WO2022179479A1 - 一种mems器件及其制作方法 - Google Patents

一种mems器件及其制作方法 Download PDF

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Publication number
WO2022179479A1
WO2022179479A1 PCT/CN2022/077173 CN2022077173W WO2022179479A1 WO 2022179479 A1 WO2022179479 A1 WO 2022179479A1 CN 2022077173 W CN2022077173 W CN 2022077173W WO 2022179479 A1 WO2022179479 A1 WO 2022179479A1
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WO
WIPO (PCT)
Prior art keywords
acoustic wave
wave filter
layer
surface acoustic
cavity
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PCT/CN2022/077173
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English (en)
French (fr)
Inventor
黄河
罗海龙
李伟
Original Assignee
中芯集成电路（宁波）有限公司上海分公司
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Publication of WO2022179479A1 publication Critical patent/WO2022179479A1/zh
Priority to US18/211,049 priority Critical patent/US20230336157A1/en

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/0032—Packages or encapsulation
    • B81B7/0035—Packages or encapsulation for maintaining a controlled atmosphere inside of the chamber containing the MEMS
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/0032—Packages or encapsulation
    • B81B7/007—Interconnections between the MEMS and external electrical signals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
    • B81C1/00261—Processes for packaging MEMS devices
    • B81C1/00277—Processes for packaging MEMS devices for maintaining a controlled atmosphere inside of the cavity containing the MEMS
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
    • B81C1/00261—Processes for packaging MEMS devices
    • B81C1/00301—Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
    • 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
    • H03H3/08—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 resonators or networks using surface acoustic waves
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/0538—Constructional combinations of supports or holders with electromechanical or other electronic elements
    • H03H9/0547—Constructional combinations of supports or holders with electromechanical or other electronic elements consisting of a vertical arrangement
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/25—Constructional features of resonators using surface acoustic waves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2201/00—Specific applications of microelectromechanical systems
    • B81B2201/02—Sensors
    • B81B2201/0257—Microphones or microspeakers
    • 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
    • H03H2003/0071—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks of bulk acoustic wave and surface acoustic wave elements in the same process

Definitions

  • the invention relates to the field of MEMS device manufacturing, in particular to a MEMS device and a manufacturing method thereof.
  • Micro-Electro-Mechanical System MEMS
  • integrated circuit IC
  • monolithic integration refers to the fabrication of MEMS structure and CMOS on one chip
  • hybrid integration refers to the fabrication of MEMS and IC on the same chip.
  • the MEMS bare chips with bumps are connected to the IC chip in the form of flip-chip bonding or wire bonding to form SIP; semi-hybrid is to use three-dimensional integration technology to realize MEMS The three-dimensional integration of chips and CMOS; monolithic integration is an important development direction of MEMS and IC integration technology, especially for RF RF thin-film bulk acoustic wave filters.
  • Transceiver can achieve higher precision; secondly, the integrated system is reduced in size and low in power consumption; thirdly, the number of components is reduced, the number of package pins is reduced, and the reliability is high.
  • the currently produced MEMS devices have problems such as single frequency band, low integration and complicated production process, which cannot meet the requirements of high-performance radio frequency systems.
  • the purpose of the present invention is to provide a MEMS device and a manufacturing method thereof, which can solve the technical problems of single frequency band, low integration and complicated manufacturing process of the manufactured MEMS device.
  • the present invention provides a MEMS device, comprising: a surface acoustic wave filter, the surface acoustic wave filter includes an interdigital transducer; a first structure layer, the first structure layer is located in the Above the surface acoustic wave filter; the bulk acoustic wave filter, the bulk acoustic wave filter is located above the first structural layer; the bulk acoustic wave filter includes a carrier substrate, which is located on the surface of the carrier substrate for acoustic reflection structure, and a piezoelectric laminated structure on the acoustic reflection structure, the piezoelectric laminated structure includes a first electrode, a piezoelectric layer and a second electrode stacked in sequence; the first structure layer has a first cavity, so The effective resonance region of the piezoelectric laminated structure and the interdigital transducer of the surface acoustic wave filter cover the first cavity.
  • the present invention also provides a method for manufacturing a MEMS device, including: providing a surface acoustic wave filter, the surface acoustic wave filter comprising an interdigital transducer; providing a bulk acoustic wave filter, the bulk acoustic wave filter comprising: A carrier substrate, a support layer formed on the surface of the carrier substrate, and a piezoelectric laminate structure enclosing a second cavity with the carrier substrate and the support layer; the bulk acoustic wave filter is bonded through the first structural layer combined on the surface acoustic wave filter and form a first cavity with the surface acoustic wave filter; the effective resonance region of the piezoelectric laminated structure and the interdigital transducer of the surface acoustic wave filter cover the first cavity.
  • the beneficial effect of the structure of the present invention is that: by providing the first structural layer of the first cavity between the surface acoustic wave filter and the bulk acoustic wave filter, the effective resonance area of the piezoelectric laminated structure of the bulk acoustic wave filter and the The interdigital transducers of the surface acoustic wave filter cover the first cavity together, realize vertical integration, reduce the package volume of the whole system, realize miniaturization, and greatly improve the integration degree; not only retain the high frequency and low insertion of the bulk acoustic wave filter In addition, the process cost is reduced to meet the requirement of multiple frequency bands; the effective resonance region of the piezoelectric laminated structure is located in the first cavity, which effectively improves the quality factor of the bulk acoustic wave filter.
  • the electrical connection structure with the bulk acoustic wave filter and the surface acoustic wave filter respectively, the electrical connection with the external circuit is realized, the mutual interference between the signals of the surface acoustic wave filter and the bulk acoustic wave filter is avoided, and the improvement is improved. MEMS device performance.
  • the effective resonance region of the bulk acoustic wave filter is defined by the first groove and the second groove, the first groove and the second groove respectively penetrate the first electrode and the second electrode, and the piezoelectric layer maintains a complete film.
  • the layer is not etched, which ensures the structural strength of the bulk acoustic wave filter and improves the yield of the bulk acoustic wave filter.
  • the bulk acoustic wave filter is bonded to the surface acoustic wave filter through a bonding process and forms a first cavity with the surface acoustic wave filter;
  • the piezoelectric stack The effective resonance region of the layer structure and the interdigital transducer of the surface acoustic wave filter cover the first cavity, so that the functional regions of the surface acoustic wave filter and the bulk acoustic wave filter share a cavity, and vertical integration is realized , reduces the package volume of the entire system, realizes miniaturization, and greatly improves the integration; not only retains the advantages of high frequency and low insertion loss of the bulk acoustic wave filter, simplifies the manufacturing process, but also reduces the production cost; the piezoelectric laminated structure The effective resonance region is located in the first cavity, so that the upper and lower parts of the effective resonance region are completely in the air, which effectively improves the quality factor of the bulk acoustic wave filter.
  • At least one of the surface acoustic wave filter and the bulk acoustic wave filter is a wafer, and the subsequent processes such as bonding process and electrical connection are completed on the wafer size, realizing the simultaneous production of different...
  • the demand for frequency band filters reduces the difficulty of the process and greatly increases the output.
  • the first structural layer is a photolithographic organic cured film, which can alleviate the bonding stress between the surface acoustic wave filter and the bulk acoustic wave filter, and the bonding reliability with the surface acoustic wave filter and the bulk acoustic wave filter is reliable. High, the first cavity lithography can be obtained, and the damage to the filter surface is low.
  • forming a passivation layer on the surface acoustic wave filter can improve the dustproof, waterproof and anti-corrosion effects of the surface acoustic wave filter.
  • FIGS. 1 is a schematic structural diagram of a MEMS device provided by an embodiment of the present invention
  • FIGS. 2 to 6 are schematic structural diagrams corresponding to different steps in a manufacturing method of a MEMS device provided by an embodiment of the present invention
  • FIGS. 7 to 10 are Schematic diagrams of structures corresponding to different steps in the method for fabricating a MEMS device provided by an embodiment of the present invention
  • FIGS. 11 to 12 are schematic diagrams of structures corresponding to different steps in the method for fabricating a MEMS device provided by an embodiment of the present invention.
  • the substrate material of the surface acoustic wave filter is lithium niobate or lithium tantalate.
  • the material properties and thermal expansion coefficient are different from those of ordinary substrates, which are easy to break and difficult to combine with the commonly used silicon wafer manufacturing process. Therefore, it is not easy to integrate the surface acoustic wave filter with the bulk acoustic wave filter wafer-level process in the prior art; in addition, due to the process and device characteristics of the bulk acoustic wave filter, it is relatively difficult to realize the fabrication of multiple frequency bands on one wafer.
  • Embodiment 1 provides a MEMS device, and FIG. 1 shows a schematic structural diagram of a MEMS device in Embodiment 1.
  • the MEMS device includes: a surface acoustic wave filter, the surface acoustic wave
  • the wave filter includes an interdigital transducer 11; a first structural layer 13, the first structural layer 13 is located above the surface acoustic wave filter; a bulk acoustic wave filter, the bulk acoustic wave filter is located on the first Above a structural layer 13;
  • the bulk acoustic wave filter includes a carrier substrate 100, an acoustic reflection structure (not shown in the figure) located on the surface of the carrier substrate 100, and a piezoelectric laminated structure on the acoustic reflection structure
  • the piezoelectric stack structure includes a first electrode 102, a piezoelectric layer 103 and a second electrode 104 stacked in sequence; the first structure layer 13 has a first cavity 120a, and the piezoelectric stack structure
  • the BAW filter can also be a thin-film BAW resonator or a solid-state assembled resonator.
  • the acoustic reflection structure can be a BAW filter or a thin-film BAW resonator.
  • the acoustic reflection structure includes a Bragg reflection
  • the layer is formed, it can be a solid-state assembled resonator.
  • a bulk acoustic wave filter is used as an example to describe the present invention in detail.
  • the first cavity 120a may be formed by etching the first structure layer 13 through an etching process.
  • the technology of the present invention is not limited only to this. It should be noted that there is a bonding interface between the first structural layer 13 and the bulk acoustic wave filter, the first structural layer 13 is bonded and connected to the bulk acoustic wave filter through the bonding interface, and the first structural layer 13 is passed through a bonding process.
  • the bulk acoustic wave filter is bonded to the first structural layer 13 on the surface acoustic wave filter and forms a first cavity 120a with the surface acoustic wave filter, and the bulk acoustic wave filter is realized in the device manufacturing stage
  • the vertical integration with the SAW filter eliminates the back-end system-level packaging process, simplifies the manufacturing process, reduces the packaging volume of the entire system, and greatly improves the integration; the bonding methods include: metal bonding, covalent bonding Bonding, adhesive bonding or fusion bonding.
