CN114070224A

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Info

Publication number: CN114070224A
Application number: CN202010785120.2A
Authority: CN
Inventors: 庞慰; 张巍; 张孟伦; 郝龙; 徐洋
Original assignee: ROFS Microsystem Tianjin Co Ltd
Current assignee: ROFS Microsystem Tianjin Co Ltd
Priority date: 2020-08-06
Filing date: 2020-08-06
Publication date: 2022-02-18
Also published as: WO2022028401A1

Abstract

Translated fromChinese

本发明涉及一种体声波谐振器组件，包括：基底；至少两个谐振器，所述至少两个谐振器为体声波谐振器且在基底的一侧在基底的厚度方向上叠置，所述至少两个谐振器包括第一谐振器和第二谐振器，第二谐振器在第一谐振器的上方，第一谐振器具有第一顶电极、第一压电层、第一底电极和第一声学镜，第二谐振器具有第二顶电极、第二压电层、第二底电极和第二声学镜，其中：第一顶电极与第二底电极之间设置有空腔形式的声学解耦层，所述声学解耦层作为所述第二声学镜。本发明还涉及一种体声波谐振器组件的制造方法，一种滤波器以及一种电子设备。

The present invention relates to a bulk acoustic wave resonator assembly, comprising: a substrate; at least two resonators, the at least two resonators are bulk acoustic wave resonators and are stacked on one side of the substrate in the thickness direction of the substrate, the The at least two resonators include a first resonator and a second resonator, the second resonator being above the first resonator, the first resonator having a first top electrode, a first piezoelectric layer, a first bottom electrode and a first resonator. an acoustic mirror, the second resonator has a second top electrode, a second piezoelectric layer, a second bottom electrode, and a second acoustic mirror, wherein: a cavity-like structure is arranged between the first top electrode and the second bottom electrode an acoustic decoupling layer, the acoustic decoupling layer serves as the second acoustic mirror. The invention also relates to a manufacturing method of a bulk acoustic wave resonator assembly, a filter and an electronic device.

Description

Bulk acoustic wave resonator assembly with acoustic decoupling layer, manufacturing method of bulk acoustic wave resonator assembly, filter and electronic device

Technical Field

Embodiments of the present invention relate to the field of semiconductors, and in particular, to a bulk acoustic wave resonator assembly and a method of manufacturing the same, a filter having the resonator assembly, and an electronic device.

Background

With the rapid development of wireless communication technology, the application of miniaturized portable terminal equipment is becoming more and more extensive, and thus the demand for high-performance and small-size radio frequency front-end modules and devices is becoming more and more urgent. In recent years, filter devices such as filters and duplexers based on Film Bulk Acoustic Resonators (FBARs) have been increasingly favored in the market. On one hand, the material has excellent electrical properties such as low insertion loss, steep transition characteristic, high selectivity, high power capacity, strong anti-static discharge (ESD) capability and the like, and on the other hand, the material has the characteristics of small volume and easy integration.

However, there is a real need for further reduction of the size of the filter device.

In addition, in the prior art, bulk acoustic wave resonators are combined in series and parallel to form a filter, and a plurality of resonators are required to be formed on a substrate, and the resonators are separated at different horizontal positions of the substrate and connected by horizontal metal leads, as shown in fig. 1, wherein thetop electrode 104 of theresonator 100 within the dashed box is connected to thebottom electrode 102 of theresonator 200 through the conductive via 10, in order to ensure the electrical signal transmission and the limitation of the manufacturing process, the connection width of the conductive via 10 and thetop electrode 104 of theresonator 100, the width of the conductive via 10, the width of thetop electrode 104 of theresonator 100 and the width of thebottom electrode 102 of theresonator 200 are required, and the total length is generally greater than 5 μm, which causes the connection line to introduce large electrical loss, especially for high-frequency resonators, at electrode thicknesses <1000A, the insertion loss is degraded by more than 0.1 dB.

Disclosure of Invention

The present invention has been made to mitigate or solve at least one of the above-mentioned problems in the prior art.

