实施例中，压电层22中也可以不刻蚀形成第一沟槽25，为完整的膜层。设置第一沟槽25的有益之处参见实施例1，不设置第一沟槽25的有益之处参见实施例2，此处不再赘述。本实施例薄膜体声波谐振器的其它结构特征与实施例1相同，此处不再赘述。
实施例 4
实施例4提供了一种薄膜体声波谐振器的制造方法，薄膜体声波谐振器的制造方法包括：S01：形成第一电极、压电层和第二电极，压电层位于第一电极和第二电极之间；S02：在第一电极、第二电极至少其中之一上形成贯穿相应电极的环形沟槽；S03：在具有环形沟槽的电极上形成具有拱形桥的电极引出结构，包括：形成环形牺牲凸起；形成覆盖环形牺牲凸起、边缘搭接在有效谐振区电极边缘上的电极引出结构；S04：在第一电极上形成具有牺牲层的支撑层；S05：去除牺牲层形成第一空腔；去除环形牺牲凸起形成环形空隙，环形空隙和环形沟槽相对。
步骤S0N不代表先后顺序。
第一电极21、第二电极24中的一个设置电极引出结构，以在第一电极31上形成电极引出结构为例，图4至图7为本实施例的一种薄膜体声波谐振器的制造方法的相应步骤对应的结构示意图，参考图4至7详细说明本实施例提供的薄膜体声波谐振器的制造方法。
参考图4至图7，本实施例中，形成第一电极21、压电层22和第二电极24的方法包括：提供承载衬底4；在承载衬底4上依次形成第二电极23、形成压电层22、形成第一电极21；在第一电极21上形成支撑层12后，去除承载衬底4。具体地，在形成第一电极后，在第一电极上形成电极引出结构。具体为：参考图4，提供承载衬底4，承载衬底4可以半导体材料，如硅(Si)、锗(Ge)、锗硅(SiGe)、碳硅(SiC)、碳锗硅(SiGeC)、砷化铟(InAs)、砷化镓(GaAs)、磷化铟(InP)或者其它III/V化合物半导体。依次在承载衬底4上形成第二电极23、形成压电层22、形成第一电极21，其中第一电极21和第二电极23可以通过物理气相沉积工艺和刻蚀形成，第一电极21、第二电极24的材料参照实施例1。另外，第一电极21和/或第二电极23的四周延伸至后续形成的第一空腔外围的支撑层12上，其有益效果参照实施例1。压电层22可以使用化学气相沉积、物理气相沉积或原子层沉积等本领域技术人员熟知的任何适合的方法沉积形成，压电层22的材料参照实施例1。通过将压电层22形成在平整的第二电极23上，使压电层22的上表面和下表面均为平面，从而确保压电层22具有较好的晶格取向，提高压电层22的压电特性，进而提高谐振器的整体性能。
继续参照图4，在形成环形牺牲凸起之前，刻蚀第一电极21形成环形沟槽24。在本实施例中，在刻蚀形成环形沟槽24的过程中，还可以对压电层22进行刻蚀，形成贯穿压电层22的第一沟槽25，压电层22上形成第一沟槽25的有益效果参照上述实施例1，此处不再赘述。需要说明的是，后续形成的环形牺牲凸起围成的区域为有效谐振区。
在本实施例中，第一沟槽25为封闭的环形，有效谐振区内的压电层22和有效谐振区外的压电层22相互隔离；或者，第一沟槽25为间断的环形，有效谐振区内的压电层22通过间断处与有效谐振区外的压电层22相互隔离，有效谐振区内的压电层22通过非间断处与有效谐振区外的压电层22相互连接。当第一电极21上不形成电极引出结构3时，此步骤可以省去。
参照图5，在第一电极21上沉积形第一牺牲材料，第一牺牲材料填充环形沟槽和第一沟槽且覆盖部分位于环形沟槽周边区域的第一电极21，第一牺牲材料包括磷硅玻璃、低温二氧化硅、硼磷硅玻璃、锗、非晶碳、聚酰亚胺或光阻剂。图形化位于第一电极21上的第一牺牲材料形成环形牺牲凸起32’，环形牺牲凸起32’为连续的结构，围成封闭的环形，并通过该环形的边界界定谐振器有效谐振区的边界。
