CN109150127B - Film bulk acoustic resonator, manufacturing method thereof and filter - Google Patents
Film bulk acoustic resonator, manufacturing method thereof and filter Download PDFInfo
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- CN109150127B CN109150127B CN201810842153.9A CN201810842153A CN109150127B CN 109150127 B CN109150127 B CN 109150127B CN 201810842153 A CN201810842153 A CN 201810842153A CN 109150127 B CN109150127 B CN 109150127B
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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
- H03H9/02007—Details of bulk acoustic wave devices
- H03H9/02015—Characteristics of piezoelectric layers, e.g. cutting angles
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
- H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
- H03H9/171—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator implemented with thin-film techniques, i.e. of the film bulk acoustic resonator [FBAR] type
- H03H9/172—Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume
- H03H9/174—Membranes
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
- H03H9/547—Notch filters, e.g. notch BAW or thin film resonator filters
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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
- H03H2003/023—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks the resonators or networks being of the membrane type
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- Physics & Mathematics (AREA)
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- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
The disclosure provides a film bulk acoustic resonator, a manufacturing method thereof and a filter; wherein, this film bulk acoustic resonator includes: the piezoelectric element comprises a first substrate and a piezoelectric stacking structure formed on the first substrate, wherein the piezoelectric stacking structure is provided with a first contact hole and a second contact hole; and a second substrate having a first protrusion and a second protrusion; the first convex part and the second convex part of the second substrate are respectively bonded with the first contact hole and the second contact hole of the piezoelectric stack structure, and a first air cavity is formed between the second substrate and the piezoelectric stack structure. The film bulk acoustic resonator, the manufacturing method thereof and the filter avoid a complex CMP process, avoid a sacrificial material release technology, reduce the manufacturing difficulty and the production cost of devices, and improve the reliability of the bulk acoustic resonator.
Description
Technical Field
The disclosure belongs to the technical field of wireless communication, and particularly relates to a film bulk acoustic resonator, a manufacturing method thereof and a filter.
Background
With the development of wireless communication technology, people have higher and higher requirements on data transmission speed, and spectrum resources are more and more crowded. To meet the data rate requirements, the spectrum must be fully utilized, and therefore a handset must be able to cover a wide range of frequency bands, so that different people's devices can be allocated sufficient spectrum bandwidth in the event of crowding. Meanwhile, carrier aggregation technology is also used from 4G, so that one device can transmit data by using different carrier spectrums at the same time. On the other hand, in order to support a sufficient data transmission rate within a limited bandwidth, communication protocols are becoming more and more complex, and thus stringent requirements are also placed on various performances of the radio frequency system.
The radio frequency filter is used as an important component in a radio frequency front-end module, and can filter interference and noise outside a communication frequency spectrum so as to meet the requirements of a radio frequency system and a communication protocol on signal to noise ratio. With the complexity of communication protocols, the performance requirements of filters are higher and higher, and the design of filters is more and more challenging. In addition, as the number of frequency bands that a mobile phone needs to support increases, the number of filters that a mobile phone needs to use increases because each frequency band needs to have its own filter. Generally, the number of filters needed in a conventional 4G mobile phone can reach more than 30.
At present, the most popular implementations of rf filters are Surface Acoustic Wave (SAW) devices and Bulk Acoustic Wave (BAW) devices.
SAW has been widely used because of its simple structure and low manufacturing cost. However, since the operating frequency is inversely proportional to the electrode line width, when the operating frequency exceeds 2GHz, the electrode line width is less than 0.5um, which may cause the quality factor and power endurance of the SAW device to be reduced, and thus, the SAW device is not suitable for high frequency applications.
The BAW filter is different from a SAW filter, the acoustic wave in the BAW filter vertically propagates, the frequency of the acoustic wave is inversely proportional to the thickness of the film, and theoretically, the BAW filter can meet the communication requirement within 20 GHz. Therefore, with the popularization of 4G and the commissioning of 5G, the application of BAW filters will become more and more extensive.
The bulk acoustic wave resonators are basic components forming the bulk acoustic wave filter, and the bulk acoustic wave filters with different performances can be manufactured by cascading different bulk acoustic wave resonators so as to meet different market requirements.