According to an aspect of an embodiment of the present invention, there is provided a bulk acoustic wave resonator assembly including:

a substrate;

at least two resonators which are bulk acoustic wave resonators and are stacked in a thickness direction of the substrate on one side of the substrate, the at least two resonators including a first resonator and a second resonator, the second resonator being above the first resonator, the first resonator having a first top electrode, a first piezoelectric layer, a first bottom electrode and a first acoustic mirror, the second resonator having a second top electrode, a second piezoelectric layer, a second bottom electrode and a second acoustic mirror,

wherein:

an acoustic decoupling layer in the form of a cavity is arranged between the first top electrode and the second bottom electrode, and the acoustic decoupling layer serves as the second acoustic mirror.

The embodiment of the invention also relates to a bulk acoustic wave resonator assembly, which comprises at least two resonators adjacently stacked from bottom to top in the thickness direction of the assembly, wherein the at least two resonators are bulk acoustic wave resonators, the at least two resonators comprise a first resonator and a second resonator, an acoustic decoupling layer in a cavity form is arranged between a top electrode of the first resonator and a bottom electrode of the second resonator, and the acoustic decoupling layer is used as an acoustic mirror of the second resonator.

Embodiments of the present invention also relate to a method of manufacturing a bulk acoustic wave resonator assembly, comprising:

step 1: forming a first structure for a first bulk acoustic wave resonator on a surface of a substrate, the first bulk acoustic wave resonator comprising a first acoustic mirror, a first bottom electrode, a first piezoelectric layer, a first top electrode;

step 2: arranging a patterned sacrificial material layer on the first structure formed in thestep 1;

and step 3: forming a second structure for a second bulk acoustic wave resonator on the structure of step 2, the second bulk acoustic wave resonator including a second acoustic mirror, a second bottom electrode, a second piezoelectric layer, and a second top electrode, the sacrificial material layer being located between the first top electrode and the second bottom electrode in a thickness direction of the substrate;

and 4, step 4: releasing the sacrificial material layer to form a cavity constituting a second acoustic mirror of a second bulk acoustic wave resonator.

Embodiments of the present invention are also directed to a filter comprising the bulk acoustic wave resonator assembly described above.

Embodiments of the invention also relate to an electronic device comprising a filter as described above or a resonator assembly as described above.

Drawings

These and other features and advantages of the various embodiments of the disclosed invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate like parts throughout, and in which:

figure 1 is a schematic cross-sectional view of an electrical connection between two adjacent bulk acoustic wave resonators in a prior art design;

FIG. 2 is a schematic top view of a bulk acoustic wave resonator assembly according to an exemplary embodiment of the present invention;

figure 3A is a schematic cross-sectional view of a bulk acoustic wave resonator taken along line a-a' in figure 2, according to an exemplary embodiment of the present invention;

FIG. 3B is a schematic cross-sectional view of a bulk acoustic wave resonator taken along line B-B' of FIG. 2, according to an exemplary embodiment of the present invention;

figure 3C is a schematic cross-sectional view of a bulk acoustic wave resonator taken along line C-C' in figure 2, in accordance with an exemplary embodiment of the present invention;

FIG. 3D is a graph illustrating a comparison of insertion loss curves for the structure of FIG. 3A relative to the structure of FIG. 1;

3E-3G are schematic cross-sectional views of a bulk acoustic wave resonator taken along line A-A' in FIG. 2 showing electrodes defining a common cavity having an outwardly convex shape relative to the common cavity, in accordance with various embodiments of the present invention;

fig. 4A is a schematic cross-sectional view of the bulk acoustic wave resonator taken along line a-a' in fig. 2, in which a portion of the non-electrode connection end of the bottom electrode of the upper resonator in the circumferential direction is electrically connected to the non-electrode connection end of the top electrode of the lower resonator, according to an exemplary embodiment of the present invention;

fig. 4B is a schematic cross-sectional view of the bulk acoustic wave resonator taken along line B-B' in fig. 2, in which an electrode connection terminal of the bottom electrode of the upper resonator is electrically connected to an electrode connection terminal of the top electrode of the lower resonator, according to an exemplary embodiment of the present invention;