继续参照图5，在第一电极21上形成覆盖环形牺牲凸起32’、边缘搭接在有效谐振区电极边缘上的电极引出结构3，具体包括：在第一电极21上沉积导电材料，形成电极引出结构3，电极引出结构3覆盖第一电极21和设置于第一电极21上的环形牺牲凸起32’，并延伸至第一空腔外围的支撑层12上；或，在第一电极21上沉积导电材料，以覆盖设置于第一电极21上的环形牺牲凸起32’；刻蚀导电材料，去除位于环形牺牲凸起32’围成的区域内的导电材料，形成电极引出结构3，形成的电极引出结构3覆盖位于环形沟槽四周的部分第一电极21并延伸至第一空腔外围的支撑层12上。在实际制作过程中，电极引出结构3仅需用于连接被环形沟槽断开的第一电极21并延伸至后续形成的第一空腔外围的支撑层上以与外部电连。形成的电极引出结构3的结构及其有益效果参照实施例1此处不再赘述。
在第一电极21上形成电极引出结构3时，还包括对电极引出结构图形化，以使电极引出结构3与后续形成的第二电极在有效谐振区外围至少部分相互错开，具体结构及有益效果参照实施例1，此处不再赘述。另外，形成的电极引出结构3的结构及其与第一电极21的位置关系也参照实施例1，此处不再赘述。
在后续工艺中将去除环形牺牲凸起32’，形成环形空隙，环形空隙为封闭的环形结构，且环形空隙与环形沟槽相对。关于形成带有拱形桥31结构的电极引出结构3及环形空隙与环形沟槽相对的有益效果参照实施例1。当第一电极21上未形成电极引出结构3时，此步骤可以省去。
参照图6，在第一电极21上形成具有牺牲层121’的支撑层。具体为：在第一电极21上形成牺牲层121’，覆盖部分电极引出结构3及其相应的部分第一电极21；形成支撑层12，覆盖牺牲层121’和牺牲层121’的外周；去除牺牲层121’，形成第一空腔。需要注意的是，牺牲层121’至少覆盖电极引出结构3的拱形桥31结构，以使有效谐振区形成于第一空腔的上方，从而便于反射有效谐振区内的纵波，提高声波利用率。支撑层12覆盖牺牲层121’和位于牺牲层121’外周的电极引出结构3、第一电极21。牺牲层121’材料的选择参照前文所述第一牺牲材料，此处不再赘述。应当注意，当第一电极21上不形成电极引出结构3时，牺牲层121’只覆盖部分第一电极21。
去除牺牲层121’的方法包括：在支撑层12上形成暴露牺牲层121’的第一释放孔，通过第一释放孔去除牺牲层121’。在去除牺牲层121’的过程中，根据牺牲层121’材料，采用相对应的去除方法，比如当牺牲层121’材料为聚酰亚胺或光阻剂时，采用灰化的方法去除，灰化的方法具体为在250摄氏度的温度下，氧气通过空气与牺牲层材料发生化学反应，生成气体物质挥发掉，当牺牲层121’材料为低温二氧化硅时，用氢氟酸溶剂和低温二氧化硅发生反应去除，以形成第一空腔121，第一空腔121的形状与牺牲层121’形状相同。需要注意的是，牺牲层121’也可以在后续去除环形牺牲凸起32’时，一并去除。
另外，在形成支撑层12后，还可以在支撑层12上形成基底11，支撑层12与基底11的结合方式可参照实施例1。
参照图7，去除承载衬底，并将上述结构翻转。可以通过研磨工艺或者湿法腐蚀工艺去除承载衬底，也可以在形成第二电极23之前在承载衬底上形成隔离层，通过去除隔离层的方式剥离承载衬底。隔离层的材质包括但不限于二氧化硅、氮化硅、氧化铝和氮化铝中或热膨胀胶带中的至少一种。在去除承载衬底之后，对第二电极23进行图形化，使第二电极23与形成于第一电极21上的电极引出结构3至少部分在环形空隙32的外围相互错开。
