WO2022188777A1 - 体声波谐振器及其制造方法、滤波器及电子设备 - Google Patents

体声波谐振器及其制造方法、滤波器及电子设备 Download PDF

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WO2022188777A1
WO2022188777A1 PCT/CN2022/079746 CN2022079746W WO2022188777A1 WO 2022188777 A1 WO2022188777 A1 WO 2022188777A1 CN 2022079746 W CN2022079746 W CN 2022079746W WO 2022188777 A1 WO2022188777 A1 WO 2022188777A1
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layer
electrode
resonator
bottom electrode
connection end
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PCT/CN2022/079746
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English (en)
French (fr)
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张孟伦
庞慰
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诺思(天津)微系统有限责任公司
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    • 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
    • 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
    • H03H9/15—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

  • Embodiments of the present invention relate to the field of semiconductors, and in particular, to a bulk acoustic wave resonator and a method for manufacturing the same, a filter having the resonator, and an electronic device.
  • FBAR Film Bulk Acoustic Resonator
  • BAW Bulk Acoustic Resonator
  • the main structure of the thin film bulk acoustic wave resonator is a "sandwich" structure composed of a bottom electrode-piezoelectric film or a piezoelectric layer-top electrode, that is, a piezoelectric material is sandwiched between two metal electrode layers.
  • the FBAR uses the inverse piezoelectric effect to convert the input electrical signal into mechanical resonance, and then uses the piezoelectric effect to convert the mechanical resonance into an electrical signal output.
  • the present invention is proposed to alleviate or solve at least one aspect of the above-mentioned problems in the prior art.
  • a bulk acoustic wave resonator including a substrate, an acoustic mirror, a bottom electrode, a top electrode, and a piezoelectric layer disposed between the bottom electrode and the top electrode.
  • the piezoelectric layer is a flat piezoelectric layer
  • a support layer is arranged between the substrate and the piezoelectric layer
  • the piezoelectric layer and the substrate are spaced apart from each other in the thickness direction of the resonator and arranged substantially parallel to each other.
  • a high linearity material layer is provided on the outer side in the horizontal direction of the non-electrode connection end of the bottom electrode.
  • Embodiments of the present invention relate to a method for manufacturing a bulk acoustic wave resonator, the bulk acoustic wave resonator includes a substrate, an acoustic mirror, a bottom electrode, a top electrode and a piezoelectric layer, wherein the piezoelectric layer is disposed between the bottom electrode and the top electrode and is a flat piezoelectric layer, the method includes the steps of: disposing a support layer between the substrate and the piezoelectric layer, so that the piezoelectric layer and the substrate are spaced apart from each other in the thickness direction of the resonator and arranged substantially parallel to each other; and A high linearity material layer is provided on the outer side in the horizontal direction of the non-electrode connection end of the bottom electrode.
  • Embodiments of the present invention also relate to a filter comprising the above-mentioned bulk acoustic wave resonator.
  • Embodiments of the present invention also relate to an electronic device comprising the above-mentioned filter or the above-mentioned resonator.
  • FIG. 1 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention
  • Fig. 1A is the enlarged schematic diagram of A part in Fig. 1;
  • FIG. 2 is a schematic cross-sectional view of a bulk acoustic wave resonator according to another exemplary embodiment of the present invention.
  • FIG. 3 is a schematic cross-sectional view of a bulk acoustic wave resonator according to yet another exemplary embodiment of the present invention.
  • FIG. 4A is a schematic cross-sectional view of a bulk acoustic wave resonator according to yet another exemplary embodiment of the present invention.
  • FIG. 4B is a schematic cross-sectional view of a bulk acoustic wave resonator according to yet another exemplary embodiment of the present invention.
  • FIG. 5 is a schematic cross-sectional view of a bulk acoustic wave resonator according to yet another exemplary embodiment of the present invention.
  • 6A-6K are schematic cross-sectional views exemplarily illustrating a manufacturing process of the bulk acoustic wave resonator shown in FIG. 1 .
  • Substrate, optional materials are single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.
  • Auxiliary substrate, optional materials are single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.
  • Acoustic mirror which can be a cavity, or a Bragg reflector and other equivalent forms. Cavities are used in the illustrated embodiment of the present invention.
  • a sacrificial material layer the material of which can be silicon dioxide, doped silicon dioxide, polysilicon, amorphous silicon, and the like.
  • a support layer the material is a highly linear material, including but not limited to NEBSG, SiO 2 , doped SiO 2 , ALN or doped ALN, GaAS, GaN, SiC, SiN, and the like.
  • the bottom electrode material can be: gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al) ), titanium (Ti), osmium (Os), magnesium (Mg), gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), germanium (Ge) ), copper (Cu), aluminum (Al), chromium (Cr), arsenic-doped gold and other similar metals, composites of the above metals or their alloys, etc.
  • Piezoelectric layer which can be a single crystal piezoelectric material, optional, such as: single crystal aluminum nitride, single crystal gallium nitride, single crystal lithium niobate, single crystal potassium niobate, single crystal quartz film, or Materials such as single crystal lithium tantalate can also be polycrystalline piezoelectric materials (corresponding to single crystals, non-single crystal materials), optional, such as polycrystalline aluminum nitride, zinc oxide, PZT, etc., can also include the above
  • the rare earth element doped material with a certain atomic ratio of the material for example, can be doped aluminum nitride, and the doped aluminum nitride contains at least one rare earth element, such as scandium (Sc), yttrium (Y), magnesium (Mg), titanium (Ti), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm),
  • Top electrode which can be: gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), Titanium (Ti), Osmium (Os), Magnesium (Mg), Gold (Au), Tungsten (W), Molybdenum (Mo), Platinum (Pt), Ruthenium (Ru), Iridium (Ir), Germanium (Ge), Copper (Cu), aluminum (Al), chromium (Cr), arsenic-doped gold and other similar metals, composites of the above metals or alloys thereof, and the like.
  • the top and bottom electrode materials are generally the same, but can also be different.
  • connection hole 112 a connection hole, passing through the piezoelectric layer, and the bottom electrode lead-out portion 113 is electrically connected to the bottom electrode through the connection hole.
  • the bottom electrode lead-out portion which can be prepared simultaneously with the top electrode, and the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or a composite of the above metals or their alloys.
  • a bridge structure that defines a void A bridge structure that defines a void.
  • FIG. 1 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention
  • FIG. 1A is an enlarged schematic view of part A in FIG. 1
  • the right edge of the bottom electrode 107 ie, the non-electrode connection end of the bottom electrode
  • the support layer 105 As shown in FIG. 1 , the non-electrode connection end of the bottom electrode 107 is in the resonator is disposed between the piezoelectric layer 109 and the support layer 105 in the thickness direction, and the outer edge of the support layer 105 is outside the non-electrode connection end of the bottom electrode 107 in the horizontal direction.
  • the piezoelectric layer 109 is a flat piezoelectric layer, that is, the piezoelectric layer does not have steps or bends.
  • the piezoelectric layer 109 may be a single crystal piezoelectric layer or a flat polycrystalline piezoelectric layer.
  • the support layer 105 is disposed between the piezoelectric layer 109 and the substrate 101, which are spaced apart from each other in the thickness direction of the resonator and disposed generally parallel to each other.
  • the acoustic mirror 103 of the BAW resonator shown in FIG. 1 is an acoustic mirror cavity. It can be seen in Figure 1 that the support layer 105 serves as the boundary of the acoustic mirror cavity in the lateral direction.
