WO2023006089A1 - Film bulk acoustic resonator having multiple bottom electrode layers, filter, and electronic device - Google Patents

Film bulk acoustic resonator having multiple bottom electrode layers, filter, and electronic device Download PDF

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Publication number
WO2023006089A1
WO2023006089A1 PCT/CN2022/109099 CN2022109099W WO2023006089A1 WO 2023006089 A1 WO2023006089 A1 WO 2023006089A1 CN 2022109099 W CN2022109099 W CN 2022109099W WO 2023006089 A1 WO2023006089 A1 WO 2023006089A1
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layer
electrode
barrier
electrode layer
material layer
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PCT/CN2022/109099
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French (fr)
Chinese (zh)
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徐洋
庞慰
郝龙
张巍
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诺思(天津)微系统有限责任公司
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Publication of WO2023006089A1 publication Critical patent/WO2023006089A1/en

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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

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  • Embodiments of the present invention relate to the field of semiconductors, and in particular to a bulk acoustic wave resonator and a manufacturing method thereof, a filter with the resonator, and an electronic device.
  • FBAR Film Bulk Acoustic Resonator
  • BAW Bulk Acoustic Resonator
  • SAW surface acoustic wave
  • the structural body of the film bulk acoustic resonator is a "sandwich" structure composed of electrodes-piezoelectric film-electrodes, that is, a layer of piezoelectric material is sandwiched between two layers of metal electrode layers.
  • FBAR uses the inverse piezoelectric effect to convert the input electrical signal into a mechanical resonance, and then uses the piezoelectric effect to convert the mechanical resonance into an electrical signal output.
  • the resonator For the bulk acoustic wave resonator, a form in which the bottom electrode is provided to include multilayer electrodes is employed. As shown in FIG. 1 , the resonator includes a substrate 101 , an acoustic mirror 102 , a bottom electrode layer 103 , a bottom electrode layer 104 , a piezoelectric layer 105 , a top electrode 106 , and a passivation or process layer 107 . For the formation of the bottom electrode, when a bottom electrode layer is etched or patterned, the surface structure of the film layer under the bottom electrode layer may be damaged.
  • the etching of the two bottom electrode layers will cause a certain degree of damage to the substrate 101 in the region without the bottom electrode (such as the A region in FIG.
  • the top electrode can form severe defects that can affect the performance of the resonator.
  • a bulk acoustic wave resonator includes a substrate, a bottom electrode, a top electrode and a piezoelectric layer.
  • the bottom electrode includes a plurality of electrode layers at least including a first electrode layer and a second electrode layer arranged in the thickness direction of the resonator, and the materials of the first electrode layer and the second electrode layer are different.
  • the resonator also includes a plurality of barrier layers including at least a first barrier layer and a second barrier layer. The first electrode layer covers at least a part of the upper side of the first barrier layer in surface contact, and the second electrode layer covers at least a part of the upper side of the second barrier layer in surface contact.
  • a method for manufacturing the above bulk acoustic wave resonator including: forming a first electrode material layer on the first barrier material layer, and patterning the first electrode material layer to form The first electrode layer, the first barrier material layer is formed as a protective layer of the surface below the first barrier material layer.
  • Embodiments of the present invention also relate to a filter, including the above bulk acoustic wave resonator.
  • Embodiments of the present invention also relate to an electronic device, including the above-mentioned filter or the above-mentioned resonator.
  • Fig. 1 is a schematic cross-sectional view of a known bulk acoustic wave resonator
  • FIG. 2 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention
  • 3A-3D are cross-sectional schematic diagrams schematically showing the manufacturing process of the bulk acoustic wave resonator in FIG. 2 according to an exemplary embodiment of the present invention
  • FIG. 4 is a schematic cross-sectional view of a bulk acoustic wave resonator according to 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.
  • the present invention proposes a technical scheme of etching multilayer electrodes separately, and adding corresponding barrier layers to each electrode layer under the electrode layer to pattern the multilayer electrodes respectively, so as to ensure the front and back of each electrode layer and subsequent film layers. Neither layer structure is destroyed by, for example, etching.
  • the optional material is single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.
  • Acoustic mirror which can be a cavity, for example, Bragg reflection layer and other equivalent forms can also be used.
  • the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or composites of the above metals or alloys thereof.
  • the bottom electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or their alloys, etc., the bottom electrode layer 103 and the bottom electrode layer 104 Materials can vary.
  • the material can be aluminum nitride, gallium nitride, lithium niobate, lead zirconate titanate (PZT), potassium niobate, quartz film, zinc oxide, etc., or a certain atomic ratio of the above materials
  • the rare earth element doped material for example, can be doped aluminum nitride, which 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), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium ( Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc
  • Sc scandium
  • the top electrode the material of which can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or composites of the above metals or alloys thereof.
  • the top and bottom electrodes are typically of the same material, but can also be different.
  • a dielectric layer or a process layer the material of which is generally a dielectric material, such as aluminum nitride, silicon dioxide, silicon nitride, etc. As can be understood, no dielectric layer or process layer may be provided.
  • a seed layer or a barrier layer the material of which may be AlN, SiN or the like.
  • a seed layer or a barrier layer the material of which may be AlN, SiN, etc.
  • Acoustic impedance mismatching structure it can be air, SiO 2 , SiN, etc., as mentioned later, and the acoustic impedance mismatching structure may not be provided.
  • the acoustic impedance mismatch structure is one of the acoustic mismatch structures.
  • Protruding structure the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the above metals or their alloys, etc., and the protruding structure may not be provided.
  • the raised structure is one of the acoustically mismatched structures.
  • acoustically mismatching structures such as recessed structures, bridge structures, cantilever structures, etc. may also be provided.
  • Bottom electrode layer the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the above metals or their alloys.
  • the material may be AlN, SiN, SiO 2 and so on.
  • FIG. 2 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention.
  • the bulk acoustic wave resonator includes: a substrate 101; an acoustic mirror 102, which is in the form of a cavity in Figure 2; a bottom electrode, including a bottom electrode layer 103 and a bottom electrode layer arranged in the thickness direction of the resonator 104, the materials of the bottom electrode layer 103 and the bottom electrode layer 104 are different from each other, and here, the different materials of the two reflect that the bottom electrode includes two bottom electrode layers instead of the superposition of metal layers of the same material; the top electrode 106;
  • the electrical layer 105 is disposed between the bottom electrode and the top electrode 106 .
  • the resonator further includes a dielectric layer or process layer 107 .
  • the dielectric layer or process layer 107 may not be provided.
  • the resonator also includes a barrier layer 108 and a barrier layer 109, the bottom electrode layer 104 covers at least a part of the upper side of the barrier layer 109 in a surface-contact manner, and the bottom electrode layer 103 covers the barrier layer in a surface-contact manner At least a portion of the upper side of 108.
  • the bottom electrode layer above the barrier layer constitutes a protective layer or barrier layer when the barrier layer is removed.
  • the end surface of the bottom electrode layer 103 is in contact with the end surface of the barrier layer 108
  • the end surface of the bottom electrode layer 104 is in contact with the end surface of the barrier layer 109 .
  • the end surface of the barrier layer 108 is inside the end surface of the bottom electrode layer 103
  • the end surface of the barrier layer 109 is at the bottom The inner side of the end surface of the electrode layer 104 .
  • the bottom electrode may not only include the bottom electrode layer 103 and the bottom electrode layer 104 , but may also include more bottom electrode layers.
  • the barrier layer may not only include two barrier layers 108 and 109, but may also include more barrier layers when more bottom electrode layers are provided. layer.
  • the film layer below the electrode layer can be protected from damage when the electrode layer above the blocking layer is etched or patterned.
  • the role of barrier layer 108 and barrier layer 109 are readily understood in the steps described with reference to FIGS. 3A-3D .
  • the lower side of the barrier layer 109 is in contact with the upper side of the substrate 101 , and the piezoelectric layer 105 covers the end surface of the barrier layer 109 and the upper side of the substrate 101 at the non-electrode connection end of the bottom electrode.
  • the barrier on the outside of the bottom electrode layer 104 can be removed in a manner that does not damage the upper surface of the substrate 101, such as wet etching.
  • the layer 109 in this way, can overcome or at least alleviate the technical problem that the piezoelectric layer and the top electrode grown subsequently in the region A in FIG. 1 will form serious defects mentioned in the background art.
  • the manufacturing process of the resonator structure shown in FIG. 2 is exemplarily described below with reference to FIGS. 3A-3D .
  • a substrate 101 is provided and a cavity or groove is formed on the upper side of the substrate 101 , and the cavity or groove is filled with a sacrificial layer 115 .
  • the sacrificial layer 115 may be formed by a CMP (Chemical Mechanical Polishing, chemical mechanical polishing) process as shown in FIG. Structure.
  • the sacrificial layer 115 can be released in a subsequent step to form the acoustic mirror structure of the resonator.
  • a barrier material layer (corresponding to 109) and a barrier material layer (corresponding to 108) are sequentially deposited; then a bottom electrode is deposited on the barrier material layer (corresponding to 108) material layer (corresponding to the bottom electrode layer 103); then, the bottom electrode material layer (corresponding to the bottom electrode layer 103) is patterned to form the bottom electrode layer 103, and the barrier material layer (corresponding to 108) is used as a protective lower film layer
  • the barrier material layer (corresponding to 108) is an etching barrier layer;
  • the surface of the material layer (corresponding to 109) is, for example, wet-etched to remove the barrier material layer on the outside of the bottom electrode layer 103 (the outside of the non-electrode connection end) to form a layer as shown in FIG.
  • barrier layer 108 barrier layer 108 . It can be seen that in FIG. 3B , because the bottom electrode layer 103 is used as a protective layer when patterning the barrier material layer, the end surface of the bottom electrode layer 103 is finally in contact with the end surface of the barrier layer 108 . In an optional embodiment, the end surface of the barrier layer 108 is inside the end surface of the bottom electrode layer 103 .
  • the end surface of the bottom electrode layer 104 is finally in contact with the end surface of the barrier layer 109 .
  • the end surface of the barrier layer 109 is inside the end surface of the bottom electrode layer 104 .
  • a piezoelectric layer 105 is deposited. It can be seen that in FIG. 3D , at the non-electrode connection end of the bottom electrode, the piezoelectric layer 105 covers the end surface of the barrier layer 109 and the upper side of the substrate 101 .