继续参照图7，去除环形牺牲凸32’起形成环形空隙32，环形空隙32和环形沟槽24相对。具体为，在第二电极23上形成贯穿第二电极23露出位于第一沟槽25和环形沟槽24内的第一牺牲材料的第二释放孔，通过第二释放孔去除环形牺牲凸起。应当注意的是，去除环形牺牲凸起的方法可参照牺牲层的去除方法，此处不再赘述。
在其他实施例中，当第一电极21未设置电极引出结构3时，需要在第二电极23上形成电极引出结构3，在第二电极上形成电极引出结构3的过程，省去实施例4中在第一电极21上形成环形沟槽24和电极引出结构3的步骤，并在形成第二电极23后，在第二电极23上形成环形沟槽和电极引出结构，其形成过程可参照在第一电极21上形成电极引出结构3的过程，此处不再赘述。需要注意的是，在此过程中，第一沟槽25可以在形成贯穿第二电极23的环形沟槽24时形成，也可以在形成压电层22之后、形成第二电极23之前形成，当第一沟槽在形成压电层22之后、形成第二电极23之前形成时，需要现在第一沟槽25内填充牺牲层材料，使其上表面与压电层22表面保持平整，再形成第二电极23。
在另一实施例中，参照图8-10，形成第一电极21、压电层22和第二电极23的方法还包括：提供承载衬底4；在承载衬底4上形成第一电极21；在第一电极21上形成支撑层12后，去除承载衬底4；再依次在第一电极21上形成压电层22、形成第二电极23；第一电极21上形成电极引出结构3；在第一电极21上形成电极引出结构3包括：在形成第一电极21后、形成支撑层12之前，在第一电极21上形成电极引出结构3。具体为：参照图8，提供承载衬底4，在承载衬底4上形成第一电极21。在本实施例中，环形沟槽24可以在后续去除承载衬底4之后、形成压电层22之前形成。在其他实施例中，环形沟槽24可以在形成第一电极21后、形成电极引出结构3之前通过刻蚀形成。
参照图9，在第一电极21上形成电极引出结构3和具有第一空腔的支撑层12，其具体步骤可参照实施例4所述，其中，环形牺牲凸起32’填充环形沟槽并覆盖环形沟槽周边区域的第一电极21。
参照图10，去除承载衬底，并翻转上述结构，再依次在第一电极21上沉积形成压电层22和第二电极23。在本实施例中，在形成压电层22后，刻蚀压电层22，形成贯穿压电层22和第一电极21的沟槽，其中，贯穿第一电极21的部分为环形沟槽，贯穿压电层22的部分为第一沟槽，环形沟槽与第一沟槽在压电层22表面的投影完全重叠；在沟槽内填充牺牲材料，使其上表面与压电层22表面齐平；再在压电层22上形成第二电极23。在其他实施例中，在形成压电层22之前，刻蚀第一电极21形成贯穿第一电极21的环形沟槽；在环形沟槽内填充牺牲材料，使其上表面与第一电极21上表面齐平；再在第一电极21上形成压电层22，并刻蚀压电层22形成贯穿压电层22的第一沟槽；在第一沟槽内填充牺牲材料，使其上表面与压电层22上表面齐平；再在压电层22上形成第二电极23，第一沟槽与环形沟槽相对。需要注意的是，在形成第二电极23之后，去除牺牲材料和环形牺牲凸起，其去除方法参照实施例4，此处不再赘述。
当第一电极21上未形成电极引出结构时，在第二电极23上形成电极引出结构3，其形成步骤可参照上述步骤和实施例4，此处不再赘述。
在另一实施例中，参照图11-13，形成第一电极21、压电层22和第二电极23的方法还包括：提供承载衬底4；在承载衬底4上依次形成压电层22、形成第一电极21；在第一电极21上形成支撑层12后，去除承载衬底4；再在压电层22上形成第二电极23；第一电极21上形成电极引出结构3；在第一电极21上形成电极引出结构3包括：在形成第一电极21后、形成支撑层12之前，在第一电极21上形成电极引出结构3。具体为：参照图11，提供承载衬底4，在承载衬底4上形成压电层22，在压电层22上形成第一电极21，刻蚀第一电极21和压电层22，形成贯穿第一电极21和压电层22的沟槽，其中贯穿第一电极21的部分为环形沟槽24，贯穿压电层22的部分为第一沟槽25。在其他实施例中，环形沟槽24和第一沟槽25的刻蚀可以在后续形成第二电极23之前对压电层22和第一电极21同步或分步进行刻蚀。