Qorvo usa company uses a multilayer thin film to form a bragg reflective layer, and a bulk acoustic wave resonator is formed above the bragg reflective layer. Acoustic wave energy is confined in the device structure by the bragg reflector layer. On one hand, the method needs to add a multilayer film process, the process complexity is high, the design difficulty is high, and on the other hand, a small amount of sound wave energy leaks into the substrate, so that the quality factor Q of the device is influenced.
US7802349B2 teaches a method of fabricating an air-gap bulk acoustic wave resonator using a sacrificial material to form a cavity. The method requires introduction of a Chemical Mechanical Polishing (CMP) technique and a sacrificial layer release technique, has high process complexity, has limitations in material selection, and may affect the reliability of the device.
The chinese invention patent CN104767500A proposes a method for manufacturing an acoustic wave resonator of air gap type body by using a preparation substrate to form a cavity. The method needs to utilize a temporary bonding process, has limitation on substrate material selection, is complex in manufacturing process, and may damage a device structure in a thin film transfer process, thereby affecting yield.
In summary, the prior art mainly has the following technical defects:
(1) In the manufacturing process, a CMP technology is required, the process is complex, the equipment is expensive, and the manufacturing cost is high.
(2) The sacrificial material release process requires that the materials used for the substrate and device must be insoluble in the release chemistry.
(3) The sacrificial material release process can result in long term exposure of the device to chemical solutions, affecting device reliability.
(4) The Bragg reflection layer is complex in manufacturing process, high in cost, high in design difficulty, and cannot be further improved in quality factor due to acoustic wave leakage.
Disclosure of Invention
Technical problem to be solved
Based on the above problems, an object of the present disclosure is to provide a thin film bulk acoustic resonator, a method for manufacturing the same, and a filter, which are used to solve at least one of the above technical problems.
(II) technical scheme
In order to achieve the above object, as one aspect of the present disclosure, there is provided a thin film bulk acoustic resonator comprising:
the piezoelectric device comprises a first substrate and a piezoelectric stacking structure formed on the first substrate, wherein the piezoelectric stacking structure is provided with a first contact hole and a second contact hole; and
a second substrate having a first convex portion and a second convex portion;
the first convex part and the second convex part of the second substrate are respectively bonded with the first contact hole and the second contact hole of the piezoelectric stack structure, and a first air cavity is formed between the second substrate and the piezoelectric stack structure.
In some embodiments, the first protrusion corresponds to the first contact hole, the second protrusion corresponds to the second contact hole, and heights of the first protrusion and the second protrusion are greater than depths of the first contact hole and the second contact hole, respectively.
In some embodiments, a second air cavity is formed on the first substrate, and the second air cavity is opposite to the first air cavity in position;
a third contact hole and a fourth contact hole are respectively formed on two sides of the second air cavity, the third contact hole is opposite to the first contact hole, and the fourth contact hole is opposite to the second contact hole;
a first pad is formed at the third contact hole and a second pad is formed at the fourth contact hole.
In some embodiments, the piezoelectric stack structure comprises: a first electrode, a piezoelectric layer formed on the first electrode, and a second electrode formed on the piezoelectric layer;
the first convex part is bonded with the first contact hole and is contacted with the first surface of the second electrode through the first contact hole, and the second convex part is bonded with the second contact hole and is contacted with the first surface of the first electrode through the second contact hole;
the first pad is in contact with the second surface of the second electrode through the third contact hole, and the second pad is in contact with the second surface of the first electrode through the fourth contact hole;
the first surface of the first electrode is opposite to a second surface of the first electrode, and the first surface of the second electrode is opposite to a second surface of the second electrode;
the second air cavity is located on the first substrate and is opposite to an overlapping region of the first electrode and the second electrode in the piezoelectric stack structure, and the area of the second air cavity is larger than or equal to that of the overlapping region.
In some embodiments, the first substrate and the second substrate are made of silicon,SOI, glass, sapphire, silicon carbide, gaAs, gaN, liNbO 3 Or LiTaO 3 ；
The film bulk acoustic resonator also comprises an isolation layer on the first substrate, and the isolation layer is made of SiO 2 、Si 3 N 4 One or more of silicon oxynitride or AlN;
the first electrode and the second electrode are made of one or a combination of more of Mo, W, al, cu, ir, ru and Si;
the piezoelectric film is made of quartz, alN, znO, PZT and LiNbO 3 、LiTaO 3 And their combination, or quartz, alN, znO, PZT, liNbO doped with rare earth elements 3 、LiTaO 3 And combinations thereof;
the film bulk acoustic resonator also comprises a passivation layer on the second electrode, and the passivation layer is made of SiO 2 、Si 3 N 4 Silicon oxynitride, alN or Al 2 O 3 。
According to another aspect of the present disclosure, there is provided a method for manufacturing a thin film bulk acoustic resonator, including:
forming a piezoelectric stack structure having a first contact hole and a second contact hole on a first substrate;
forming a first convex portion and a second convex portion on a second substrate; and
and aligning and bonding the first convex part and the second convex part of the second substrate with the first contact hole and the second contact hole of the piezoelectric stack structure respectively, and forming a first air cavity between the second substrate and the piezoelectric stack structure.