  • the barrier material layer on the outside of the bottom electrode layer 104 (outside of the electrode connection end) is removed in a manner that does not damage the upper surface of the substrate 101, for example, by wet etching. While forming the barrier layer 109 as shown in FIG. 3C , the surface of the substrate 101 at the non-electrode connection end is not damaged so that the flatness is high enough, thus avoiding the problem in the area A in FIG. 1 .
  • the top electrode 106 and the process layer 107 can be formed on the basis of the structure shown in FIG. 3D , so as to obtain the resonator structure shown in FIG. 2 .
  • the acoustic impedance of the bottom electrode layer 104 in FIG. 2 may be higher than the acoustic impedance of the bottom electrode layer 103.
  • the conductivity of the bottom electrode layer 103 is higher than that of the bottom electrode layer 104 .
  • barrier layer 108 may be AlN and barrier layer 109 may be SiN.
  • the barrier layer 108 and the barrier layer 109 can be made of other materials, which are all within the protection scope of the present invention.
  • the acoustic mirror 102 is disposed in the substrate 101, and the barrier layer 109 covers the upper side of the acoustic mirror 102, the barrier layer 108 covers the upper side of the barrier layer 109, and the bottom electrode layer 103 covers the upper side of the barrier layer 109. side and between the barrier layer 108 and the bottom electrode layer 104 in the thickness direction of the resonator.
  • the bottom electrode layer 104 covers the end surface of the barrier layer 108 at the non-electrode connection end of the bottom electrode layer 103 .
  • the resonator may also be provided with an acoustically mismatched structure arranged along the active area of the resonator.
  • Figure 4 shows such an exemplary structure.
  • the top electrode is provided with an acoustic impedance mismatch structure 110 and a protruding structure 111 at both the non-electrode connection end and the electrode connection end. Both the acoustic impedance mismatch structure 110 and the protruding structure 111 belong to the acoustic mismatch structure.
  • acoustic impedance mismatching structure 110 or the protruding structure 111 may be provided, or other acoustic mismatching structures such as a concave structure may also be provided.
  • the position of the acoustically mismatched structure in the thickness direction of the resonator is not limited to being between the top electrode 106 and the piezoelectric layer 105 as shown in FIG. Layer and bottom electrode, etc., these are within the protection scope of the present invention.
  • the acoustic mirror 102 is disposed in the base 101 , but the present invention is not limited thereto.
  • the acoustic mirror can also be arranged in the bottom electrode, so that the bottom electrode is a gap electrode; the acoustic mirror can also be arranged between the bottom electrode and the substrate.
  • FIG. 5 is a schematic cross-sectional view of a BAW resonator according to yet another exemplary embodiment of the present invention.
  • the acoustic mirror of the resonator is disposed in the bottom electrode.
  • a gap layer 102 is defined between the bottom electrode layer 112 and the bottom electrode layer 103 .
  • the material of the bottom electrode layer 112 may be different from that of the bottom electrode layer 103 .
  • barrier layer 108 defines at least a portion of the upper boundary of void layer 102 .
  • the bottom electrode further includes a bottom electrode layer 104, and at the non-electrode connection end of the bottom electrode, the bottom electrode layer 104 covers the upper side of the bottom electrode layer 112, covers the bottom electrode layer 103 and On the end surface of the barrier layer 108 , the material of the bottom electrode layer 104 is different from that of the bottom electrode layer 103 .
  • the material of the bottom electrode layer 104 can be the same as that of the bottom electrode layer 112 , and further, at the non-electrode connection end of the bottom electrode, the end surface of the bottom electrode layer 104 can be flush with the end surface of the bottom electrode layer 112 .
  • the bottom electrode layer 104 is at the non-electrode connection end of the bottom electrode, covering the end face of the barrier layer 108 and the end face of the bottom electrode layer 103 at the same time, but as can be understood, at the end face of the barrier layer 108
  • the bottom electrode layer 104 covers the end surface of the bottom electrode layer 103 but not the end surface of the barrier layer 108 , which is also within the protection scope of the present invention.
  • the acoustic impedance of the bottom electrode layer 104 is higher than that of the bottom electrode layer 103, and the conductivity of the bottom electrode layer 103 is higher than that of the bottom electrode layer 104.
  • the bottom electrode layer 104 is provided.
  • the bottom electrode layer 104 may not be provided.
  • the piezoelectric layer 105 directly covers the upper surface of the bottom electrode layer 103 .
  • the manufacturing process of the resonator structure shown in FIG. 5 is illustrated as follows.
  • the left side of the barrier material layer (corresponding to 108) can be patterned (to facilitate subsequent electrode material layers corresponding to the bottom electrode layer 103 and electrode material layer (corresponding to 112) electrical contact) while leaving its right side.
  • an electrode material layer corresponding to the bottom electrode layer 103 is deposited, and the electrode material layer is patterned to form the bottom electrode layer 103 (at this time, the barrier material layer (corresponding to 108 ) serves as a protection layer).
  • the right side of the barrier material layer (corresponding to 108) is patterned by wet etching to form the barrier layer 108 as shown in FIG.
  • the electrode material layer corresponding to the bottom electrode layer 112 The end surface of the finally formed barrier layer 108 may be in contact with the end surface of the bottom electrode layer 103 , or may be located inside the end surface of the bottom electrode layer 103 .
  • a layer of electrode material corresponding to the bottom electrode layer 104 may be deposited to cover the bottom electrode layer 103 and a layer of electrode material corresponding to the bottom electrode layer 112 . Then pattern the electrode material layer corresponding to the bottom electrode layer 104 and the electrode material layer corresponding to the bottom electrode layer 112 to form the bottom electrode layer 104 and the bottom electrode layer 112 .
  • the barrier material layer corresponding to the barrier layer 109 acts as a protection layer for the surface of the substrate 101 .
  • the barrier layer 109 outside the non-electrode connection end of the bottom electrode layer 112 formed after patterning is removed without damaging the upper surface of the substrate 101 during removal.
  • a piezoelectric layer 105 is provided to cover the end surface of the barrier layer 109 at the non-electrode connection end of the bottom electrode layer 112 with the piezoelectric layer 105 and to cover at least a part of the exposed surface of the substrate 101 with the piezoelectric layer 105 .
  • the acoustic mirror 102 is formed after the sacrificial layer (the area corresponding to 102 ) is released.
  • an acoustically mismatched structure similar to that of FIG. 4 may also be provided.
  • the arrangement of the acoustically mismatched structure described above with reference to FIG. 4 is also applicable to the structure shown in FIG. 5 , and will not be repeated here.
  • wet etching is used as an example to illustrate the etching of the barrier material layer to form a barrier layer
  • the present invention is not limited to wet etching, as long as "only the barrier material layer is etched, But do not damage the film layer below this barrier material layer, make its thickness constant (in the present invention, the constant thickness not only includes the situation that the thickness keeps the original thickness, but also includes the situation that the thickness is basically constant, such as the loss of thickness in the process. The situation within the allowable range)" etching process is included in the scope of "wet etching" in the claims of the present invention.
  • up and down are relative to the bottom surface of the base of the resonator.
  • the side close to the bottom surface is the bottom side
  • the side away from the bottom surface is the top side.
  • inner and outer are relative to 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) (i.e. the center of the effective area )
  • the side or end of a component that is close to the center of the effective area is the inner or inner end, while the side or end of the component that is far from the center of the effective area is the outer or outer end.
  • the bulk acoustic wave resonator according to the present invention can be used to form filters or electronic devices.
  • a bulk acoustic wave resonator comprising:
  • the bottom electrode includes a plurality of electrode layers, the plurality of electrode layers at least include a first electrode layer and a second electrode layer arranged in the thickness direction of the resonator, and the materials of the first electrode layer and the second electrode layer different;
  • the resonator further includes a plurality of barrier layers, the plurality of barrier layers includes at least a first barrier layer and a second barrier layer, and the first electrode layer covers at least an upper side of the first barrier layer in a surface-contact manner.
  • the second electrode layer covers at least a part of the upper side of the second barrier layer in surface contact.
  • the end surface of the first electrode layer is in contact with the end surface of the first barrier layer
  • the end surface of the first barrier layer is inside the end surface of the first electrode layer.
  • the underside of the first barrier layer is in contact with the upper side of the substrate
  • the piezoelectric layer covers the end surface of the first barrier layer and the upper side of the substrate.
  • the acoustic mirror of the resonator is arranged in a substrate, and the first barrier layer is arranged to cover the acoustic mirror of the resonator;
  • the second barrier layer is in contact with the first barrier layer and disposed on the upper side of the first barrier layer, the second electrode layer is disposed between the first electrode layer and the second barrier layer, and the first barrier layer the material of the layer is different from the material of said second barrier layer;
  • the first electrode layer covers the end face of the second barrier layer.
  • the end surface of the second electrode layer is in contact with the end surface of the second barrier layer
  • the end surface of the second barrier layer is inside the end surface of the second electrode layer.
  • the acoustic impedance of the first electrode layer is higher than that of the second electrode layer, and the conductivity of the second electrode layer is higher than that of the first electrode layer.
  • a void layer is defined between the first electrode layer and the second electrode layer, and the second barrier layer defines at least a portion of an upper boundary of the void layer.
  • the piezoelectric layer covers the upper side of the second electrode layer.
  • the bottom electrode also includes a third electrode layer, and at the non-electrode connection end of the bottom electrode, the third electrode layer covers at least a part of the upper side of the second electrode layer, and covers a portion of the first electrode layer. At least a part of the upper side covers the end surface of the second electrode layer, and the material of the third electrode layer is different from that of the second electrode layer.
  • the material of the third electrode layer is the same as that of the first electrode layer, and at the non-electrode connection end of the bottom electrode, the end faces of the first electrode layer and the third electrode layer are flush.
  • the acoustic impedance of the third electrode layer is higher than that of the second electrode layer, and the conductivity of the second electrode layer is higher than that of the third electrode layer.
  • the end surface of the second electrode layer is in contact with the end surface of the second barrier layer
  • the end surface of the second barrier layer is inside the end surface of the second electrode layer.
  • the resonator is also provided with an acoustically mismatched structure disposed along the active area of the resonator.
  • first electrode material layer on the first barrier material layer, and patterning the first electrode material layer to form a first electrode layer, the first barrier material layer being formed as a surface of the substrate below the first barrier material layer
  • the protective layer
  • the second barrier material layer being formed as a protection for a surface below the second barrier material layer layer.
  • first electrode material layer covering at least a part of the first barrier material layer, and patterning the first electrode material layer to form the first electrode layer so as to be exposed outside the non-electrode connection end of the first electrode layer
  • the first layer of barrier material
  • the end surface of the first barrier layer at the non-electrode connection end of the first electrode layer is covered with a piezoelectric layer, and at least a part of the exposed surface of the substrate is covered with a piezoelectric layer.