  • the acoustic mirror may not be in the form of a cavity, for example, a Bragg reflection layer.
  • the Bragg reflection layer may also be arranged at the position in the cavity as shown in FIG. 1 .
  • the upper boundary of the cavity of the acoustic mirror is the lower surface of the bottom electrode (in the present invention, the lower surface of the bottom electrode includes the region corresponding to the cavity of the acoustic mirror, the lower surface of the bottom electrode The case where other layers are not covered and the case where other layers are covered), and the lower boundary is the upper surface of the substrate (in the present invention, the upper surface of the substrate includes the area corresponding to the cavity of the acoustic mirror, and the upper surface of the substrate is not covered. case of other layers and cases where other layers are overlaid).
  • the present invention is not limited to this. Referring to FIG.
  • the cavity of the acoustic mirror is a cavity that is concave into the support layer, in other words, the lower side or lower boundary of the cavity of the acoustic mirror is supported by the support layer. layer 105 to define.
  • the electrode connection end of the bottom electrode 107 (the left side in FIG. 1 ) is covered by the support layer 105 and is located between the piezoelectric layer 109 and the support layer 105 in the thickness direction of the resonator, and the support layer 105 is The outer edge (left side in FIG. 1 ) is outside the electrode connection end of the bottom electrode 107 in the horizontal direction.
  • the piezoelectric layer 109 is provided with a through hole 112 (see FIG. 6I ). Referring to FIG.
  • the resonator further includes an electrode lead-out portion 113 that is electrically connected to the electrode connection end of the bottom electrode 107 via the through hole, and a part of the electrode lead-out portion 113 is in the
  • the upper surface of the piezoelectric layer 109 is arranged in the same layer as the top electrode 111 .
  • the electrode connection end of the bottom electrode may not be covered by the support layer 105 (that is, the electrode connection end of the bottom electrode may be located inside the boundary of the support layer, and the electrode connection end of the bottom electrode may be located inside the boundary of the support layer.
  • the lead-out portion 113 supplies power to the bottom electrode 107); in another embodiment of the present invention, the electrode connection end of the bottom electrode 107 may be covered by the support layer, but the electrode connection end may extend beyond the outer boundary of the support layer or be connected with the support layer. The outer border is flush.
  • both ends of the bottom electrode 107 are placed in the support layer 105, and the parasitic electric field between the right edge of the bottom electrode 107 (ie, the non-electrode connection end of the bottom electrode) and the right end of the top electrode 111 will pass through the support layer 105 (see FIG. 1A ), the bottom electrode 107 is buried in the support layer 105 . If the material of the support layer 105 is not properly selected, and its linearity is low (eg, silicon), the nonlinearity of the resonator and the filter using the resonator will be high. If the supporting material of the supporting layer 105 is selected from a highly linear material, the nonlinearity of the resonator and the filter can be reduced.
  • the material of the support layer is a highly linear material, such as NEBSG (Non-etchable Borosilicate Glass), SiO 2 , doped SiO 2 , ALN or doped ALN, GaAS, GaN, SiC , SiN, etc.
  • a highly linear material refers to a material whose linearity is higher than that of silicon.
  • the material When a material passes through an electric field, the material will produce an electrical response (such as current, etc.); if the frequency of the electrical response of the material is the same as the frequency of the applied electric field, the material is a material with linearity; the energy of the applied electric field frequency is certain Under the premise, the greater the energy of the material's electrical response to other frequencies, the lower the linearity of the material. Compared with silicon, under the premise that the energy of the applied electric field frequency is certain, the electrical response of the material to other frequencies is smaller, so it is a highly linear material.
  • the electric field lines of the main fringe parasitic electric field of the bottom electrode are shown in FIG. 1A . If the material of the support layer in Fig. 1 is a highly linear material, the nonlinear current from the non-electrode connection end of the bottom electrode to the top electrode can be significantly reduced, the strength of the fringe parasitic electric field can be reduced, and the linearity of the resonator in Fig. 1 can be improved. Spend.
  • FIG. 2 is a schematic cross-sectional view of a bulk acoustic wave resonator according to another exemplary embodiment of the present invention.
  • the structure shown in FIG. 2 is different from the structure shown in FIG. 1 in that the top electrode is provided with a bridge structure 115 in FIG. 2 .
  • bridge structure 115 Due to the bridge structure 115, there is a cavity or non-conductive dielectric cavity defined by the bridge structure, which further reduces the strength of the fringing parasitic electric field, thereby further reducing the nonlinearity of the resonator.
  • the inner edge of the bridge structure (ie the inner edge of the cavity it defines) is horizontally inward of the non-electrode connection end of the bottom electrode.
  • the inner edge of the bridge structure is outside the edge of the acoustic mirror.
  • the inner edge of the bridge structure can also be inside the edge of the acoustic mirror.
  • the outer edge of the bridge structure (ie the outer edge of the cavity it defines) is horizontally outside the non-electrode connection end of the bottom electrode.
  • the cavity defined by the bridge structure needs to span the end of the non-electrode connection end of the bottom electrode.
  • the non-electrode connection end of the bottom electrode is located between the inner edge and the outer edge of the bridge structure in the horizontal direction, relative to other positional relationships between the non-electrode connection end of the bottom electrode and the inner edge and outer edge of the bridge structure , which is more conducive to reducing the strength of the edge parasitic electric field, thereby further reducing the nonlinearity of the resonator.
  • the non-electrode connection end of the bottom electrode is covered or wrapped by the support layer 105.
  • the material of the support layer that wraps the non-electrode connection end of the bottom electrode is required to be a highly linear material.
  • the present invention is not limited to this.
  • FIG. 3 is a schematic cross-sectional view of a bulk acoustic wave resonator according to yet another exemplary embodiment of the present invention.
  • the difference between the structure shown in FIG. 3 and the structure shown in FIG. 1 is that, in FIG. 3 , the non-electrode connection end of the bottom electrode 107 (ie, the right end in FIG. 3 ) is not covered or wrapped by the support layer 105 , but is separated from the support layer 105 by a distance d in the horizontal direction. Therefore, in the example shown in FIG. 3 , there is a gap layer in the horizontal direction between the non-electrode connection end of the bottom electrode and the support layer, and the gap layer has a width d.
  • the gap layer may be an air gap layer (or void layer) or a vacuum gap layer.
  • the gap layer may also be other non-conductive dielectric layers.
  • the width d is not less than 10 ⁇ m.
  • the top electrode 111 is not provided with a bridge structure.
  • the present invention is not limited to this, and the top electrode may also be provided with a bridge structure.
  • 4A and 4B are schematic cross-sectional views of a bulk acoustic wave resonator according to another exemplary embodiment of the present invention. The structure shown in FIGS. 4A and 4B is different from the structure shown in FIG. 3 in that the top electrode in FIGS. 4A and 4B A bridge structure 115 is provided.
  • bridge structure 115 Due to the bridge structure 115, there is a cavity or non-conductive dielectric cavity defined by the bridge structure, which further reduces the strength of the fringing parasitic electric field, thereby further reducing the nonlinearity of the resonator.
  • the inner edge of the bridge structure (ie the inner edge of the cavity it defines) is horizontally inboard of the non-electrode connection end of the bottom electrode. As can be understood by those skilled in the art, the inner edge of the bridge structure may also be outside the non-electrode connection end of the bottom electrode.