In some embodiments, the first protrusion corresponds to the first contact hole, the second protrusion corresponds to the second contact hole, and heights of the first protrusion and the second protrusion are greater than depths of the first contact hole and the second contact hole, respectively.
In some embodiments, the method for manufacturing a film bulk acoustic resonator further includes:
forming a second air cavity on the first substrate, wherein the second air cavity is opposite to the first air cavity in position;
a third contact hole and a fourth contact hole are respectively formed on two sides of the second air cavity, the third contact hole is opposite to the first contact hole, and the fourth contact hole is opposite to the second contact hole;
a first pad is formed at the third contact hole and a second pad is formed at the fourth contact hole.
In some embodiments, the step of forming a piezoelectric stack structure having a first contact hole and a second contact hole on a first substrate includes:
providing a first substrate;
forming an isolation layer on the first substrate;
forming a first electrode on the isolation layer;
forming a piezoelectric layer on the first electrode, and etching the piezoelectric layer to form a first contact hole and a second contact hole;
forming a second electrode on the piezoelectric layer, and etching the second electrode to expose the second contact hole; and
forming a passivation layer on the second electrode, and etching the passivation layer to expose the first and second contact holes;
the step of forming a first projection and a second projection on a second substrate includes:
providing a second substrate, and
and etching the second substrate to form the first convex part and the second convex part.
According to another aspect of the present disclosure, there is provided a filter comprising a plurality of the thin film bulk acoustic resonators in cascade.
(III) advantageous effects
(1) The film bulk acoustic resonator, the manufacturing method thereof and the filter avoid a complex CMP process and reduce the manufacturing difficulty of devices.
(2) The method avoids a sacrificial material release process, so that the selection range of the manufacturing materials of the bulk acoustic wave resonator is wider, and the production cost is reduced.
(3) The device is prevented from being exposed in chemical liquid medicine for a long time, the reliability of the bulk acoustic wave resonator is improved, and meanwhile, the harm of the chemical liquid medicine to the environment is reduced.
(4) The overlapped area (the effective area of the bulk acoustic wave resonator) among the first electrode, the piezoelectric layer and the second electrode of the bulk acoustic wave resonator can be completely positioned in the air cavity and is not in contact with any substrate, so that the leakage of acoustic wave energy is reduced, and the quality factor of the bulk acoustic wave resonator is improved.
Drawings
Fig. 1 is a schematic structural diagram of a film bulk acoustic resonator according to the present disclosure.
Fig. 2 is a schematic diagram of a filter structure according to the present disclosure.
Fig. 3-9 are schematic diagrams illustrating a process for fabricating a film bulk acoustic resonator according to the present disclosure.
< description of symbols >
1-first substrate, 2-isolation layer, 3-first electrode, 4-piezoelectric layer, 5-second electrode, 6-passivation layer, 7-second substrate, 8-first pad, 9-first contact hole, 10-second contact hole, 11-first convex part, 12-second convex part, 13-first air cavity, 14-second air cavity, 15-third contact hole, 16-fourth contact hole, 17-second pad, 18-thin film bulk acoustic resonator.
Detailed Description
For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.
The present disclosure provides a thin film bulk acoustic resonator, as shown in fig. 1, including:
a first substrate 1 and a piezoelectric stack structure formed on the first substrate, the piezoelectric stack structure having a first contact hole 9 and a second contact hole 10; and
a second substrate 7 having a first convex portion 11 and a second convex portion 12;
the first convex part and the second convex part of the second substrate are respectively bonded with the first contact hole and the second contact hole of the piezoelectric stack structure, and a first air cavity 13 is formed between the second substrate and the piezoelectric stack structure.
Further, the first convex part corresponds to the first contact hole, the second convex part corresponds to the second contact hole, the height of the first convex part is larger than the depth of the first contact hole, and the height of the second convex part is larger than the depth of the second contact hole.