  • the materials of the first barrier material layer and the second barrier material layer are different from each other;
  • a first electrode material layer covering the second electrode layer and the exposed first barrier material layer is provided, and the material of the second electrode material layer is different from the material of the first electrode material layer;
  • the step of patterning the second electrode material layer and the second barrier material layer includes: patterning the second electrode material layer to form a second electrode layer, and patterning the second barrier material layer to form a second barrier layer, patterning the second
  • the first barrier material layer is a protective layer for the surface of the lower side of the first barrier material layer.
  • the exposed first resist material layer is suitable for removal by wet etching.
  • a filter comprising the bulk acoustic wave resonator according to any one of 1-13.
  • An electronic device comprising the filter according to 20, or the bulk acoustic wave resonator according to any one of 1-13.
  • the electronic equipment here includes but is not limited to intermediate products such as RF front-ends, filter amplifier modules, and terminal products such as mobile phones, WIFI, and drones.

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Abstract

The present invention relates to a film bulk acoustic resonator and a manufacturing method therefor. The resonator comprises a substrate, a bottom electrode, a top electrode, and a piezoelectric layer. The bottom electrode comprises multiple electrode layers, the multiple electrode layers at least comprise a first electrode layer and a second electrode layer provided in a thickness direction of the resonator, and the first electrode layer and the second electrode layer are made of different materials. The resonator further comprises multiple barrier layers, which comprise at least a first barrier layer and a second barrier layer. The first electrode layer covers at least a part of the upper side of the first barrier layer in a surface contact manner, and the second electrode layer covers at least a part of the upper side of the second barrier layer in a surface contact manner. The present invention also relates to a filter and an electronic device.

Description

具有多个底电极层的体声波谐振器、滤波器及电子设备Bulk acoustic wave resonators, filters and electronics with multiple bottom electrode layers 技术领域technical field
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。Embodiments of the present invention relate to the field of semiconductors, and in particular to a bulk acoustic wave resonator and a manufacturing method thereof, a filter with the resonator, and an electronic device.
背景技术Background technique
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。As the basic elements of electronic equipment, electronic devices have been widely used, including mobile phones, automobiles, home appliances, etc. In addition, technologies such as artificial intelligence, the Internet of Things, and 5G communications that will change the world in the future still need to rely on electronic devices as the basis.
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。Film Bulk Acoustic Resonator (FBAR, also known as Bulk Acoustic Resonator, also known as BAW), as an important member of piezoelectric devices, is playing an important role in the field of communication, especially FBAR filters in radio frequency filters The field market share is increasing. FBAR has excellent characteristics such as small size, high resonance frequency, high quality factor, large power capacity, and good roll-off effect. Its filters are gradually replacing traditional surface acoustic wave (SAW) filters. And ceramic filters play a huge role in the radio frequency field of wireless communication, and its high sensitivity advantages can also be applied to sensing fields such as biology, physics, and medicine.
薄膜体声波谐振器的结构主体为由电极-压电薄膜-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。The structural body of the film bulk acoustic resonator is a "sandwich" structure composed of electrodes-piezoelectric film-electrodes, that is, a layer of piezoelectric material is sandwiched between two layers of metal electrode layers. By inputting a sinusoidal signal between two electrodes, FBAR uses the inverse piezoelectric effect to convert the input electrical signal into a mechanical resonance, and then uses the piezoelectric effect to convert the mechanical resonance into an electrical signal output.
对于体声波谐振器，采用了将底电极设置为包括多层电极的形式。如图1所示，该谐振器包括基底101、声学镜102、底电极层103、底电极层104、压电层105、顶电极106、钝化层或工艺层107。对于底电极的形成，在刻蚀或图形化一层底电极层的时候，存在对该底电极层下方的膜层表面结构造成损伤的情形。For the bulk acoustic wave resonator, a form in which the bottom electrode is provided to include multilayer electrodes is employed. As shown in FIG. 1 , the resonator includes a substrate 101 , an acoustic mirror 102 , a bottom electrode layer 103 , a bottom electrode layer 104 , a piezoelectric layer 105 , a top electrode 106 , and a passivation or process layer 107 . For the formation of the bottom electrode, when a bottom electrode layer is etched or patterned, the surface structure of the film layer under the bottom electrode layer may be damaged.
例如，因为对于两个底电极层的刻蚀会对没有底电极的区域(例如图1中的A区域)的基底101造成一定程度的损伤，这导致图中A区域后续生长的压电层以及顶电极会形成严重缺陷，从而影响谐振器的性能。For example, because the etching of the two bottom electrode layers will cause a certain degree of damage to the substrate 101 in the region without the bottom electrode (such as the A region in FIG. The top electrode can form severe defects that can affect the performance of the resonator.
发明内容Contents of the invention
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。In order to alleviate or solve at least one aspect of the above-mentioned problems in the prior art, the present invention is proposed.
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。所述体声波谐振器包括基底、底电极、顶电极和压电层。底电极包括多个电极层，所述多个电极层至少包括在谐振器的厚度方向上设置的第一电极层和第二电极层，第一电极层和第二电极层的材料不同。所述谐振器还包括多个阻挡层，所述多个阻挡层至少包括第一阻挡层和第二阻挡层。第一电极层以面接触的方式覆盖第一阻挡层的上侧的至少一部分，第二电极层以面接触的方式覆盖第二阻挡层的上侧的至少一部分。According to an aspect of the embodiments of the present invention, a bulk acoustic wave resonator is provided. The bulk acoustic wave resonator includes a substrate, a bottom electrode, a top electrode and a piezoelectric layer. The bottom electrode includes a plurality of electrode layers at least including a first electrode layer and a second electrode layer arranged in the thickness direction of the resonator, and the materials of the first electrode layer and the second electrode layer are different. The resonator also includes a plurality of barrier layers including at least a first barrier layer and a second barrier layer. The first electrode layer covers at least a part of the upper side of the first barrier layer in surface contact, and the second electrode layer covers at least a part of the upper side of the second barrier layer in surface contact.
根据本发明的实施例的另一方面，提出了一种上述体声波谐振器的制造方法，包括：在第一阻挡材料层上形成第一电极材料层，以及图形化第一电极材料层以形成第一电极层，第一阻挡材料层形成为第一阻挡材料层下方的表面的保护层。According to another aspect of the embodiments of the present invention, a method for manufacturing the above bulk acoustic wave resonator is proposed, including: forming a first electrode material layer on the first barrier material layer, and patterning the first electrode material layer to form The first electrode layer, the first barrier material layer is formed as a protective layer of the surface below the first barrier material layer.
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。Embodiments of the present invention also relate to a filter, including the above bulk acoustic wave resonator.
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。Embodiments of the present invention also relate to an electronic device, including the above-mentioned filter or the above-mentioned resonator.
附图说明Description of drawings
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：These and other features and advantages of the various disclosed embodiments of the present invention can be better understood from the following description and accompanying drawings, in which the same reference numerals refer to the same parts throughout, wherein:
图1为已知的体声波谐振器的截面示意图；Fig. 1 is a schematic cross-sectional view of a known bulk acoustic wave resonator;
图2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；2 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention;
图3A-3D为根据本发明的一个示例性实施例的示意性示出图2中的体声波谐振器的制造过程的截面示意图；3A-3D are cross-sectional schematic diagrams schematically showing the manufacturing process of the bulk acoustic wave resonator in FIG. 2 according to an exemplary embodiment of the present invention;
图4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；以及4 is a schematic cross-sectional view of a bulk acoustic wave resonator according to another exemplary embodiment of the present invention; and
图5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。Fig. 5 is a schematic cross-sectional view of a bulk acoustic wave resonator according to yet another exemplary embodiment of the present invention.
具体实施方式Detailed ways
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。The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals designate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention, but should not be construed as a limitation of the present invention. Some, but not all, embodiments of the invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention belong to the protection scope of the present invention.
本发明提出一种分别刻蚀多层电极，并在电极层下对各电极层增设对应阻挡层而对多层电极分别进行图形化的技术方案，以保证每个电极层以及后续膜层的前层结构都不会因例如刻蚀而被破坏。The present invention proposes a technical scheme of etching multilayer electrodes separately, and adding corresponding barrier layers to each electrode layer under the electrode layer to pattern the multilayer electrodes respectively, so as to ensure the front and back of each electrode layer and subsequent film layers. Neither layer structure is destroyed by, for example, etching.
本发明中的附图标记说明如下：Reference numerals in the present invention are explained as follows:
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。101: substrate, the optional material is single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.
102：声学镜，可为空腔，例也可采用布拉格反射层及其他等效形式。102: Acoustic mirror, which can be a cavity, for example, Bragg reflection layer and other equivalent forms can also be used.
103：底电极层，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。103: Bottom electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or composites of the above metals or alloys thereof.
104：底电极层，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，底电极层103与底电极层104的材料可以不同。104: The bottom electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or their alloys, etc., the bottom electrode layer 103 and the bottom electrode layer 104 Materials can vary.
105：压电层，材料可以为氮化铝、氮化镓、铌酸锂、锆钛酸铅(PZT)、铌酸钾、石英薄膜、氧化锌等，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。105: Piezoelectric layer, the material can be aluminum nitride, gallium nitride, lithium niobate, lead zirconate titanate (PZT), potassium niobate, quartz film, zinc oxide, etc., or a certain atomic ratio of the above materials The rare earth element doped material, for example, can be doped aluminum nitride, which 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), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium ( Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.
106：顶电极，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。顶电极和底电极材料一般相同，但也可以不同。106: The top electrode, the material of which can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or composites of the above metals or alloys thereof. The top and bottom electrodes are typically of the same material, but can also be different.
107：介质层或工艺层，其材料一般为介质材料，例如可以为氮化铝、二氧化硅、氮化硅等。如能够理解的，也可以不设置介质层或工艺层。107: A dielectric layer or a process layer, the material of which is generally a dielectric material, such as aluminum nitride, silicon dioxide, silicon nitride, etc. As can be understood, no dielectric layer or process layer may be provided.
108：种子层或者阻挡层，材料可选AlN、SiN等。108: a seed layer or a barrier layer, the material of which may be AlN, SiN or the like.
109：种子层或者阻挡层，材料可选AlN、SiN等。109: a seed layer or a barrier layer, the material of which may be AlN, SiN, etc.