  • the outer edge of the bridge structure (ie the outer edge of the cavity it defines) is horizontally outside the non-electrode connection end of the bottom electrode. As understood by those skilled in the art, the outer edge of the bridge structure may also be inside the non-electrode connection end of the bottom electrode.
  • the non-electrode connection end of the bottom electrode is located between the inner and outer edges of the bridge structure in the horizontal direction, relative to the distance between the non-electrode connection end of the bottom electrode and the inner and outer edges of the bridge structure.
  • Other positional relationships are more conducive to reducing the strength of the edge parasitic electric field, thereby further reducing the nonlinearity of the resonator.
  • FIG. 4A The difference between the structures shown in FIG. 4A and FIG. 4B is that the shape of the cavity of the acoustic mirror is different, which is determined based on the manufacturing process.
  • FIG. 4A an obtuse angle is formed between the boundary of the acoustic mirror cavity and the upper surface of the substrate 101
  • FIGS. 6A-6K show the manufacturing process of the acoustic mirror cavity forming the acute angle.
  • an acute angle is formed between the boundary of the acoustic mirror cavity and the upper surface of the substrate 101 .
  • FIG. 5 is a schematic cross-sectional view of a bulk acoustic wave resonator according to yet another exemplary embodiment of the present invention.
  • the difference between the structure shown in FIG. 5 and FIG. 4A is that in FIG. 5 , as already mentioned, the cavity of the acoustic mirror is a cavity concave into the support layer, in other words, the lower side of the cavity of the acoustic mirror or The lower boundary is defined by the support layer 105 .
  • the top electrode is provided with a bridge structure, but the top electrode in FIG. 5 may not be provided with a bridge structure.
  • the non-electrode connection end of the bottom electrode is not wrapped by the support layer 105 , but the non-electrode connection end of the bottom electrode in FIG. 5 can also adopt the arrangement shown in FIGS. 1 and 2 . The above are all within the protection scope of the present invention.
  • the manufacturing process of the bulk acoustic wave resonator shown in FIG. 1 is exemplarily described below with reference to FIGS. 6A-6K .
  • a piezoelectric thin film layer 109 such as single crystal aluminum nitride (AlN), gallium nitride (GaN), is grown on the surface of the auxiliary substrate 102 (such as silicon, silicon carbide), and the deposition process used includes but is not limited to MOCVD (Metal Organic Chemical Vapor Deposition), MBE (Molecular Beam Epitaxy), CBE (Chemical Molecular Beam Epitaxy), LPE (Liquid Phase Epitaxy), etc.; ) surface is formed by ion implantation to form an interface layer, and a piezoelectric layer 109 is formed above the interface layer. At this time, the material of the piezoelectric layer 1 is the same as that of the auxiliary substrate 102 .
  • MOCVD Metal Organic Chemical Vapor Deposition
  • MBE Molecular Beam Epitaxy
  • CBE Chemical Molecular Beam Epitaxy
  • LPE Liquid Phase Epitaxy
  • a metal layer is deposited on the surface of the piezoelectric layer 109 and patterned into the bottom electrode 107 .
  • a sacrificial material layer which may be silicon dioxide, is deposited on the surfaces of the piezoelectric layer 109 and the bottom electrode 107 of the structure obtained in FIG. 6B, and then the sacrificial material layer is patterned to obtain the sacrificial material layer 104 .
  • a support material layer (represented by 105 ) is deposited on the surfaces of the piezoelectric layer 109 , the sacrificial material layer 104 and the bottom electrode 107 of the structure obtained in FIG. 6C .
  • the material of the support material layer is, for example, doped nitride. aluminum.
  • the support material layer is polished by CMP (Chemical Mechanical Polishing) method until the sacrificial material layer 104 is exposed, and the support material layer becomes the support layer 105 at the same time.
  • CMP Chemical Mechanical Polishing
  • the support layer 105 wraps the ends of the bottom electrode (in FIG. 6E, the left and right ends are included).
  • the substrate 101 is bonded on one side of the support layer 105 and the sacrificial material layer 104 .
  • the surface of the substrate 101 may also have an auxiliary bonding layer (not shown in the figure), such as silicon dioxide, silicon nitride and other materials.
  • the structure in FIG. 6F is turned over, and the auxiliary substrate 102 is removed by grinding, etching process or ion implantation layer separation to expose the upper surface of the piezoelectric layer 109, optionally, and The separation interface is processed by CMP to make the surface smooth and have lower roughness.
  • a layer of electrode material for the top electrode 111 is deposited and then patterned to obtain the top electrode 111 .
  • through holes 112 are etched in the piezoelectric layer 109 through photolithography and etching processes, and at the same time, a sacrificial layer release hole (not shown in the figure) is etched on the piezoelectric layer 109.
  • the via hole directly leads to the electrode connection end of the bottom electrode, or the via hole directly communicates with the cavity of the acoustic mirror or directly leads to the sacrificial material layer located in the cavity of the acoustic mirror.
  • a conductive material for forming the bottom electrode lead-out portion 113 is deposited at the through hole 112 to form the bottom electrode lead-out portion 113 .
  • the etchant is passed through the release hole to release the sacrificial material layer 104 in the cavity 103 of the acoustic mirror, so as to obtain the structure corresponding to FIG. 1 .
  • the sacrificial material layer 104 is formed first, and then the support layer 105 is formed, so that the angle between the boundary of the support layer and the surface of the substrate 101 is an obtuse angle, as shown in FIG. 1 or FIG. 4A or FIG. 6K .
  • the support layer 105 is first fabricated, and then the sacrificial material layer 104 is fabricated, so that the angle between the boundary of the support layer and the surface of the substrate 101 is an acute angle, as shown in FIG. 4B . .
  • the through hole 112 can be formed on the piezoelectric layer 109 first, and then the electrode material layer can be deposited and patterned on the piezoelectric layer.
  • the bottom electrode lead-out portion 113 and the top electrode 111 are formed at the same time.
  • the piezoelectric layer is further provided with a release hole communicating with the cavity of the acoustic mirror, in the process of forming the top electrode 111, the release hole will also deposit an electrode material layer, so there is still a possibility to etch away the hole in the subsequent process. The step of releasing the electrode material within the pores.
  • the present invention also proposes a method for manufacturing a bulk acoustic wave resonator, which includes the steps of: disposing a support layer between the substrate and the piezoelectric layer, so that the piezoelectric layer and the substrate are spaced apart from each other in the thickness direction of the resonator and are generally arranged parallel to each other; and a high linearity material layer is arranged on the outer side of the non-electrode connection end of the bottom electrode in the horizontal direction.
  • the high linearity material layer is the support layer.
  • the layer of highly linear material can also be, for example, a void layer or an insulating dielectric layer.
  • each numerical range except that it is clearly indicated that it does not include the endpoint value, can be the endpoint value, and can also be the median value of each numerical range, and these are all within the protection scope of the present invention. .
  • upper and lower are relative to the bottom surface of the base of the resonator.
  • the side close to the bottom surface is the lower side, and the side away from the bottom surface is the upper side.
  • the center of the effective area of the resonator (the overlapping area of the piezoelectric layer, the top electrode, the bottom electrode and the acoustic mirror in the thickness direction of the resonator constitutes the effective area) (ie, the center of the effective area).
