CN210444236U

CN210444236U - FBAR filter

Info

Publication number: CN210444236U
Application number: CN201921406463.2U
Authority: CN
Inventors: 李国强
Original assignee: Guangzhou Everbright Technology Co Ltd
Current assignee: Guangzhou Everbright Technology Co Ltd
Priority date: 2019-08-27
Filing date: 2019-08-27
Publication date: 2020-05-01
Anticipated expiration: 2029-08-27

Abstract

The utility model provides a FBAR filter, FBAR filter includes: the bonding substrate, one side of the bonding substrate is provided with a second bonding layer in bonding connection with the first bonding layer, and the supporting layer is arranged on one side, far away from the second bonding layer, of the first bonding layer; the first electrode is arranged on one side, far away from the first bonding layer, of the supporting layer, the cavity of the supporting layer penetrates through the supporting layer and the second bonding layer, and two ends of the cavity of the supporting layer are respectively contacted with the first electrode and the bonding substrate; the piezoelectric film is arranged on one side, away from the supporting layer, of the first electrode, the electrode up-leading structure penetrates through the piezoelectric film and is connected with the first electrode, and the top electrode is arranged on one side, away from the first electrode, of the piezoelectric film and is connected with the electrode up-leading structure part; and the first through hole penetrates through the bonding substrate and is connected with the cavity of the supporting layer. The utility model discloses need not to set up the sacrificial layer, remain piezoelectric film's integrality to this kind of structural design of trompil on the bonding substrate, stable in structure is difficult for subsiding, improvement piezoelectric film's that can be fine quality.

Description

FBAR filter

Technical Field

The utility model relates to an electronic communication device technical field especially relates to a FBAR filter.

Background

The multifunctional development of the wireless communication terminal puts high technical requirements on miniaturization, high frequency, high performance, low power consumption, low cost and the like on a radio frequency device. The traditional surface acoustic wave filter (SAW) has large insertion loss in a high frequency band above 2.4GHz, and the dielectric filter has good performance but large volume. The Film Bulk Acoustic Resonator (FBAR) technology is a new radio frequency device technology which has appeared in recent years along with the improvement of the technological level of processing and the rapid development of modern wireless communication technology, especially personal wireless communication technology. The surface acoustic wave resonator has the advantages of extremely high quality factor Q value (more than 1000) and being capable of being integrated on an IC chip, and is compatible with a Complementary Metal Oxide Semiconductor (CMOS) process, and meanwhile, the defect that the surface acoustic wave resonator and the dielectric resonator cannot be compatible with the CMOS process is effectively avoided.

The basic principle of FBAR is based on the mechanical and electrical energy conversion of piezoelectric materials, so the quality factor of the piezoelectric composite membrane affects the loss and roll-off characteristics of FBAR filters. Generally FBAR filters are shown in figure 1. The device comprises a substrate, an air cavity on the substrate, and a bottom electrode, a piezoelectric layer and a top electrode which are sequentially manufactured on the substrate across the air cavity. The general process method is as follows: a pit is first anisotropically etched on a substrate, and then the pit is filled with a sacrificial layer material, which may be Al, Mg, Ge or silicon dioxide. And sputtering to grow a metal film on the surface of the sacrificial layer after CMP polishing, and etching a bottom electrode pattern at a position above the sacrificial layer correspondingly. Then a layer of piezoelectric film is deposited above the bottom electrode, after etching, the piezoelectric film covers the boundary of the pit on the substrate and exposes the leading-out end of the bottom electrode, and then a layer of metal film is deposited on the piezoelectric film, and the top electrode pattern is etched. A release window is then etched in the piezoelectric layer by dry etching to expose portions of the sacrificial layer. And finally, releasing the sacrificial layer from the etched release window, and manufacturing the FBAR on the substrate across the air cavity, wherein the sacrificial layer releasing method leaves a plurality of release channel holes on the piezoelectric layer, so that the piezoelectric film is greatly damaged, the cavity structure is easy to collapse, the Q value and the electromechanical coupling coefficient are low, the insertion loss is large, and the performance of the device is influenced.

SUMMERY OF THE UTILITY MODEL

In order to overcome the not enough of prior art, the utility model provides a FBAR filter, structural design through trompil on the bonded substrate can keep supporting layer cavity stable in structure, is difficult for subsiding, and the quality of improvement piezoelectric film that can be fine reduces the insertion loss of filter, has improved Q value and electromechanical coupling coefficient, will become the solution that is applicable to radio frequency filter under following high frequency, the high power occasion.