110：声阻抗不匹配结构：可以是空气、SiO 2、SiN等，如后面提及的，也可以不设置声阻抗不匹配结构。声阻抗不匹配结构是声学不匹配结构中的一种。 110: Acoustic impedance mismatching structure: it can be air, SiO 2 , SiN, etc., as mentioned later, and the acoustic impedance mismatching structure may not be provided. The acoustic impedance mismatch structure is one of the acoustic mismatch structures.
111：凸起结构，材料可选钼、钌、金、铝、镁、钨、铜、钛、铱、锇、铬或以上金属的符合或其合金等，也可以不设置凸起结构。凸起结构是声学不匹配结构中的一种。虽然在图中没有示出，也可以设置例如凹陷结构、桥结构、悬翼结构等声学不匹配结构。111: Protruding structure, the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the above metals or their alloys, etc., and the protruding structure may not be provided. The raised structure is one of the acoustically mismatched structures. Although not shown in the drawings, acoustically mismatching structures such as recessed structures, bridge structures, cantilever structures, etc. may also be provided.
112：底电极层，材料可选钼、钌、金、铝、镁、钨、铜、钛、铱、锇、铬或以上金属的符合或其合金等。112: Bottom electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the above metals or their alloys.
115：牺牲层，材料可以是AlN、SiN、SiO 2等。 115: a sacrificial layer, the material may be AlN, SiN, SiO 2 and so on.
图2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。如图2所示，体声波谐振器包括：基底101；声学镜102，在图2中其为空腔形式；底电极，包括在谐振器的厚度方向上设置的底电极层103和底电极层104，底电极层103和底电极层104的材料彼此不同，在这里，两者材料不同体现出底电极包括了两个底电极层而不是相同材料的金属层的叠加；顶电极106；和压电层105，设置在底电极与顶电极106之间。FIG. 2 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention. As shown in Figure 2, the bulk acoustic wave resonator includes: a substrate 101; an acoustic mirror 102, which is in the form of a cavity in Figure 2; a bottom electrode, including a bottom electrode layer 103 and a bottom electrode layer arranged in the thickness direction of the resonator 104, the materials of the bottom electrode layer 103 and the bottom electrode layer 104 are different from each other, and here, the different materials of the two reflect that the bottom electrode includes two bottom electrode layers instead of the superposition of metal layers of the same material; the top electrode 106; The electrical layer 105 is disposed between the bottom electrode and the top electrode 106 .
在图2中，谐振器还包括介质层或工艺层107，如前所述的，也可以不设置介质层或工艺层107。In FIG. 2 , the resonator further includes a dielectric layer or process layer 107 . As mentioned above, the dielectric layer or process layer 107 may not be provided.
如图2所示，谐振器还包括阻挡层108和阻挡层109，底电极层104以面接触的方式覆盖阻挡层109的上侧的至少一部分，底电极层103以面接触的方式覆盖阻挡层108的上侧的至少一部分。As shown in Figure 2, the resonator also includes a barrier layer 108 and a barrier layer 109, the bottom electrode layer 104 covers at least a part of the upper side of the barrier layer 109 in a surface-contact manner, and the bottom electrode layer 103 covers the barrier layer in a surface-contact manner At least a portion of the upper side of 108.
如图2所示，如后面提及的，在图形化阻挡层的过程中，阻挡层上方的底电极层构成阻挡层被移除时的保护层或阻挡层，相应的，在底电极的非电极连接端，底电极层103的端面与阻挡层108的端面相接，和/或底电极层104的端面与阻挡层109的端面相接。在可选的实施例中，例如基于不同的刻蚀时间，在底电极的非电极连接端，阻挡层108的端面处于底电极层103的端面的内侧，和/或阻挡层109的端面处于底电极层104的端面的内侧。As shown in FIG. 2, as mentioned later, in the process of patterning the barrier layer, the bottom electrode layer above the barrier layer constitutes a protective layer or barrier layer when the barrier layer is removed. For electrode connection ends, the end surface of the bottom electrode layer 103 is in contact with the end surface of the barrier layer 108 , and/or the end surface of the bottom electrode layer 104 is in contact with the end surface of the barrier layer 109 . In an optional embodiment, for example, based on different etching times, at the non-electrode connection end of the bottom electrode, the end surface of the barrier layer 108 is inside the end surface of the bottom electrode layer 103, and/or the end surface of the barrier layer 109 is at the bottom The inner side of the end surface of the electrode layer 104 .
在图2所示的实施例中，如能够理解的，底电极可以不是仅仅包括底电极层103和底电极层104，还可以包括更多的底电极层。In the embodiment shown in FIG. 2 , as can be understood, the bottom electrode may not only include the bottom electrode layer 103 and the bottom electrode layer 104 , but may also include more bottom electrode layers.
在图2所示的实施例中，如能够理解的，阻挡层也可以不仅仅包括两 个阻挡层108和109，在设置了更多的底电极层的情况下，还可以包括更多的阻挡层。In the embodiment shown in FIG. 2, as can be understood, the barrier layer may not only include two barrier layers 108 and 109, but may also include more barrier layers when more bottom electrode layers are provided. layer.
在本发明中，通过设置阻挡层，可以在刻蚀或图形化位于阻挡层上侧的电极层时，保护处于该电极层下方的膜层免受损害。对于图2所示的结构，在参照图3A-3D所描述的步骤中，很容易理解阻挡层108和阻挡层109的作用。In the present invention, by providing the blocking layer, the film layer below the electrode layer can be protected from damage when the electrode layer above the blocking layer is etched or patterned. For the structure shown in FIG. 2 , the role of barrier layer 108 and barrier layer 109 are readily understood in the steps described with reference to FIGS. 3A-3D .
如图2所示，阻挡层109的下侧与基底101的上侧面接触，且在底电极的非电极连接端，压电层105覆盖阻挡层109的端面和基底101的上侧。如后面参照图3A-3D所描述的，在图形化了底电极层104之后，可以采用不损害基底101的上表面的方式，例如湿法刻蚀，移除在底电极层104的外侧的阻挡层109，如此，可以克服或至少缓解背景技术中提及的图1中的A区域后续生长的压电层以及顶电极会形成严重缺陷这样的技术问题。As shown in FIG. 2 , the lower side of the barrier layer 109 is in contact with the upper side of the substrate 101 , and the piezoelectric layer 105 covers the end surface of the barrier layer 109 and the upper side of the substrate 101 at the non-electrode connection end of the bottom electrode. As described later with reference to FIGS. 3A-3D , after patterning the bottom electrode layer 104, the barrier on the outside of the bottom electrode layer 104 can be removed in a manner that does not damage the upper surface of the substrate 101, such as wet etching. The layer 109, in this way, can overcome or at least alleviate the technical problem that the piezoelectric layer and the top electrode grown subsequently in the region A in FIG. 1 will form serious defects mentioned in the background art.
下面参照图3A-3D示例性说明图2所示的谐振器结构的制造过程。The manufacturing process of the resonator structure shown in FIG. 2 is exemplarily described below with reference to FIGS. 3A-3D .
如图3A所示，提供基底101以及在基底101的上侧形成空腔或凹槽，空腔或凹槽中填充了牺牲层115。如能够理解的，牺牲层115可以是在基底101的上侧设置牺牲材料层(其会填充基底上侧的空腔)后，采用CMP(Chemical Mechanical Polishing，化学机械抛光)工艺形成图3A所示的结构。牺牲层115在后续的步骤中可以被释放以形成谐振器的声学镜结构。As shown in FIG. 3A , a substrate 101 is provided and a cavity or groove is formed on the upper side of the substrate 101 , and the cavity or groove is filled with a sacrificial layer 115 . As can be understood, the sacrificial layer 115 may be formed by a CMP (Chemical Mechanical Polishing, chemical mechanical polishing) process as shown in FIG. Structure. The sacrificial layer 115 can be released in a subsequent step to form the acoustic mirror structure of the resonator.
如图3B所示，在图3A所示结构的基础上，依次沉积阻挡材料层(对应于109)和阻挡材料层(对应于108)；然后在阻挡材料层(对应于108)上沉积底电极材料层(对应于底电极层103)；接着，对底电极材料层(对应于底电极层103)图形化以形成底电极层103，此时阻挡材料层(对应于108)作为保护下方膜层的保护层，例如在以刻蚀的方式图形化第一底电极材料层以形成底电极层103的过程中，阻挡材料层(对应于108)为刻蚀阻挡层；再接着，以不伤害阻挡材料层(对应于109)的表面的方式，例如，以湿法刻蚀的方式，移除在底电极层103的外侧(非电极连接端的外侧)的阻挡材料层而形成如图3B所示的阻挡层108。可以看到，在图3B中，因为底电极层103作为图形化阻挡材料层时的保护层，最终底电极层103的端面与阻挡层108的端面相接。在可选的实施例中，阻挡层108的端面处于底电极层103的端面的内侧。As shown in Figure 3B, on the basis of the structure shown in Figure 3A, a barrier material layer (corresponding to 109) and a barrier material layer (corresponding to 108) are sequentially deposited; then a bottom electrode is deposited on the barrier material layer (corresponding to 108) material layer (corresponding to the bottom electrode layer 103); then, the bottom electrode material layer (corresponding to the bottom electrode layer 103) is patterned to form the bottom electrode layer 103, and the barrier material layer (corresponding to 108) is used as a protective lower film layer For example, in the process of patterning the first bottom electrode material layer by etching to form the bottom electrode layer 103, the barrier material layer (corresponding to 108) is an etching barrier layer; The surface of the material layer (corresponding to 109) is, for example, wet-etched to remove the barrier material layer on the outside of the bottom electrode layer 103 (the outside of the non-electrode connection end) to form a layer as shown in FIG. 3B barrier layer 108 . It can be seen that in FIG. 3B , because the bottom electrode layer 103 is used as a protective layer when patterning the barrier material layer, the end surface of the bottom electrode layer 103 is finally in contact with the end surface of the barrier layer 108 . In an optional embodiment, the end surface of the barrier layer 108 is inside the end surface of the bottom electrode layer 103 .