  • the side or end of a component close to the center of the effective area is the inner or inner end
  • the side or end of the component away from the center of the effective area is the outer or outer end.
  • BAW resonators may be used to form filters or electronic devices.
  • a bulk acoustic wave resonator comprising:
  • a piezoelectric layer arranged between the bottom electrode and the top electrode
  • the piezoelectric layer is a flat piezoelectric layer, a support layer is arranged between the substrate and the piezoelectric layer, the piezoelectric layer and the substrate are spaced apart from each other in the thickness direction of the resonator, and are generally arranged parallel to each other;
  • a high linearity material layer is provided on the outer side in the horizontal direction of the non-electrode connection end of the bottom electrode.
  • the non-electrode connection end of the bottom electrode is covered by the supporting layer and is located between the piezoelectric layer and the supporting layer in the thickness direction of the resonator, and the outer edge of the supporting layer is in the non-electrode connection of the bottom electrode in the horizontal direction the outside of the end;
  • the support layer is a high linearity material support layer, and the support layer on the outer side of the non-electrode connection end of the bottom electrode in the horizontal direction constitutes the high linearity material layer.
  • a gap layer exists between the non-electrode connecting end of the bottom electrode and the support layer in the horizontal direction, and the gap layer is an air gap layer or a true gap layer or a solid state.
  • the width of the gap layer is not less than 10 ⁇ m.
  • top electrode comprises a bridge structure in a region corresponding to the non-electrode connection end of the bottom electrode.
  • the outer edge of the bridge structure is horizontally outside the inner edge of the support layer;
  • the outer edge of the bridge structure is located outside the outer edge of the non-electrode connection end of the bottom electrode in the horizontal direction.
  • the support layer is made of one of the following materials: non-etchable borosilicate glass (NEBSG), silicon dioxide, doped silicon dioxide, nitride Aluminum, Doped Aluminum Nitride, Gallium Arsenide, Gallium Nitride, Silicon Carbide, Silicon Nitride.
  • NBSG non-etchable borosilicate glass
  • the acoustic mirror is an acoustic mirror cavity
  • the support layer defines the boundary of the acoustic mirror in the horizontal direction.
  • the outer edge of the support layer is horizontally outside the electrode connection end of the bottom electrode
  • the piezoelectric layer is provided with a through hole
  • the resonator further includes an electrode lead-out portion electrically connected to the electrode connecting end of the bottom electrode through the through hole, and a part of the electrode lead-out portion is located on the upper surface of the piezoelectric layer It is arranged in the same layer as the top electrode.
  • the piezoelectric layer is made of single crystal aluminum nitride, single crystal gallium nitride, single crystal lithium niobate, single crystal potassium niobate, single crystal quartz film, or Single crystal lithium tantalate.
  • a method for manufacturing a bulk acoustic wave resonator comprising a substrate, an acoustic mirror, a bottom electrode, a top electrode and a piezoelectric layer, wherein the piezoelectric layer is arranged between the bottom electrode and the top electrode and is straight piezoelectric layer,