In order to solve the above problem, the utility model discloses a technical scheme do: an FBAR filter, the FBAR filter comprising: the bonding substrate, there is the second bonding layer that is bonded and connected with first bonding layer on one side of the said bonding substrate, the supporting layer is set up in the first bonding layer and far away from one side of the second bonding layer; the first electrode is arranged on one side, far away from the first bonding layer, of the supporting layer, a cavity of the supporting layer penetrates through the supporting layer and the second bonding layer, and two ends of the cavity of the supporting layer are respectively contacted with the first electrode and the bonding substrate; the piezoelectric film is arranged on one side, away from the supporting layer, of the first electrode, the electrode lead-up structure penetrates through the piezoelectric film and is connected with the first electrode, and the top electrode is arranged on one side, away from the first electrode, of the piezoelectric film and is connected with the electrode lead-up structure part; and the first through hole penetrates through the bonding substrate and is connected with the cavity of the supporting layer.

Further, the number of the first electrodes is 4, and the first electrodes are arranged at intervals through the supporting layer.

Furthermore, the number of the lead structures on the electrodes is 2, the lead structures are arranged at intervals and are respectively connected with different first electrodes.

Further, the top electrode comprises a first top electrode and a second top electrode, and one end of the first top electrode, which is close to the second top electrode, is connected with the electrode upper lead structure.

Further, the thickness of the piezoelectric film is 0.02 to 10 micrometers.

Furthermore, the number of the supporting layer cavities and the first through holes is 2, and the supporting layer cavities correspond to and are communicated with the first through holes one to one.

Further, the thickness of the first electrode and the top electrode is 20 nm to 500 nm.

Further, the second bonding layer has a thickness of 0.3 to 3 micrometers.

Further, the first through hole is circular, and the aperture is 2 microns to 30 microns.

Further, the FBAR filter includes an FBAR filter in a frequency range of 10MHZ to 100 GHZ.

Compared with the prior art, the beneficial effects of the utility model reside in that: the utility model discloses be connected first bonding layer and second bonding layer bonding to form closed cavity between first electrode and bonding substrate, and make first through-hole run through bonding substrate and this closed cavity intercommunication, the utility model discloses a FBAR filter need not to set up the sacrificial layer, has kept piezoelectric film's integrality, thereby has overcome the problem that produces harmful effects to the filter structure at the in-process that the sacrificial layer got rid of, and this kind of structural design of trompil on the bonding substrate, stable in structure is difficult for subsiding, the quality of improvement piezoelectric film that can be fine, reduces the insertion loss of wave filter, has improved Q value and electromechanical coupling coefficient, will become the solution that is applicable to following high frequency, radio frequency filter under the high power occasion.

Drawings

FIG. 1 is a diagram of an embodiment of a conventional FBAR filter;

fig. 2 is a structural diagram of an embodiment of the FBAR filter of the present invention;

fig. 3 is a flowchart illustrating an embodiment of a method for improving the manufacturing yield of the FBAR filter in the FBAR filter of the present invention;

FIG. 4 is a schematic diagram illustrating an embodiment of forming a piezoelectric film on a first substrate in the method of improving the yield of the FBAR filter of FIG. 3;

FIG. 5 is a schematic diagram of one embodiment of forming a first electrode on a piezoelectric film in the method of FIG. 3 for improving the yield of the FBAR filter;

FIG. 6 is a schematic diagram illustrating an embodiment of forming a first insulating layer in the method of FIG. 3 for improving the yield of the FBAR filter;

FIG. 7 is a schematic diagram illustrating an embodiment of forming a second insulating layer in the method of FIG. 3 for improving the yield of the FBAR filter;

FIG. 8 is a schematic diagram illustrating an embodiment of forming a support layer in the method of FIG. 3 for improving the yield of FBAR filter fabrication;

FIG. 9 is a schematic diagram illustrating one embodiment of forming a first supporting layer cavity in the method for improving the manufacturing yield of the FBAR filter of FIG. 3;