如图3C所示，在图3B所示结构的基础上，沉积底电极材料层(对应 于104)，其覆盖底电极层103、阻挡材料层(对应于109)；然后，对底电极材料层(对应于104)图形化以形成底电极层104，此时阻挡材料层(对应于109)作为防止基底的上侧受到损伤的保护层；接着，以不伤害基底101上表面的方式，例如，以湿法刻蚀的方式，移除在底电极层104的外侧(非电极连接端的外侧)的阻挡材料层而形成如图3C所示的阻挡层109。可以看到，在图3C中，因为底电极层104作为图形化阻挡材料层时的保护层，最终底电极层104的端面与阻挡层109的端面相接。在可选的实施例中，阻挡层109的端面处于底电极层104的端面的内侧。As shown in Figure 3C, on the basis of the structure shown in Figure 3B, deposit a bottom electrode material layer (corresponding to 104), which covers the bottom electrode layer 103, barrier material layer (corresponding to 109); then, the bottom electrode material layer (corresponding to 104) patterning to form the bottom electrode layer 104, at this time the barrier material layer (corresponding to 109) is used as a protective layer to prevent the upper side of the substrate from being damaged; then, in a manner that does not damage the upper surface of the substrate 101, for example, By wet etching, the barrier material layer on the outside of the bottom electrode layer 104 (outside of the electrode connection end) is removed to form a barrier layer 109 as shown in FIG. 3C . It can be seen that in FIG. 3C , because the bottom electrode layer 104 is used as a protective layer when patterning the barrier material layer, the end surface of the bottom electrode layer 104 is finally in contact with the end surface of the barrier layer 109 . In an optional embodiment, the end surface of the barrier layer 109 is inside the end surface of the bottom electrode layer 104 .
如图3D所示，在图3C所示结构的基础上，沉积压电层105。可以看到，在图3D中，在底电极的非电极连接端，压电层105覆盖阻挡层109的端面和所述基底101的上侧。由于在图3C所示的步骤中，以不伤害基底101上表面的方式，例如，以湿法刻蚀的方式，移除在底电极层104的外侧(非电极连接端的外侧)的阻挡材料层而形成如图3C所示的阻挡层109，基底101在非电极连接端的表面并未受损从而平坦度足够高，这样就避免了图1中A区域所存在的问题。As shown in FIG. 3D , based on the structure shown in FIG. 3C , a piezoelectric layer 105 is deposited. It can be seen that in FIG. 3D , at the non-electrode connection end of the bottom electrode, the piezoelectric layer 105 covers the end surface of the barrier layer 109 and the upper side of the substrate 101 . In the step shown in FIG. 3C , the barrier material layer on the outside of the bottom electrode layer 104 (outside of the electrode connection end) is removed in a manner that does not damage the upper surface of the substrate 101, for example, by wet etching. While forming the barrier layer 109 as shown in FIG. 3C , the surface of the substrate 101 at the non-electrode connection end is not damaged so that the flatness is high enough, thus avoiding the problem in the area A in FIG. 1 .
虽然没有示出，如本领域技术人员能够理解的，可以在图3D所示结构的基础上形成顶电极106以及工艺层107，从而得到图2所示的谐振器结构。Although not shown, as those skilled in the art can understand, the top electrode 106 and the process layer 107 can be formed on the basis of the structure shown in FIG. 3D , so as to obtain the resonator structure shown in FIG. 2 .
在进一步可选的实施例中，对于底电极层103和底电极层104的材料不同，可以是图2中的底电极层104的声阻抗高于底电极层103的声阻抗，图2中的底电极层103的导电率高于底电极层104的导电率。In a further optional embodiment, for the different materials of the bottom electrode layer 103 and the bottom electrode layer 104, the acoustic impedance of the bottom electrode layer 104 in FIG. 2 may be higher than the acoustic impedance of the bottom electrode layer 103. The conductivity of the bottom electrode layer 103 is higher than that of the bottom electrode layer 104 .
在图2所示的实施例中，阻挡层108和阻挡层109由于彼此面接触，其材料需要不同，即在例如图形化阻挡层108的时候，阻挡层109不会被刻蚀或者刻蚀很少部分。在可选的实施例中，阻挡层108可以为AlN，而阻挡层109可以为SiN。如本领域技术人员能够理解的，阻挡层108和阻挡层109可以为其他材料，这均在本发明的保护范围之内。In the embodiment shown in FIG. 2 , the materials of the barrier layer 108 and the barrier layer 109 need to be different due to their surface contact with each other, that is, when the barrier layer 108 is patterned, for example, the barrier layer 109 will not be etched or etched very quickly. A small part. In an alternative embodiment, barrier layer 108 may be AlN and barrier layer 109 may be SiN. As those skilled in the art can understand, the barrier layer 108 and the barrier layer 109 can be made of other materials, which are all within the protection scope of the present invention.
如图2所示，声学镜102设置在基底101中，而阻挡层109则覆盖在声学镜102的上侧，阻挡层108覆盖阻挡层109的上侧，底电极层103覆盖阻挡层109的上侧且在谐振器的厚度方向上处于阻挡层108与底电极层104之间。此外，在图2中，如图所示，在底电极层103的非电极连接端，底电极层104覆盖阻挡层108的端面。As shown in Figure 2, the acoustic mirror 102 is disposed in the substrate 101, and the barrier layer 109 covers the upper side of the acoustic mirror 102, the barrier layer 108 covers the upper side of the barrier layer 109, and the bottom electrode layer 103 covers the upper side of the barrier layer 109. side and between the barrier layer 108 and the bottom electrode layer 104 in the thickness direction of the resonator. In addition, in FIG. 2 , as shown in the figure, the bottom electrode layer 104 covers the end surface of the barrier layer 108 at the non-electrode connection end of the bottom electrode layer 103 .
在本发明的一个实施例中，谐振器还可设置有沿谐振器的有效区域设置的声学不匹配结构。图4示出了这样的示例性结构。图4中，顶电极在非电极连接端以及电极连接端均设置有声阻抗不匹配结构110和凸起结构111。声阻抗不匹配结构110和凸起结构111均属于声学不匹配结构。在另外具体的实施例中，可以仅设置声阻抗不匹配结构110或凸起结构111，或者，还可以设置凹陷结构等其他的声学不匹配结构。此外，声学不匹配结构在谐振器的厚度方向上的位置也不限于图4中所示的处于顶电极106与压电层105之间，也可以设置在压电层中，或者设置在压电层与底电极之间等，这些均在本发明的保护范围之内。In one embodiment of the present invention, the resonator may also be provided with an acoustically mismatched structure arranged along the active area of the resonator. Figure 4 shows such an exemplary structure. In FIG. 4 , the top electrode is provided with an acoustic impedance mismatch structure 110 and a protruding structure 111 at both the non-electrode connection end and the electrode connection end. Both the acoustic impedance mismatch structure 110 and the protruding structure 111 belong to the acoustic mismatch structure. In another specific embodiment, only the acoustic impedance mismatching structure 110 or the protruding structure 111 may be provided, or other acoustic mismatching structures such as a concave structure may also be provided. In addition, the position of the acoustically mismatched structure in the thickness direction of the resonator is not limited to being between the top electrode 106 and the piezoelectric layer 105 as shown in FIG. Layer and bottom electrode, etc., these are within the protection scope of the present invention.
在图2-图4所示的实施例中，声学镜102设置在基底101中，但是本发明不限于此。声学镜也可以设置在底电极中，从而底电极为间隙电极；声学镜也可以设置在底电极与基底之间。这些均在本发明的保护范围之内。In the embodiments shown in FIGS. 2-4 , the acoustic mirror 102 is disposed in the base 101 , but the present invention is not limited thereto. The acoustic mirror can also be arranged in the bottom electrode, so that the bottom electrode is a gap electrode; the acoustic mirror can also be arranged between the bottom electrode and the substrate. These are all within the protection scope of the present invention.
图5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，在图5所示的结构中，谐振器的声学镜设置在底电极中。如图5所示，底电极层112与底电极层103之间限定有空隙层102。底电极层112的材料可以不同于底电极层103的材料。如图5所示，阻挡层108限定空隙层102的上侧边界的至少一部分。FIG. 5 is a schematic cross-sectional view of a BAW resonator according to yet another exemplary embodiment of the present invention. In the structure shown in FIG. 5 , the acoustic mirror of the resonator is disposed in the bottom electrode. As shown in FIG. 5 , a gap layer 102 is defined between the bottom electrode layer 112 and the bottom electrode layer 103 . The material of the bottom electrode layer 112 may be different from that of the bottom electrode layer 103 . As shown in FIG. 5 , barrier layer 108 defines at least a portion of the upper boundary of void layer 102 .
在进一步的实施例中，如图5所示，底电极还包括底电极层104，在底电极的非电极连接端，底电极层104覆盖底电极层112的上侧、覆盖底电极层103和阻挡层108的端面，底电极层104的材料不同于底电极层103的材料。In a further embodiment, as shown in FIG. 5 , the bottom electrode further includes a bottom electrode layer 104, and at the non-electrode connection end of the bottom electrode, the bottom electrode layer 104 covers the upper side of the bottom electrode layer 112, covers the bottom electrode layer 103 and On the end surface of the barrier layer 108 , the material of the bottom electrode layer 104 is different from that of the bottom electrode layer 103 .
底电极层104的材料可以与底电极层112的材料相同，进一步的，在底电极的非电极连接端，底电极层104的端面可以与底电极层112的端面齐平。The material of the bottom electrode layer 104 can be the same as that of the bottom electrode layer 112 , and further, at the non-electrode connection end of the bottom electrode, the end surface of the bottom electrode layer 104 can be flush with the end surface of the bottom electrode layer 112 .
在图5所示的实施例中，底电极层104在底电极的非电极连接端，同时覆盖了阻挡层108的端面以及底电极层103的端面，但是如能够理解的，在阻挡层108的端部处于底电极层103的端部的内侧的情况下，底电极层104覆盖了底电极层103的端面而没有覆盖阻挡层108的端面，该方案也在本发明的保护范围之内。In the embodiment shown in FIG. 5 , the bottom electrode layer 104 is at the non-electrode connection end of the bottom electrode, covering the end face of the barrier layer 108 and the end face of the bottom electrode layer 103 at the same time, but as can be understood, at the end face of the barrier layer 108 When the end is inside the end of the bottom electrode layer 103 , the bottom electrode layer 104 covers the end surface of the bottom electrode layer 103 but not the end surface of the barrier layer 108 , which is also within the protection scope of the present invention.
在图5所示的实施例中，可选的，底电极层104的声阻抗高于底电极 层103的声阻抗，且底电极层103的导电率高于底电极层104的导电率。In the embodiment shown in FIG. 5 , optionally, the acoustic impedance of the bottom electrode layer 104 is higher than that of the bottom electrode layer 103, and the conductivity of the bottom electrode layer 103 is higher than that of the bottom electrode layer 104.
