CN115276600B - Film bulk acoustic resonator and preparation method thereof - Google Patents
Film bulk acoustic resonator and preparation method thereof Download PDFInfo
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- CN115276600B CN115276600B CN202211062831.2A CN202211062831A CN115276600B CN 115276600 B CN115276600 B CN 115276600B CN 202211062831 A CN202211062831 A CN 202211062831A CN 115276600 B CN115276600 B CN 115276600B
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- 238000002360 preparation method Methods 0.000 title abstract description 9
- 239000000758 substrate Substances 0.000 claims description 87
- 239000010409 thin film Substances 0.000 claims description 40
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 11
- 238000005530 etching Methods 0.000 claims description 10
- 238000000059 patterning Methods 0.000 claims description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 8
- 238000000151 deposition Methods 0.000 claims description 8
- 235000012239 silicon dioxide Nutrition 0.000 claims description 4
- 239000000377 silicon dioxide Substances 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 description 22
- 238000010586 diagram Methods 0.000 description 20
- 239000010408 film Substances 0.000 description 9
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 1
Classifications
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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
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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
- H03H9/02086—Means for compensation or elimination of undesirable effects
- H03H9/02118—Means for compensation or elimination of undesirable effects of lateral leakage between adjacent resonators
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- 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)
- Acoustics & Sound (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
The application provides a film bulk acoustic resonator and a preparation method thereof, and relates to the technical field of film bulk acoustic devices. The first air bridge limits the sound wave energy passing through the bottom electrode, and meanwhile, the first groove is formed in the piezoelectric layer in the non-effective area so as to reduce the transverse sound wave leakage of the piezoelectric layer, so that the sound wave energy leakage is sufficiently reduced, and the Q value of the resonator is improved.
Description
Technical Field
The application relates to the technical field of film bulk acoustic wave devices, in particular to a film bulk acoustic wave resonator and a preparation method thereof.
Background
The conventional thin film bulk acoustic resonator is composed of a three-layer laminated structure, as shown in fig. 1, in which a bottom electrode, a piezoelectric layer, and a top electrode are laminated in this order on a substrate, and the region where the bottom electrode, the piezoelectric layer, and the top electrode overlap is an effective region. The resonator vibrates up and down during operation to generate standing waves to form resonance, but part of the acoustic wave energy leaks in the inactive area, so that the Q value of the resonator is reduced, as shown by the wavy line in fig. 1, and the wavy line represents the leaked acoustic wave energy.
In the prior art, when the acoustic wave energy leakage is solved, the corresponding structure is basically designed on the electrode to reduce the transverse acoustic wave leakage, and the structure designed on the electrode to reflect the acoustic wave leakage passing through the electrode part can be reflected to the greatest extent. However, the reflection efficiency of the leakage of the sound wave existing in the piezoelectric material is greatly reduced, and the sound wave in the piezoelectric material cannot be reflected well.
Disclosure of Invention
The embodiment of the application aims to provide a film bulk acoustic resonator and a preparation method thereof, which can reduce transverse acoustic leakage of a piezoelectric material layer, fully reduce acoustic energy leakage and improve the Q value of the resonator.
In one aspect of the embodiment of the application, a thin film bulk acoustic resonator is provided, which comprises a substrate, wherein a bottom electrode, a piezoelectric layer and a top electrode are sequentially laminated on the substrate, a cavity is formed between the substrate and the bottom electrode, an effective area is formed in a region where projections of the bottom electrode, the piezoelectric layer and the top electrode on the substrate overlap, a first air bridge is formed between the bottom electrode and the piezoelectric layer, a first groove is formed on the piezoelectric layer outside the effective area, the first groove is positioned on one side of the piezoelectric layer, which is away from the bottom electrode, and the first groove and the first air bridge are correspondingly arranged in a projection direction.
Optionally, the first groove communicates with the first air bridge.
Optionally, a second air bridge is formed between the top electrode and the piezoelectric layer, a second groove is formed on the piezoelectric layer outside the effective area at a position corresponding to the second air bridge in the projection direction, and the second groove is communicated with the cavity.
Optionally, the second groove communicates with the second air bridge.