fig. 5A is a schematic cross-sectional view of a bulk acoustic wave resonator taken along line a-a' in fig. 2, in which a non-electrode connecting end of a bottom electrode of an upper resonator is not electrically connected to a non-electrode connecting end of a top electrode of a lower resonator, an end of the non-electrode connecting end of the bottom electrode of the upper resonator being disposed on an upper surface of a piezoelectric layer of the lower resonator, according to an exemplary embodiment of the present invention;

fig. 5B is a schematic cross-sectional view of the bulk acoustic wave resonator taken along line a-a' in fig. 2, in which the non-electrode connecting end of the bottom electrode of the upper resonator is not electrically connected to the non-electrode connecting end of the top electrode of the lower resonator, an end of a part of the non-electrode connecting end of the bottom electrode of the upper resonator is disposed on an upper surface of the piezoelectric layer of the lower resonator and an end of the other part is located inside a boundary of the common cavity in a lateral direction, according to an exemplary embodiment of the present invention;

figure 5C is a schematic cross-sectional view of a bulk acoustic wave resonator taken along line C-C' in figure 2, in accordance with an exemplary embodiment of the present invention;

6A-6C are cross-sectional schematic views of a bulk acoustic wave resonator assembly according to various embodiments of the present invention showing a cavity between the bottom electrode of the upper resonator and the top electrode of the lower resonator and a support disposed thereon;

FIGS. 7A-7E are schematic diagrams illustrating a fabrication process for the structure shown in FIG. 3A;

FIGS. 8A and 8B illustrate a schematic structural view of a method of making the support of FIGS. 6A-6C;

FIG. 9 is a schematic cross-sectional view of a bulk acoustic wave resonator assembly according to an exemplary embodiment of the present invention;

fig. 10 is a cross-sectional view of a resonator assembly in which upper and lower resonator active areas are acoustically isolated by a cavity, and the upper and lower resonators are electrically isolated from each other in a left side view of fig. 10 and are electrically connected to each other in a right side view of fig. 10, according to an exemplary embodiment of the present invention.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be construed as limiting the invention. Some, but not all embodiments of the invention are described. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

The reference numerals in the present invention are explained as follows:

11: and the electrode of the bottom electrode of the lower resonator is led out.

12: and the electrode of the top electrode of the lower resonator is led out.

13: and the electrode of the bottom electrode of the upper resonator is led out.

14: the electrode of the top electrode of the upper resonator is led out. The above electrode pair outer leads 11 to 14 are connected to the corresponding electrodes,

s: the substrate can be selected from monocrystalline silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond and the like.

101,201: theacoustic mirror 101 may be a cavity, and a bragg reflector or other equivalent forms may be used. Theacoustic mirror 201 employs a cavity, which constitutes an acoustic decoupling layer.

102,202: the bottom electrode is made of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or their composite or their alloy.

103,203: the piezoelectric layer can be a single crystal piezoelectric material, and can be selected from the following: the material may be polycrystalline piezoelectric material (corresponding to single crystal, non-single crystal material), optionally, polycrystalline aluminum nitride, zinc oxide, PZT, or a rare earth element doped material containing at least one rare earth element, such as scandium (Sc), yttrium (Y), magnesium (Mg), titanium (Ti), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), erbium (Ho), erbium (holmium), thulium (Tm), ytterbium (Yb), lutetium (Lu), or the like.

104,204: the top electrode can be made of the same material as the bottom electrode, and the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or the alloy thereof, and the like. The top and bottom electrode materials are typically the same, but may be different.

105,205: the passivation layer is typically a dielectric material such as silicon dioxide, aluminum nitride, silicon nitride, etc.