在图5所示的实施例中，设置了底电极层104，但是，也可以不设置底电极层104，此时，压电层105直接覆盖底电极层103的上表面。该方案虽然没有示出，也在本发明的保护范围之内。In the embodiment shown in FIG. 5 , the bottom electrode layer 104 is provided. However, the bottom electrode layer 104 may not be provided. In this case, the piezoelectric layer 105 directly covers the upper surface of the bottom electrode layer 103 . Although this scheme is not shown, it is also within the protection scope of the present invention.
下面示例性说明图5所示的谐振器结构的制造过程。The manufacturing process of the resonator structure shown in FIG. 5 is illustrated as follows.
对于图5中的底电极层103的形成，如图5所示，可以先对阻挡材料层(对应于108)的左侧图形化(便于后续对应于底电极层103的电极材料层与电极材料层(对应于112)电接触)而保留其右侧。接着，沉积对应于底电极层103的电极材料层，对该电极材料层图形化以形成底电极层103(此时阻挡材料层(对应于108)作为保护层)。然后，对阻挡材料层(对应于108)的右侧以湿法刻蚀图形化以形成如图5所示的阻挡层108，在此过程中，不伤害阻挡层108对应的阻挡材料层下方的底电极层112对应的电极材料层。最终形成的阻挡层108的端面可以与底电极层103的端面相接，也可以处于底电极层103的端面的内侧。For the formation of the bottom electrode layer 103 in Figure 5, as shown in Figure 5, the left side of the barrier material layer (corresponding to 108) can be patterned (to facilitate subsequent electrode material layers corresponding to the bottom electrode layer 103 and electrode material layer (corresponding to 112) electrical contact) while leaving its right side. Next, an electrode material layer corresponding to the bottom electrode layer 103 is deposited, and the electrode material layer is patterned to form the bottom electrode layer 103 (at this time, the barrier material layer (corresponding to 108 ) serves as a protection layer). Then, the right side of the barrier material layer (corresponding to 108) is patterned by wet etching to form the barrier layer 108 as shown in FIG. The electrode material layer corresponding to the bottom electrode layer 112 . The end surface of the finally formed barrier layer 108 may be in contact with the end surface of the bottom electrode layer 103 , or may be located inside the end surface of the bottom electrode layer 103 .
在形成了阻挡层108之后，可以沉积与底电极层104对应于电极材料层以覆盖底电极层103和对应于底电极层112的电极材料层。接着对与底电极层104对应于电极材料层以及与底电极层112对应的电极材料层图形化，以形成底电极层104和底电极层112。After the barrier layer 108 is formed, a layer of electrode material corresponding to the bottom electrode layer 104 may be deposited to cover the bottom electrode layer 103 and a layer of electrode material corresponding to the bottom electrode layer 112 . Then pattern the electrode material layer corresponding to the bottom electrode layer 104 and the electrode material layer corresponding to the bottom electrode layer 112 to form the bottom electrode layer 104 and the bottom electrode layer 112 .
在图形化对应的底电极材料层以底电极层104以及112的过程中，对应于阻挡层109的阻挡材料层作为基底101的表面的保护层。之后，将在图形化后而形成的底电极层112的非电极连接端的外侧的阻挡层109移除，且在移除时不损害基底101的上表面。再然后，设置压电层105，以压电层105覆盖阻挡层109在底电极层112的非电极连接端的端面，以及以压电层105覆盖露出的基底101表面的至少一部分。During the process of patterning the corresponding bottom electrode material layers as bottom electrode layers 104 and 112 , the barrier material layer corresponding to the barrier layer 109 acts as a protection layer for the surface of the substrate 101 . Afterwards, the barrier layer 109 outside the non-electrode connection end of the bottom electrode layer 112 formed after patterning is removed without damaging the upper surface of the substrate 101 during removal. Then, a piezoelectric layer 105 is provided to cover the end surface of the barrier layer 109 at the non-electrode connection end of the bottom electrode layer 112 with the piezoelectric layer 105 and to cover at least a part of the exposed surface of the substrate 101 with the piezoelectric layer 105 .
如能够理解的，将牺牲层(102所对应区域)释放后就形成声学镜102。As can be understood, the acoustic mirror 102 is formed after the sacrificial layer (the area corresponding to 102 ) is released.
虽然没有示出，如能够理解的，在图5所示的结构中，也可以类似于图4的设置声学不匹配结构。上述参照图4所述的声学不匹配结构的设置也适用于图5所示的结构，这里不再赘述。Although not shown, as can be appreciated, in the structure shown in FIG. 5 , an acoustically mismatched structure similar to that of FIG. 4 may also be provided. The arrangement of the acoustically mismatched structure described above with reference to FIG. 4 is also applicable to the structure shown in FIG. 5 , and will not be repeated here.
在本发明中，虽然以湿法刻蚀为例示例性说明对于阻挡材料层的刻蚀以形成阻挡层，但是本发明不限于湿法刻蚀，只要是能够实现“只刻蚀阻挡材料层，但是不伤害该阻挡材料层下方的膜层，使其厚度不变(在本发 明中厚度不变不仅包括厚度保持原厚度的情况，也包括了厚度基本不变的情形，例如厚度损失在工艺所许可的范围内的情形)”的刻蚀工艺，都包括在本发明的权利要求中的“湿法刻蚀”的范围之内。In the present invention, although wet etching is used as an example to illustrate the etching of the barrier material layer to form a barrier layer, the present invention is not limited to wet etching, as long as "only the barrier material layer is etched, But do not damage the film layer below this barrier material layer, make its thickness constant (in the present invention, the constant thickness not only includes the situation that the thickness keeps the original thickness, but also includes the situation that the thickness is basically constant, such as the loss of thickness in the process. The situation within the allowable range)" etching process is included in the scope of "wet etching" in the claims of the present invention.
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。In the present invention, up and down are relative to the bottom surface of the base of the resonator. For a component, the side close to the bottom surface is the bottom side, and the side away from the bottom surface is the top side.
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。In the present invention, inner and outer are relative to 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) (i.e. the center of the effective area ) In terms of the transverse or radial direction, the side or end of a component that is close to the center of the effective area is the inner or inner end, while the side or end of the component that is far from the center of the effective area is the outer or outer end. For a reference position, being located inside the position means that it is between the position and the center of the effective area in the lateral direction or radial direction, and being located outside the position means that it is farther away from the position in the lateral direction or radial direction. Effective area center.
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。As can be understood by those skilled in the art, the bulk acoustic wave resonator according to the present invention can be used to form filters or electronic devices.
基于以上，本发明提出了如下技术方案：Based on the above, the present invention proposes the following technical solutions:
1、一种体声波谐振器，包括：1. A bulk acoustic wave resonator, comprising:
基底；base;
底电极；bottom electrode;
顶电极；和top electrode; and
压电层，piezoelectric layer,
其中：in:
所述底电极包括多个电极层，所述多个电极层至少包括在谐振器的厚度方向上设置的第一电极层和第二电极层，所述第一电极层和第二电极层的材料不同；The bottom electrode includes a plurality of electrode layers, the plurality of electrode layers at least include a first electrode layer and a second electrode layer arranged in the thickness direction of the resonator, and the materials of the first electrode layer and the second electrode layer different;
所述谐振器还包括多个阻挡层，所述多个阻挡层至少包括第一阻挡层和第二阻挡层，所述第一电极层以面接触的方式覆盖第一阻挡层的上侧的至少一部分，所述第二电极层以面接触的方式覆盖第二阻挡层的上侧的至少一部分。The resonator further includes a plurality of barrier layers, the plurality of barrier layers includes at least a first barrier layer and a second barrier layer, and the first electrode layer covers at least an upper side of the first barrier layer in a surface-contact manner. In one part, the second electrode layer covers at least a part of the upper side of the second barrier layer in surface contact.
2、根据1所述的谐振器，其中：2. The resonator according to 1, wherein:
在底电极的非电极连接端，所述第一电极层的端面与所述第一阻挡层的端面相接；或者At the non-electrode connection end of the bottom electrode, the end surface of the first electrode layer is in contact with the end surface of the first barrier layer; or
在底电极的非电极连接端，所述第一阻挡层的端面处于所述第一电极层的端面的内侧。At the non-electrode connection end of the bottom electrode, the end surface of the first barrier layer is inside the end surface of the first electrode layer.
3、根据1所述的谐振器，其中：3. The resonator according to 1, wherein:
所述第一阻挡层的下侧与所述基底的上侧面接触；且the underside of the first barrier layer is in contact with the upper side of the substrate; and
在所述底电极的非电极连接端，所述压电层覆盖第一阻挡层的端面和所述基底的上侧。At the non-electrode connection end of the bottom electrode, the piezoelectric layer covers the end surface of the first barrier layer and the upper side of the substrate.
4、根据1-3中任一项所述的谐振器，其中：4. The resonator according to any one of 1-3, wherein:
所述谐振器的声学镜设置在基底中，所述第一阻挡层设置成覆盖所述谐振器的声学镜；The acoustic mirror of the resonator is arranged in a substrate, and the first barrier layer is arranged to cover the acoustic mirror of the resonator;
所述第二阻挡层与第一阻挡层面接触且设置在第一阻挡层的上侧，所述第二电极层设置在第一电极层与所述第二阻挡层之间，所述第一阻挡层的材料不同于所述第二阻挡层的材料；The second barrier layer is in contact with the first barrier layer and disposed on the upper side of the first barrier layer, the second electrode layer is disposed between the first electrode layer and the second barrier layer, and the first barrier layer the material of the layer is different from the material of said second barrier layer;
在所述底电极的非电极连接端，所述第一电极层覆盖第二阻挡层的端面。At the non-electrode connection end of the bottom electrode, the first electrode layer covers the end face of the second barrier layer.
5、根据4所述的谐振器，其中：5. The resonator according to 4, wherein:
在底电极的非电极连接端，所述第二电极层的端面与所述第二阻挡层的端面相接；或者At the non-electrode connection end of the bottom electrode, the end surface of the second electrode layer is in contact with the end surface of the second barrier layer; or
在底电极的非电极连接端，所述第二阻挡层的端面处于所述第二电极层的端面的内侧。At the non-electrode connection end of the bottom electrode, the end surface of the second barrier layer is inside the end surface of the second electrode layer.
6、根据4所述的谐振器，其中：6. The resonator according to 4, wherein:
所述第一电极层的声阻抗高于所述第二电极层的声阻抗，且所述第二电极层的导电率高于所述第一电极层的导电率。The acoustic impedance of the first electrode layer is higher than that of the second electrode layer, and the conductivity of the second electrode layer is higher than that of the first electrode layer.