In another aspect of the embodiments of the present application, a method for preparing a thin film bulk acoustic resonator is provided, which is used for preparing the thin film bulk acoustic resonator, including: providing a substrate with a groove, wherein the groove is formed on one side of the substrate; forming a bottom electrode on the substrate at a side where the groove is provided, and forming a cavity between the substrate and the bottom electrode through the groove; depositing a first sacrificial layer in the groove, and patterning the first sacrificial layer to form a first air bridge, wherein the bottom electrode covers the substrate and exposes part of the substrate; forming a piezoelectric layer with a first groove on the patterned bottom electrode, so that the piezoelectric layer covers the substrate, wherein the first groove is formed on one side away from the bottom electrode; and forming and patterning a top electrode on the piezoelectric layer, and enabling the top electrode to cover the piezoelectric layer and expose the area of the piezoelectric layer where the first groove is formed.
Optionally, the providing a substrate with a groove, the groove formed on one side of the substrate includes: providing the substrate; and etching the substrate to form the groove.
Optionally, a bottom electrode is formed on the side, on which the groove is formed, of the substrate, and a cavity is formed between the substrate and the bottom electrode through the groove; depositing a first sacrificial layer within the recess and patterning the first sacrificial layer for forming a first air bridge, the bottom electrode overlying the substrate and exposing a portion of the substrate comprising: etching a groove for forming the first air bridge on the first sacrificial layer; the bottom electrode is formed on the substrate, and the cavity is formed at the groove.
Optionally, the forming a piezoelectric layer with a first groove on the patterned bottom electrode, so that the piezoelectric layer covers the substrate, where the first groove is formed on a side facing away from the bottom electrode includes: depositing a second sacrificial layer at the position of the bottom electrode corresponding to the groove so as to enable the surfaces of the second sacrificial layer and the bottom electrode to be flush; the piezoelectric layer is deposited on the bottom electrode.
Optionally, the forming and patterning a top electrode on the piezoelectric layer, and covering the piezoelectric layer with the top electrode, and exposing a region of the piezoelectric layer where the first groove is provided includes: forming the top electrode on the piezoelectric layer, and patterning the top electrode so that the top electrode partially covers the piezoelectric layer; and etching the first groove at the exposed position of the piezoelectric layer corresponding to the groove, and simultaneously releasing the first sacrificial layer and the second sacrificial layer to respectively form the cavity and the first air bridge.
Optionally, the material of the substrate comprises silicon, and the material of the first sacrificial layer and the second sacrificial layer comprises silicon dioxide.
According to the thin film bulk acoustic resonator and the preparation method thereof provided by the embodiment of the application, the bottom electrode, the piezoelectric layer and the top electrode are sequentially laminated on the substrate with the cavity, the cavity is arranged between the substrate and the bottom electrode, the effective area is formed in the area where projections of the bottom electrode, the piezoelectric layer and the top electrode are overlapped on the substrate respectively, a first air bridge is formed between the bottom electrode and the piezoelectric layer outside the effective area, a first groove corresponding to the projection direction of the first air bridge is formed on the piezoelectric layer, the first groove is arranged on one side of the piezoelectric layer, which is away from the bottom electrode, and the first air bridge is used for limiting acoustic wave energy passing through the bottom electrode, and meanwhile, the first groove is formed on the piezoelectric layer in the non-effective area so as to reduce transverse acoustic wave leakage of the piezoelectric layer, so that the leakage of the acoustic wave energy is reduced sufficiently, and the Q value of the resonator is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a thin film bulk acoustic resonator according to one embodiment;
FIG. 2 is a schematic diagram of a thin film bulk acoustic resonator according to a second embodiment;
FIG. 3 is a third schematic diagram of a thin film bulk acoustic resonator according to the present embodiment;
FIG. 4 is a schematic diagram of a thin film bulk acoustic resonator according to the present embodiment;