参照图12，在第一电极21上形成电极引出结构3和具有第一空腔的支撑层12，其具体步骤可参照实施例4所述，此处不再赘述。其中，形成电极引出结构3拱形桥结构的环形牺牲凸起32’填充环形沟槽和第一沟槽，并覆盖环形沟槽周边区域的部分第一电极21。
参照图13，去除承载衬底，并翻转上述结构，在压电层22上沉积形成第二电极23。需要注意的是，在形成第二电极23之后，还需要去除环形牺牲凸起。
当第一电极21上未形成电极引出结构时，在第二电极23上形成电极引出结构3，其形成步骤可参照上述步骤和实施例4，此处不再赘述。
实施例 5
实施例5提供了一种薄膜体声波谐振器的制造方法，图14为根据本实施例薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图，本实施例与实施例4的区别在于，实施例4中的压电层22形成有第一沟槽25，本实施例中的压电层22为完整的膜层，省去上述实施例4中对压电层22的刻蚀这一步骤，其余步骤参照上述实施例4。压电层22为完整膜层的有益效果可参照上述实施例2，此处不再赘述。
实施例 6
实施例6提供了一种薄膜体声波谐振器的制造方法，图15-21为根据本实施例薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图，本实施例与实施例4的区别在于，实施例4中第一电极21、第二电极23中的一个设有电极引出结构3，本实施例中第一电极21和第二电极24均设有电极引出结构4。具体为：参照图15-17，在本实施例中，在承载衬底4上依次形成第二电极23、形成压电层22、形成第一电极21；刻蚀第一电极21，形成贯穿第一电极21、压电层22和第二电极23的沟槽，其中，贯穿第一电极21和第二电极23的部分为环形沟槽；贯穿压电层22的部分为第一沟槽25，参照图15。相应的，在第一电极21上沉积第一牺牲材料形成环形牺牲凸起时，第一牺牲材料填充沟槽并覆盖沟槽周边区域的第一电极21，再在第一电极21上形成覆盖环形牺牲凸起的电极引出结构3，参照图16。再采用牺牲层方式在第一电极21上形成具有第一空腔121的支撑层12，去除承载衬底4，并翻转上述结构。在第二电极21上形成另一环形牺牲凸起，该环形牺牲凸起连接上述环形牺牲凸起并覆盖部分第二电极23表面，再在第二电极23上形成覆盖该环形牺牲凸起的电极引出结构3，参照图17。最后，去除牺牲材料。上述步骤的具体形成过程以及该薄膜体声波谐振器的其余步骤参照上述实施例4，此处不再赘述。
应当注意，在第一电极21上形成电极引出结构3时还包括图形化该电极引出结构，在第二电极23上形成电极引出结构3时还包括图形化该电极引出结构，使形成于第一电极21上的电极引出结构3和形成于第二电极23上的电极引出结构3至少部分在环形空隙的外围相互错开，即在环形空隙外围，形成于第一电极21上的电极引出结构3与形成于第二电极23上的电极引出结构3在压电层22表面的投影至少部分不重叠，以避免由于存在电位浮空产生的高频耦合问题，防止形成寄生电容，有利于提高谐振器品质因数。当形成于第一电极21上的电极引出结构3和形成于第二电极23上的电极引出结构3在环形空隙的外围完全相互错开时，可以较好的避免高频耦合问题。