  • the method includes the steps:
  • a high linearity material layer is provided on the outer side in the horizontal direction of the non-electrode connection end of the bottom electrode.
  • the step of disposing the support layer includes forming the support layer using a high linearity material
  • the step of disposing a high linearity material layer on the outer side of the non-electrode connection end of the bottom electrode in the horizontal direction includes: making the support layer cover the non-electrode connection end of the bottom electrode, and the outer edge of the support layer is in the bottom electrode in the horizontal direction. the outside of the non-electrode connection end.
  • the gap layer is an air gap layer or a true gap layer or a solid insulating medium layer, and the gap layer is an air gap layer or a true gap layer In this case, the width of the gap layer is not less than 10 ⁇ m.
  • the piezoelectric layer is made of single crystal aluminum nitride, single crystal gallium nitride, single crystal lithium niobate, single crystal potassium niobate, single crystal quartz film, or single crystal Crystalline lithium tantalate.
  • a filter comprising the bulk acoustic wave resonator of any one of 1-18.
  • An electronic device comprising the filter according to 24, or the bulk acoustic wave resonator according to any one of 1-18.
  • the electronic equipment here includes but is not limited to intermediate products such as RF front-end, filter and amplifier modules, and terminal products such as mobile phones, WIFI, and drones.

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Abstract

本发明涉及一种体声波谐振器及其制造方法，该谐振器包括：基底；声学镜；底电极；顶电极；和压电层，设置在底电极与顶电极之间，其中：所述压电层为平直压电层；基底与压电层之间设置有支撑层，所述压电层为平直压电层，压电层与基底在谐振器的厚度方向上彼此间隔开且大体相互平行设置，所述底电极的非电极连接端在水平方向上的外侧设置有高线性材料层。本发明还涉及一种滤波器以及一种电子设备。

Description

体声波谐振器及其制造方法、滤波器及电子设备 技术领域
本发明的实施例涉及半导体领域，尤其涉及一种体声波谐振器及其制造方法、一种具有该谐振器的滤波器，以及一种电子设备。
背景技术
电子器件作为电子设备的基本元素，已经被广泛应用，其应用范围包括移动电话、汽车、家电设备等。此外，未来即将改变世界的人工智能、物联网、5G通讯等技术仍然需要依靠电子器件作为基础。
薄膜体声波谐振器(Film Bulk Acoustic Resonator，简称FBAR，又称为体声波谐振器，也称BAW)作为压电器件的重要成员正在通信领域发挥着重要作用，特别是FBAR滤波器在射频滤波器领域市场占有份额越来越大，FBAR具有尺寸小、谐振频率高、品质因数高、功率容量大、滚降效应好等优良特性，其滤波器正在逐步取代传统的声表面波(SAW)滤波器和陶瓷滤波器，在无线通信射频领域发挥巨大作用，其高灵敏度的优势也能应用到生物、物理、医学等传感领域。
薄膜体声波谐振器的结构主体为由底电极-压电薄膜或压电层-顶电极组成的“三明治”结构，即两层金属电极层之间夹一层压电材料。通过在两电极间输入正弦信号，FBAR利用逆压电效应将输入电信号转换为机械谐振，并且再利用压电效应将机械谐振转换为电信号输出。
已知结构的体声波谐振器中，在谐振器的有效区域的边缘，底电极的非电极连接端与顶电极之间会产生边缘寄生电场，边缘寄生电场会产生不希望的非线性电流，从而降低谐振器的线性度。
对于包括体声波谐振器的滤波器，同样也存在提升滤波器的线性度的需求。
发明内容
为缓解或解决现有技术中的上述问题的至少一个方面，提出本发明。
根据本发明的实施例的一个方面，提出了一种体声波谐振器，包括基底、声学镜、底电极、顶电极和设置在底电极与顶电极之间的压电层。所述压电层为平直压电层，基底与压电层之间设置有支撑层，压电层与基底在谐振器的厚度方向上彼此间隔开且大体相互平行设置。所述底电极的非电极连接端 在水平方向上的外侧设置有高线性材料层。
本发明的实施例涉及一种体声波谐振器的制造方法，所述体声波谐振器包括基底、声学镜、底电极、顶电极和压电层，压电层设置在底电极与顶电极之间且为平直压电层，所述方法包括步骤：在基底与压电层之间设置支撑层，使得压电层与基底在谐振器的厚度方向上彼此间隔开且大体相互平行设置；和在底电极的非电极连接端在水平方向上的外侧设置高线性材料层。
本发明的实施例还涉及一种滤波器，包括上述的体声波谐振器。
本发明的实施例也涉及一种电子设备，包括上述的滤波器或者上述的谐振器。
附图说明
以下描述与附图可以更好地帮助理解本发明所公布的各种实施例中的这些和其他特点、优点，图中相同的附图标记始终表示相同的部件，其中：
图1为根据本发明的一个示例性实施例的体声波谐振器的截面示意图；
图1A为图1中的A部分的放大示意图；
图2为根据本发明的另一个示例性实施例的体声波谐振器的截面示意图；
图3为根据本发明的又一个示例性实施例的体声波谐振器的截面示意图；
图4A为根据本发明的还一个示例性实施例的体声波谐振器的截面示意图；
图4B为根据本发明的又一个示例性实施例的体声波谐振器的截面示意图；
图5为根据本发明的再一个示例性实施例的体声波谐振器的截面示意图；以及
图6A-图6K为示例性示出图1所示的体声波谐振器的制作过程的截面示意图。
具体实施方式
下面通过实施例，并结合附图，对本发明的技术方案作进一步具体的说明。在说明书中，相同或相似的附图标号指示相同或相似的部件。下述参照 附图对本发明实施方式的说明旨在对本发明的总体发明构思进行解释，而不应当理解为对本发明的一种限制。发明的一部分实施例，而并不是全部的实施例。基于本发明中的实施例，本领域普通技术人员所获得的所有其他实施例，都属于本发明保护的范围。
在本发明中，附图标记说明如下：
101：基底，可选材料为单晶硅、氮化镓、砷化镓、蓝宝石、石英、碳化硅、金刚石等。
102：辅助基底，可选材料为单晶硅、氮化镓、砷化镓、蓝宝石、石英、碳化硅、金刚石等。