FIG. 5 is a schematic view of a substrate in a method for manufacturing a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 6 is a schematic diagram of forming a cavity on a substrate in a method for manufacturing a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 7 is a schematic diagram of a second cavity formed on a substrate in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 8 is a schematic diagram of depositing a first sacrificial layer in a cavity in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 9 is a schematic diagram showing a second method for depositing a first sacrificial layer in a cavity in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 10 is a schematic diagram of etching a trench in a first sacrificial layer in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 11 is a schematic diagram of a second sacrificial layer etching a trench in the method for manufacturing a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 12 is a schematic diagram of forming a bottom electrode on a substrate in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 13 is a second schematic diagram of a bottom electrode formed on a substrate in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 14 is a schematic diagram of a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application, in which a second sacrificial layer is deposited on a bottom electrode;
FIG. 15 is a schematic diagram showing a second sacrificial layer deposited on a bottom electrode in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 16 is a schematic diagram of a piezoelectric layer formed on a bottom electrode in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 17 is a schematic diagram of a second piezoelectric layer formed on a bottom electrode in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 18 is a schematic diagram of forming a top electrode on a piezoelectric layer in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 19 is a schematic diagram of a second example of forming a top electrode on a piezoelectric layer in a method for fabricating a thin film bulk acoustic resonator according to an embodiment of the present application;
FIG. 20 is a schematic diagram of forming a first groove and a first air bridge in a method for manufacturing a film bulk acoustic resonator according to an embodiment of the present application;
fig. 21 is a second schematic diagram of forming a first groove and a first air bridge in the method for manufacturing a film bulk acoustic resonator according to an embodiment of the present application.
Icon: 1-a substrate; a 2-piezoelectric layer; 3-top electrode; 4-a first groove; 5-a bottom electrode; 6-cavity; 7-a first air bridge; 8-a second groove; 9-a second air bridge; 10-release holes; 11-a first sacrificial layer; 12-grooves; 13-a second sacrificial layer.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.
In the description of the present application, it should be noted that, the azimuth or positional relationship indicated by the terms "inner", "outer", etc. are based on the azimuth or positional relationship shown in the drawings, or the azimuth or positional relationship that is commonly put in use of the product of this application, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and therefore should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
It should also be noted that the terms "disposed," "coupled," and "connected" are to be construed broadly, and may be, for example, fixedly coupled, detachably coupled, or integrally coupled, unless otherwise specifically defined and limited; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.
In the existing film bulk acoustic resonator, transverse acoustic leakage is reduced by designing a corresponding structure on the electrode, and the structure for reflecting the acoustic wave on the electrode can reflect the acoustic wave leakage passing through the electrode to the greatest extent so as to solve the problem of acoustic wave energy leakage. However, the reflection efficiency of the leakage of the sound wave existing in the piezoelectric material is greatly reduced, and the sound wave in the piezoelectric material cannot be reflected well.
In order to solve the above-mentioned problems, referring to fig. 1, an embodiment of the present application provides a thin film bulk acoustic resonator, which includes a substrate 1, a bottom electrode 5, a piezoelectric layer 2 and a top electrode 3 sequentially stacked on the substrate 1, a cavity 6 is formed between the substrate 1 and the bottom electrode 5, an effective area is formed in a region where projections of the bottom electrode 5, the piezoelectric layer 2 and the top electrode 3 on the substrate 1 overlap, a first air bridge 7 is formed between the bottom electrode 5 and the piezoelectric layer 2, a first groove 4 is formed on the piezoelectric layer 2 outside the effective area, the first groove 4 is located on a side of the piezoelectric layer 2 away from the bottom electrode 5, and the first groove 4 and the first air bridge 7 are correspondingly disposed in a projection direction.
The bottom electrode 5, the piezoelectric layer 2 and the top electrode 3 are stacked on the substrate 1, the piezoelectric layer 2 fully covers the substrate 1 along the transverse direction in fig. 1, and the bottom electrode 5 and the top electrode 3 do not fully cover the substrate 1, so that an effective area is formed in the area where the projections of the bottom electrode 5, the piezoelectric layer 2 and the top electrode 3 on the substrate 1 overlap respectively, and accordingly, the area outside the effective area is an inactive area, in other words, the area where the projections of the bottom electrode 5, the piezoelectric layer 2 and the top electrode 3 on the substrate 1 do not overlap respectively is an inactive area.