由于环形空隙32围成的区域为有效谐振区，因此形成于第一电极21上的电极引出结构3的拱形桥31结构与形成于第二电极23上的电极引出结构3的拱形桥31结构相对设置，即形成于第一电极21上的拱形桥31结构与形成于第二电极23上的拱形桥31结构在压电层22表面的投影相处重叠，使得两拱形桥内的环形空隙围成的有效谐振区为同一区域。另外，设置于第一电极21上的电极引出结构3和设置于第二电极23上的电极引出结构3分别具有延伸至有效谐振区外的第二部分，以作为电极连接端。
在另一实施例中，参照图18-19，执行上述实施例4的步骤，并在去承载时衬底之后，去除位于第一电极21上的环形牺牲凸起之前，刻蚀第二电极23，形成贯穿第二电极23的环形沟槽，参照图18。在第二电极23上形成环形牺牲凸起，覆盖第一牺牲材料并覆盖部分第二电极23，在第二电极23上形成覆盖环形牺牲凸起的电极引出结构3，参照图19。去除第一牺牲材料及环形牺牲凸起。上述步骤对应的具体形成过程参照实施例4，此处不再赘述。该薄膜体声波谐振器的其余步骤参照上述实施例4，此处不再赘述。
在另一实施例中，参照图20-21，在承载衬底4上依次形成第二电极23、形成压电层22、形成第一电极21；在第一电极21上形成电极引出结构，参照图20。采用牺牲层的方式形成具有第一空腔121的支撑层12；去除承载衬底4，并翻转上述结构。在第二电极23上刻蚀形成贯穿第二电极23、压电层22和第一电极21的沟槽；在沟槽内填充牺牲材料，并覆盖部分沟槽周边区域的第二电极23；在填充导电材料，覆盖第二电极23表面的牺牲材料和部分第二电极23，形成电极引出结构，参照图21。去除牺牲材料。上述步骤的具体形成过程参照实施例4，此处不再赘述。
实施例 7
实施例7提供了一种薄膜体声波谐振器的制造方法，图22为根据本实施例薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图，本实施例与实施例6的区别在于，实施例6中的压电层22形成有第一沟槽25，本实施例中的压电层22不刻蚀形成第一沟槽25，为完整的膜层，省去上述实施例6中对压电层22的刻蚀这一步骤，其余步骤参照上述实施例6。压电层22为完整膜层的有益效果可参照上述实施例2，此处不再赘述。
在上述实施例6和实施例7中，第一电极21和第二电极23均设有电极引出结构3，两者之间的相对关系参照实施例1，此处不再赘述。
实施例 8
本发明实施例8提供了一种薄膜体声波谐振器的制造方法，图23是根据本实施例薄膜体声波谐振器的制造方法制造的薄膜体声波谐振器的结构示意图，本实施例与实施例4-7的区别在于，实施例4-7中任意一个都是在支撑层12中形成第一空腔121，而本实施例中是在支撑层12中形成声学反射镜，具体包括：S01：形成第一电极、压电层和第二电极，压电层位于第一电极和第二电极之间；S02：在第一电极、第二电极至少其中之一上形成贯穿相应电极的环形沟槽；S03：在具有环形沟槽的电极上形成具有拱形桥的电极引出结构，包括：形成环形牺牲凸起；在相应电极上形成覆盖环形牺牲凸起的电极引出结构；S04：在第一电极上形成具有声反射镜的支撑层；S05：去除环形牺牲凸起形成环形空隙，环形空隙围成的区域为有效谐振区。
在本实施例中，在第一电极21上形成具有声反射镜51的的支撑层12的方法包括：在第一电极21上依次形成若干交替叠置的高、低声阻抗反射膜层，反射膜层覆盖部分第一电极21或覆盖部分第一21电极和位于第一电极21上的电极引出结构21。另外，还可以在支撑层12形成第二衬底5。其余步骤可参照上述实施例4-7中的任意一个，此处不再赘述。
实施例 9