A second air cavity 14 is formed on the first substrate, and the second air cavity is opposite to the first air cavity in position; preferably, the second air cavity is located on the first substrate, opposite to an overlapping region of the first electrode and the second electrode in the piezoelectric stack structure, and the area of the second air cavity is greater than or equal to the area of the overlapping region. A third contact hole 15 and a fourth contact hole 16 are respectively formed on two sides of the second air cavity, the third contact hole is opposite to the first contact hole, and the fourth contact hole is opposite to the second contact hole; a first pad 8 is formed at the third contact hole and a second pad 17 is formed at the fourth contact hole.
The piezoelectric stack structure includes: a first electrode 3, a piezoelectric layer 4 formed on the first electrode, and a second electrode 5 formed on the piezoelectric layer; the first electrode, the piezoelectric layer and the second electrode form a sandwich-like structure, and the overlapping area of the three layers and the cavity is an Active area (Active area) of the resonator. Optionally, the piezoelectric stack structure further includes: an isolation layer 2 on which the first electrode 3 is formed, and a passivation layer 6 on which the passivation layer 6 is formed.
The first convex part is bonded with the first contact hole and is contacted with the first surface of the second electrode through the first contact hole, and the second convex part is bonded with the second contact hole and is contacted with the first surface of the first electrode through the second contact hole; the first pad is in contact with the second surface of the second electrode through the third contact hole, and the second pad is in contact with the second surface of the first electrode through the fourth contact hole; the first surface of the first electrode is opposite to a second surface of the first electrode, and the first surface of the second electrode is opposite to a second surface of the second electrode.
In addition, the film bulk acoustic resonator may further include an electronic component formed on the second substrate, and the electronic component may include a capacitor unit, an inductor unit, or another electronic component having an independent function.
The bulk acoustic wave resonator structure directly manufactured on the substrate is fixed in an air cavity in a bonding mode, the substrate part on the other side of the bulk acoustic wave resonator is removed through a back etching process, and air interfaces are formed on the upper interface and the lower interface of the bulk acoustic wave resonator.
Specifically, the first substrate and the second substrate may be made of silicon, SOI, glass, sapphire, silicon carbide, gaAs, gaN, liNbO 3 、LiTaO 3 And the like.
The isolation layer can be made of SiO 2 、Si 3 N 4 Silicon oxynitride, alN, and the like.
The first electrode can be a composite structure formed by one or more of Mo, W, al, cu, ir, ru and Si.
The piezoelectric film is made of quartz, alN, znO, PZT and LiNbO 3 、LiTaO 3 And their combination, or quartz, alN, znO, PZT, liNbO doped with rare earth elements 3 、LiTaO 3 And combinations thereof.
The material of the second electrode can be one or more of Mo, W, al, cu, ir, ru and Si, and can be the same material as or different from that of the first electrode.
The passivation layer can be made of SiO 2 、Si 3 N 4 Silicon oxynitride, alN, al 2 O 3 And the like.
The bonding pad can be in one or more composite structures of Al, cu, au, ti, ni, ag, W, tiW and the like.
The present disclosure also provides a filter, as shown in fig. 2, which includes a plurality of thin film bulk acoustic resonators 18 connected in cascade, at least one of the thin film bulk acoustic resonators being in the series branch, and at least one of the thin film bulk acoustic resonators being in the parallel branch.
In addition, the present disclosure also provides a method for manufacturing a film bulk acoustic resonator, including:
forming a piezoelectric stack structure with a first contact hole and a second contact hole on a first substrate;
forming a first convex portion and a second convex portion on a second substrate; and
and bonding the first convex part and the second convex part of the second substrate with the first contact hole and the second contact hole of the piezoelectric stack structure, and forming a first air cavity between the second substrate and the piezoelectric stack structure.
Further, the method for manufacturing the film bulk acoustic resonator may further include, after the step of bonding: etching away a part of the first substrate at the back surface of the first substrate, thereby forming a third contact hole, a fourth contact hole and a second air cavity (the third contact hole and the fourth contact hole are respectively formed at two sides of the second air cavity); the third contact hole is in contact with the second electrode of the piezoelectric stack structure, the fourth contact hole is in contact with the first electrode of the piezoelectric stack structure, the second air cavity is located below the overlapping area of the first electrode and the second electrode in the piezoelectric stack structure, and the area of the second air cavity is larger than or equal to the area of the overlapping area of the first electrode and the second electrode.