Wherein the substrate 1 is provided with a cavity 6, the cavity 6 is positioned on one side of the substrate 1 close to the bottom electrode 5, a first air bridge 7 is formed between the bottom electrode 5 and the piezoelectric layer 2, and the bridge surface of the first air bridge 7 is arched to the cavity 6. And outside the active area, i.e. in the inactive area, a first groove 4 corresponding to the first air bridge 7 in the projection direction is formed on the piezoelectric layer 2, the notch of the first groove 4 faces to the side facing away from the bottom electrode 5, and the top electrode 3 does not cover to the notch position of the first groove 4, so that the notch of the first groove 4 is exposed.
By forming the first groove 4 on the piezoelectric layer 2 in the non-effective area, the transmission path of sound waves to the side is blocked, the transverse sound wave leakage of the piezoelectric layer 2 is reduced, meanwhile, a first air bridge 7 is formed at the position corresponding to the first groove 4 of the piezoelectric layer 2, the first air bridge 7 can limit the sound wave energy passing through the bottom electrode 5, the first groove 4 can be surrounded by air, the air can well reflect the sound waves, the sound wave leakage inside the piezoelectric layer 2 is reduced, and the Q value of the resonator is further improved.
In summary, in the thin film bulk acoustic resonator provided by the embodiment of the application, the bottom electrode 5, the piezoelectric layer 2 and the top electrode 3 are sequentially stacked on the substrate 1 with the cavity 6, the cavity 6 is located between the substrate 1 and the bottom electrode 5, the areas where the projections of the bottom electrode 5, the piezoelectric layer 2 and the top electrode 3 are overlapped on the substrate 1 respectively form an effective area, a first air bridge 7 is formed between the bottom electrode 5 and the piezoelectric layer 2 outside the effective area, a first groove 4 corresponding to the projection direction of the first air bridge 7 is formed on the piezoelectric layer 2, the first groove 4 is located on one side of the piezoelectric layer 2 away from the bottom electrode 5, the acoustic wave energy passing through the bottom electrode 5 is limited by the first air bridge 7, meanwhile, the transverse acoustic wave leakage of the piezoelectric layer 2 is reduced by forming the first groove 4 on the piezoelectric layer 2 in a non-effective area, the leakage of the acoustic wave energy is fully reduced, and the Q value of the resonator is improved.
As shown in fig. 1, the first groove 4 and the first air bridge 7 are correspondingly disposed in the foregoing, and the first groove 4 does not penetrate the piezoelectric layer 2, in other words, the first groove 4 and the first air bridge 7 are not communicated; in addition, the axes of the first air bridge 7 and the first groove 4 are collinear; of course, the first air bridge 7 and the first groove 4 may also be slightly staggered, and specifically, the first air bridge and the first groove may be selected according to actual needs, which is not limited to the above.
Further, in another possible manner of the present application, as shown in fig. 2, the first groove 4 is in communication with the first air bridge 7, so that air can enter the first groove 4, and sound waves are reflected better, so that leakage of sound waves inside the piezoelectric layer 2 is reduced.
On the basis, a second air bridge 9 is formed between the top electrode 3 and the piezoelectric layer 2, a second groove 8 is formed on the piezoelectric layer 2 outside the effective area at a position corresponding to the second air bridge 9 in the projection direction, and the second groove 8 is communicated with the cavity 6.
As shown in fig. 3, a second air bridge 9 is formed between the top electrode 3 and the piezoelectric layer 2, the bridge deck of the second air bridge 9 arches in a direction away from the piezoelectric layer 2, the projection directions of the second air bridge 9 and the second groove 8 correspond, and the second groove 8 is located in the inactive area. Similar to the first air bridge 7 and the first groove 4, the second groove 8 is formed on the piezoelectric layer 2 in the non-effective area to block the transmission path of sound waves to the side, so that the transverse sound wave leakage of the piezoelectric layer 2 is reduced, meanwhile, the second air bridge 9 corresponding to the second groove 8 limits the sound wave energy passing through the top electrode 3, the second groove 8 is surrounded by air to reflect sound waves, the sound wave leakage inside the piezoelectric layer 2 is reduced, and the Q value of the resonator is improved.