FIG. 10 is a diagram illustrating an embodiment of forming a first bonding layer in the method of FIG. 3 for improving the yield of manufacturing FBAR filters;

fig. 11 is a schematic diagram illustrating an embodiment of forming a second bonding layer on a bonding substrate in the method for improving the manufacturing yield of the FBAR filter of fig. 3;

FIG. 12 is a schematic diagram illustrating an embodiment of forming first vias in the method of FIG. 3 for improving the yield of FBAR filter fabrication;

FIG. 13 is a schematic diagram illustrating one embodiment of forming cavities in the second support layer in the method of improving the yield of the FBAR filter of FIG. 3;

fig. 14 is a schematic diagram illustrating an embodiment of bonding and connecting the first bonding layer and the second bonding layer in the method for improving the manufacturing yield of the FBAR filter in fig. 3;

fig. 15 is a structural diagram of an embodiment of a bonding connection between a first bonding layer and a second bonding layer in the method for improving the manufacturing yield of the FBAR filter in fig. 3;

FIG. 16 is a schematic view of the FBAR filter manufacturing yield improvement method of FIG. 3 with the first substrate removed according to one embodiment;

FIG. 17 is a schematic diagram illustrating one embodiment of forming via holes on electrodes in the method of improving the yield of the FBAR filter of FIG. 3;

FIG. 18 is a schematic diagram of one embodiment of forming a top electrode and an electrode pull-up structure in the method of FIG. 3 for improving the yield of FBAR filter fabrication;

fig. 19 is a structural diagram of an embodiment of the FBAR filter formed in the method for improving the manufacturing yield of the FBAR filter in fig. 3.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that the embodiments or technical features described below can be arbitrarily combined to form a new embodiment without conflict.

Please refer to fig. 2-19, wherein fig. 2 is a structural diagram of an embodiment of an FBAR filter according to the present invention; fig. 3 is a flowchart illustrating an embodiment of a method for improving the manufacturing yield of the FBAR filter in the FBAR filter of the present invention; FIG. 4 is a schematic diagram illustrating an embodiment of forming a piezoelectric film on a first substrate in the method of improving the yield of the FBAR filter of FIG. 3; FIG. 5 is a schematic diagram of one embodiment of forming a first electrode on a piezoelectric film in the method of FIG. 3 for improving the yield of the FBAR filter; FIG. 6 is a schematic diagram illustrating an embodiment of forming a first insulating layer in the method of FIG. 3 for improving the yield of the FBAR filter; FIG. 7 is a schematic diagram illustrating an embodiment of forming a second insulating layer in the method of FIG. 3 for improving the yield of the FBAR filter; FIG. 8 is a schematic diagram illustrating an embodiment of forming a support layer in the method of FIG. 3 for improving the yield of FBAR filter fabrication; FIG. 9 is a schematic diagram illustrating one embodiment of forming a first supporting layer cavity in the method for improving the manufacturing yield of the FBAR filter of FIG. 3; FIG. 10 is a diagram illustrating an embodiment of forming a first bonding layer in the method of FIG. 3 for improving the yield of manufacturing FBAR filters; fig. 11 is a schematic diagram illustrating an embodiment of forming a second bonding layer on a bonding substrate in the method for improving the manufacturing yield of the FBAR filter of fig. 3; FIG. 12 is a schematic diagram illustrating an embodiment of forming first vias in the method of FIG. 3 for improving the yield of FBAR filter fabrication; FIG. 13 is a schematic diagram illustrating one embodiment of forming cavities in the second support layer in the method of improving the yield of the FBAR filter of FIG. 3; fig. 14 is a schematic diagram illustrating an embodiment of bonding and connecting the first bonding layer and the second bonding layer in the method for improving the manufacturing yield of the FBAR filter in fig. 3; fig. 15 is a structural diagram of an embodiment of a bonding connection between a first bonding layer and a second bonding layer in the method for improving the manufacturing yield of the FBAR filter in fig. 3; FIG. 16 is a schematic view of the FBAR filter manufacturing yield improvement method of FIG. 3 with the first substrate removed according to one embodiment; FIG. 17 is a schematic diagram illustrating one embodiment of forming via holes on electrodes in the method of improving the yield of the FBAR filter of FIG. 3; FIG. 18 is a schematic diagram of one embodiment of forming a top electrode and an electrode pull-up structure in the method of FIG. 3 for improving the yield of FBAR filter fabrication; fig. 19 is a structural diagram of an embodiment of the FBAR filter formed in the method for improving the manufacturing yield of the FBAR filter in fig. 3. The FBAR filter of the present invention will be described in detail with reference to fig. 2 to 19.