Wherein the step of forming a piezoelectric stack structure having a first contact hole and a second contact hole on a first substrate includes:
providing a first substrate;
forming an isolation layer on the first substrate;
forming a first electrode on the isolation layer;
forming a piezoelectric layer on the first electrode, and etching the piezoelectric layer to form a first contact hole and a second contact hole;
forming a second electrode on the piezoelectric layer, and etching the second electrode to expose the second contact hole; and
forming a passivation layer on the second electrode, and etching the passivation layer to expose the first and second contact holes.
Optionally, a material for bonding is formed at the first contact hole and the second contact hole.
Further, the step of forming a first convex portion and a second convex portion on the second substrate includes:
providing a second substrate, and
and etching the second substrate to form the first convex part and the second convex part.
Alternatively, a material for bonding is formed on the first convex portion and the second convex portion.
The following describes the fabrication process of the film bulk acoustic resonator according to the present disclosure in detail with reference to fig. 3 to 9. The manufacturing method of the film bulk acoustic resonator specifically comprises the following steps:
s1, manufacturing an isolation layer and a first electrode, wherein the manufacturing method comprises the following substeps:
s11, depositing an isolation layer 2 on a first substrate 1; wherein the isolation layer 2 completely covers the front surface of the first substrate 1.
S12, depositing a layer of first electrode 3 on the isolation layer 2; wherein the first electrode 3 partially covers the isolation layer 2, as shown in fig. 3. Specifically, a layer of metal is grown on the isolation layer 2, and then the layer of metal is etched into the first electrode 3, which can be formed by sputtering, photolithography, etching, and other processes.
S2, manufacturing a piezoelectric layer:
specifically, a layer of piezoelectric material is deposited on the first electrode 3, and then the layer of piezoelectric material is etched into the piezoelectric layer 4, as shown in fig. 4. Wherein the piezoelectric material is etched to form a piezoelectric layer having a first contact hole 9 and a second contact hole 10. At the moment, etching is stopped at the front surface of the isolating layer at the first contact hole; at the second contact hole, the etching is terminated at the first surface (i.e. the front surface) of the first electrode.
S3, manufacturing a second electrode and a passivation layer, wherein the manufacturing method comprises the following substeps:
s31, growing a layer of metal on the piezoelectric layer 4, etching the layer of metal into the second electrode 5, and etching the second electrode to expose the second contact hole, wherein deposition, photolithography, etching and other processes may be used.
And S32, depositing a passivation layer 6 on the second electrode 5, and then etching the passivation layer to expose the first contact hole and the second contact hole, wherein deposition, photoetching, etching and other processes can be adopted. The passivation layer 6 does not cover the first contact hole and the second contact hole locations, as shown in fig. 5.
S4, fabricating a second substrate 7, specifically, etching the second substrate 7 to form a first protrusion 11 and a second protrusion 12, as shown in fig. 6.
S5, bonding the first substrate 1 and the second substrate 7, and thinning the first substrate 1, specifically, bonding the first contact hole and the second contact hole of the first substrate 1 with the first protrusion and the second protrusion of the second substrate 7, respectively, to form a first air cavity 13, and thinning the back surface of the first substrate 1, as shown in fig. 7. Specifically, bonding can be achieved by thermocompression bonding, anodic bonding, eutectic bonding, polymer bonding, and the like.
And S6, manufacturing a bonding pad.
As shown in fig. 8, the first substrate 1 is etched from its back surface, a portion of the first substrate is removed, and a third contact hole 15, a fourth contact hole 16 and a second cavity 14 are formed on the first substrate 1, thereby forming an air interface at the back of the device.
Further, a first pad 8 and a second pad 17 are formed at the third contact hole 15 and the fourth contact hole 16, the first pad 8 is connected to the second electrode 5 of the piezoelectric stack structure through the third contact hole 15, the second pad 17 is connected to the first electrode 3 of the piezoelectric stack structure through the fourth contact hole 16, and the first pad 8 and the second pad 17 extend from the third contact hole 15 and the fourth contact hole 16 to the back surface of the first substrate 1 respectively
In the above steps of the method, the etching method includes, but is not limited to, a wet etching technique, inductively Coupled Plasma (ICP) etching, reactive Ion Etching (RIE), and the like. The deposition methods include, but are not limited to, chemical vapor deposition, magnetron sputtering, electrochemical deposition, atomic Layer Deposition (ALD), molecular Beam Epitaxy (MBE), and the like.