7、根据1-3中任一项所述的谐振器，其中：7. The resonator according to any one of 1-3, wherein:
所述第一电极层与第二电极层之间限定有空隙层，所述第二阻挡层限定所述空隙层的上侧边界的至少一部分。A void layer is defined between the first electrode layer and the second electrode layer, and the second barrier layer defines at least a portion of an upper boundary of the void layer.
8、根据7所述的谐振器，其中：8. The resonator according to 7, wherein:
所述压电层覆盖所述第二电极层的上侧。The piezoelectric layer covers the upper side of the second electrode layer.
9、根据7所述的谐振器，其中：9. The resonator according to 7, wherein:
所述底电极还包括第三电极层，在所述底电极的非电极连接端，所述第三电极层覆盖所述第二电极层的上侧的至少一部分、覆盖所述第一电极层的上侧的至少一部分、覆盖所述第二电极层的端面，所述第三电极层的 材料不同于所述第二电极层。The bottom electrode also includes a third electrode layer, and at the non-electrode connection end of the bottom electrode, the third electrode layer covers at least a part of the upper side of the second electrode layer, and covers a portion of the first electrode layer. At least a part of the upper side covers the end surface of the second electrode layer, and the material of the third electrode layer is different from that of the second electrode layer.
10、根据9所述的谐振器，其中：10. The resonator according to 9, wherein:
所述第三电极层的材料与所述第一电极层的材料相同，在所述底电极的非电极连接端，所述第一电极层和所述第三电极层的端面齐平。The material of the third electrode layer is the same as that of the first electrode layer, and at the non-electrode connection end of the bottom electrode, the end faces of the first electrode layer and the third electrode layer are flush.
11、根据9所述的谐振器，其中：11. The resonator according to 9, wherein:
所述第三电极层的声阻抗高于所述第二电极层的声阻抗，且所述第二电极层的导电率高于所述第三电极层的导电率。The acoustic impedance of the third electrode layer is higher than that of the second electrode layer, and the conductivity of the second electrode layer is higher than that of the third electrode layer.
12、根据9所述的谐振器，其中：12. The resonator according to 9, wherein:
在底电极的非电极连接端，所述第二电极层的端面与所述第二阻挡层的端面相接；或者At the non-electrode connection end of the bottom electrode, the end surface of the second electrode layer is in contact with the end surface of the second barrier layer; or
在底电极的非电极连接端，所述第二阻挡层的端面处于所述第二电极层的端面的内侧。At the non-electrode connection end of the bottom electrode, the end surface of the second barrier layer is inside the end surface of the second electrode layer.
13、根据1-12中任一项所述的谐振器，其中：13. The resonator according to any one of 1-12, wherein:
所述谐振器还设置有沿所述谐振器的有效区域设置的声学不匹配结构。The resonator is also provided with an acoustically mismatched structure disposed along the active area of the resonator.
14、一种根据1所述的体声波谐振器的制造方法，包括步骤：14. A method for manufacturing a bulk acoustic wave resonator according to 1, comprising the steps of:
在第一阻挡材料层上形成第一电极材料层，以及图形化所述第一电极材料层以形成第一电极层，所述第一阻挡材料层形成为第一阻挡材料层下方的基底表面的保护层。forming a first electrode material layer on the first barrier material layer, and patterning the first electrode material layer to form a first electrode layer, the first barrier material layer being formed as a surface of the substrate below the first barrier material layer The protective layer.
15、根据14所述的方法，还包括步骤：15. The method according to 14, further comprising the steps of:
在第二阻挡材料层上形成第二电极材料层，以及图形化所述第二电极材料层以形成第二电极层，所述第二阻挡材料层形成为第二阻挡材料层下方的表面的保护层。forming a second electrode material layer on the second barrier material layer, and patterning the second electrode material layer to form a second electrode layer, the second barrier material layer being formed as a protection for a surface below the second barrier material layer layer.
16、根据15所述的方法，包括步骤：16. The method according to 15, comprising the steps of:
形成覆盖所述基底的第一阻挡材料层；forming a first layer of barrier material overlying the substrate;
形成覆盖所述第一阻挡材料层的至少一部分的第一电极材料层，图形化所述第一电极材料层以形成所述第一电极层，以露出在第一电极层的非电极连接端的外侧的第一阻挡材料层；forming a first electrode material layer covering at least a part of the first barrier material layer, and patterning the first electrode material layer to form the first electrode layer so as to be exposed outside the non-electrode connection end of the first electrode layer The first layer of barrier material;
移除露出的所述第一阻挡材料层而形成所述第一阻挡层，以露出处于底电极的非电极连接端的外侧的基底表面；以及removing the exposed first barrier material layer to form the first barrier layer to expose the substrate surface outside the non-electrode connection end of the bottom electrode; and
以压电层覆盖所述第一阻挡层在第一电极层的非电极连接端的端面， 以及以压电层覆盖露出的所述基底表面的至少一部分。The end surface of the first barrier layer at the non-electrode connection end of the first electrode layer is covered with a piezoelectric layer, and at least a part of the exposed surface of the substrate is covered with a piezoelectric layer.
17、根据16所述的方法，还包括步骤：17. The method according to 16, further comprising the steps of:
在形成覆盖所述基底的第一阻挡材料层之后，形成覆盖所述第一阻挡材料层的第二阻挡材料层，第一阻挡材料层与第二阻挡材料层的材料彼此不同；After forming the first barrier material layer covering the base, forming a second barrier material layer covering the first barrier material layer, the materials of the first barrier material layer and the second barrier material layer are different from each other;
在第二阻挡材料层上形成第二电极材料层；forming a second electrode material layer on the second barrier material layer;
图形化第二电极材料层以及第二阻挡材料层，以形成第二阻挡层和第二电极层以及露出部分第一阻挡材料层；patterning the second electrode material layer and the second barrier material layer to form the second barrier layer and the second electrode layer and expose part of the first barrier material layer;
设置覆盖第二电极层以及露出的第一阻挡材料层的第一电极材料层，第二电极材料层的材料不同于第一电极材料层的材料；A first electrode material layer covering the second electrode layer and the exposed first barrier material layer is provided, and the material of the second electrode material layer is different from the material of the first electrode material layer;
图形化所述第一电极材料层，以形成所述第一电极层和在所述第一电极层的非电极连接端的外侧露出第一阻挡材料层。Patterning the first electrode material layer to form the first electrode layer and exposing the first barrier material layer outside the non-electrode connection end of the first electrode layer.
18、根据17所述的方法，其中：18. The method according to 17, wherein:
图形化第二电极材料层以及第二阻挡材料层的步骤包括：图形化第二电极材料层以形成第二电极层，以及图形化第二阻挡材料层以形成第二阻挡层，图形化第二阻挡材料层时所述第一阻挡材料层为所述第一阻挡材料层下侧的表面的保护层。The step of patterning the second electrode material layer and the second barrier material layer includes: patterning the second electrode material layer to form a second electrode layer, and patterning the second barrier material layer to form a second barrier layer, patterning the second When the barrier material layer is used, the first barrier material layer is a protective layer for the surface of the lower side of the first barrier material layer.
19、根据16或17所述的方法，其中：19. The method according to 16 or 17, wherein:
露出的所述第一阻抗材料层适于以湿法刻蚀移除。The exposed first resist material layer is suitable for removal by wet etching.
20、一种滤波器，包括根据1-13中任一项所述的体声波谐振器。20. A filter comprising the bulk acoustic wave resonator according to any one of 1-13.
21、一种电子设备，包括根据20所述的滤波器，或者根据1-13中任一项所述的体声波谐振器。21. An electronic device comprising the filter according to 20, or the bulk acoustic wave resonator according to any one of 1-13.
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。The electronic equipment here includes but is not limited to intermediate products such as RF front-ends, filter amplifier modules, and terminal products such as mobile phones, WIFI, and drones.
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。While embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by The appended claims and their equivalents are defined.

Claims (21)

  1. 一种体声波谐振器，包括：A bulk acoustic wave resonator comprising:
    基底；base;
    底电极；bottom electrode;
    顶电极；和top electrode; and
    压电层，piezoelectric layer,
    其中：in:
    所述底电极包括多个电极层，所述多个电极层至少包括在谐振器的厚度方向上设置的第一电极层和第二电极层，所述第一电极层和第二电极层的材料不同；以及The bottom electrode includes a plurality of electrode layers, the plurality of electrode layers at least include a first electrode layer and a second electrode layer arranged in the thickness direction of the resonator, and the materials of the first electrode layer and the second electrode layer different; and
    所述谐振器还包括多个阻挡层，所述多个阻挡层至少包括第一阻挡层和第二阻挡层，所述第一电极层以面接触的方式覆盖第一阻挡层的上侧的至少一部分，所述第二电极层以面接触的方式覆盖第二阻挡层的上侧的至少一部分。The resonator further includes a plurality of barrier layers, the plurality of barrier layers includes at least a first barrier layer and a second barrier layer, and the first electrode layer covers at least an upper side of the first barrier layer in a surface-contact manner. In one part, the second electrode layer covers at least a part of the upper side of the second barrier layer in surface contact.
  2. 根据权利要求1所述的谐振器，其中：The resonator of claim 1, wherein:
    在底电极的非电极连接端，所述第一电极层的端面与所述第一阻挡层的端面相接；或者At the non-electrode connection end of the bottom electrode, the end surface of the first electrode layer is in contact with the end surface of the first barrier layer; or
    在底电极的非电极连接端，所述第一阻挡层的端面处于所述第一电极层的端面的内侧。At the non-electrode connection end of the bottom electrode, the end surface of the first barrier layer is inside the end surface of the first electrode layer.
  3. 根据权利要求1所述的谐振器，其中：The resonator of claim 1, wherein:
    所述第一阻挡层的下侧与所述基底的上侧面接触；且the underside of the first barrier layer is in contact with the upper side of the substrate; and
    在所述底电极的非电极连接端，所述压电层覆盖第一阻挡层的端面和所述基底的上侧。At the non-electrode connection end of the bottom electrode, the piezoelectric layer covers the end face of the first barrier layer and the upper side of the substrate.
  4. 根据权利要求1-3中任一项所述的谐振器，其中：A resonator according to any one of claims 1-3, wherein:
    所述谐振器的声学镜设置在基底中，所述第一阻挡层设置成覆盖所述谐振器的声学镜；The acoustic mirror of the resonator is arranged in a substrate, and the first barrier layer is arranged to cover the acoustic mirror of the resonator;
    所述第二阻挡层与第一阻挡层面接触且设置在第一阻挡层的上侧，所述第二电极层设置在第一电极层与所述第二阻挡层之间，所述第一阻挡层的材料不同于所述第二阻挡层的材料；以及The second barrier layer is in contact with the first barrier layer and disposed on the upper side of the first barrier layer, the second electrode layer is disposed between the first electrode layer and the second barrier layer, and the first barrier layer the material of the layer is different from the material of said second barrier layer; and
    在所述底电极的非电极连接端，所述第一电极层覆盖第二阻挡层的端 面。At the non-electrode connection end of the bottom electrode, the first electrode layer covers the end surface of the second barrier layer.