  • the first structural layer and the filter are bonded through a bonding layer, and the material of the bonding layer includes a photolithographic organic cured film, silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride or ethyl silicate or Metal.
  • the first structural layer 13 may also be located on the bulk acoustic wave filter, and there is a bonding interface between the first structural layer 13 and the surface acoustic wave filter, and the first structural layer 13 communicates with the acoustic wave through the bonding interface.
  • the surface wave filter is bonded and connected to realize the bonded connection of the bulk acoustic wave filter and the surface acoustic wave filter.
  • the shape of the bottom surface of the first cavity 120a is a rectangle, but in other embodiments, the shape of the first cavity 120a may also be a circle, an ellipse, or a polygon other than a rectangle, such as a pentagon , hexagon, etc.
  • the effective resonance region of the piezoelectric laminated structure and the The interdigital transducers 11 jointly cover the first cavity 120a, realize vertical integration, reduce the package volume of the entire system, realize miniaturization, and greatly improve the integration degree; not only the advantages of high frequency and low insertion loss of the bulk acoustic wave filter are retained, The process cost is also reduced to meet the requirement of multiple frequency bands; the effective resonance region of the piezoelectric laminated structure is located in the first cavity 120a, which effectively improves the quality factor of the bulk acoustic wave filter.
  • the effective resonance region of the piezoelectric laminated structure and the interdigital transducer 11 of the surface acoustic wave filter jointly cover the first cavity 120a, for example, the effective resonance region and the interdigital transducer 11 face the first cavity 120a, and cover the first cavity 120a respectively.
  • the first cavity 120a, or at least one of the first cavity 120a protrudes into the interior of the first cavity 120a.
  • the first cavity 120a penetrates through the first structural layer 13; the first structural layer 13 includes a photolithographic organic curable film or an oxide layer.
  • the first structural layer 13 is a photolithographic organic curing film, which has single-sided or double-sided adhesiveness, a film-like material or a liquid material, which can be photoetched and cured, and has an elastic modulus Relatively small, it can relieve the bonding stress between the surface acoustic wave filter and the bulk acoustic wave filter, and the bonding reliability with the surface acoustic wave filter and the bulk acoustic wave filter is high.
  • the first structural layer 13 is obtained by photolithography.
  • the cavity 120a has less damage to the surface of the filter and further improves the quality factor of the device.
  • the thickness of the first structural layer 13 ranges from 5 ⁇ m to 50 ⁇ m.
  • the surface acoustic wave filter is subsequently bonded to the bulk acoustic wave filter, and needs to reach a certain thickness, and the first isolation groove is subsequently formed on the first structural layer 13 . It also needs to have a certain depth. Therefore, in this embodiment, by limiting the thickness range of the first structural layer 13 to 5 ⁇ 50um, it can meet the bonding conditions of the surface acoustic wave filter and the subsequent bulk acoustic wave filter and save energy. cost. In other embodiments, the thickness range of the first structural layer 13 may also be higher or lower than this range.
  • a passivation layer 12 is provided between the first structural layer 13 and the surface acoustic wave filter.
  • the passivation layer 12 By disposing the passivation layer 12 on the surface acoustic wave filter, the surface acoustic wave filter can be activated. To protect, improve the structural strength and device performance of the surface acoustic wave filter.
  • the passivation layer 12 includes an oxide layer 121 and an etch stop layer 122, the oxide layer 121 is located on the upper surface of the surface acoustic wave filter, and the etch stop layer 122 is located on the oxide layer 121, so
  • the material of the oxide layer 121 is at least one of any insulating materials such as silicon oxide, silicon oxynitride, and silicon nitride. and waterproofing.
  • An etch stop layer 122 is provided on the oxide layer 121.
  • the material of the etch stop layer 122 includes but is not limited to silicon nitride and silicon oxynitride. In this embodiment, it is silicon nitride.
  • the strength can improve the waterproof and anti-corrosion effect of the surface acoustic wave filter.
  • the etch stop layer 122 can be used to increase the structural stability of the final fabricated filter, and on the other hand, the etch stop layer 122 has a lower etching rate compared with the photolithographic organic cured film, During the process of etching the organic cured film to form the first cavity 110a, over-etching can be prevented, and the surface of the structure located thereunder is protected from damage, thereby improving device performance and reliability.
  • the passivation layer 12 may only include one of the oxide layer 121 and the etch stop layer 122, or the passivation layer 12 may also have other structures, which are not limited here.
  • the surface acoustic wave filter further includes a carrier substrate 10 and a dielectric layer 20 on the carrier substrate 10 .
  • the surface acoustic wave filter is formed by evaporating a layer of metal film on a material substrate with piezoelectric effect, and then by photolithography, a pair of interdigitated electrodes are formed at each end; the surface acoustic wave filter It has the advantages of high working efficiency, wide frequency bandwidth, good frequency selection characteristics, small size and light weight, and can adopt the same production process as integrated circuits, with simple manufacturing and low cost.
  • the carrier substrate 10 has opposite first and second surfaces, the dielectric layer 20 is located on the first surface of the carrier substrate 10 , and the interdigital transducer 11 is located in the dielectric layer 20 on the first surface of the carrier substrate 10 .
  • the interdigital transducer 11 includes a transmitting transducer and a receiving transducer. When a signal voltage is applied to the transmitting transducer, an electric field is formed between the input interdigital electrodes to cause the piezoelectric material to mechanically vibrate to generate ultrasonic waves. The form propagates to both sides, and the receiving transducer converts the mechanical vibration into electrical signals, which are output by the output interdigital electrodes.
  • the bulk acoustic wave filter is located above the first structural layer 13; the bulk acoustic wave filter includes a carrier substrate 100, a support layer 101 on the surface of the carrier substrate 100, and the The carrier substrate 100 and the support layer 101 form a piezoelectric laminate structure in which the second cavity 110a is enclosed.
  • the projections of the first cavity 120a and the second cavity 110a on the piezoelectric laminate structure at least partially overlap, so that both the upper and lower sides of the effective resonance region of the piezoelectric laminate structure are in the air, which can further improve the bulk acoustic wave filtering. quality factor of the device.
  • the carrier substrate 100 may be at least one of the following mentioned materials: silicon (Si), germanium (Ge), silicon germanium (SiGe), silicon carbon (SiC), silicon germanium carbon (SiGeC), indium arsenide (InAs), gallium arsenide (GaAs), indium phosphide (InP) or other III/V compound semiconductors, also including multilayer structures composed of these semiconductors, etc., and can also be ceramic substrates such as alumina, quartz or glass substrates Wait.
  • the support layer 101 is bonded to the carrier substrate 100 , and forms a second cavity 110 a with the piezoelectric stacked structure, and the second cavity 110 a exposes the carrier substrate 100 .
  • the second cavity 110a is an annular closed cavity, and the second cavity 110a can be formed by etching the support layer through an etching process.
  • the technology of the present invention is not limited only to this. It should be noted that, the support layer 101 is combined with the carrier substrate 100 by bonding, and the bonding method includes metal bonding, covalent bonding, adhesive bonding or fusion bonding.
  • the support layer 101 and the carrier substrate 100 are bonded through a bonding layer, and the material of the bonding layer includes silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride or ethyl silicate.
  • the shape of the bottom surface of the second cavity 110a is a rectangle, but in other embodiments of the present invention, the shape of the bottom surface of the second cavity 110a on the bottom surface of the first electrode 102 may also be a circle, an ellipse, or a Polygons other than rectangles, such as pentagons, hexagons, etc.
  • the material of the support layer 101 may be any suitable dielectric material, including but not limited to one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride and other materials.
  • the material of the support layer 101 and the bonding layer may be the same.
  • a piezoelectric laminated structure is disposed above the second cavity 110a, and the piezoelectric laminated structure includes a first electrode 102, a piezoelectric layer 103 and a second electrode 104 in sequence.
  • the first electrode 102 is located on the support layer 101
  • the piezoelectric layer 103 is located on the first electrode 102
  • the second electrode 104 is located on the piezoelectric layer 103 .
  • the piezoelectric layer 103 covers the second cavity 110a, and covering the second cavity 110a should be understood as the piezoelectric layer 103 is a complete film layer without being etched. It does not mean that the piezoelectric layer 103 completely covers the second cavity 110a to form a sealed cavity. Of course, the piezoelectric layer 103 can completely cover the second cavity 110a to form a sealed cavity.
  • the piezoelectric layer 103 can ensure that the piezoelectric layered structure has a certain thickness without being etched, so that the bulk acoustic wave filter has a certain structural strength. Improve the yield of making bulk acoustic wave filters.
  • an etch stop layer is further disposed between the support layer 101 and the first electrode 102 , and its material includes but not limited to silicon nitride (Si3N4) and silicon oxynitride (SiON).
  • the etch stop layer can be used to increase the structural stability of the final manufactured bulk acoustic wave resonator; 101 prevents over-etching in the process of forming the second cavity 110a, and protects the surface of the first electrode 102 located thereunder from damage, thereby improving device performance and reliability.
  • the surface of the piezoelectric laminate structure further includes a first trench 105 and a second trench 106 , and the first trench 105 is located on the lower surface of the piezoelectric laminate structure and on the side where the second cavity 110a is located. bottom of the first electrode 102 .
  • the second trench 106 is located on the upper surface of the piezoelectric stacked structure and penetrates through the second electrode 104 .
  • the two ends of the first trench 105 and the two ends of the second trench 106 are disposed opposite to each other, so that the projections of the first trench 105 and the second trench 106 on the carrier substrate 100 are opposite to each other.
  • the two junctions meet or have a gap.
  • the projection of the first trench 105 and the second trench 106 on the carrier substrate 100 is a closed pattern.
  • the first electrode 102 , the piezoelectric layer 103 and the second electrode 104 above the second cavity 120 a are provided with overlapping regions in the direction perpendicular to the carrier substrate 100 and located between the first trench 105 and the second trench 106 The overlapping area between them is the effective resonance area.
  • the effective resonance area of the BAW filter is defined by the first groove 105 and the second groove 106.
  • the first groove 105 and the second groove 106 respectively penetrate the first electrode 102 and
  • the second electrode 104 and the piezoelectric layer 103 are kept intact without being etched, which ensures the structural strength of the bulk acoustic wave filter and improves the yield of the bulk acoustic wave filter.
  • the SAW filter is electrically connected to an external circuit through the first electrical connection structure 14 and the fourth electrical connection structure 17
  • the bulk acoustic wave filter is electrically connected to the external circuit through the second electrical connection structure 15 and the third electrical connection structure 17
  • the connection structure 16 is electrically connected to an external circuit.