In the present embodiment, the FBAR filter includes: a bonding substrate 109, wherein a second bonding layer 108 bonded and connected with the first bonding layer 112 is arranged on one side of the bonding substrate 109, and the support layer 106 is arranged on one side of the first bonding layer 112 away from the second bonding layer 108; the first electrode 103 is arranged on one side of the support layer 106 far away from the first bonding layer 112, a cavity of the support layer penetrates through the support layer 106 and the second bonding layer 108, and two ends of the cavity of the support layer are respectively contacted with the first electrode 103 and the bonding substrate 109; the piezoelectric film 101 is arranged on one side of the first electrode 103, which is far away from the supporting layer 106, the electrode up-drawing structure 115 penetrates through the piezoelectric film 101 and is connected with the first electrode 103, and the top electrode is arranged on one side of the piezoelectric film 101, which is far away from the first electrode 103, and is partially connected with the electrode up-drawing structure 115; and a first through hole 111, wherein the first through hole 111 penetrates through the bonding substrate 109 to be connected with the cavity of the support layer.

In this embodiment, the number of the supporting layer cavities and the first through holes 111 is 2, and the supporting layer cavities are in one-to-one correspondence and communication with the first through holes 111.

The utility model discloses a FBAR filter obtains through a method preparation that improves FBAR filter preparation yield, and the following process of preparing FBAR filter through the method that improves FBAR preparation yield is right the utility model discloses a FBAR filter does further describe.

In this embodiment, the utility model discloses the method for improving FBAR preparation yield includes following steps:

s1: a piezoelectric film is formed on a first substrate, and at least one first electrode is formed on the piezoelectric film on a side away from the first substrate.

In this embodiment, the first substrate 102 is used as a growth substrate of the piezoelectric thin film 101, and the first substrate 102 may be at least one of a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, an aluminum nitride substrate, an AlxGa1-xN buffer layer substrate, a LiGaO2, glass, and a metal substrate, and in other embodiments, may be another substrate that can be used as a growth substrate of the piezoelectric thin film 101, and is not limited herein.

The structure 100 in fig. 4 includes a piezoelectric thin film 101 and a first substrate 102, where the piezoelectric thin film 101 covers the first substrate 102, and may be a high-quality single crystal piezoelectric thin film grown by epitaxy, a high C-axis oriented polycrystalline piezoelectric thin film grown by sputtering, or a thin film with piezoelectric properties such as AlN, ZnO, PZT, or the like.

In the present embodiment, the thickness of the piezoelectric thin film 101 is 0.02 to 10 micrometers.

Fig. 5 shows a schematic view of a structure 200 in which a first electrode 103 is formed on a piezoelectric thin film 101, the first electrode 103 is formed on a side of the piezoelectric thin film 101 away from a first substrate 102 by an electron beam lift-off method or a magnetron sputtering method, and partially covers the first substrate 102, wherein a thickness of the first electrode 103 is between 0.1 nm and 500 nm, and a material forming the first electrode 103 may be one or more of Al, Mo, W, Pt, Cu, Ag, Au, and ZrN, or may be other materials with good conductivity, such as non-metallic materials like graphene.

In a specific embodiment, the number of the first electrodes 103 is 4, and the first electrodes are spaced apart from each other on the side of the piezoelectric film 101 away from the first substrate 102.

S2: and forming a supporting layer covering the first electrode, etching the supporting layer to form a first supporting layer cavity, and forming a first bonding layer on one side of the supporting layer, which is far away from the piezoelectric film.

In this embodiment, the support layer 106 covering the first electrode 103 may be formed of the first insulating layer 104 and the second insulating layer 105 formed on the piezoelectric thin film 101, or may be formed of a third insulating layer covering the first electrode 103. Fig. 6 is a schematic diagram of forming the first insulating layer 104, fig. 7 is a schematic diagram of forming the second insulating layer 105, fig. 8 is a schematic diagram of forming the supporting layer 106, fig. 9 is a schematic diagram of etching the supporting layer 106 to form the first supporting layer cavity 107, and fig. 10 is a schematic diagram of forming the first bonding layer 108 on the supporting layer 106.