In general, the method for manufacturing a film bulk acoustic resonator mainly includes: sequentially manufacturing an isolation layer, a first electrode, a piezoelectric layer, a second electrode and a passivation layer on a first substrate; placing one side of the device in a cavity by substrate bonding; and partially removing the substrate on the back side of the device and forming an air interface on the back side of the device. In addition, a connecting electrode, a bonding pad and the like can be introduced into the back surface of the device, so that the device is conveniently connected with other circuits.
Furthermore, the above definitions of the various elements and methods are not limited to the particular structures, shapes or arrangements of parts mentioned in the examples, which may be easily modified or substituted by one of ordinary skill in the art, for example:
(1) The film bulk acoustic resonator can also not comprise an isolation layer;
(2) The film bulk acoustic resonator can be additionally provided with a third electrode and a fourth electrode above or below the second electrode;
(3) The piezoelectric layer may be formed of a doped piezoelectric material or a non-doped piezoelectric material, without affecting the implementation of the present disclosure.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, this disclosure should not be construed to reflect the intent: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
It is also noted that the examples provided herein include parameters of particular values, but these parameters need not be exactly equal to the corresponding values, but may be approximated to the corresponding values within acceptable error margins or design constraints. Directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only directions referring to the drawings, and do not limit the scope of the present invention. Further, unless steps are specifically described or must occur in sequence, the order of the steps is not limited to that listed above and may be changed or rearranged as desired by the desired design. The embodiments described above may be mixed and matched with each other or with other embodiments based on design and reliability considerations, i.e., technical features in different embodiments may be freely combined to form further embodiments.
The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.
Claims (10)
1. A thin film bulk acoustic resonator comprising:
the piezoelectric device comprises a first substrate and a piezoelectric stacking structure formed on the first substrate, wherein the piezoelectric stacking structure is provided with a first contact hole and a second contact hole; and
a second substrate having a first protrusion and a second protrusion;
the first convex part and the second convex part of the second substrate are respectively bonded with the first contact hole and the second contact hole of the piezoelectric stack structure, and a first air cavity is formed between the second substrate and the piezoelectric stack structure; and a second air cavity is formed on the first substrate and is opposite to the first air cavity.
2. The film bulk acoustic resonator according to claim 1, wherein the first convex portion corresponds to the first contact hole, the second convex portion corresponds to the second contact hole, and heights of the first convex portion and the second convex portion are larger than depths of the first contact hole and the second contact hole, respectively.
3. The thin film bulk acoustic resonator of claim 2,
a third contact hole and a fourth contact hole are respectively formed on two sides of the second air cavity, the third contact hole is opposite to the first contact hole, and the fourth contact hole is opposite to the second contact hole;
a first pad is formed at the third contact hole and a second pad is formed at the fourth contact hole.
4. The thin film bulk acoustic resonator of claim 3, wherein the piezoelectric stack comprises: a first electrode, a piezoelectric layer formed on the first electrode, and a second electrode formed on the piezoelectric layer;
the first convex part is bonded with the first contact hole and is contacted with the first surface of the second electrode through the first contact hole, and the second convex part is bonded with the second contact hole and is contacted with the first surface of the first electrode through the second contact hole;
the first pad is in contact with the second surface of the second electrode through the third contact hole, and the second pad is in contact with the second surface of the first electrode through the fourth contact hole;
the first surface of the first electrode is opposite to a second surface of the first electrode, and the first surface of the second electrode is opposite to a second surface of the second electrode;
the second air cavity is located on the first substrate and is opposite to an overlapping region of the first electrode and the second electrode in the piezoelectric stack structure, and the area of the second air cavity is larger than or equal to that of the overlapping region.