  • the electrical connection structure is formed by the bulk acoustic wave filter and the surface acoustic wave filter respectively, so as to realize the electrical connection with the external circuit, avoid the mutual interference between the signals of the surface acoustic wave filter and the bulk acoustic wave filter, and improve the performance of the MEMS device. performance.
  • the first electrical connection structure 14 includes a first interconnection hole (not shown in the figure) and a first conductive interconnection layer 141 located in the first interconnection hole, and the first interconnection hole extends from the first interconnection hole.
  • One side of the carrier substrate 100 penetrates and extends to the interdigital transducer 11 of the surface acoustic wave filter;
  • the second electrical connection structure 15 includes a second interconnection hole (not shown in the figure) and is located on the surface of the surface acoustic wave filter.
  • the second conductive interconnection layer 151 in the second interconnection hole, the second interconnection hole penetrates from one side of the carrier substrate 100 and extends to all the outside of the effective resonance region of the piezoelectric stack structure. on the first electrode 102.
  • the carrier substrate 100 is provided with interconnect lines 18 , the first conductive interconnect layer 141 includes a first plug, the second conductive interconnect layer 151 includes a second plug, and the first plug and the second plug is electrically connected to the interconnection line 18 .
  • the input end and the output end of the interdigital transducer 11 are provided with interdigital electrodes, and the first electrical connection structure is used to introduce electrical signals into the input end of the interdigital transducer.
  • an electrical signal is input to the input end of the transducer, under the action of the alternating electric field of the input electrical signal, mechanical vibration is excited on the surface of the substrate of the interdigital transducer due to the piezoelectric effect of the crystal, forming a surface acoustic wave.
  • the electrical connection structure is used to connect the output end of the interdigital transducer.
  • the surface acoustic wave formed at the input end propagates along the surface of the substrate to the interdigital electrode at the output end.
  • the electric field is changed by mechanical vibration.
  • Output electrical signal; the second electrical connection structure is used to introduce the electrical signal into the second electrode of the effective resonant area, the third electrical connection structure is used to introduce the electrical signal into the first electrode of the effective resonant area, the first electrode 103 and the second electrode
  • a pressure difference is generated on the upper and lower surfaces of the piezoelectric layer 104 to form a standing wave oscillation.
  • the first electrical connection structure 14 includes: a first interconnection hole, and the first interconnection hole penetrates from one side of the carrier substrate 100 and extend to the interdigital transducer 11 of the surface acoustic wave filter; the first conductive interconnection layer 141 covers the inner surface of the first interconnection hole, and the interconnection on the surface of the carrier substrate 100 The wiring 18 is electrically connected; the second electrical connection structure 15 includes: a second interconnection hole, the second interconnection hole penetrates from one side of the carrier substrate 100 and extends to the side of the piezoelectric stack structure on the first electrode 102 outside the effective resonance region and exposing the first electrode 102; a second conductive interconnection layer 151, covering the inner surface of the second interconnection hole, and located on the carrier substrate 100 The interconnect lines 18 on the surface are electrically connected.
  • the second electrical connection structure 15 is not directly electrically connected to the second electrode 104, but is connected to the first electrode 102 outside the effective resonant region.
  • the second electrode 104 in the resonance area is electrically connected, and the third electrical connection structure 16 is electrically connected with the first electrode 102 inside the effective resonance area to supply power to the first electrode 102 inside the effective resonance area; it can be seen that the first electrical connection structure 14 and the fourth electrical connection structure 17 are the same in structure, but the location is different.
  • the second electrical connection structure 15 and the third electrical connection structure 16 are also the same in structure, but the location is different, and will not be repeated here.
  • the structure of the three electrical connection structures 16 and the fourth electrical connection structure 17 are not directly electrically connected to the second electrode 104, but is connected to the first electrode 102 outside the effective resonant region.
  • the second electrode 104 in the resonance area is electrically connected
  • the third electrical connection structure 16 is electrically connected with the first electrode 102 inside the effective resonance area to supply power to the first electrode 102 inside the effective
  • the MEMS device further includes: an insulating layer covering the interconnection lines 18 and the surface of the carrier substrate 100 ; conductive bumps 19 disposed on the surface of the carrier substrate 100 , and the surface of the carrier substrate 100 .
  • the interconnection lines 18 are electrically connected.
  • Embodiment 2 of the present invention provides a method for manufacturing a MEMS device, including the following steps: S01: providing a surface acoustic wave filter, the surface acoustic wave filter comprising an interdigital transducer; S02: providing a bulk acoustic wave filter, The bulk acoustic wave filter includes: a carrier substrate, a support layer formed on the surface of the carrier substrate, and a piezoelectric laminated structure that forms a second cavity with the carrier substrate and the support layer; S03: the The bulk acoustic wave filter is bonded to the surface acoustic wave filter through the first structural layer and forms a first cavity with the surface acoustic wave filter; S04: the effective resonance area of the piezoelectric laminated structure and all The interdigital transducer of the surface acoustic wave filter covers the first cavity.
  • Step S0N does not represent a sequential order.
  • FIGS. 2 to 12 are structural schematic diagrams corresponding to corresponding steps of the method for fabricating the MEMS device of the present embodiment, and referring to FIGS. 2 to 12 , the fabrication method of the MEMS device provided by the present embodiment is described in detail.
  • a surface acoustic wave filter is provided.
  • the forming process of the surface acoustic wave filter includes: providing a carrier substrate 10; forming an interdigital transducer 11 on the carrier substrate 10; forming a dielectric layer 20 on the first surface of the carrier substrate 10, the The dielectric layer 20 covers the first surface of the carrier substrate 10 and the interdigital transducer 11; the carrier substrate 10 includes opposite first and second surfaces, and the interdigital transducer 11 is formed on the The first surface of the carrier substrate 10 is described.
  • a passivation layer 12 is formed on the surface acoustic wave filter.
  • the specific process of forming the passivation layer 12 includes: referring to FIG. 3 , forming an oxide layer 121 on the dielectric layer 20 .
  • an etch stop layer 122 is formed on the oxide layer 121 , and the etch stop layer 122 and the oxide layer 121 constitute the passivation layer 12 .
  • the material and function of the etch stop layer 122 can be referred to in the foregoing Embodiment 1, and will not be repeated here.
  • a first structural layer 13 is formed on the passivation layer 12 .
  • the first structural layer 13 is a photolithographic organic cured film, and the function of the organic cured film is the same as that in the foregoing embodiment 1.
  • the first structural layer 13 is not formed on the passivation layer 12, but can be formed on the piezoelectric laminated structure of the bulk acoustic wave filter.
  • the specific forming process please refer to FIGS. 7 to 7 below. 10. I will not describe too much here.
  • the first structure layer 13 is etched to form a first isolation trench 120a', so that the interdigital transducer 11 is opposite to the first isolation trench 120a'.
  • a bulk acoustic wave filter includes: a carrier substrate, a support layer formed on the surface of the carrier substrate, and the carrier substrate and the support layer enclose a second Cavity piezoelectric laminate structure.
  • the bulk acoustic wave filter includes: a carrier substrate, a support layer formed on the surface of the carrier substrate, and the carrier substrate and the support layer enclose a second Cavity piezoelectric laminate structure.
  • a temporary substrate 200 is provided.
  • the temporary substrate 200 may be any suitable substrate known to those skilled in the art, and may be at least one of the following materials: silicon (Si), germanium (Ge), silicon germanium (SiGe), arsenide Indium (Ins), indium phosphide (InP) or other III/V compound semiconductors, also including multilayer structures composed of these semiconductors, or silicon-on-insulator (SOI), silicon-on-insulator (SSOI), on-insulator Laminated silicon germanium (S-SiGeOI), silicon germanium on insulator (SiGeOI) and germanium on insulator (GeOI), or double-sided polished silicon wafers (DSP), aluminum oxide, etc. of ceramic substrates, quartz or glass substrates, etc.
  • the temporary substrate 200 is a P-type high-resistance single crystal silicon wafer with a ⁇ 100> crystal orientation.
  • the second electrode layer 104 ′, the piezoelectric layer 103 and the first electrode 102 are sequentially formed on the temporary substrate 200 .
  • the material of the second electrode layer 104' and the first electrode 102 can be any suitable conductive material or semiconductor material known to those skilled in the art, wherein the conductive material can be a metal material with conductive properties, for example, made of molybdenum (Mo) , Aluminum (Al), Copper (Cu), Tungsten (W), Tantalum (Ta), Platinum (Pt), Ruthenium (Ru), Rhodium (Rh), Iridium (Ir), Chromium (Cr), Titanium (Ti) , gold (Au), osmium (Os), rhenium (Re), palladium (Pd) and other metals, or a laminate of the above metals, semiconductor materials such as Si, Ge, SiGe, SiC, SiGeC et al.
  • the second electrode layer 104' and the first electrode 102 may be formed by physical vapor deposition such as magnetron sputtering, evaporation, or chemical vapor deposition.
  • the piezoelectric layer 103 can be made of aluminum nitride (AlN), zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO3), quartz (Quartz), potassium niobate (KNbO3) or tantalic acid Piezoelectric materials having a wurtzite crystal structure, such as lithium (LiTaO3), and combinations thereof.
  • the piezoelectric layer 103 may further include a rare earth metal such as at least one of scandium (Sc), erbium (Er), yttrium (Y), and lanthanum (La).
  • the piezoelectric layer may further include a transition metal such as at least one of zirconium (Zr), titanium (Ti), manganese (Mn), and hafnium (Hf).
  • the piezoelectric layer 103 may be deposited using any suitable method known to those skilled in the art, such as chemical vapor deposition, physical vapor deposition, or atomic layer deposition.
  • the second electrode layer 104' and the first electrode 102 are made of metal molybdenum (Mo)
  • the piezoelectric layer 103 is made of aluminum nitride (AlN).
  • the first trench 105 is formed through the first electrode 102 by etching the first electrode 102 .
  • the first trench 105 is located in the subsequently formed first cavity 120a, and the sidewall of the first trench 105 may be inclined or vertical.
  • the sidewall of the first trench 105 forms a right angle with the plane where the piezoelectric layer 103 is located (the longitudinal section (section along the film thickness direction) of the first trench 105 is rectangular).
  • the sidewall of the first trench 105 and the plane where the piezoelectric layer 103 is located form an obtuse angle.
  • the projection of the first groove 105 on the plane where the piezoelectric layer 103 is located is a half-ring or a polygon similar to a half-ring.
  • a carrier substrate 100 including a second cavity 110a is formed on the piezoelectric layer, the carrier substrate 100 covers part of the first electrode, and the effective resonance region of the first electrode is located in the The second cavity 110a is enclosed within the boundaries of the region.