Fig. 2 is a schematic top view of a bulk acoustic wave resonator assembly according to an exemplary embodiment of the present invention, in fig. 2, a line a-a ' corresponds to a section passing through non-electrode connection ends of top electrodes of upper and lower resonators and a non-electrode connection end of a bottom electrode, a line B-B ' corresponds to a section passing through an electrode connection end of a bottom electrode of a lower resonator and an electrode connection end of a top electrode of a lower resonator, and a line C-C ' corresponds to a section passing through an electrode connection end of a bottom electrode of an upper resonator and an electrode connection end of a top electrode of an upper resonator.

Fig. 3A is a schematic cross-sectional view of a bulk acoustic wave resonator taken along line a-a' in fig. 2 according to an exemplary embodiment of the present invention.

Although not shown, the top electrode of the resonator may also have a process layer disposed thereon, which may cover the top electrode, and which may function as a mass tuning load or passivation layer. The passivation layer may be made of dielectric material, such as silicon dioxide, aluminum nitride, silicon nitride, etc.

Further, in the structure shown in fig. 3A, two resonators are formed at the same horizontal position of the substrate S, and the two resonators are different in spatial position in the vertical direction or in the thickness direction of the substrate.

As can be appreciated by those skilled in the art, three resonators or more may also be stacked. Figure 9 is a schematic cross-sectional view of a bulk acoustic wave resonator assembly according to an exemplary embodiment of the present invention. As shown in fig. 9, the resonator assembly includes a first resonator, a second resonator, and a third resonator stacked in the thickness direction, an acoustic decoupling layer 201 (a cavity in this embodiment) is provided between atop electrode 104 of the first resonator and abottom electrode 202 of the second resonator, an acoustic decoupling layer 301 (a cavity in this embodiment) is provided between atop electrode 204 of the second resonator and abottom electrode 302 of the third resonator, and theacoustic decoupling layer 301 constitutes an acoustic mirror of the third resonator. Optionally, as shown in fig. 9, the boundary of theacoustic decoupling layer 301 is outside the boundary of theacoustic decoupling layer 201 in the horizontal direction. As can be appreciated, the assembly structures shown in other embodiments of the invention may also be stacked.

In the structure shown in fig. 3A, two resonators above and below are shown, wherein the effective area of the upper resonator is the overlapping area of thetop electrode 204, thepiezoelectric layer 203, thebottom electrode 202, and thecavity 201 in the thickness direction. The lower resonator is an overlapping area of thecavity 201, thetop electrode 104, thepiezoelectric layer 103, thebottom electrode 102, and theacoustic mirror 101 in the thickness direction.

Accordingly, in fig. 9, the effective area of the uppermost third resonator is the overlapping area of thetop electrode 304, thepiezoelectric layer 303, thebottom electrode 302, and thecavity 301 in the thickness direction, the effective area of the middle second resonator is the overlapping area of thecavity 301, thetop electrode 204, thepiezoelectric layer 203, thebottom electrode 202, and thecavity 201 in the thickness direction, and the effective area of the lowermost first resonator is the overlapping area of thecavity 201, thetop electrode 104, thepiezoelectric layer 103, thebottom electrode 102, and thecavity 101 in the thickness direction.

In the structure shown in fig. 3A, the upper resonator is acoustically separated from the lower resonator by acavity 201, i.e. thecavity 201 constitutes an acoustic decoupling layer between the upper and lower resonators, thereby completely avoiding the acoustic coupling problem that may result from the adjacent stacking of the upper and lower resonators.

Thecavity 201 is used as an acoustic decoupling layer, complete acoustic decoupling of the upper resonator and the lower resonator can be achieved, and therefore the performance of the resonators is better. Further, in the case where thecavity 201 is directly surrounded by thetop electrode 104 of the lower resonator and thebottom electrode 202 of the upper resonator (the structure defining the position of the cavity in other embodiments further includes the piezoelectric layer of the upper resonator and/or the lower resonator), such as the structures shown in fig. 3A to 3C, 3E to 3G, and 9, the overall structure is stable and reliable, and the manufacturing process is simple.