In this embodiment, the support layer cavities include a first support layer cavity 107 and a second support layer cavity, the first support layer cavity 107 being opposite the second support layer cavity and communicating to form the support layer cavity.

In a preferred embodiment, a first insulating layer 104 with the same thickness as the first electrode 103 is formed on the side of the piezoelectric thin film 101 away from the first substrate 102, and the first insulating layer 104 on the first electrode 103 is removed; a second insulating layer 105 is formed on the first insulating layer 104 and the first electrode 103 layer, and the second insulating layer 105 is subjected to a planarization process to form a support layer 106.

Wherein, the first insulating layer 104 separates the first electrode 103, the first insulating layer 104 on the first electrode 103 is removed by means of wet or dry etching, and the second insulating layer 105 covers the first electrode 103 and the first insulating layer 104.

In another preferred embodiment, a third insulating layer is formed on the piezoelectric film 101 on the side away from the first substrate 102 to cover the first electrode 103, and the support layer 106 is formed through the third insulating layer. Wherein the support layer 106 is formed by mechanical polishing and planarization through the third insulating layer.

In the present embodiment, the first insulating layer 104, the second insulating layer 105, and the third insulating layer are made of a dielectric material such as SiO2 or Si3N4, but the first insulating layer 104, the second insulating layer 105, and the third insulating layer may be made of another dielectric material that can insulate the first electrode 103, and are not limited thereto.

In a specific embodiment, the first support layer cavities 107 are formed by patterned etching of the support layer 106, and are two in number, spaced apart and in contact with different first electrodes 103.

In this embodiment, the first bonding layer 108 is formed on the side of the supporting layer 106 away from the piezoelectric film 101 by forming the first bonding layer 108 on the side of the supporting layer 106 away from the piezoelectric film 101 by one of sputtering, electron beam evaporation, and reactive vapor deposition. The first bonding layer 108 may be a metal or a non-metal material, and any bonding method and material commonly used in the industry may be used for the first bonding layer 108.

In a specific embodiment, a first bonding layer 108 covers a portion of handle layer 106 on a side away from first electrode 103 where a cavity of handle layer 106 is disposed, and other structures of the FBAR filter are connected through first bonding layer 108.

S3: and forming a second bonding layer used for being in bonding connection with the first bonding layer on one side of the bonding substrate, forming at least one mark point on the other side of the bonding substrate, and forming a first through hole penetrating through the bonding substrate on the bonding substrate, wherein the positions of the first bonding layer and the first through hole on the bonding substrate respectively correspond to the positions of the first bonding layer and the first supporting layer cavity on the first base plate.

In the present embodiment, the bond substrate 109 may be made of at least one of a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, an aluminum nitride substrate, and an AlxGa1-xN buffer layer substrate, as in the case of the material of the first substrate 102.

The structure 500 in fig. 11 is a schematic diagram of forming the second bonding layer 112 on the bonding substrate 109, and in this embodiment, the manner and the material used for forming the second bonding layer 112 may be the same as or different from those of the first bonding layer 108, and only the first bonding layer 108 and the second bonding layer are required to be connected, which is not limited herein.

In the present embodiment, the thickness of the second bonding layer 112 is 0.3 to 3 micrometers, and the thickness of the cavity of the second support layer is 0.5 to 3 micrometers.

In this embodiment, the mark points 110 are two grooves on the bonding substrate 109, which are opposite to the second bonding layer 112, located on two sides of the cavity of the second support layer, and spaced apart from one side of the bonding substrate 109 away from the second bonding layer 112. In other embodiments, the number of the mark points 110 may also be one, three or another, and only the mark points 110 are required to achieve the aligned bonding of the first base plate 102 and the bonding substrate 109 and to form the first through holes 111 penetrating through the bonding substrate 109.

Fig. 12 is a schematic diagram of forming first through holes 111 on a bonding substrate 109, in this embodiment, the number of the first through holes 111 is 2, and the first through holes 111 are disposed in a region of a second bonding layer 112 at a position of the bonding substrate 109, in other embodiments, the number of the first through holes 111 may be 1, 3, or other numbers, and only the position of the first through hole 111 corresponds to the position of the first support layer cavity 107, and after the first bonding layer 108 and the second bonding layer 112 are bonded and connected, air in the first support layer cavity 107 can be exhausted through the first through hole 111, which is not limited herein.