Accordingly, as shown in fig. 3, the second groove 8 does not penetrate the piezoelectric layer 2, and it may also be the case that, as shown in fig. 4, the second groove 8 communicates with the second air bridge 9 to better reflect the sound wave and reduce the leakage of the sound wave inside the piezoelectric layer 2. The first air bridge 7 and the first groove 4, the second air bridge 9 and the second groove 8 in fig. 2, 3 and 4 are slightly offset, that is, the axes of the two are not collinear.
In summary, in the thin film bulk acoustic resonator provided by the embodiment of the application, grooves (the first groove 4 and the second groove 8) are formed in the piezoelectric layer 2 by etching, and meanwhile, an air bridge is arranged in the electrode layer (the bottom electrode 5 forms the first air bridge 7, and the top electrode 3 forms the second air bridge 9), so that acoustic energy leakage of the top electrode 3, the bottom electrode 5 and the piezoelectric layer 2 is reduced, and the Q value of the resonator is improved.
In another aspect, an embodiment of the present application further provides a method for preparing a thin film bulk acoustic resonator, where the method is used to prepare the thin film bulk acoustic resonator, and the method includes:
s100: a substrate 1 with a recess formed in one side of the substrate 1 is provided.
As shown in fig. 5, a substrate 1 is provided, and the substrate 1 may be a silicon substrate 1; a recess is then etched in the substrate 1, the recess being used to form the cavity 6, the recess being located on one side of the substrate 1. As shown in fig. 6 and 7, an etched groove is formed on the substrate 1, and a plurality of release holes 10 are formed around the groove, the release holes 10 being used for subsequent release of the sacrificial layer.
S110: forming a bottom electrode 5 on a side of the substrate 1 where a recess is provided, through which a cavity 6 is formed between the substrate 1 and the bottom electrode 5; a first sacrificial layer 11 is deposited in the recess and the first sacrificial layer 11 is patterned for forming a first air bridge 7, the bottom electrode 5 covering the substrate 1 and exposing a part of the substrate 1.
As shown in fig. 8 and 9, after the substrate 1 is formed into a recess, a first sacrificial layer 11 is deposited in the recess to fill up the recess. The first sacrificial layer 11 is made of silicon dioxide material, the first sacrificial layer 11 is filled in the groove and the release hole 10 is filled by diffusion; as shown in fig. 10 and 11, a trench 12 for forming the first air bridge 7 is then etched on the first sacrificial layer 11, as shown in fig. 12 and 13, the bottom electrode 5 is formed on the first sacrificial layer 11, and the bottom electrode 5 is patterned at the trench 12 such that the bottom electrode 5 has a trench 12 pattern matching the trench 12.
The bottom electrode 5 partially covers the substrate 1, the substrate 1 is not entirely covered with the bottom electrode 5, and a part of the substrate 1 is exposed.
S120: a piezoelectric layer 2 having a first recess 4 is formed on the patterned bottom electrode 5 such that the piezoelectric layer 2 covers the substrate 1, the first recess 4 being formed on a side facing away from the bottom electrode 5.
As shown in fig. 14 and 15, a second sacrificial layer 13 is deposited at the position of the bottom electrode 5 corresponding to the trench 12 so that the second sacrificial layer 13 is flush with the surface of the bottom electrode 5, and the second sacrificial layer 13 fills the position of the bottom electrode 5 corresponding to the trench 12; the bottom electrode 5 does not entirely cover the substrate 1, and as shown in fig. 16 and 17, the piezoelectric layer 2 is deposited on the bottom electrode 5 so that the piezoelectric layer 2 entirely covers the substrate 1. The second sacrificial layer 13 may also be a silicon dioxide material.
S130: a top electrode 3 is formed on the piezoelectric layer 2 and the top electrode 3 is patterned, and the top electrode 3 is made to cover the piezoelectric layer 2 and expose a region of the piezoelectric layer 2 where the first grooves 4 are provided.
An inclined step is formed on the piezoelectric layer 2, so that two planes with height differences are formed on the upper surface of the piezoelectric layer 2; as shown in fig. 18 and 19, the top electrode 3 is formed on the piezoelectric layer 2, and the top electrode 3 is patterned so that the top electrode 3 is formed to have a structure corresponding to the oblique steps of the piezoelectric layer 2, and the upper surface of the top electrode 3 is also formed to have two planes with a height difference. And the top electrode 3 partially covers the piezoelectric layer 2 to form an active region, exposing a partial region as a non-active region for etching the first recess 4.