本发明实施例9提供了一种滤波器，包括至少一个如上所述的薄膜体声波谐振器。通过上述薄膜体声波谐振器连接形成滤波器，以确保该滤波器具有较好的结构稳定性，且由于谐振器的电极阻抗较低，可以提高滤波器的导电率，提高滤波的准确性。
需要说明的是，本说明书中的各个实施例均采用相关的方式描述，各个实施例之间相同相似的部分互相参见即可，每个实施例重点说明的都是与其他实施例的不同之处。尤其，对于结构实施例而言，由于其基本相似于方法实施例，所以描述的比较简单，相关之处参见方法实施例的部分说明即可。
上述描述仅是对本发明较佳实施例的描述，并非对本发明范围的任何限定，本发明领域的普通技术人员根据上述揭示内容做的任何变更、修饰，均属于权利要求书的保护范围。

Claims (28)

  1. 一种薄膜体声波谐振器，其特征在于，包括：压电叠层结构，所述压电叠层结构包括依次从下至上叠置的第一电极、压电层和第二电极，所述第一电极、所述第二电极至少其中之一具有贯穿相应电极的环形沟槽；在设有所述环形沟槽的相应电极上设置电极引出结构，所述电极引出结构遮盖至少部分所述环形沟槽并延伸至无效谐振区，所述电极引出结构包括向远离所述压电层方向凸起的环形拱形桥，所述拱形桥的内表面围成环形空隙，所述环形空隙与所述环形沟槽相对。
  2. 根据权利要求1所述的薄膜体声波谐振器，其特征在于，所述电极引出结构的阻抗低于相应电极的阻抗。
  3. 根据权利要求1所述的薄膜体声波谐振器，其特征在于，电极引出结构的材料为金属材料，所述金属材料包括金、银、钨、铂、铝、铜、钛、锡、镍中的一种或多种。
  4. 根据权利要求1所述的薄膜体声波谐振器，其特征在于，所述环形空隙为封闭的环形空隙。
    5根据权利要求1所述的薄膜体声波谐振器，其特征在于，所述压电叠层结构位于具有第一空腔的第一衬底上，所述压电叠层结构遮盖所述第一空腔；或者，所述压电叠层结构位于具有声反射镜的第二衬底上。
  5. 根据权利要5所述的薄膜体声波谐振器，其特征在于，所述第一电极和/或所述第二电极的四周延伸至所述第一空腔或所述声反射镜外围的所述第一衬底上。
  6. 根据权利要5所述的薄膜体声波谐振器，其特征在于，所述电极引出结构从所述环形空隙的四周延伸至所述第一空腔或所述声反射镜外围的所述第一衬底上。
  7. 根据权利要求1所述的薄膜体声波谐振器，其特征在于，所述第一电极、所述第二电极其中之一设有电极引出结构，所述电极引出结构和未设有所述电极引出结构的相应电极分别具有延伸至所述有效谐振区外的第一部分，所述第一部分作为电极连接端。
  8. 根据权利要求8所述的薄膜体声波谐振器，其特征在于，所述电极引出结构与未设有所述电极引出结构的相应电极至少部分在所述环形空隙的外围相互错开。
  9. 根据权利要求1所述的薄膜体声波谐振器，其特征在于，所述第一电极和所述第二电极均设有电极引出结构，设置于所述第一电极上的电极引出结构和设置于所述第二电极上的电极引出结构分别具有延伸至所述有效谐振区外的第二部分，所述第二部分作为电极连接端。
  10. 根据权利要求10所述的薄膜体声波谐振器，其特征在于，设置于所述第一电极上的电极引出结构和设置于所述第二电极上的电极引出结构至少部分在所述环形空隙的外围相互错开；
    设置于所述第一电极上的电极引出结构的拱形桥结构与设置于所述第二电极上的电极引出结构的拱形桥结构相对设置。
  11. 根据权利要求5所述的薄膜体声波谐振器，其特征在于，所述压电层为完整的膜层，遮盖所述第一空腔且延伸至所述第一空腔外；或，所述压电层中设有第一沟槽，所述第一沟槽与所述环形沟槽相对。