In this embodiment, the first through hole 111 may be circular, and the aperture is 2 micrometers to 30 micrometers, in other embodiments, the first through hole 111 may also be in other shapes, and only the first through hole 111 penetrates through the bonding substrate 109, which is not limited herein.

The structure 601 in fig. 13 is a schematic diagram of forming a second support layer cavity on the bonding substrate 109, after forming the first through hole 111 penetrating through the bonding substrate 109 on the bonding substrate 109, forming a second support layer cavity on the side of the bonding substrate 109 where the second bonding layer 112 is disposed, where the position of the second support layer cavity on the bonding substrate 109 corresponds to the position of the first support layer cavity 107 on the first base plate 102.

In this embodiment, the second support layer cavity is formed by etching the bonding substrate 109, is disposed on the side of the bonding substrate 109 where the second bonding layer 112 is disposed, is located on the region of the bonding substrate 109 where the second bonding layer 112 is not formed, and is connected to the first through hole 111.

In the present embodiment, the number of the cavities of the second support layer is 2, and the cavities are respectively connected to different first through holes 111.

S4: and bonding and connecting the first bonding layer and the second bonding layer, removing the first substrate, and forming a top electrode and an electrode up-lead structure connected with the first electrode on one side of the piezoelectric film, which is far away from the first electrode, so as to form the FBAR filter.

Fig. 14 is a schematic diagram of a structure 700 in fig. 14 illustrating bonding connection between a first bonding layer 108 and a second bonding layer 112, and fig. 15 is a structural diagram of a device formed by bonding connection between the first bonding layer 108 and the second bonding layer 112, in this embodiment, the bonding connection between the first bonding layer 108 and the second bonding layer 112 may be different bonding connection manners according to the environment of the wafer and the materials of the first bonding layer 108 and the second bonding layer 112, where the bonding connection manner may be a metal diffusion or a metal eutectic bonding manner, if a metal diffusion or a metal eutectic bonding is adopted, a high vacuum and a high temperature condition may be encountered during the bonding process, if there is no first through hole 111, the bonding is completed under a vacuum condition, and after the bonding is completed, a closed cavity formed by a cavity 107 of the first support layer and a cavity of the second support layer is a closed space, after the first substrate 102 is subsequently removed, the piezoelectric film 101 is crushed by atmospheric pressure without the constraint of the first substrate 102, so that the piezoelectric film 101 is broken, the device fails, if the strength of the piezoelectric film 101 is enough and the piezoelectric film 101 is not broken, the piezoelectric film 101 has large stress, the performance of the device is greatly affected, and the closed cavity is also cracked due to thermal expansion in the subsequent process under the condition of hundreds of degrees centigrade.

Fig. 16 is a schematic diagram of removing the first substrate 102, and in this embodiment, the first substrate 102 is removed by laser lift-off or mechanical thinning combined with wet etching or dry etching.

The step of forming the top electrode and the electrode up-drawing structure 115 connected with the interconnection hole of the first electrode 103 on the side of the piezoelectric film 101 away from the first electrode 103 includes: forming an electrode upper lead hole 114 penetrating through the piezoelectric thin film 101 on the piezoelectric thin film 101, and forming a top electrode in a region of the piezoelectric thin film 101, which is far away from the first electrode 103 and is not penetrated through by the electrode upper lead hole 114; an electrode lead-up structure 115 filling the electrode lead-up hole 114 is formed, wherein the electrode lead-up structure 115 is connected to the first electrode 103 through the electrode lead-up hole 114 and partially extends to the side of the piezoelectric film 101 away from the first electrode 103.

Fig. 17 is a schematic diagram of forming an electrode upper lead hole 114 on the piezoelectric film 101, and fig. 18 is a schematic diagram of forming an electrode upper lead structure 115 and a top electrode, in this embodiment, the electrode upper lead hole 114 is formed by dry etching or wet etching, and the top electrode and the electrode upper lead structure 115 are formed by sputtering or electron beam evaporation.