103：声学镜，可为空腔，也可采用布拉格反射层及其他等效形式。本发明所示的实施例中采用的是空腔。
104：牺牲材料层，其材料可以为二氧化硅、掺杂二氧化硅、多晶硅、非晶硅等。
105：支撑层，材料为高线性材料，包括但不限于NEBSG、SiO 2、掺杂SiO 2、ALN或掺杂ALN、GaAS、GaN、SiC、SiN等。
107：底电极，底电极材料可为：金(Au)、钨(W)、钼(Mo)、铂(Pt)，钌(Ru)、铱(Ir)、钛钨(TiW)、铝(Al)、钛(Ti)、锇(Os)、镁(Mg)、金(Au)、钨(W)、钼(Mo)、铂(Pt)、钌(Ru)、铱(Ir)、锗(Ge)、铜(Cu)、铝(Al)、铬(Cr)、砷掺杂金等类似金属，以上金属的复合或其合金等。
109：压电层，可以为单晶压电材料，可选的，如：单晶氮化铝、单晶氮化镓、单晶铌酸锂、单晶铌酸钾、单晶石英薄膜、或者单晶钽酸锂等材料，也可以为多晶压电材料(与单晶相对应，非单晶材料)，可选的，如多晶氮化铝、氧化锌、PZT等，还可是包含上述材料的一定原子比的稀土元素掺杂材料，例如可以是掺杂氮化铝，掺杂氮化铝至少含一种稀土元素，如钪(Sc)、钇(Y)、镁(Mg)、钛(Ti)、镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钷(Pm)、钐(Sm)、铕(Eu)、钆(Gd)、铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)等。
111：顶电极，其可为：金(Au)、钨(W)、钼(Mo)、铂(Pt)，钌(Ru)、铱(Ir)、钛钨(TiW)、铝(Al)、钛(Ti)、锇(Os)、镁(Mg)、金(Au)、钨(W)、钼(Mo)、铂(Pt)、钌(Ru)、铱(Ir)、锗(Ge)、铜(Cu)、铝(Al)、铬(Cr)、砷掺杂金等类似金属，以上金属的复合或其合金等。顶电极和底电极材料一般相同，但也可以不同。
112：连接用孔，穿过压电层，底电极引出部113经由该连接用孔与底电极电连接。
113：底电极引出部，其可与顶电极同时制得，材料可选钼、钌、金、铝、镁、钨、铜，钛、铱、锇、铬或以上金属的复合或其合金等。
115：桥结构，其限定了空隙。
图1为根据本发明的一个示例性实施例的体声波谐振器的截面示意图，图1A为图1中的A部分的放大示意图。在图1所示的实施例中，底电极107的右侧边缘(即底电极的非电极连接端)被支撑层105覆盖，如图1所示，底电极107的非电极连接端在谐振器的厚度方向上设置在压电层109与支撑层105之间，且支撑层105的外边缘在水平方向上处于底电极107的非电极连接端的外侧。
如图1所示，压电层109为平直压电层，即该压电层不存在台阶部或者弯折。如前面已经提及的，压电层109可以是单晶压电层，也可以是平直的多晶压电层。
同样参见图1，可以看到，支撑层105设置在压电层109与基底101之间，压电层109与基底101在谐振器的厚度方向上彼此间隔开，且大体相互平行设置。
如图1所示的体声波谐振器的声学镜103为声学镜空腔。可以看到，在图1中，支撑层105作为声学镜空腔在横向方向上的边界。
如本领域技术人员能够理解的，声学镜也可以不是空腔的形式，例如为布拉格反射层，此时布拉格反射层也可以设置在如图1所示的空腔中的位置等。
在图1所示的实施例中，声学镜空腔的上边界为底电极的下表面(在本发明中，底电极的下表面包括了在声学镜空腔对应的区域，底电极的下表面没有覆盖其他层的情形以及覆盖了其他层的情形)，而下边界为基底的上表面(在本发明中，基底的上表面包括了在声学镜空腔对应的区域，基底的上表面没有覆盖其他层的情形以及覆盖了其他层的情形)。但是，本发明不限于此，参照后面也提及的图5，可以看到，声学镜空腔为下凹到支撑层内的空腔，换言之，声学镜空腔的下侧或下边界由支撑层105来限定。
在图1中，底电极107的电极连接端(图1中的左侧)被支撑层105覆盖而在谐振器的厚度方向上位于压电层109与支撑层105之间，且支撑层105的外边缘(图1中的左侧)在水平方向上处于底电极107的电极连接端的外侧。压电层109设置有通孔112(参见图6I)，参见图1，谐振器还包括经由通孔而与底电极107的电极连接端电连接的电极引出部113，电极引出部113的一部分处于压电层109的上表面而与顶电极111同层布置。
需要指出的是，在本发明的一个实施例中，底电极的电极连接端也可以 不被支撑层105覆盖(即底电极的电极连接端可以处于支撑层的边界的内侧，此时可以经由电极引出部113向底电极107供电)；在本发明的另一个实施例中，底电极107的电极连接端可以被支撑层覆盖，但是，该电极连接端可以延伸超过支撑层的外边界或者与该外边界齐平。这些均在本发明的保护范围之内。
在图1中，底电极107的两端置于支撑层105内，底电极107右侧边缘(即底电极的非电极连接端)和顶电极111的右端间的边缘寄生电场会穿过支撑层105(参见图1A)，底电极107埋入支撑层105。若支撑层105的材料选择不合适，其线性度较低(例如硅)，则谐振器和使用了该谐振器的滤波器的非线性度较高。若支撑层105的支撑材料选择高线性材料，则可以减小谐振器和滤波器的非线性。需要强调的是，由于底电极107的右边缘侧边集中了大部分的边缘寄生电场，边缘寄生电场强度较高，且底电极右边缘侧边完全被支撑层包裹，因此，此处起包裹作用的支撑层材料线性度非常关键。
在图1所示的示例中，支撑层的材料为高线性材料，例如NEBSG(不可刻蚀硼硅酸盐玻璃)、SiO 2、掺杂SiO 2、ALN或掺杂ALN、GaAS、GaN、SiC、SiN等。在本发明中，高线性材料是指线性度高于硅线性度的材料。当一种材料有电场穿过时，材料会产生电学响应(如电流等)；如果材料电学响应的频率与施加电场的频率相同，则材料为具有线性度的材料；在施加电场频率的能量一定的前提下，材料电学响应其他频率的能量越大，则材料的线性度越低。上述几种材料和硅相比，在施加电场频率的能量一定的前提下，材料电学响应其他频率的能量更小，从而为高线性材料。
图1A中示出了底电极的主要边缘寄生电场的电场线。如果图1中的支撑层的材料为高线性材料，则可以显著降低从底电极的非电极连接端到顶电极的非线性电流，降低边缘寄生电场的强度，从而提高图1中的谐振器的线性度。
在图1所示的谐振器中，顶电极并不存在桥结构。但是，本发明不限于此，顶电极也可以设置桥结构。图2为根据本发明的另一个示例性实施例的体声波谐振器的截面示意图，图2所示结构与图1所示结构不同在于，在图2中顶电极设置有桥结构115。
由于桥结构115，所以存在由桥结构限定的空腔或不导电介质腔，这会进一步减少边缘寄生电场的强度，从而进一步减小谐振器的非线性。
在图2所示的结构中，桥结构的内边缘(即其限定的空腔的内边缘)在水平方向上处于底电极的非电极连接端的内侧。在图2所示的结构中，桥结构的内边缘在声学镜边缘的外侧，可选的，桥结构的内边缘也可以在声学镜 边缘的内侧。同样参见图2，桥结构的外边缘(即其限定的空腔的外边缘)在水平方向上处于底电极的非电极连接端的外侧。在本发明的一个实施例中，桥结构限定的空腔需跨越底电极的非电极连接端的端部。
在图2中，底电极的非电极连接端在水平方向上处于桥结构的内边缘与外边缘之间，相对于底电极的非电极连接端与桥结构的内边缘与外边缘的其他位置关系，更有利于减少边缘寄生电场的强度，从而进一步减小谐振器的非线性。
在图1和图2所示的实施例中，底电极的非电极连接端被支撑层105包覆或包裹，此时，要求包裹底电极的非电极连接端的支撑层的材料为高线性材料，但是本发明不限于此。
图3为根据本发明的又一个示例性实施例的体声波谐振器的截面示意图。在图3所示的结构与图1所示的结构的区别在于，在图3中，底电极107的非电极连接端(即图3中的右端)并未被支撑层105覆盖或包裹，而是在水平方向上与支撑层105间隔开一个距离d。因此，在图3所示的示例中，底电极的非电极连接端与支撑层之间在水平方向上存在一个间隙层，该间隙层具有宽度d。如能够理解的，在图3中，该间隙层可以是空气间隙层(或空隙层)，也可以是真空间隙层。虽然没有示出，如本领域技术人员能够理解的，该间隙层也可以是其他的不导电介质层。
在本发明的一个实施例中，若间隙层为空气间隙层或真空间隙层，则该宽度d不小于10μm。
在图3中，顶电极111并未设置桥结构。但是，本发明不限于此，顶电极也可以设置桥结构。图4A和图4B为根据本发明的另外示例性实施例的体声波谐振器的截面示意图，图4A和图4B所示结构与图3所示结构不同在于，在图4A和图4B中顶电极设置有桥结构115。