  • a support layer 101 is also formed on the piezoelectric layer.
  • the support layer 101 is bonded to the carrier substrate 100 and forms a second cavity 110a with the piezoelectric layer.
  • the second cavity 110a exposes the carrier Substrate 100 .
  • the second cavity 110a is an annular closed cavity, and the second cavity 110a can be formed by etching the support layer through an etching process.
  • the technology of the present invention is not limited only to this.
  • the support layer 101 is combined with the carrier substrate 100 by bonding, and the bonding method includes metal bonding, covalent bonding, adhesive bonding or fusion bonding.
  • the support layer 101 and the carrier substrate 100 are bonded through a bonding layer, and the material of the bonding layer includes silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride or ethyl silicate.
  • the shape of the bottom surface of the second cavity 110a is a rectangle, but in other embodiments of the present invention, the shape of the bottom surface of the second cavity 110a on the bottom surface of the first electrode 102 may also be a circle, an ellipse, or a Polygons other than rectangles, such as pentagons, hexagons, etc.
  • the material of the support layer 101 may be any suitable dielectric material, including but not limited to one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride and other materials.
  • the material of the support layer 101 and the bonding layer may be the same.
  • the temporary substrate 200 is removed.
  • the second electrode layer 104' is patterned to form the second electrode 104.
  • the first electrode, the piezoelectric layer and the second electrode form a piezoelectric stack structure; on the second electrode 104 A second trench 106 is formed through the second electrode 104 ; the second trench 106 is formed on the opposite side of the first trench 105 .
  • the first trench 105 and the second trench 106 meet at two junctions of the projection of the carrier substrate 100 to form a closed irregular polygon.
  • the structure and formation method of the second trench 106 refer to the structure and formation method of the first trench 105 . In other embodiments, only the first trench 105 or the second trench 106 may be formed alone.
  • the structures and functions of the first trench 105 and the second trench 106 refer to Embodiment 1, and are not repeated here.
  • the effective resonance region includes a region where the first electrode 102 , the piezoelectric layer 103 and the second electrode 104 overlap each other in a direction perpendicular to the surface of the piezoelectric laminate structure.
  • a first structure layer 13 is formed on the second electrode 104 , and the first structure layer 13 is etched to form a first isolation trench 120a'.
  • the first isolation trench 120a' exposes at least the effective resonance region of the second electrode 104.
  • the method further includes forming an etching stop layer (not shown in the figure) on the second electrode 104 , and forming the first structure layer 13 on the etching stop layer, the first structure layer 13
  • an etching stop layer (not shown in the figure)
  • the first structure layer 13 is formed on the etching stop layer, the first structure layer 13
  • the oxide layer materials and uses of the oxide layer and the etch stop layer, reference is made to the foregoing embodiments, which will not be repeated here.
  • the first structure layer 13 may also be formed on the surface acoustic wave filter.
  • the first structure layer 13 may also be formed on the surface acoustic wave filter.
  • the bulk acoustic wave filter is bonded to the surface acoustic wave filter, so that the first isolation groove 120a' is sandwiched between the surface acoustic wave filter and the surface acoustic wave filter.
  • the first cavity 120a is formed between the bulk acoustic wave filters.
  • the first structural layer 13 is formed on the bulk acoustic wave filter, the first structural layer 13 is bonded to the surface acoustic wave filter, and the first structural layer 13 is bonded to the surface acoustic wave filter.
  • the first isolation groove 120a' is sandwiched between the surface acoustic wave filter and the bulk acoustic wave filter to form the first cavity 120a.
  • the effective resonance region of the piezoelectric laminated structure and the interdigital transducer 11 of the surface acoustic wave filter cover the first cavity 120a.
  • the bulk acoustic wave filter is bonded to the surface acoustic wave filter through a bonding process and forms a first cavity 120a with the surface acoustic wave filter; the effective resonance region of the piezoelectric laminated structure and The interdigital transducer 11 of the surface acoustic wave filter covers the first cavity 120a, so that the functional areas of the surface acoustic wave filter and the bulk acoustic wave filter share a cavity, which realizes vertical integration and reduces the overall system cost.
  • the effective resonance area of the piezoelectric laminated structure is located in all In the first cavity 120a, the upper and lower parts of the effective resonance region are completely in the air, which effectively improves the quality factor of the bulk acoustic wave filter.
  • At least one of the surface acoustic wave filter and the bulk acoustic wave filter is a wafer, and subsequent processes such as bonding process and electrical connection are completed on the wafer size, which realizes the simultaneous production of different frequency band filters on one wafer.
  • the demand of the device is reduced, the process difficulty is reduced, and the output is greatly improved.
  • the surface acoustic wave filter forms a first electrical connection structure 14 and a fourth electrical connection structure electrically connected to an external circuit.
  • a connection structure 17, the bulk acoustic wave filter forms a second electrical connection structure 15 and a third electrical connection structure 16 that are electrically connected to the external circuit.
  • the method for forming the first electrical connection structure 14 includes: forming a first interconnection hole (not shown in the figure) through an etching process, and the first interconnection hole penetrates and extends from one side of the carrier substrate 100 to the interdigital transducer 11 of the surface acoustic wave filter; a first conductive interconnection layer 141 is formed in the first interconnection hole, and the first conductive interconnection layer 141 covers the first interconnection The inner surface of the connection hole; the method for forming the second electrical connection structure 15 includes: forming a second interconnection hole (not shown in the figure) through an etching process, and the second interconnection hole is formed from the carrier substrate.
  • One side of 100 penetrates and extends to the first electrode 102 outside the effective resonance region of the piezoelectric stack structure; a second conductive interconnection layer 151 is formed in the second interconnection hole, and the second conductive interconnection layer 151 is formed in the second interconnection hole.
  • the conductive interconnection layer 151 covers the inner surface of the second interconnection hole.
  • an interconnection line 18 is formed on the surface of the carrier substrate 100; an insulating layer is formed on the interconnection line 18, and the insulating layer Covering the interconnection lines 18 and the surface of the carrier substrate 100; the conductive bumps 19 disposed on the surface of the carrier substrate 100 and electrically connected to the interconnection lines 18, the conductive bumps 19 and The external circuit is electrically connected, and the first conductive interconnection layer 141 and the second conductive interconnection layer 151 are electrically connected with the interconnection line 18 .
  • the first conductive interconnect layer 141 includes a first plug
  • the second conductive interconnect layer 151 includes a second plug
  • one end of the first plug is connected to the input end of the interdigital transducer 11 for providing a signal voltage to the transmitting transducer, and the other end is connected to an interconnection line 18, which is used to connect to an external circuit;
  • One end of the two plugs is connected to the first electrode 102 outside the effective resonant area, and is used to introduce electrical signals into the second electrode 104 of the effective resonant area; the third electrical connection structure 16 is used to introduce electrical signals into the effective resonant area.
  • the fourth electrical connection structure 17 is used to connect the output end of the interdigital transducer 11.
  • the surface acoustic wave formed at the input end propagates along the surface of the substrate to the interdigital electrode at the output end. Due to the pressure effect, the electric field changes due to the mechanical vibration. , outputs an electrical signal at the output end, the third electrical connection structure 16 and the second electrical connection structure 15 are formed in the same way, and the fourth electrical connection structure 17 and the first electrical connection structure 14 are formed in the same way, which will not be repeated here.
  • the above process of completing the bonding of the surface acoustic wave filter and the bulk acoustic wave filter also includes placing multiple surface acoustic wave filters in the surface acoustic wave filter wafer, and/or multiple bulk acoustic wave filters.
  • the device is located in the bulk acoustic wave filter wafer, and after the bonding step, the method further includes, separating and forming a single bonding body of the surface acoustic wave filter and the bulk acoustic wave filter.