  5. 根据权利要求4所述的谐振器，其中：The resonator according to claim 4, wherein:
    在底电极的非电极连接端，所述第二电极层的端面与所述第二阻挡层的端面相接；或者At the non-electrode connection end of the bottom electrode, the end surface of the second electrode layer is in contact with the end surface of the second barrier layer; or
    在底电极的非电极连接端，所述第二阻挡层的端面处于所述第二电极层的端面的内侧。At the non-electrode connection end of the bottom electrode, the end surface of the second barrier layer is inside the end surface of the second electrode layer.
  6. 根据权利要求4所述的谐振器，其中，所述第一电极层的声阻抗高于所述第二电极层的声阻抗，且所述第二电极层的导电率高于所述第一电极层的导电率。The resonator according to claim 4, wherein the acoustic impedance of the first electrode layer is higher than the acoustic impedance of the second electrode layer, and the conductivity of the second electrode layer is higher than that of the first electrode layer conductivity.
  7. 根据权利要求1-3中任一项所述的谐振器，其中，所述第一电极层与第二电极层之间限定有空隙层，所述第二阻挡层限定所述空隙层的上侧边界的至少一部分。The resonator according to any one of claims 1-3, wherein a void layer is defined between the first electrode layer and the second electrode layer, and the second barrier layer defines an upper side of the void layer at least part of the boundary.
  8. 根据权利要求7所述的谐振器，其中，所述压电层覆盖所述第二电极层的上侧。The resonator according to claim 7, wherein the piezoelectric layer covers an upper side of the second electrode layer.
  9. 根据权利要求7所述的谐振器，其中，所述底电极还包括第三电极层，在所述底电极的非电极连接端，所述第三电极层覆盖所述第二电极层的上侧的至少一部分、覆盖所述第一电极层的上侧的至少一部分、覆盖所述第二电极层的端面，所述第三电极层的材料不同于所述第二电极层。The resonator according to claim 7, wherein the bottom electrode further comprises a third electrode layer, and at the non-electrode connection end of the bottom electrode, the third electrode layer covers the upper side of the second electrode layer at least a part of the upper side of the first electrode layer, covering at least a part of the upper side of the first electrode layer, and the end surface of the second electrode layer, and the material of the third electrode layer is different from that of the second electrode layer.
  10. 根据权利要求9所述的谐振器，其中，所述第三电极层的材料与所述第一电极层的材料相同，在所述底电极的非电极连接端，所述第一电极层和所述第三电极层的端面齐平。The resonator according to claim 9, wherein the material of the third electrode layer is the same as that of the first electrode layer, and at the non-electrode connection end of the bottom electrode, the first electrode layer and the The end faces of the third electrode layer are flush with each other.
  11. 根据权利要求9所述的谐振器，其中，所述第三电极层的声阻抗高于所述第二电极层的声阻抗，且所述第二电极层的导电率高于所述第三电极层的导电率。The resonator according to claim 9, wherein the acoustic impedance of the third electrode layer is higher than the acoustic impedance of the second electrode layer, and the conductivity of the second electrode layer is higher than that of the third electrode layer conductivity.
  12. 根据权利要求9所述的谐振器，其中：The resonator of claim 9, wherein:
    在底电极的非电极连接端，所述第二电极层的端面与所述第二阻挡层的端面相接；或者At the non-electrode connection end of the bottom electrode, the end surface of the second electrode layer is in contact with the end surface of the second barrier layer; or
    在底电极的非电极连接端，所述第二阻挡层的端面处于所述第二电极层的端面的内侧。At the non-electrode connection end of the bottom electrode, the end surface of the second barrier layer is inside the end surface of the second electrode layer.
  13. 根据权利要求1-12中任一项所述的谐振器，其中，所述谐振器还设置有沿所述谐振器的有效区域设置的声学不匹配结构。The resonator according to any one of claims 1-12, wherein the resonator is further provided with an acoustically mismatched structure arranged along an active area of the resonator.
  14. 一种根据权利要求1所述的体声波谐振器的制造方法，包括：A method of manufacturing a bulk acoustic wave resonator according to claim 1, comprising:
    在第一阻挡材料层上形成第一电极材料层，以及图形化所述第一电极材料层以形成第一电极层，所述第一阻挡材料层形成为第一阻挡材料层下方的基底表面的保护层。forming a first electrode material layer on the first barrier material layer, and patterning the first electrode material layer to form a first electrode layer, the first barrier material layer being formed as a surface of the substrate below the first barrier material layer The protective layer.
  15. 根据权利要求14所述的方法，还包括：The method of claim 14, further comprising:
    在第二阻挡材料层上形成第二电极材料层，以及图形化所述第二电极材料层以形成第二电极层，所述第二阻挡材料层形成为第二阻挡材料层下方的表面的保护层。forming a second electrode material layer on the second barrier material layer, and patterning the second electrode material layer to form a second electrode layer, the second barrier material layer being formed as a protection for a surface below the second barrier material layer layer.
  16. 根据权利要求15所述的方法，还包括：The method of claim 15, further comprising:
    形成覆盖所述基底的第一阻挡材料层；forming a first layer of barrier material overlying the substrate;
    形成覆盖所述第一阻挡材料层的至少一部分的第一电极材料层，图形化所述第一电极材料层以形成所述第一电极层，以露出在第一电极层的非电极连接端的外侧的第一阻挡材料层；forming a first electrode material layer covering at least a part of the first barrier material layer, and patterning the first electrode material layer to form the first electrode layer so as to be exposed outside the non-electrode connection end of the first electrode layer The first layer of barrier material;
    移除露出的所述第一阻挡材料层而形成所述第一阻挡层，以露出处于底电极的非电极连接端的外侧的基底表面；以及removing the exposed first barrier material layer to form the first barrier layer to expose the substrate surface outside the non-electrode connection end of the bottom electrode; and
    以压电层覆盖所述第一阻挡层在第一电极层的非电极连接端的端面，以及以压电层覆盖露出的所述基底表面的至少一部分。The end face of the first barrier layer at the non-electrode connection end of the first electrode layer is covered with a piezoelectric layer, and at least a part of the exposed surface of the substrate is covered with a piezoelectric layer.
  17. 根据权利要求16所述的方法，还包括：The method of claim 16, further comprising:
    在形成覆盖所述基底的第一阻挡材料层之后，形成覆盖所述第一阻挡材料层的第二阻挡材料层，第一阻挡材料层与第二阻挡材料层的材料彼此不同；After forming the first barrier material layer covering the base, forming a second barrier material layer covering the first barrier material layer, the materials of the first barrier material layer and the second barrier material layer are different from each other;
    在第二阻挡材料层上形成第二电极材料层；forming a second electrode material layer on the second barrier material layer;
    图形化第二电极材料层以及第二阻挡材料层，以形成第二阻挡层和第二电极层以及露出部分第一阻挡材料层；patterning the second electrode material layer and the second barrier material layer to form the second barrier layer and the second electrode layer and expose part of the first barrier material layer;
    设置覆盖第二电极层以及露出的第一阻挡材料层的第一电极材料层，第二电极材料层的材料不同于第一电极材料层的材料；和providing a first electrode material layer covering the second electrode layer and the exposed first barrier material layer, the material of the second electrode material layer being different from the material of the first electrode material layer; and
    图形化所述第一电极材料层，以形成所述第一电极层和在所述第一电极层的非电极连接端的外侧露出第一阻挡材料层。Patterning the first electrode material layer to form the first electrode layer and exposing the first barrier material layer outside the non-electrode connection end of the first electrode layer.
  18. 根据权利要求17所述的方法，其中，所述图形化第二电极材料层以及第二阻挡材料层的步骤包括：The method according to claim 17, wherein the step of patterning the second electrode material layer and the second barrier material layer comprises:
    图形化第二电极材料层以形成第二电极层，以及图形化第二阻挡材料层 以形成第二阻挡层，图形化第二阻挡材料层时所述第一阻挡材料层为所述第一阻挡材料层下侧的表面的保护层。patterning the second electrode material layer to form a second electrode layer, and patterning the second barrier material layer to form a second barrier layer, the first barrier material layer is the first barrier material layer when patterning the second barrier material layer A protective layer for the surface of the underside of the material layer.
  19. 根据权利要求16或17所述的方法，其中，露出的所述第一阻抗材料层适于以湿法刻蚀移除。The method according to claim 16 or 17, wherein the exposed first resistive material layer is suitable for removal by wet etching.
  20. 一种滤波器，包括根据权利要求1-13中任一项所述的体声波谐振器。A filter comprising the bulk acoustic wave resonator according to any one of claims 1-13.
  21. 一种电子设备，包括根据权利要求20所述的滤波器，或者根据权利要求1-13中任一项所述的体声波谐振器。An electronic device, comprising the filter according to claim 20, or the bulk acoustic wave resonator according to any one of claims 1-13.
PCT/CN2022/109099 2021-07-29 2022-07-29 Film bulk acoustic resonator having multiple bottom electrode layers, filter, and electronic device WO2023006089A1 (en)

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US20180034438A1 (en) * 2016-07-27 2018-02-01 Qorvo Us, Inc. Acoustic resonator devices and methods with noble metal layer for functionalization
US20190326880A1 (en) * 2018-04-19 2019-10-24 Avago Technologies General Ip (Singapore) Pte. Ltd. Bulk acoustic wave resonators having doped piezoelectric material and an adhesion and diffusion barrier layer
CN111010133A (en) * 2019-09-03 2020-04-14 天津大学 Bulk acoustic wave resonator, method of manufacturing the same, filter, and electronic apparatus

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CN106899275A (en) * 2015-12-18 2017-06-27 三星电机株式会社 Acoustic resonator and its manufacture method
US20180034438A1 (en) * 2016-07-27 2018-02-01 Qorvo Us, Inc. Acoustic resonator devices and methods with noble metal layer for functionalization
US20190326880A1 (en) * 2018-04-19 2019-10-24 Avago Technologies General Ip (Singapore) Pte. Ltd. Bulk acoustic wave resonators having doped piezoelectric material and an adhesion and diffusion barrier layer
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