由于桥结构115，所以存在由桥结构限定的空腔或不导电介质腔，这会进一步减少边缘寄生电场的强度，从而进一步减小谐振器的非线性。
在图4A和图4B所示的结构中，桥结构的内边缘(即其限定的空腔的内边缘)在水平方向上处于底电极的非电极连接端的内侧。如本领域技术人员能够理解的，桥结构的内边缘也可以在底电极的非电极连接端的外侧。同样参见图4A和图4B，桥结构的外边缘(即其限定的空腔的外边缘)在水平方向上处于底电极的非电极连接端的外侧。如本领域技术人员理解的，桥结构的外边缘也可以在底电极的非电极连接端的内侧。
在图4A和图4B中，底电极的非电极连接端在水平方向上处于桥结构的内边缘与外边缘之间，相对于底电极的非电极连接端与桥结构的内边缘与 外边缘的其他位置关系，更有利于减少边缘寄生电场的强度，从而进一步减小谐振器的非线性。
图4A和图4B所示的结构的不同在于声学镜空腔的形状不一样，这是基于制造流程决定的。在图4A中，声学镜空腔的边界与基底101的上表面之间形成钝角，图6A-6K中示出了形成锐角的声学镜空腔的制作流程。在图4B中，声学镜空腔的边界与基底101的上表面之间形成锐角。
图5为根据本发明的再一个示例性实施例的体声波谐振器的截面示意图。图5所示的结构与图4A的区别在于，在图5中，如前已经提及的，声学镜空腔为下凹到支撑层内的空腔，换言之，声学镜空腔的下侧或下边界由支撑层105来限定。
在图5中，顶电极设置有桥结构，但是，图5中的顶电极也可以不设置桥结构。在图5中，底电极的非电极连接端并未被支撑层105包裹，但是，图5中底电极的非电极连接端也可以采用图1和图2中所示的布置方式。以上均在本发明的保护范围之内。
下面参照附图6A-6K示例性说明图1所示的体声波谐振器的制作过程。
如图6A所示，在辅助基底102(如硅、碳化硅)表面上生长压电薄膜层109，如单晶氮化铝(AlN)、氮化镓(GaN)，所用沉积工艺包括但不限于MOCVD(金属有机化学气相沉积)、MBE(分子束外延)、CBE(化学分子束外延)、LPE(液相外延)等；或者通过在辅助衬底102(如铌酸锂、钽酸锂衬底)表面通过离子注入形成一个分界层，在分界层上方形成压电层109，此时压电层1材料与辅助基底102材料相同。
如图6B所示，在压电层109表面沉积金属层并将金属层图形化成底电极107。
如图6C所示，在图6B所得到的结构的压电层109及底电极107的表面沉积一层牺牲材料层，其可以是二氧化硅，接着对该牺牲材料层图形化以获得牺牲材料层104。
如图6D所示，在图6C所得到的结构的压电层109、牺牲材料层104以及底电极107的表面沉积支撑材料层(以105表示)，支撑材料层的材料例如为掺杂氮化铝。
如图6E所示，通过CMP(化学机械研磨)法将支撑材料层磨平直至露出牺牲材料层104，同时支撑材料层成为支撑层105。如图6E所示，支撑层105包裹了底电极的端部(在图6E中，包括了左端和右端)。
如图6F所示，将基底101键合(bonding)在支撑层105以及牺牲材料层104的一侧。可选的，基底101的表面还可以有辅助键合层(图中没有示 出)，如二氧化硅、氮化硅等材料。
如图6G所示，将图6F中的结构翻转，以及通过研磨、刻蚀工艺或离子注入层分离的方法将辅助基底102去除，以露出压电层109的上表面，可选的，并对其分离界面进行CMP处理，使其表面光整，具有较低的粗糙度。
如图6H所示，沉积用于顶电极111的电极材料层，接着对该电极材料层图形化以获得顶电极111。
如图6I所示，通过光刻和刻蚀的工艺在压电层109中刻蚀出通孔112，同时，在压电层109上蚀刻出牺牲层释放孔(图中没有示出)，该过孔直接通到底电极的电极连接端，或该过孔直接与声学镜空腔相通或者直接通到位于声学镜空腔中的牺牲材料层。
如图6J所示，在通孔112处沉积用于形成底电极引出部113的导电材料，以形成底电极引出部113。
如图6K所示，经由释放孔通入刻蚀剂以释放声学镜空腔103内的牺牲材料层104，以得到对应于图1的结构。
在上述的制造过程中，先制作牺牲材料层104，然后制作支撑层105，因此使得支撑层的边界与基底101的表面之间的角度为钝角，如图1或图4A或图6K所示。基于制作流程的不同，例如在上述制造过程中，先制作支撑层105，然后制作牺牲材料层104，则可以使得支撑层的边界与基底101的表面之间的角度为锐角，如图4B所示。
在上述制作过程中，如果底电极引出部113的材料与顶电极111的材料相同，则可以先在压电层109上形成通孔112，然后在压电层上沉积和图形化电极材料层，以同时形成底电极引出部113以及顶电极111。不过，在压电层还设置了与声学镜空腔相通的释放孔的情况下，在形成顶电极111的过程中，该释放孔也会沉积电极材料层，因此在后续还存在刻蚀掉该释放孔内的电极材料的步骤。
基于以上，本发明也提出了一种体声波谐振器的制造方法，其包括步骤：在基底与压电层之间设置支撑层，使得压电层与基底在谐振器的厚度方向上彼此间隔开且大体相互平行设置；以及在底电极的非电极连接端在水平方向上的外侧设置高线性材料层。在上述参照图6A-6K描述的流程中，该高线性材料层为支撑层。但是，如前面已经提及的，高线性材料层也可以是例如空隙层或绝缘介质层。
需要指出的是，在本发明中，各个数值范围，除了明确指出不包含端点值之外，除了可以为端点值，还可以为各个数值范围的中值，这些均在本发明的保护范围之内。
在本发明中，上和下是相对于谐振器的基底的底面而言的，对于一个部件，其靠近该底面的一侧为下侧，远离该底面的一侧为上侧。
在本发明中，内和外是相对于谐振器的有效区域(压电层、顶电极、底电极和声学镜在谐振器的厚度方向上的重叠区域构成有效区域)的中心(即有效区域中心)在横向方向或者径向方向上而言的，一个部件的靠近有效区域中心的一侧或一端为内侧或内端，而该部件的远离有效区域中心的一侧或一端为外侧或外端。对于一个参照位置而言，位于该位置的内侧表示在横向方向或径向方向上处于该位置与有效区域中心之间，位于该位置的外侧表示在横向方向或径向方向上比该位置更远离有效区域中心。
如本领域技术人员能够理解的，根据本发明的体声波谐振器可以用于形成滤波器或电子设备。
基于以上，本发明提出了如下技术方案：
1、一种体声波谐振器，包括：
基底；
声学镜；
底电极；
顶电极；和
压电层，设置在底电极与顶电极之间，
其中：
所述压电层为平直压电层，基底与压电层之间设置有支撑层，压电层与基底在谐振器的厚度方向上彼此间隔开，且大体相互平行设置；
所述底电极的非电极连接端在水平方向上的外侧设置有高线性材料层。
2、根据1所述的谐振器，其中：
所述底电极的非电极连接端被所述支撑层覆盖而在谐振器的厚度方向上位于压电层与支撑层之间，且支撑层的外边缘在水平方向上处于底电极的非电极连接端的外侧；且
所述支撑层为高线性材料支撑层，且在底电极的非电极连接端在水平方向上的外侧的支撑层构成所述高线性材料层。
3、根据1所述的谐振器，其中，所述底电极的非电极连接端在水平方向上与所述支撑层之间存在间隙层，所述间隙层为空气隙层或者真空隙层或者固态绝缘介质层，在间隙层为空气隙层或者真空隙层的情况下所述间隙层的宽度不小于10μm。
4、根据3所述的谐振器，其中，所述支撑层为高线性材料支撑层。
5、根据1所述的谐振器，其中，所述顶电极在底电极的非电极连接端 的对应区域是平直。
6、根据1所述的谐振器，其中，所述顶电极在底电极的非电极连接端的对应区域包括桥结构。
7、根据6所述的谐振器，其中，所述桥结构的内边缘在水平方向上处于所述底电极的非电极连接端的外边缘的内侧。
8、根据7所述的谐振器，其中：
在顶电极的电极连接端，所述桥结构的外边缘在水平方向上处于所述支撑层的内边缘的外侧；或者
所述桥结构的外边缘在水平方向上处于所述底电极的非电极连接端的外边缘的外侧。
9、根据1所述的谐振器，其中，所述支撑层由如下材料中的一种制成：不可刻蚀硼硅酸盐玻璃(NEBSG)、二氧化硅、掺杂二氧化硅、氮化铝、掺杂氮化铝、砷化镓、氮化镓、碳化硅、氮化硅。
10、根据1所述的谐振器，其中：
所述声学镜为声学镜空腔；且
所述支撑层在水平方向上限定声学镜的边界。
11、根据10所述的谐振器，其中，所述空腔的边界与所述基底的上表面形成钝角。
12、根据10所述的谐振器，其中，所述空腔的边界与所述基底的上表面形成锐角。
13、根据10所述的谐振器，其中，所述声学镜空腔的下边界由所述基底的上表面限定。
14、根据10所述的谐振器，其中，所述声学镜空腔为凹入到支撑层内的形状，且声学镜空腔的下边界由所述支撑层限定。