Abstract

一种MEMS器件及其制作方法，包括：包括叉指换能器(11)的声表面波滤波器；位于声表面波滤波器上方的第一结构层(13)；体声波滤波器包括承载衬底(100)，位于承载衬底(100)表面的声反射结构，及声反射结构上的压电叠层结构，压电叠层结构包括依次层叠的第一电极(102)、压电层(103)和第二电极(104)；第一结构层(13)具有第一空腔(120a)，压电叠层结构的有效谐振区和声表面波滤波器的叉指换能器覆盖第一空腔(120a)。通过在声表面波滤波器和体声波滤波器之间设有第一空腔(120a)的第一结构层(13)，使得压电叠层结构的有效谐振区和声表面波滤波器的叉指换能器共同覆盖第一空腔，实现垂直集成，降低了整个系统的封装体积，实现小型化、高集成度。

Description

一种MEMS器件及其制作方法 技术领域
本发明涉及MEMS器件制造领域，尤其涉及一种MEMS器件及其制作方法。
 背景技术
微机械系统(Micro-Electro-Mechanical System, MEMS)与集成电路(integrated circuit, IC)目前是半导体产业最重要的两个发展领域，在全球科技迅速发展的推动下，MEMS与IC的集成成为一种必然趋势，其集成方法有三种：单片集成、半混合(键合)集成和混合集成；单片集成是指MEMS结构与CMOS制造在一个芯片上；混合集成是将MEMS和IC分别制造在不同的管芯上，然后封装在一个管壳中，将带凸点的MEMS裸片以倒装焊形式或者引线键合方式与IC芯片相互连接，形成SIP；半混合是利用三维集成技术实现MEMS芯片和CMOS的立体集成；单片集成是MEMS与IC是集成技术的重要发展方向，尤其对于射频RF薄膜体声波滤波器而言有很多优点，首先，处理电路靠近微结构，对信号的检测、收发能够实现更高的精度；其次，集成系统体积减小，功耗低；再次，器件数量减少、封装管脚数降低，可靠性高。
 技术问题
在现有的射频(Radio Frequency, RF)体声波滤波器制造技术中，大多采用系统级封装(systemin a package, SIP)将滤波器、驱动电路以及处理电路合封在一起，随着对射频系统性能的要求越来越高，需要在一片晶圆上制作多个频段的滤波器，由于体声波滤波器的工艺和器件特点，比较难实现一片晶圆上制作多个频段的滤波器，即使能实现，其工艺复杂度也非常高，但是体声波滤波器的优势显著，如插损低、隔离度高，在一些应用场合必须使用体声波滤波器。
因此，目前制作出的MEMS器件，存在制作的MEMS器件频段单一、集成度低和制作工艺繁琐等问题，无法满足高性能的射频系统的需求。
 技术解决方案
本发明的目的在于提供一种MEMS器件及其制作方法，能够解决制作的MEMS器件频段单一、集成度低和制作工艺繁琐等技术问题。
为实现上述目的，本发明提出了一种MEMS器件，包括：声表面波滤波器，所述声表面波滤波器包括叉指换能器；第一结构层，所述第一结构层位于所述声表面波滤波器的上方；体声波滤波器，所述体声波滤波器位于所述第一结构层的上方；所述体声波滤波器包括承载衬底，位于所述承载衬底表面的声反射结构，及声反射结构上的压电叠层结构，所述压电叠层结构包括依次层叠的第一电极、压电层和第二电极；所述第一结构层具有第一空腔，所述压电叠层结构的有效谐振区和所述声表面波滤波器的叉指换能器覆盖所述第一空腔。
本发明还提供了一种MEMS器件的制作方法，包括：提供声表面波滤波器，所述声表面波滤波器包括叉指换能器；提供体声波滤波器，所述体声波滤波器包括：承载衬底，形成于所述承载衬底表面的支撑层，与所述承载衬底、支撑层围成第二空腔的压电叠层结构；所述体声波滤波器通过第一结构层键合在所述声表面波滤波器上并与所述声表面波滤波器形成第一空腔；所述压电叠层结构的有效谐振区和所述声表面波滤波器的叉指换能器覆盖所述第一空腔。
 有益效果
本发明结构的有益效果在于：通过在声表面波滤波器和体声波滤波器之间设有第一空腔的第一结构层，使得体声波滤波器的压电叠层结构的有效谐振区和声表面波滤波器的叉指换能器共同覆盖第一空腔，实现垂直集成，降低了整个系统的封装体积，实现小型化，集成度大大提高；不仅保留体声波滤波器高频和低插损的优势，还降低工艺成本实现多频段的需求；将压电叠层结构的有效谐振区位于所述第一空腔中，有效提高了体声波滤波器的品质因数。
进一步的，通过体声波滤波器与声表面波滤波器分别形成电连接结构，实现与外部电路的电连接，避免了声表面波滤波器和所述体声波滤波器的信号相互产生干扰，提高了MEMS器件的性能。
进一步的，通过第一沟槽和第二沟槽定义出体声波滤波器的有效谐振区，第一沟槽和第二沟槽分别贯穿第一电极和第二电极，压电层保持完整的膜层未经过刻蚀，保证了体声波滤波器的结构强度，提高了体声波滤波器的成品率。
本发明制作方法的有益效果：通过键合工艺使得所述体声波滤波器键合在所述声表面波滤波器上并与所述声表面波滤波器形成第一空腔；所述压电叠层结构的有效谐振区和声表面波滤波器的所述叉指换能器覆盖所述第一空腔，使得声表面波滤波器和体声波滤波器的功能区共用一个空腔，实现垂直集成，降低了整个系统的封装体积，实现小型化，集成度大大提高；不仅保留体声波滤波器高频和低插损的优势，简化了制造工艺，还降低了生产成本；将压电叠层结构的有效谐振区位于所述第一空腔中，使得有效谐振区的上下面完全处于空气中，有效提高了体声波滤波器的品质因数。
进一步的，声表面波滤波器和体声波滤波器至少其一为晶圆，键合工艺及电连接等后续制程，是在晶圆尺寸上完成，实现了在一片晶圆上同时……制作不同频段滤波器的需求，降低工艺难度，且产量大幅度提高。
进一步的，第一结构层为可光刻的有机固化膜，能够缓解声表面波滤波器与体声波滤波器的键合应力，且与声表面波滤波器和体声波滤波器的粘结可靠性高，第一空腔光刻可得，对滤波器表面损伤较低。
进一步的，在声表面波滤波器上形成钝化层，能够提高声表面波滤波器防尘、防水和防腐蚀的作用。
 附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本发明一实施例所提供的MEMS器件的结构示意图；图2至图6为本发明一实施例所提供的MEMS器件的制作方法中不同步骤对应的结构示意图；图7至图10为本发明一实施例所提供的MEMS器件的制作方法中不同步骤对应的结构示意图；图11至图12是本发明一实施例所提供的MEMS器件的制作方法中不同步骤对应的结构示意图。
附图标记：10、承载基底；11、叉指换能器；12、钝化层；121、氧化层；122、刻蚀停止层；13、第一结构层；14、第一电连接结构；141、第一导电互连层；15、第二电连接结构；151、第二导电互连层； 16、第三电连接结构；17、第四电连接结构；18、互连线；19、导电凸起；20、介质层；100、承载衬底；101、支撑层；102、第一电极；103、压电层；104＇、第二电极层；104、第二电极； 105、第一沟槽；106、第二沟槽；110a、第二空腔；120a、第一空腔；120a＇、第一隔离槽。
 本发明的实施方式
声表面波滤波器的衬底材料为铌酸锂或钽酸锂，材料特性、热膨胀系数和普通衬底不同，容易破碎，与常用的硅晶圆制程不易结合。因此，现有技术不容易将声表面波滤波器与体声波滤波器晶圆级工艺集成在一起；另外，由于体声波滤波器的工艺和器件特点，比较难实现一片晶圆上制作多个频段的滤波器，即使能实现，其工艺复杂度也非常高，但是体声波滤波器的优势显著，如插损低、隔离度高，在一些应用场合必须使用体声波滤波器；声表面波滤波器的工艺和器件特点，决定了其易于实现一片晶圆上制作多个频段，因此使用声表面波滤波器更具成本优势。因此，如何将声表面波滤波器与体声波滤波器键合在一起，解决目前的MEMS器件频段单一、集成度低和制作工艺繁琐等问题，是亟待解决的问题。
以下结合附图和具体实施例对本发明的MEMS器件及其制作方法作进一步详细说明。根据下面的说明和附图，本发明的优点和特征将更清楚，然而，需说明的是，本发明技术方案的构思可按照多种不同的形式实施，并不局限于在此阐述的特定实施例。附图均采用非常简化的形式且均使用非精准的比例，仅用以方便、明晰地辅助说明本发明实施例的目的。
在说明书和权利要求书中的术语“第一”“第二”等用于在类似要素之间进行区分，且未必是用于描述特定次序或时间顺序。要理解，在适当情况下，如此使用的这些术语可替换，例如可使得本文所述的本发明实施例能够以不同于本文所述的或所示的其他顺序来操作。类似的，如果本文所述的方法包括一系列步骤，且本文所呈现的这些步骤的顺序并非必须是可执行这些步骤的唯一顺序，且一些所述的步骤可被省略和/或一些本文未描述的其他步骤可被添加到该方法。若某附图中的构件与其他附图中的构件相同，虽然在所有附图中都可轻易辨认出这些构件，但为了使附图的说明更为清楚，本说明书不会将所有相同构件的标号标于每一图中。
实施例 1
本实施例1提供了一种MEMS器件，图1示出了本实施例1的一种MEMS器件的结构示意图，请参考图1，所述MEMS器件包括：声表面波滤波器，所述声表面波滤波器包括叉指换能器11；第一结构层13，所述第一结构层13位于所述声表面波滤波器的上方；体声波滤波器，所述体声波滤波器位于所述第一结构层13的上方；所述体声波滤波器包括承载衬底100，位于所述承载衬底100表面的声反射结构（图中未示出），及声反射结构上的压电叠层结构，所述压电叠层结构包括依次层叠的第一电极102、压电层103和第二电极104；所述第一结构层13具有第一空腔120a，所述压电叠层结构的有效谐振区和所述声表面波滤波器的叉指换能器11覆盖所述第一空腔120a。
体声波滤波器还可以为薄膜体声波谐振器或者固态装配型谐振器的一种，当声反射结构包括空腔时可以为体声波滤波器或薄膜体声波谐振器，当声反射结构包括布拉格反射层时，可以为固态装配型谐振器，本实施例以体声波滤波器为例对本发明进行详细说明。
第一空腔120a可以通过刻蚀工艺刻蚀第一结构层13形成。但本发明的技术不仅仅限定于此。需要说明的是，第一结构层13与体声波滤波器之间具有键合界面，第一结构层13通过键合界面与体声波滤波器键合连接，将第一结构层13通过键合工艺使得所述体声波滤波器键合在所述声表面波滤波器上的第一结构层13上并与所述声表面波滤波器形成第一空腔120a，在器件制作阶段实现体声波滤波器与声表面波滤波器的垂直集成，省去了后端的系统级封装制程，简化了制造工艺，降低了整个系统的封装体积，集成度大大提高；键合的方式包括：金属键合、共价键键合、粘结键合或熔融键合。第一结构层和滤波器通过键合层实现键合，键合层的材料包括可光刻的有机固化膜、氧化硅、氮化硅、氮氧化硅、碳氮化硅或硅酸乙酯或金属。在其它实施例中，第一结构层13也可以位于体声波滤波器上，将第一结构层13与声表面波滤波器之间具有键合界面，第一结构层13通过键合界面与声表面波滤波器键合连接，实现体声波滤波器与声表面波滤波器的键合连接。