  12. 根据权利要求12所述的薄膜体声波谐振器，其特征在于，所述第一沟槽为封闭的环形，所述有效谐振区内的压电层和所述有效谐振区外的压电层相互隔离；或，所述第一沟槽为间断的环形，所述有效谐振区内的压电层通过间断处与所述有效谐振区外的所述压电层相互隔离。
  13. 根据权利要求5所述的薄膜体声波谐振器，其特征在于，所述第一衬底包括基底和支撑层，所述支撑层和所述压电叠层结构依次层叠于所述基底上，所述第一空腔设置于所述支撑层中；或者，所述第一衬底包括半导体衬底，所述第一空腔设置于所述半导体衬底中。
  14. 根据权利要求14所述的薄膜体声波谐振器，其特征在于，所述第一空腔延伸至所述支撑层的部分厚度；或者，所述第一空腔贯穿所述支撑层。
  15. 根据权利要求1所述的薄膜体声波谐振器，其特征在于，所述第一电极或所述第二电极的材料包括：钼、铝、铜、钨、钽、铂、钌、铑、铱、铬、钛、金、锇、铼或钯中的一种或多种的组合。
  16. 根据权利要求1所述的薄膜体声波谐振器，其特征在于，所述压电层的材料包括：氮化铝、氧化锌、锆钛酸铅、铌酸锂、石英、铌酸钾或钽酸锂。
  17. 一种薄膜体声波谐振器的制造方法，其特征在于，包括：形成第一电极、压电层和第二电极，所述压电层位于所述第一电极和所述第二电极之间；在所述第一电极、所述第二电极至少其中之一上形成贯穿相应电极的环形沟槽；在具有所述环形沟槽的电极上形成具有拱形桥的电极引出结构，包括：形成环形牺牲凸起；形成覆盖所述环形牺牲凸起、边缘搭接在有效谐振区电极边缘上的电极引出结构；在所述第一电极上形成具有牺牲层的支撑层；去除所述牺牲层形成第一空腔；去除所述环形牺牲凸起形成环形空隙，所述环形空隙和所述环形沟槽相对。
  18. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，所述形成第一电极、压电层和第二电极的方法包括：提供承载衬底；在所述承载衬底上依次形成所述第二电极、形成压电层和形成第一电极；在所述第一电极上形成支撑层后，去除所述承载衬底；
    所述第一电极、所述第二电极至少其中之一形成所述电极引出结构；在所述第一电极上形成电极引出结构包括：在形成第一电极后、形成支撑层之前，在所述第一电极上形成电极引出结构；在所述第二电极上形成电极引出结构包括：去除所述承载衬底后，在所述第二电极上形成所述电极引出结构；或，提供承载衬底；在所述承载衬底上形成所述第一电极；在所述第一电极形成支撑层后，去除所述承载衬底；再依次在所述第一电极上形成压电层、形成第二电极；所述第一电极、所述第二电极至少其中之一形成所述电极引出结构；在所述第一电极上形成电极引出结构包括：在形成所述第一电极后、形成所述支撑层之前，在所述第一电极上形成电极引出结构；在所述第二电极上形成电极引出结构包括：去除所述承载衬底后，在所述第二电极上形成所述电极引出结构；或，提供承载衬底；在所述承载衬底上依次形成压电层、形成第一电极；在所述第一电极上形成支撑层后，去除所述承载衬底；再在所述压电层上形成所述第二电极；所述第一电极、所述第二电极至少其中之一形成所述电极引出结构；在所述第一电极上形成电极引出结构包括：在形成所述第一电极后、形成所述支撑层之前，在所述第一电极上形成电极引出结构；在所述第二电极上形成电极引出结构包括：去除所述承载衬底后，在所述第二电极上形成所述电极引出结构。
  19. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，在形成相应电极之后，刻蚀相应电极形成贯穿相应电极的环形沟槽；在相应电极上形成所述环形沟槽之前或之后，在相应电极上形成电极引出结构。