Fig. 19 is a structural diagram of the FBAR filter formed, in this embodiment, the number of the electrode lead-up structures 115 is 2, and the electrode lead-up structures are arranged at intervals and respectively connected to different first electrodes 103, and the top electrodes include a first top electrode and a second top electrode. The electrode upper lead structure 115 and the top electrode on the piezoelectric film 101 are sequentially arranged in the manner of the electrode upper lead structure 115 and the top electrode, and one end of the first top electrode positioned in the middle of the piezoelectric film 101, which is close to the second top electrode, is connected with one electrode upper lead structure 115. In other embodiments, the number of the electrode lead-up structures 115 and the top electrode may also be 1 or other numbers, which are not limited herein.

In the present embodiment, the material forming the top electrode is one or a combination of two of Al, Mo, W, Pt, Cu, Ag, Au, ZrN, and has a thickness of 20 nm to 500 nm.

In the present embodiment, the FBAR filter formed is an FBAR filter of any frequency, including an FBAR filter in a frequency range from 10MHZ to 100 GHZ.

Advantageous effect the utility model discloses be connected first bonding layer and second bonding layer bonding, thereby form closed cavity between first electrode and bonding substrate, and make first through-hole run through bonding substrate and this closed cavity intercommunication, the utility model discloses a FBAR filter need not to set up the sacrificial layer, has remain piezoelectric film's integrality, thereby has overcome the problem that produces harmful effects to the filter structure at the in-process that the sacrificial layer got rid of, and this kind of structural design of trompil on the bonding substrate, stable in structure, difficult the subsides, improvement piezoelectric film's quality that can be fine, reduces the insertion loss of wave filter, has improved Q value and electromechanical coupling coefficient, will become the solution that is applicable to radio frequency filter under following high frequency, the high power occasion.

Based on the same inventive concept, the utility model also provides a FBAR filter, wherein, this FBAR filter obtains through the FBAR filter as described in the above-mentioned embodiment, and the repetition is not done here.

In the several embodiments provided in the present disclosure, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the modules or partitions may be merely logical partitions, and may be implemented in other ways, e.g., multiple modules or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, devices or indirect coupling or communication connection, and may be in an electrical, mechanical or other form.

The components described as separate parts may or may not be physically separate, and the components shown may or may not be physical, that is, may be located in one place, or may be distributed on a plurality of networks. Some or all of them can be selected according to actual needs to achieve the purpose of the embodiment.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims

1. An FBAR filter, the FBAR filter comprising:

the bonding substrate, there is the second bonding layer that is bonded and connected with first bonding layer on one side of the said bonding substrate, the supporting layer is set up in the first bonding layer and far away from one side of the second bonding layer;

the first electrode is arranged on one side, far away from the first bonding layer, of the supporting layer, a cavity of the supporting layer penetrates through the supporting layer and the second bonding layer, and two ends of the cavity of the supporting layer are respectively contacted with the first electrode and the bonding substrate;

the piezoelectric film is arranged on one side, away from the supporting layer, of the first electrode, the electrode lead-up structure penetrates through the piezoelectric film and is connected with the first electrode, and the top electrode is arranged on one side, away from the first electrode, of the piezoelectric film and is connected with the electrode lead-up structure part;

and the first through hole penetrates through the bonding substrate and is connected with the cavity of the supporting layer.

2. The FBAR filter as claimed in claim 1, wherein the number of the first electrodes is 4, and the first electrodes are spaced apart on the piezoelectric film.

3. The FBAR filter of claim 2 wherein the number of the lead-up structures on the electrodes is 2, and the lead-up structures are spaced apart from each other and connected to different ones of the first electrodes.

4. The FBAR filter of claim 3, wherein the top electrode comprises a first top electrode, a second top electrode, and an end of the first top electrode proximate the second top electrode is connected to the electrode up lead structure.

5. The FBAR filter of claim 1 wherein the thickness of the piezoelectric film is 0.02 to 10 microns.

6. The FBAR filter of claim 1, wherein the number of the support layer cavities and the first through holes is 2, and the support layer cavities correspond to and communicate with the first through holes one to one.

7. The FBAR filter of claim 1 wherein the thickness of the first electrode and the top electrode is 20 nm to 500 nm.

8. The FBAR filter of claim 1 wherein the second bonding layer has a thickness of 0.3 microns to 3 microns.

9. The FBAR filter of claim 1 wherein the first via is circular and has a pore size of 2 microns to 30 microns.

10. The FBAR filter of claim 1 wherein the FBAR filter comprises an FBAR filter in the frequency range of 10MHZ to 100 GHZ.