在本实施例中，第一空腔120a的底面的形状为矩形，但在其他实施例中，第一空腔120a形状还可以是圆形、椭圆形或是矩形以外的多边形，例如五边形、六边形等。
需要说明的是，通过在声表面波滤波器和体声波滤波器之间设有第一空腔120a的第一结构层13，使得压电叠层结构的有效谐振区和声表面波滤波器的叉指换能器11共同覆盖第一空腔120a，实现垂直集成，降低了整个系统的封装体积，实现小型化，集成度大大提高；不仅保留体声波滤波器高频和低插损的优势，还降低工艺成本实现多频段的需求；将压电叠层结构的有效谐振区位于所述第一空腔120a中，有效提高了体声波滤波器的品质因数。
压电叠层结构的有效谐振区和声表面波滤波器的叉指换能器11共同覆盖第一空腔120a，如有效谐振区和叉指换能器11面向第一空腔120a，分别覆盖第一空腔120a，或至少其一突出至第一空腔120a内部。
在本实施例中，所述第一空腔120a贯穿所述第一结构层13；第一结构层13包括可光刻有机固化膜或氧化层。在本实施例中，所述第一结构层13为可光刻的有机固化膜，其具有单面或双面粘性，膜状材料或液态材料，可被光刻，可以被固化，弹性模量相对小，能够缓解声表面波滤波器与体声波滤波器的键合应力，且与声表面波滤波器和体声波滤波器的粘结可靠性高，通过光刻第一结构层13获取第一空腔120a，对滤波器表面损伤较低，进一步提高器件的品质因数。所述第一结构层13的厚度范围包括5~50μm，声表面波滤波器后续与体声波滤波器键合，需要达到一定的厚度，且后续在第一结构层13上形成的第一隔离槽也需要具有一定的深度，因此，本实施例中，通过将第一结构层13的厚度范围限制在5~50um，能够满足声表面波滤波器与后续体声波滤波器的键合条件且能够节省成本。在其它实施例中，第一结构层13的厚度范围也可以高于或者低于这个范围。
本实施例中，在所述第一结构层13与声表面波滤波器之间设置有钝化层12，通过在声表面波滤波器上设钝化层12，能够对声表面波滤波器起到保护作用，提高声表面波滤波器的结构强度和器件性能。所述钝化层12包括氧化层121和刻蚀停止层122，所述氧化层121位于所述声表面波滤波器的上表面，所述刻蚀停止层122位于所述氧化层121上，所述氧化层121的材料为氧化硅、氮氧化硅、氮化硅等任一绝缘材料中的至少一种，通过在声表面波滤波器的表面设氧化层121，提高声表面波滤波器防尘和防水的作用。在氧化层121上设有刻蚀停止层122，刻蚀停止层122的材质包括但不限于氮化硅和氮氧化硅，本实施例中为氮化硅，氮化硅具有较高的密度和强度，能够提高声表面波滤波器防水、防腐蚀的作用。
另外，刻蚀停止层122一方面可以用于增加最终制造的滤波器的结构稳定性，另一方面，刻蚀停止层122与可光刻的有机固化膜相比具有较低的刻蚀速率，可以在刻蚀有机固化膜形成第一空腔110a的过程中防止过刻蚀，保护位于其下的结构的表面不受到损伤，从而提高器件性能与可靠性。
在其它实施例中，钝化层12也可以只包含氧化层121和刻蚀停止层122的一种，或者钝化层12也可以为其它结构，在这里并不做限制。
在本实施例中，所述声表面波滤波器还包括承载基底10和位于所述承载基底10上的介质层20。
需要说明的是，声表面波滤波器是在一块具有压电效应的材料基片上蒸发一层金属膜，然后经过光刻，在两端各形成一对叉指形电极组成；声表面波滤波器具有工作效率高、通频带宽、选频特性好、体积小和重量轻等优点，并且可采用与集成电路相同的生产工艺，制造简单，成本低。
承载基底10具有相对的第一表面和第二表面，所述介质层20位于所述承载基底10的第一表面，叉指换能器11位于承载基底10的第一表面的介质层20内。叉指换能器11包括发射换能器和接收换能器，当在发射换能器上加上信号电压后，就在输入叉指电极间形成一个电场使压电材料发生机械振动以超声波的形式向两边传播，接收换能器将机械振动再转化为电信号，并由输出叉指形电极输出。
在本实施例中，所述体声波滤波器位于所述第一结构层13的上方；所述体声波滤波器包括承载衬底100，位于所述承载衬底100表面的支撑层101，与所述承载衬底100、支撑层101围成第二空腔110a的压电叠层结构。
具体的，第一空腔120a和第二空腔110a在压电叠层结构的投影至少部分重叠，使得压电叠层结构的有效谐振区的上下面均处于空气中，能够进一步提高体声波滤波器的品质因数。
承载衬底100可以为以下所提到的材料中的至少一种：硅(Si)、锗(Ge)、锗硅 (SiGe)、碳硅(SiC)、碳锗硅(SiGeC)、砷化铟(InAs)、砷化镓(GaAs)、磷化铟(InP)或者其它III/V化合物半导体，还包括这些半导体构成的多层结构等，也可为氧化铝等的陶瓷基底、石英或玻璃基底等。
支撑层101键合于承载衬底100上，且与压电叠层结构围成第二空腔110a，所述第二空腔110a暴露出所述承载衬底100。本实施例中，第二空腔110a为环形的封闭空腔，第二空腔110a可以通过刻蚀工艺刻蚀支撑层形成。但本发明的技术不仅仅限定于此。需要说明的是，支撑层101是通过键合的方式与承载衬底100结合，键合的方式包括：金属键合、共价键键合、粘结键合或熔融键合。本实施例中，支撑层101和承载衬底100通过键合层实现键合，键合层的材料包括氧化硅、氮化硅、氮氧化硅、碳氮化硅或硅酸乙酯。
本实施例中，第二空腔110a的底面的形状为矩形，但在本发明的其他实施例中，第二空腔110a在第一电极102底面的形状还可以是圆形、椭圆形或是矩形以外的多边形，例如五边形、六边形等。支撑层101的材料可以是任意适合的介电材料，包括但不限于氧化硅、氮化硅、氮氧化硅、碳氮化硅等材料中的一种。所述支撑层101与所述键合层的材料可以相同。
第二空腔110a的上方设有压电叠层结构，压电叠层结构依次包括第一电极102、压电层103和第二电极104。第一电极102位于支撑层101上，压电层103位于第一电极102上，第二电极104位于压电层103上。
本实施例中，压电层103遮盖所述第二空腔110a，遮盖所述第二空腔110a应当理解为压电层103为完整的膜层，没有经过刻蚀。并不意味着压电层103将第二空腔110a全部遮盖，形成密封的空腔。当然，压电层103可以完全遮盖第二空腔110a，形成密封的空腔。压电层103不经过刻蚀可以保证压电叠层结构具有一定的厚度，使体声波滤波器具有一定的结构强度。提高制作体声波滤波器的成品率。
在一个实施例中，支撑层101与第一电极102之间还设置有刻蚀停止层，其材质包括但不限于氮化硅（Si3N4）和氮氧化硅（SiON）。刻蚀停止层一方面可以用于增加最终制造的体声波谐振器的结构稳定性，另一方面，刻蚀停止层与支撑层101相比具有较低的刻蚀速率，可以在刻蚀支撑层101形成第二空腔110a的过程中防止过刻蚀，保护位于其下的第一电极102的表面不受到损伤，从而提高器件性能与可靠性。
本实施例中，压电叠层结构的表面还包括第一沟槽105和第二沟槽106，第一沟槽105位于压电叠层结构的下表面、所述第二空腔110a所在侧的底部，贯穿所述第一电极102。第二沟槽106位于压电叠层结构的上表面，贯穿所述第二电极104。第一沟槽105的两个端部与第二沟槽106的两个端部相对设置，使所述第一沟槽105与所述第二沟槽106在所述承载衬底100的投影的两个交界处相接或设有间隙。本实施例中，第一沟槽105与第二沟槽106在所述承载衬底100的投影为封闭的图形。第二空腔120a的上方的第一电极102、压电层103和第二电极104在垂直于承载衬底100的方向上设有重叠区域，位于第一沟槽105和第二沟槽106之间的重叠区域为有效谐振区，通过第一沟槽105和第二沟槽106定义出体声波滤波器的有效谐振区，第一沟槽105和第二沟槽106分别贯穿第一电极102和第二电极104，压电层103保持完整的膜层未经过刻蚀，保证了体声波滤波器的结构强度，提高了体声波滤波器的成品率。
在本实施例中，所述声表面波滤波器通过第一电连接结构14和第四电连接结构17与外部电路电连接，所述体声波滤波器通过第二电连接结构15和第三电连接结构16与外部电路电连接。通过体声波滤波器与声表面波滤波器分别形成电连接结构，实现与外部电路的电连接，避免了声表面波滤波器和所述体声波滤波器的信号相互产生干扰，提高了MEMS器件的性能。
所述第一电连接结构14包括第一互连孔（图中未示出）和位于所述第一互连孔中的第一导电互连层141，所述第一互连孔从所述承载衬底100的一面贯穿并延伸至所述声表面波滤波器的叉指换能器11上；所述第二电连接结构15包括第二互连孔（图中未示出）和位于所述第二互连孔中的第二导电互连层151，所述第二互连孔从所述承载衬底100的一面贯穿并延伸至所述压电叠层结构的有效谐振区外部的所述第一电极102上。
所述承载衬底100上设有互连线18，所述第一导电互连层141包括第一插塞，所述第二导电互连层151包括第二插塞，所述第一插塞和所述第二插塞与所述互连线18电连接。
需要说明的是，叉指换能器11的输入端和输出端设有叉指形电极，第一电连接结构用于将电信号引入到叉指换能器的输入端，当给叉指换能器的输入端输入电信号时，在输入电信号的交变电场作用下，由于晶体的压电效应，在叉指换能器的基片表面激起机械振动，形成声表面波，第四电连接结构用于连接叉指换能器的输出端，在输入端形成声的声表面波沿基片表面传播到输出端的叉指电极，由于压力效应，由机械振动产生电场变化，在输出端输出电信号；第二电连接结构用于将电信号引入有效谐振区的第二电极，第三电连接结构用于将电信号引入有效谐振区的第一电极，第一电极103和第二电极105通电后，压电层104上下表面产生压差，形成驻波振荡。具体的第一电连接结构14和第二电连接结构15的结构如下：第一电连接结构14包括：第一互连孔，所述第一互连孔从所述承载衬底100的一面贯穿并延伸至所述声表面波滤波器的叉指换能器11上；第一导电互连层141，覆盖所述第一互连孔的内表面，与位于所述承载衬底100表面的互连线18电连接；所述第二电连接结构15包括：第二互连孔，所述第二互连孔从所述承载衬底100的一面贯穿并延伸至所述压电叠层结构的有效谐振区外部的所述第一电极102上并暴露出所述第一电极102；第二导电互连层151，覆盖所述第二互连孔的内表面，与位于所述承载衬底100表面的互连线18电连接。
需要说明的是，第二电连接结构15并不直接与第二电极104电连接，而是连接于有效谐振区外部的第一电极102，通过导电互连结构（图中未示出）与有效谐振区的第二电极104电连接，第三电连接结构16与有效谐振区内部的第一电极102电连接，给有效谐振区内部的第一电极102供电；可以看出，第一电连接结构14和第四电连接结构17在结构上一致，只是设置的位置不同，第二电连接结构15和第三电连接结构16在结构上也一致，只是设置的位置不同，此处不再赘述第三电连接结构16和第四电连接结构17的结构。