  20. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，所述在相应电极上形成覆盖所述环形牺牲凸起、边缘搭接在有效谐振区电极边缘上的电极引出结构的方法包括：在相应电极上沉积导电材料，形成所述电极引出结构，所述电极引出结构覆盖相应电极和形成于相应电极上的所述环形牺牲凸起；或，在相应电极上沉积导电材料，所述导电材料覆盖相应电极和形成于相应电极上的所述环形牺牲凸起；刻蚀所述导电材料，去除位于所述环形牺牲凸起围成的区域内的部分导电材料，形成电极引出结构。
  21. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，所述第一电极和/或所述第二电极的四周延伸至所述第一空腔外围的支撑层上。
  22. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，所述第一电极、所述第二电极其中之一形成有所述电极引出结构，形成所述电极引出结构时还包括图形化所述电极引出结构，形成未设有所述电极引出结构的相应电极时还包括图形化所述相应电极，以使所述电极引出结构与未设有所述电极引出结构的相应电极至少部分在所述环形空隙的外围相互错开；或，所述第一电极和所述第二电极均设有电极引出结构，形成所述电极引出结构时还包括图形化所述电极引出结构，使设置于所述第一电极上的电极引出结构和设置于所述第二电极上的电极引出结构至少部分在所述环形空隙的外围相互错开；设置于所述第一电极上的电极引出结构的拱形桥结构与设置于所述第二电极上的电极引出结构的拱形桥结构相对设置。
  23. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，形成的压电层遮盖所述第一空腔并延伸至所述第一空腔外围；或，形成所述压电层后，刻蚀所述压电层，形成贯穿所述压电层的第一沟槽，所述第一沟槽与所述环形沟槽相对。
  24. 根据权利要求24所述的薄膜体声波谐振器的制造方法，其特征在于，所述第一沟槽为封闭的环形，所述有效谐振区内的压电层和所述有效谐振区外的压电层相互隔离；或者，
    所述第一沟槽为间断的环形，所述有效谐振区内的压电层通过间断处与所述有效谐振区外的所述压电层相互隔离。
  25. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，所述环形牺牲凸起的材料包括磷硅玻璃、低温二氧化硅、硼磷硅玻璃、锗、非晶碳、聚酰亚胺或光阻剂。
  26. 根据权利要求18所述的薄膜体声波谐振器的制造方法，其特征在于，所述在所述第一电极上形成具有牺牲层的支撑层的方法包括：在所述第一电极上形成牺牲层，覆盖部分未设有所述电极引出结构的所述第一电极或覆盖部分所述电极引出结构及部分相应所述第一电极；形成支撑层，覆盖所述牺牲层和所述牺牲层的外周；去除所述牺牲层，形成第一空腔。
  27. 一种薄膜体声波谐振器的制造方法，其特征在于，包括：形成第一电极、压电层和第二电极，所述压电层位于所述第一电极和所述第二电极之间；在所述第一电极、所述第二电极至少其中之一上形成贯穿相应电极的环形沟槽；在具有环形沟槽的电极上形成具有拱形桥的电极引出结构，包括：形成环形牺牲凸起；形成覆盖所述环形牺牲凸起、边缘搭接在有效谐振区电极边缘上的电极引出结构；在所述第一电极上形成具有声反射镜的支撑层；去除所述环形牺牲凸起形成环形空隙，所述环形空隙和所述环形沟槽相对。
  28. 一种滤波器，其特征在于，包括至少一个如权利要求1-28中任一所述的薄膜体声波谐振器。
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