Then, as shown in fig. 20 and 21, the first recess 4 is etched at the corresponding trench 12 of the piezoelectric layer 2, the first recess 4 being located at the edge of the piezoelectric layer 2 near the top electrode 3, in the inactive region, while the first sacrificial layer 11 and the second sacrificial layer 13 are released to form the cavity 6 and the first air bridge 7.
The structures of the above three other embodiments are similar to each other, and the preparation methods are not repeated here, and can be deduced by those skilled in the art according to the same manner as the preparation methods.
The preparation method of the film bulk acoustic resonator comprises the same structure and beneficial effects as the film bulk acoustic resonator in the previous embodiment. The structure and the beneficial effects of the thin film bulk acoustic resonator have been described in detail in the foregoing embodiments, and are not described in detail herein.
The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. A thin film bulk acoustic resonator, comprising: the substrate, laminate bottom electrode, piezoelectric layer and top electrode on the said substrate in proper order, there is cavity between said substrate and said bottom electrode, said piezoelectric layer and said top electrode overlap the area that the projection on the said substrate overlaps separately and form the effective area, there is the first air bridge between said bottom electrode and said piezoelectric layer, there is the first recess on said piezoelectric layer outside said effective area, said first recess is located one side that the said piezoelectric layer deviates from said bottom electrode, said first recess and said first air bridge are set up correspondingly in the projection direction; the bridge deck of the first air bridge arches to the cavity, the notch of the first groove faces to one side facing away from the bottom electrode, and the top electrode does not cover to the notch position of the first groove, so that the notch of the first groove is exposed.
2. The thin film bulk acoustic resonator of claim 1 wherein the first recess and the first air bridge are in communication.
3. The thin film bulk acoustic resonator of claim 1, wherein a second air bridge is formed between the top electrode and the piezoelectric layer, and a second recess is formed in the piezoelectric layer outside the effective region at a position corresponding to the second air bridge in the projection direction, the second recess being in communication with the cavity.
4. A thin film bulk acoustic resonator according to claim 3, characterized in that the second recess communicates with the second air bridge.
5. A method of manufacturing a thin film bulk acoustic resonator as claimed in any one of claims 1 to 4, comprising:
providing a substrate with a groove, wherein the groove is formed on one side of the substrate;
forming a bottom electrode on the substrate at a side where the groove is provided, and forming a cavity between the substrate and the bottom electrode through the groove; depositing a first sacrificial layer in the groove, and patterning the first sacrificial layer to form a first air bridge, wherein the bottom electrode covers the substrate and exposes part of the substrate;
forming a piezoelectric layer with a first groove on the patterned bottom electrode, so that the piezoelectric layer covers the substrate, wherein the first groove is formed on one side away from the bottom electrode;
and forming and patterning a top electrode on the piezoelectric layer, and enabling the top electrode to cover the piezoelectric layer and expose the area of the piezoelectric layer where the first groove is formed.
6. The method of manufacturing a thin film bulk acoustic resonator according to claim 5, wherein providing a substrate with a recess formed in one side of the substrate comprises:
providing the substrate;
and etching the substrate to form the groove.
7. The method of manufacturing a thin film bulk acoustic resonator according to claim 5, wherein a bottom electrode is formed on the side of the substrate on which the groove is provided, and a cavity is formed between the substrate and the bottom electrode through the groove; depositing a first sacrificial layer within the recess and patterning the first sacrificial layer for forming a first air bridge, the bottom electrode overlying the substrate and exposing a portion of the substrate comprising:
etching a groove for forming the first air bridge on the first sacrificial layer;
the bottom electrode is formed on the substrate, and the cavity is formed at the groove.
8. The method of manufacturing a thin film bulk acoustic resonator according to claim 7, wherein forming a piezoelectric layer having a first groove on the patterned bottom electrode such that the piezoelectric layer covers the substrate, the first groove being formed on a side facing away from the bottom electrode comprises:
depositing a second sacrificial layer at the position of the bottom electrode corresponding to the groove so as to enable the surfaces of the second sacrificial layer and the bottom electrode to be flush;
the piezoelectric layer is deposited on the bottom electrode.