在本实施例中，MEMS器件还包括：绝缘层，覆盖所述互连线18和所述承载衬底100的表面；导电凸起19，设置于所述承载衬底100的表面、与所述互连线18电连接。
实施例2
本发明实施例2提供了一种MEMS器件的制作方法，包括以下步骤： S01：提供声表面波滤波器，所述声表面波滤波器包括叉指换能器；S02：提供体声波滤波器，所述体声波滤波器包括：承载衬底，形成于所述承载衬底表面的支撑层，与所述承载衬底、支撑层围成第二空腔的压电叠层结构；S03：所述体声波滤波器通过第一结构层键合在所述声表面波滤波器上并与所述声表面波滤波器形成第一空腔；S04：所述压电叠层结构的有效谐振区和所述声表面波滤波器的叉指换能器覆盖所述第一空腔。
步骤S0N不代表先后顺序。
参考图2至图12为本实施例的MEMS器件的制作方法的相应步骤对应的结构示意图，参考图2至图12，详细说明本实施例提供的MEMS器件的制作方法。
参考图2所示，提供声表面波滤波器。
所述声表面波滤波器的形成过程包括：提供承载基底10；在所述承载基底10上形成叉指换能器11；在所述承载基底10的第一表面上形成介质层20，所述介质层20覆盖所述承载基底10的第一表面和所述叉指换能器11；所述承载基底10包括相对的第一表面和第二表面，所述叉指换能器11形成于所述承载基底10的第一表面。
叉指换能器11的工作原理参考前述实施例1，此处不再赘述。
参考图3至图4所示，在所述声表面波滤波器上形成钝化层12。
形成钝化层12的具体过程包括：参考图3，在所述介质层20上形成氧化层121。
氧化层121的材料和作用参考前述实施例1，此处不再赘述。
参考图4，在所述氧化层121上形成刻蚀停止层122，所述刻蚀停止层122和所述氧化层121构成所述钝化层12。
所述刻蚀停止层122的材料和作用参考前述实施例1，此处不再赘述。
参考图5，在一个实施例中，在所述钝化层12上形成第一结构层13。
第一结构层13为可光刻的有机固化膜，有机固化膜的作用与前述实施例1中相同。
在另一个实施例中，第一结构层13不形成在所述钝化层12上，可以形成在体声波滤波器的压电叠层结构上，具体的形成过程请参考下文的图7至图10，此处不做过多描述。
参考图6，刻蚀所述第一结构层13，形成第一隔离槽120a＇，使所述叉指转能器11与所述第一隔离槽120a＇相对。
参考图7至图9，提供体声波滤波器，所述体声波滤波器包括：承载衬底，形成于所述承载衬底表面的支撑层，与所述承载衬底、支撑层围成第二空腔的压电叠层结构。体声波滤波器的具体形成过程具体请参考图7-图9。
参考图7，提供临时衬底200。
临时衬底200可以为本领域技术人员熟知的任意合适的底材，可以是以下所提到的材料中的至少一种：硅(Si)、锗(Ge)、锗硅 (SiGe)、砷化铟(Ins)、、磷化铟(InP)或者其它III/V化合物半导体，还包括这些半导体构成的多层结构等，或者为绝缘体上硅(SOI)、绝缘体上层叠硅 (SSOI)、绝缘体上层叠锗化硅(S-SiGeOI)、绝缘体上锗化硅 (SiGeOI)以及绝缘体上锗(GeOI)，或者还可以为双面抛光硅片(Doule Side Polished Wfers，DSP)，也可为氧化铝等的陶瓷基底、石英或玻璃基底等。本实施例中临时衬底200为<100>晶向的P型高阻单晶硅片。
在所述临时衬底200上依次形成第二电极层104＇、压电层103和第一电极102。
第二电极层104＇和第一电极102的材料可以使用本领域技术人员熟知的任意合适的导电材料或半导体材料，其中，导电材料可以为具有导电性能的金属材料，例如，由钼（Mo）、铝（Al）、铜（Cu）、钨（W）、钽（Ta）、铂（Pt）、钌（Ru）、铑（Rh）、铱（Ir）、铬（Cr）、钛（Ti）、金(Au)、锇(Os)、铼(Re)、钯 (Pd)等金属中一种制成或由上述金属形成的叠层制成，半导体材料例如是Si、Ge、SiGe、SiC、SiGeC等。可以通过磁控溅射、蒸镀等物理气相沉积或者化学气相沉积方法形成第二电极层104＇和第一电极102。压电层103的材料可以使用氮化铝(AlN)、氧化锌(ZnO)、锆钛酸铅(PZT)、铌酸锂(LiNbO3)、石英 (Quartz)、铌酸钾(KNbO3)或钽酸锂(LiTaO3)等具有纤锌矿型结晶结构的压电材料及它们的组合。当压电层103包括氮化铝(AlN)时，压电层103还可包括稀土金属，例如钪(Sc)、铒 (Er)、钇(Y)和镧(La)中的至少一种。此外，当压电层包括氮化铝(AlN) 时，压电层103还可包括过渡金属，例如锆(Zr)、钛(Ti)、锰(Mn)和铪(Hf)中的至少一种。可以使用化学气相沉积、物理气相沉积或原子层沉积等本领域技术人员熟知的任何适合的方法沉积形成压电层103。可选的，本实施例中，第二电极层104＇和第一电极102由金属钼（Mo）制成，压电层103由氮化铝（AlN）制成。
在本实施例中，形成第一电极102之后，通过刻蚀第一电极102，形成贯穿第一电极102的第一沟槽105。第一沟槽105位于后续形成的第一空腔120a内，第一沟槽105的侧壁可以是倾斜或者竖直的。本实施例中，第一沟槽105的侧壁与压电层103所在平面构成一直角（第一沟槽105的纵向截面（沿膜层厚度方向的截面）形状为矩形）。在其它实施例中，第一沟槽105的侧壁与压电层103所在平面构成一钝角。第一沟槽105在压电层103所在平面的投影为一半环形或类似半环形的多边形。
参考图8，在所述压电层上形成包括第二空腔110a的承载衬底100，所述承载衬底100覆盖部分所述第一电极，所述第一电极的有效谐振区位于所述第二空腔110a围成区域的边界以内。
在所述压电层上还形成支撑层101，支撑层101键合于承载衬底100上，且与压电层围成第二空腔110a，所述第二空腔110a暴露出所述承载衬底100。本实施例中，第二空腔110a为环形的封闭空腔，第二空腔110a可以通过刻蚀工艺刻蚀支撑层形成。但本发明的技术不仅仅限定于此。需要说明的是，支撑层101是通过键合的方式与承载衬底100结合，键合的方式包括：金属键合、共价键键合、粘结键合或熔融键合。本实施例中，支撑层101和承载衬底100通过键合层实现键合，键合层的材料包括氧化硅、氮化硅、氮氧化硅、碳氮化硅或硅酸乙酯。
本实施例中，第二空腔110a的底面的形状为矩形，但在本发明的其他实施例中，第二空腔110a在第一电极102底面的形状还可以是圆形、椭圆形或是矩形以外的多边形，例如五边形、六边形等。支撑层101的材料可以是任意适合的介电材料，包括但不限于氧化硅、氮化硅、氮氧化硅、碳氮化硅等材料中的一种。所述支撑层101与所述键合层的材料可以相同。
参考图9，去除所述临时衬底200。
去除所述临时衬底200之后，图形化所述第二电极层104＇，形成第二电极104，第一电极、压电层和第二电极构成压电叠层结构；在第二电极104上形成贯穿所述第二电极104的第二沟槽106；第二沟槽106形成在所述第一沟槽105相对的一侧。本实施例中，所述第一沟槽105和所述第二沟槽106在所述承载衬底100的投影的两个交界处相接，构成封闭的不规则多边形。第二沟槽106的结构和形成方法参照第一沟槽105的结构和形成方法。在其他实施例中，也可以只单独形成第一沟槽105或第二沟槽106。第一沟槽105和第二沟槽106的结构和作用参照实施例1，此处不再赘述。
所述有效谐振区包括所述第一电极102、压电层103和第二电极104在垂直于所述压电叠层结构表面方向上相互重叠的区域。
参考图10，在一实施例中，形成体声波滤波器之后，在所述第二电极104上形成第一结构层13，刻蚀所述第一结构层13，形成第一隔离槽120a＇。第一隔离槽120a＇至少暴露出第二电极104的有效谐振区域。
在形成第一结构层13之前，还包括在第二电极104上形成刻蚀停止层（图中未示出），在所述刻蚀停止层上形成第一结构层13，第一结构层13为氧化层，氧化层和刻蚀停止层的材料和用途参考前述实施例，此处不再赘述。
在另一实施例中，第一结构层13也可以形成在声表面波滤波器上，具体的请参考前述图2至图6。
参考图11，在一实施例中，基于图6，将体声波滤波器键合到声表面波滤波器上，使所述第一隔离槽120a＇夹设在所述声表面波滤波器和所述体声波滤波器之间形成所述第一空腔120a。
在另一实施例中，基于图4，在体声波滤波器上形成第一结构层13之后，键合到声表面波滤波器上，所述第一结构层13键合至所述声表面波滤波器的钝化层12上，使所述第一隔离槽120a＇夹设在所述声表面波滤波器和所述体声波滤波器之间形成所述第一空腔120a。
所述压电叠层结构的有效谐振区和所述声表面波滤波器的叉指换能器11覆盖所述第一空腔120a。
通过键合工艺使得所述体声波滤波器键合在所述声表面波滤波器上并与所述声表面波滤波器形成第一空腔120a；所述压电叠层结构的有效谐振区和声表面波滤波器的所述叉指换能器11覆盖所述第一空腔120a，使得声表面波滤波器和体声波滤波器的功能区共用一个空腔，实现垂直集成，降低了整个系统的封装体积，实现小型化，集成度大大提高；不仅保留体声波滤波器高频低插损的优势，简化了制造工艺，还降低了生产成本；将压电叠层结构的有效谐振区位于所述第一空腔120a中，使得有效谐振区的上下面完全处于空气中，有效提高了体声波滤波器的品质因数。
进一步的，声表面波滤波器和体声波滤波器至少其一为晶圆，键合工艺及电连接等后续制程，是在晶圆尺寸上完成，实现了在一片晶圆上同时制作不同频段滤波器的需求，降低工艺难度，且产量大幅度提高。
参考图12，键合所述的体声波滤波器与所述声表面波滤波器之后，还包括：所述声表面波滤波器形成与外部电路电连接的第一电连接结构14和第四电连接结构17，所述体声波滤波器形成与外部电路电连接的第二电连接结构15和第三电连接结构16。
所述第一电连接结构14的形成方法包括：通过刻蚀工艺形成第一互连孔（图中未示出），所述第一互连孔从所述承载衬底100的一面贯穿并延伸至所述声表面波滤波器的叉指换能器11上；在所述第一互连孔中形成第一导电互连层141，所述第一导电互连层141覆盖所述第一互连孔的内表面；所述第二电连接结构15的形成方法包括：通过刻蚀工艺形成第二互连孔（图中未示出），所述第二互连孔从所述承载衬底100的一面贯穿并延伸至所述压电叠层结构的有效谐振区外部的所述第一电极102上；在所述第二互连孔中形成第二导电互连层151，所述第二导电互连层151覆盖所述第二互连孔的内表面。