5. The thin film bulk acoustic resonator of claim 4,
the first substrate and the second substrate are made of silicon, SOI, glass, sapphire, silicon carbide, gaAs, gaN and LiNbO 3 Or LiTaO 3 ；
The film bulk acoustic resonator also comprises an isolation layer on the first substrate, and the isolation layer is made of SiO 2 、Si 3 N 4 One or more of silicon oxynitride or AlN;
the first electrode and the second electrode are made of one or a combination of more of Mo, W, al, cu, ir, ru and Si;
the piezoelectric layer is made of quartz, alN, znO, PZT or LiNbO 3 、LiTaO 3 And their combination, or quartz, alN, znO, PZT, liNbO doped with rare earth elements 3 、LiTaO 3 And combinations thereof;
the film bulk acoustic resonator also comprises a passivation layer on the second electrode, and the passivation layer is made of SiO 2 、Si 3 N 4 Silicon oxynitride, alN or Al 2 O 3 。
6. A method for manufacturing a film bulk acoustic resonator comprises the following steps:
forming a piezoelectric stack structure having a first contact hole and a second contact hole on a first substrate;
forming a first convex portion and a second convex portion on a second substrate; and
aligning and bonding the first convex part and the second convex part of the second substrate with the first contact hole and the second contact hole of the piezoelectric stack structure respectively, and forming a first air cavity between the second substrate and the piezoelectric stack structure; and forming a second air cavity on the first substrate, wherein the second air cavity is opposite to the first air cavity in position.
7. The method of manufacturing a thin film bulk acoustic resonator according to claim 6, wherein the first convex portion corresponds to the first contact hole, the second convex portion corresponds to the second contact hole, and heights of the first convex portion and the second convex portion are larger than depths of the first contact hole and the second contact hole, respectively.
8. The method of manufacturing a thin film bulk acoustic resonator according to claim 6, further comprising:
a third contact hole and a fourth contact hole are respectively formed on two sides of the second air cavity, the third contact hole is opposite to the first contact hole, and the fourth contact hole is opposite to the second contact hole;
a first pad is formed at the third contact hole and a second pad is formed at the fourth contact hole.
9. The method of manufacturing a thin film bulk acoustic resonator according to claim 6,
the step of forming a piezoelectric stack structure having a first contact hole and a second contact hole on a first substrate includes:
providing a first substrate;
forming an isolation layer on the first substrate;
forming a first electrode on the isolation layer;
forming a piezoelectric layer on the first electrode, and etching the piezoelectric layer to form a first contact hole and a second contact hole;
forming a second electrode on the piezoelectric layer, and etching the second electrode to expose the second contact hole; and
forming a passivation layer on the second electrode, and etching the passivation layer to expose the first and second contact holes;
the step of forming a first projection and a second projection on a second substrate includes:
providing a second substrate, and
and etching the second substrate to form the first convex part and the second convex part.
10. A filter comprising a plurality of thin film bulk acoustic resonators as claimed in any one of claims 1 to 5 in cascade.
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| CN109981070B (en) * | 2019-03-13 | 2020-06-16 | 电子科技大学 | Cavity type bulk acoustic wave resonator without preparing sacrificial layer and preparation method thereof |
| CN111010128A (en) * | 2019-06-05 | 2020-04-14 | 天津大学 | Resonator with ring structure, filter and electronic equipment |
| CN112039463B (en) * | 2019-08-09 | 2024-03-12 | 中芯集成电路（宁波）有限公司 | Method for manufacturing film bulk acoustic resonator |
| CN111030627A (en) * | 2019-12-31 | 2020-04-17 | 武汉衍熙微器件有限公司 | Method for manufacturing acoustic wave device and acoustic wave device |
| CN111030634B (en) * | 2019-12-31 | 2021-04-16 | 诺思(天津)微系统有限责任公司 | Bulk acoustic wave resonator with electrical isolation layer, method of manufacturing the same, filter, and electronic apparatus |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| JP4373949B2 (en) * | 2004-04-20 | 2009-11-25 | 株式会社東芝 | Thin film piezoelectric resonator and manufacturing method thereof |
| CN100527615C (en) * | 2004-04-20 | 2009-08-12 | 株式会社东芝 | Film bulk acoustic-wave resonator and method for manufacturing the same |
| JP4513596B2 (en) * | 2004-08-25 | 2010-07-28 | 株式会社デンソー | Ultrasonic sensor |
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| US9129942B2 (en) * | 2012-06-05 | 2015-09-08 | International Business Machines Corporation | Method for shaping a laminate substrate |
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| CN105262455B (en) * | 2015-10-09 | 2018-07-31 | 锐迪科微电子（上海）有限公司 | A kind of thin film bulk acoustic wave resonator and its manufacturing method of high reliability |
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| KR102588795B1 (en) * | 2016-02-18 | 2023-10-13 | 삼성전기주식회사 | Acoustic resonator and manufacturing method thereof |
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