9. The method of manufacturing a thin film bulk acoustic resonator according to claim 8, wherein forming and patterning a top electrode on the piezoelectric layer, and covering the piezoelectric layer with the top electrode, and exposing a region of the piezoelectric layer where the first groove is provided, comprises:
forming the top electrode on the piezoelectric layer, and patterning the top electrode so that the top electrode partially covers the piezoelectric layer;
and etching the first groove at the exposed position of the piezoelectric layer corresponding to the groove, and simultaneously releasing the first sacrificial layer and the second sacrificial layer to respectively form the cavity and the first air bridge.
10. The method of manufacturing a thin film bulk acoustic resonator according to claim 8, wherein the material of the substrate comprises silicon and the materials of the first sacrificial layer and the second sacrificial layer comprise silicon dioxide.
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| CN202211062831.2A CN115276600B (en) | 2022-09-01 | 2022-09-01 | Film bulk acoustic resonator and preparation method thereof |
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| CN202211062831.2A CN115276600B (en) | 2022-09-01 | 2022-09-01 | Film bulk acoustic resonator and preparation method thereof |
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| CN115276600A CN115276600A (en) | 2022-11-01 |
| CN115276600B true CN115276600B (en) | 2023-12-08 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020177554A1 (en) * | 2019-03-02 | 2020-09-10 | 天津大学 | Bulk acoustic resonator having recessed structure in piezoelectric layer, filter and electronic device |
| WO2021258405A1 (en) * | 2020-06-24 | 2021-12-30 | 杭州见闻录科技有限公司 | Thin film bulk acoustic resonator and manufacturing process therefor |
| WO2022028402A1 (en) * | 2020-08-06 | 2022-02-10 | 诺思(天津)微系统有限责任公司 | Bulk acoustic wave resonator assembly having acoustic decoupling layer, manufacturing method, filter, and electronic device |
| CN114826184A (en) * | 2022-05-18 | 2022-07-29 | 苏州汉天下电子有限公司 | Bulk acoustic wave resonator, preparation method and bulk acoustic wave filter |
| CN114978095A (en) * | 2022-05-18 | 2022-08-30 | 中国电子科技集团公司第二十六研究所 | Temperature compensation type film bulk acoustic resonator, manufacturing method thereof and filter |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7791434B2 (en) * | 2004-12-22 | 2010-09-07 | Avago Technologies Wireless Ip (Singapore) Pte. Ltd. | Acoustic resonator performance enhancement using selective metal etch and having a trench in the piezoelectric |
| US10284173B2 (en) * | 2011-02-28 | 2019-05-07 | Avago Technologies International Sales Pte. Limited | Acoustic resonator device with at least one air-ring and frame |
| US9608594B2 (en) * | 2014-05-29 | 2017-03-28 | Avago Technologies General Ip (Singapore) Pte. Ltd. | Capacitive coupled resonator device with air-gap separating electrode and piezoelectric layer |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020177554A1 (en) * | 2019-03-02 | 2020-09-10 | 天津大学 | Bulk acoustic resonator having recessed structure in piezoelectric layer, filter and electronic device |
| WO2021258405A1 (en) * | 2020-06-24 | 2021-12-30 | 杭州见闻录科技有限公司 | Thin film bulk acoustic resonator and manufacturing process therefor |
| WO2022028402A1 (en) * | 2020-08-06 | 2022-02-10 | 诺思(天津)微系统有限责任公司 | Bulk acoustic wave resonator assembly having acoustic decoupling layer, manufacturing method, filter, and electronic device |
| CN114826184A (en) * | 2022-05-18 | 2022-07-29 | 苏州汉天下电子有限公司 | Bulk acoustic wave resonator, preparation method and bulk acoustic wave filter |
| CN114978095A (en) * | 2022-05-18 | 2022-08-30 | 中国电子科技集团公司第二十六研究所 | Temperature compensation type film bulk acoustic resonator, manufacturing method thereof and filter |
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