形成所述第一电连接结构14和所述第二电连接结构15之后，在承载衬底100的表面上形成互连线18；在所述互连线18上形成绝缘层，所述绝缘层覆盖所述互连线18和所述承载衬底100的表面；设置于所述承载衬底100的表面、与所述互连线18电连接的导电凸起19，所述导电凸起19与外部电路电连接，所述第一导电互连层141和所述第二导电互连层151与所述互连线18电连接。
在本实施例中，所述第一导电互连层141包括第一插塞，所述第二导电互连层151包括第二插塞。
具体的，第一插塞的一端连接叉指换能器11的输入端，用于给发射换能器提供信号电压，另一端连接互连线18，互连线18用于连接外部电路；第二插塞的一端连接有效谐振区外部的所述第一电极102上，用于将电信号引入有效谐振区的第二电极104；第三电连接结构16用于将电信号引入有效谐振区的第一电极102，第一电极102和第二电极104通电后，压电层103上下表面产生压差，形成驻波振荡。第四电连接结构17用于连接叉指换能器11的输出端，在输入端形成声的声表面波沿基片表面传播到输出端的叉指电极，由于压力效应，由机械振动产生电场变化，在输出端输出电信号，第三电连接结构16和第二电连接结构15的形成方法相同，第四电连接结构17和第一电连接结构14的形成方法相同，此处不再赘述。
需要说明的是，以上声表面波滤波器与体声波滤波器完成键合的过程，还包括，将多个声表面波滤波器位于声表面波滤波器晶圆中，和/或多个体声波滤波器位于体声波滤波器晶圆中，键合步骤之后，还包括，分离形成单个所述声表面波滤波器和体声波滤波器的键合体。
需要说明的是，本说明书中的各个实施例均采用相关的方式描述，各个实施例之间相同相似的部分互相参见即可，每个实施例重点说明的都是与其他实施例的不同之处。
上述描述仅是对本发明较佳实施例的描述，并非对本发明范围的任何限定，本发明领域的普通技术人员根据上述揭示内容做的任何变更、修饰，均属于权利要求书的保护范围。

Claims (20)

  1. 一种MEMS器件，其特征在于，包括：声表面波滤波器，所述声表面波滤波器包括叉指换能器；第一结构层，所述第一结构层位于所述声表面波滤波器的上方；体声波滤波器，所述体声波滤波器位于所述第一结构层的上方；所述体声波滤波器包括承载衬底，位于所述承载衬底表面的声反射结构，及声反射结构上的压电叠层结构，所述压电叠层结构包括依次层叠的第一电极、压电层和第二电极；所述第一结构层具有第一空腔，所述压电叠层结构的有效谐振区和所述声表面波滤波器的叉指换能器覆盖所述第一空腔。
  2. 根据权利要求1所述的MEMS器件，其特征在于，所述第一空腔贯穿所述第一结构层。
  3. 根据权利要求1所述的MEMS器件，其特征在于，所述第一结构层包括可光刻有机固化膜或氧化层。
  4. 根据权利要求1所述的MEMS器件，其特征在于，所述第一结构层的厚度范围包括5~50μm。
  5. 根据权利要求1所述的MEMS器件，其特征在于，所述声表面波滤波器与所述第一结构层之间设有钝化层，所述钝化层包括氧化层和刻蚀停止层，所述氧化层位于所述声表面波滤波器的上表面，所述刻蚀停止层位于所述氧化层上。
  6. 根据权利要求1所述的MEMS器件，其特征在于，所述声反射结构包括位于所述承载衬底表面的支撑层以及所述承载衬底、支撑层与所述压电叠层结构围成所述体声波滤波器的第二空腔。
  7. 根据权利要求1所述的MEMS器件，其特征在于，所述声表面波滤波器通过第一电连接结构和第四电连接结构与外部电路电连接，所述体声波滤波器通过第二电连接结构和第三电连接结构与外部电路电连接。
  8. 根据权利要求7所述的MEMS器件，其特征在于，所述第一电连接结构包括第一互连孔和位于所述第一互连孔中的第一导电互连层，所述第一互连孔从所述承载衬底的一面贯穿并延伸至所述声表面波滤波器的叉指换能器上；
    所述第二电连接结构包括第二互连孔和位于所述第二互连孔中的第二导电互连层，所述第二互连孔从所述承载衬底的一面贯穿并延伸至所述压电叠层结构的有效谐振区外部的所述第一电极上。
  9. 9、根据权利要求8所述的MEMS器件，其特征在于，所述承载衬底上设有互连线，所述第一导电互连层包括第一插塞，所述第二导电互连层包括第二插塞，所述第一插塞和所述第二插塞与所述互连线电连接。
  10. 根据权利要求6所述的MEMS器件，其特征在于，在所述第二空腔的底部设有贯穿第一电极的第一沟槽，在与所述第一沟槽相对位置设有贯穿所述第二电极的第二沟槽，所述第一沟槽与所述第二沟槽在所述承载衬底的投影的两个交界处相接或设有间隙。
  11. 根据权利要求1所述的MEMS器件，其特征在于，所述声反射结构包括布拉格反射层。
  12. 一种MEMS器件的制作方法，其特征在于，包括：提供声表面波滤波器，所述声表面波滤波器包括叉指换能器；提供体声波滤波器，所述体声波滤波器包括：承载衬底，形成于所述承载衬底表面的支撑层，与所述承载衬底、支撑层围成第二空腔的压电叠层结构；所述体声波滤波器通过第一结构层键合在所述声表面波滤波器上并与所述声表面波滤波器形成第一空腔；所述压电叠层结构的有效谐振区和所述声表面波滤波器的叉指换能器覆盖所述第一空腔。
  13. 根据权利要求12所述的MEMS器件的制作方法，其特征在于，多个声表面波滤波器位于声表面波滤波器晶圆中，和/或多个体声波滤波器位于体声波滤波器晶圆中，键合步骤之后，还包括，分离形成单个所述声表面波滤波器和体声波滤波器的键合体。
  14. 根据权利要求12所述的MEMS器件的制作方法，其特征在于，形成所述第一空腔的方法包括：提供声表面波滤波器；在所述声表面波滤波器上形成第一结构层；刻蚀所述第一结构层，形成第一隔离槽，使所述叉指转能器与所述第一隔离槽相对；提供体声波滤波器，所述体声波滤波器键合至所述第一结构层上，使所述第一隔离槽夹设在所述声表面波滤波器和所述体声波滤波器之间形成所述第一空腔；或者，提供声表面波滤波器；提供体声波滤波器，在所述压电叠层结构上形成第一结构层；刻蚀所述第一结构层，形成第一隔离槽；所述第一结构层键合至所述声表面波滤波器上，使所述第一隔离槽夹设在所述声表面波滤波器和所述体声波滤波器之间形成所述第一空腔。
  15. 根据权利要求12所述的MEMS器件的制作方法，其特征在于，在所述声表面波滤波器与所述第一结构层之间形成钝化层。
  16. 根据权利要求15所述的MEMS器件的制作方法，其特征在于，所述钝化层包括氧化层和刻蚀停止层，所述氧化层形成于所述声表面波滤波器上，所述刻蚀停止层形成于所述氧化层上。
  17. 根据权利要求12所述的MEMS器件的制作方法，其特征在于，形成体声波滤波器的方法包括：提供临时衬底；在所述临时衬底上形成压电叠层结构，所述压电叠层结构包括从临时衬底表面由下至上依次形成的第二电极、压电层、第一电极；形成支撑材料层，覆盖所述压电叠层结构；图形化所述支撑材料层，形成第二空腔和支撑层，所述第二空腔贯穿所述支撑层；在所述支撑层上键合承载衬底，所述承载衬底覆盖所述第二空腔；去除所述临时衬底。
  18. 根据权利要求17所述的MEMS器件的制作方法，其特征在于，在键合所述的体声波滤波器与所述声表面波滤波器之后，还包括：所述声表面波滤波器形成与外部电路电连接的第一电连接结构，所述体声波滤波器形成与外部电路电连接的第二电连接结构；所述第一电连接结构的形成方法包括：通过刻蚀工艺形成第一互连孔，所述第一互连孔从所述承载衬底的一面贯穿并延伸至所述声表面波滤波器的叉指换能器上；在所述第一互连孔中形成第一导电互连层，所述第一导电互连层覆盖所述第一互连孔的内表面；所述第二电连接结构的形成方法包括：通过刻蚀工艺形成第二互连孔，所述第二互连孔从所述承载衬底的一面贯穿并延伸至所述压电叠层的有效谐振区外部的所述第一电极上；在所述第二互连孔中形成第二导电互连层，所述第二导电互连层覆盖所述第二互连孔的内表面。
  19. 根据权利要求18所述的MEMS器件的制作方法，其特征在于，形成所述第一电连接结构和所述第二电连接结构之后，在承载衬底的表面上形成互连线，所述互连线与外部电路电连接，所述第一导电互连层和所述第二导电互连层与所述互连线电连接；所述第一导电互连层包括第一插塞，所述第二导电互连层包括第二插塞。
  20. 根据权利要求12所述的MEMS器件的制作方法，其特征在于，所述第一结构层的材料包括可光刻有机固化膜、氧化硅、氮氧化硅或氮化硅等的任一种。
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9546090B1 (en) * 2015-08-14 2017-01-17 Globalfoundries Singapore Pte. Ltd. Integrated MEMS-CMOS devices and methods for fabricating MEMS devices and CMOS devices
CN111130483A (zh) * 2019-07-25 2020-05-08 珠海晶讯聚震科技有限公司 制造新型电子组件封装件的方法
CN111740715A (zh) * 2020-06-22 2020-10-02 深圳市信维通信股份有限公司 一种滤波装置、一种射频前端装置及一种无线通信装置
CN112039456A (zh) * 2019-07-19 2020-12-04 中芯集成电路（宁波）有限公司 体声波谐振器的封装方法及封装结构
CN112039472A (zh) * 2020-06-18 2020-12-04 中芯集成电路（宁波）有限公司 一种薄膜声波滤波器及其制造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9546090B1 (en) * 2015-08-14 2017-01-17 Globalfoundries Singapore Pte. Ltd. Integrated MEMS-CMOS devices and methods for fabricating MEMS devices and CMOS devices
CN112039456A (zh) * 2019-07-19 2020-12-04 中芯集成电路（宁波）有限公司 体声波谐振器的封装方法及封装结构
CN111130483A (zh) * 2019-07-25 2020-05-08 珠海晶讯聚震科技有限公司 制造新型电子组件封装件的方法
CN112039472A (zh) * 2020-06-18 2020-12-04 中芯集成电路（宁波）有限公司 一种薄膜声波滤波器及其制造方法
CN111740715A (zh) * 2020-06-22 2020-10-02 深圳市信维通信股份有限公司 一种滤波装置、一种射频前端装置及一种无线通信装置

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