15、根据1-14中任一项所述的谐振器，其中，所述底电极的电极连接端被所述支撑层覆盖而在谐振器的厚度方向上位于压电层与支撑层之间。
16、根据15所述的谐振器，其中：
支撑层的外边缘在水平方向上处于底电极的电极连接端的外侧；且
所述压电层设置有通孔，所述谐振器还包括经由所述通孔而与底电极的电极连接端电连接的电极引出部，所述电极引出部的一部分处于压电层的上表面而与顶电极同层布置。
17、根据1-14中任一项所述的谐振器，其中，所述压电层为单晶压电层。
18、根据17所述的谐振器，其中，所述压电层的材料为单晶氮化铝、 单晶氮化镓、单晶铌酸锂、单晶铌酸钾、单晶石英薄膜、或者单晶钽酸锂。
19、一种体声波谐振器的制造方法，所述体声波谐振器包括基底、声学镜、底电极、顶电极和压电层，压电层设置在底电极与顶电极之间且为平直压电层，
所述方法包括步骤：
在基底与压电层之间设置支撑层，使得压电层与基底在谐振器的厚度方向上彼此间隔开且大体相互平行设置；和
在底电极的非电极连接端在水平方向上的外侧设置高线性材料层。
20、根据19所述的方法，其中：
设置支撑层的步骤包括使用高线性材料形成支撑层；以及
所述在底电极的非电极连接端在水平方向上的外侧设置高线性材料层的步骤包括：使得支撑层覆盖底电极的非电极连接端，且支撑层的外边缘在水平方向上处于底电极的非电极连接端的外侧。
21、根据19所述的方法，其中，所述在底电极的非电极连接端在水平方向上的外侧设置高线性材料层的步骤包括：
使得底电极的非电极连接端与支撑层之间在水平方向上存在间隙层，所述间隙层为空气隙层或者真空隙层或者固态绝缘介质层，在间隙层为空气隙层或者真空隙层的情况下所述间隙层的宽度不小于10μm。
22、根据19所述的方法，其中，所述压电层为单晶压电层。
23、根据22所述的方法，其中，所述压电层的材料为单晶氮化铝、单晶氮化镓、单晶铌酸锂、单晶铌酸钾、单晶石英薄膜、或者单晶钽酸锂。
24、一种滤波器，包括根据1-18中任一项所述的体声波谐振器。
25、一种电子设备，包括根据24所述的滤波器，或者根据1-18中任一项所述的体声波谐振器。
这里的电子设备，包括但不限于射频前端、滤波放大模块等中间产品，以及手机、WIFI、无人机等终端产品。
尽管已经示出和描述了本发明的实施例，对于本领域的普通技术人员而言，可以理解在不脱离本发明的原理和精神的情况下可以对这些实施例进行变化，本发明的范围由所附权利要求及其等同物限定。

Claims (25)

  1. 一种体声波谐振器，包括：
    基底；
    声学镜；
    底电极；
    顶电极；和
    压电层，设置在底电极与顶电极之间，
    其中：
    所述压电层为平直压电层，基底与压电层之间设置有支撑层，压电层与基底在谐振器的厚度方向上彼此间隔开，且大体相互平行设置；以及
    所述底电极的非电极连接端在水平方向上的外侧设置有高线性材料层。
  2. 根据权利要求1所述的谐振器，其中：
    所述底电极的非电极连接端被所述支撑层覆盖而在谐振器的厚度方向上位于压电层与支撑层之间，且支撑层的外边缘在水平方向上处于底电极的非电极连接端的外侧；且
    所述支撑层为高线性材料支撑层，且在底电极的非电极连接端在水平方向上的外侧的支撑层构成所述高线性材料层。
  3. 根据权利要求1所述的谐振器，其中，所述底电极的非电极连接端在水平方向上与所述支撑层之间存在间隙层，所述间隙层为空气隙层或者真空隙层或者固态绝缘介质层，在间隙层为空气隙层或者真空隙层的情况下所述间隙层的宽度不小于10μm。
  4. 根据权利要求3所述的谐振器，其中，所述支撑层为高线性材料支撑层。
  5. 根据权利要求1所述的谐振器，其中，所述顶电极在底电极的非电极连接端的对应区域是平直。
  6. 根据权利要求1所述的谐振器，其中，所述顶电极在底电极的非电极连接端的对应区域包括桥结构。
  7. 根据权利要求6所述的谐振器，其中，所述桥结构的内边缘在水平方向上处于所述底电极的非电极连接端的外边缘的内侧。
  8. 根据权利要求7所述的谐振器，其中：
    在顶电极的电极连接端，所述桥结构的外边缘在水平方向上处于所述支撑层的内边缘的外侧；或者
    所述桥结构的外边缘在水平方向上处于所述底电极的非电极连接端的外边缘的外侧。
  9. 根据权利要求1所述的谐振器，其中，所述支撑层由如下材料中的一种制成：不可刻蚀硼硅酸盐玻璃(NEBSG)、二氧化硅、掺杂二氧化硅、氮化铝、掺杂氮化铝、砷化镓、氮化镓、碳化硅、氮化硅。
  10. 根据权利要求1所述的谐振器，其中：
    所述声学镜为声学镜空腔；且
    所述支撑层在水平方向上限定声学镜的边界。
  11. 根据权利要求10所述的谐振器，其中，所述空腔的边界与所述基底的上表面形成钝角。
  12. 根据权利要求10所述的谐振器，其中，所述空腔的边界与所述基底的上表面形成锐角。
  13. 根据权利要求10所述的谐振器，其中，所述声学镜空腔的下边界由所述基底的上表面限定。
  14. 根据权利要求10所述的谐振器，其中，所述声学镜空腔为凹入到支撑层内的形状，且声学镜空腔的下边界由所述支撑层限定。
  15. 根据权利要求1-14中任一项所述的谐振器，其中，所述底电极的电极连接端被所述支撑层覆盖而在谐振器的厚度方向上位于压电层与支撑层之间。
  16. 根据权利要求15所述的谐振器，其中：
    支撑层的外边缘在水平方向上处于底电极的电极连接端的外侧；以及
    所述压电层设置有通孔，所述谐振器还包括经由所述通孔而与底电极的电极连接端电连接的电极引出部，所述电极引出部的一部分处于压电层的上表面而与顶电极同层布置。
  17. 根据权利要求1-14中任一项所述的谐振器，其中，所述压电层为单晶压电层。
  18. 根据权利要求17所述的谐振器，其中，所述压电层的材料为单晶氮化铝、单晶氮化镓、单晶铌酸锂、单晶铌酸钾、单晶石英薄膜、或者单晶钽酸锂。
  19. 一种体声波谐振器的制造方法，所述体声波谐振器包括基底、声学镜、底电极、顶电极和压电层，压电层设置在底电极与顶电极之间且为平直压电层，
    所述方法包括步骤：
    在基底与压电层之间设置支撑层，使得压电层与基底在谐振器的厚度方向上彼此间隔开且大体相互平行设置；和
    在底电极的非电极连接端在水平方向上的外侧设置高线性材料层。
  20. 根据权利要求19所述的方法，其中：
    设置支撑层的步骤包括使用高线性材料形成支撑层；以及
    所述在底电极的非电极连接端在水平方向上的外侧设置高线性材料层的步骤包括：使得支撑层覆盖底电极的非电极连接端，且支撑层的外边缘在水平方向上处于底电极的非电极连接端的外侧。
  21. 根据权利要求19所述的方法，其中，所述在底电极的非电极连接端在水平方向上的外侧设置高线性材料层的步骤包括：
    使得底电极的非电极连接端与支撑层之间在水平方向上存在间隙层，所述间隙层为空气隙层或者真空隙层或者固态绝缘介质层，在间隙层为空气隙层或者真空隙层的情况下所述间隙层的宽度不小于10μm。
  22. 根据权利要求19所述的方法，其中，所述压电层为单晶压电层。
  23. 根据权利要求22所述的方法，其中，所述压电层的材料为单晶氮化铝、单晶氮化镓、单晶铌酸锂、单晶铌酸钾、单晶石英薄膜、或者单晶钽酸锂。
  24. 一种滤波器，包括根据权利要求1-18中任一项所述的体声波谐振器。
  25. 一种电子设备，包括根据权利要求24所述的滤波器，或者根据权利要求1-18中任一项所述的体声波谐振器。
PCT/CN2022/079746 2021-03-08 2022-03-08 体声波谐振器及其制造方法、滤波器及电子设备 WO2022188777A1 (zh)

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CN113497593A (zh) * 2020-04-08 2021-10-12 诺思(天津)微系统有限责任公司 单晶体声波谐振器、滤波器及电子设备

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CN109995340A (zh) * 2019-03-13 2019-07-09 电子科技大学 一种空腔型体声波谐振器及其制备方法
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