As can be understood by those skilled in the art, thecavity 201 is disposed between the bottom electrode of the upper resonator and the top electrode of the lower resonator in the thickness direction of the resonator, including not only the case where at least a portion of the upper and lower boundaries of the cavity is defined by the lower surface of the bottom electrode of the upper resonator and the upper surface of the top electrode of the lower resonator, but also the case where the upper surface of the top electrode of the lower resonator is provided with a process layer (e.g., a passivation layer) such that the process layer defines at least a portion of the lower boundary of thecavity 201. These are all within the scope of the present invention.

In the structure shown in fig. 3A, since the plurality of resonators are formed at the same horizontal position of the substrate S, the spatial positions of the plurality of resonators in the vertical direction or in the thickness direction of the substrate are different, and therefore, the area of the filter can be greatly reduced, for example, in the case where two resonators are provided as well, from the area P1 shown in fig. 1 to the area P2 shown in fig. 3A.

As shown in fig. 3A, thebottom electrode 202 of the upper resonator and thetop electrode 104 of the lower resonator are electrically connected to each other at a non-electrode connection terminal. Under the condition that the bottom electrode of the upper resonator is directly connected with the top electrode of the lower resonator, the bottom electrode of the upper resonator is directly and electrically connected with the top electrode of the lower resonator, and the length of the connecting part is shortened compared with that in the figure 1, namely, the transmission path is shortened, and the transmission loss is reduced; in addition, the transmission loss of the electrical signal output is further reduced by the sum of the thicknesses of the top electrode of the lower resonator and the bottom electrode of the upper resonator through the metal thickness. By reducing the electrical losses, the insertion loss of the final filter is optimized. As shown in fig. 3A, the length of the transmission path formed by the bottom electrode of the upper resonator and the top electrode of the lower resonator at the non-electrode-connecting end is d, which may be less than 5 μm.

With the structure of fig. 3A to 3C, for example, since the current transmission path to the lower resonator becomes short, for example, can be less than 5 μm, the transmission loss is reduced, and the thickness of thetop electrode 104 of the lower resonator and the thickness of thebottom electrode 202 of the upper resonator can be thinned, which is advantageous for further miniaturization of the resonator. In the case where the bottom electrode of the upper resonator and the top electrode of the lower resonator are electrically connected to each other, the electrode film thickness of the bottom electrode of the upper resonator and the top electrode of the upper resonator can be further reduced simultaneously while reducing the circuit transmission path loss to the bottom electrode of the upper resonator and the current transmission path loss to the top electrode of the lower resonator. Accordingly, in the case where the resonance frequency of the lower resonator is greater than 0.5GHz, the thickness of thetop electrode 104 is smaller than

And/or the thickness of thebottom electrode 202 is less than in the case where the resonance frequency of the upper resonator is greater than 0.5GHz

In a further embodiment, in the case where the resonance frequency of the lower resonator is more than 3GHz, the thickness of thetop electrode 104 may be designed to be less than

And/or in case the resonance frequency of the upper resonator is larger than 3GHz, the thickness of thebottom electrode 202 of the upper resonator may also be smaller than

As can be understood, in the present invention, the thinning of the thickness of the electrode means thinning of the thickness of the electrode in the effective region of the resonator.

Fig. 3D is a graph schematically illustrating a comparison of insertion loss curves for the structure of fig. 3A with respect to the structure of fig. 1. Fig. 3D is a comparison between the insertion loss curve (solid line) of the 3.5G band using the structure of fig. 3A of the present invention and the insertion loss curve (dotted line) of the conventional structure of fig. 1, and it can be seen that the insertion loss is improved by about 0.1dB due to the reduction of the electrode loss using the structure of fig. 3A of the present invention.

Fig. 3B is a schematic cross-sectional view of the bulk acoustic wave resonator taken along line B-B 'in fig. 2 according to an exemplary embodiment of the present invention, and fig. 3C is a schematic cross-sectional view of the bulk acoustic wave resonator taken along line C-C' in fig. 2 according to an exemplary embodiment of the present invention. It can be seen that in fig. 3B and 3C, the top electrode of the lower resonator is electrically connected to the bottom electrode of the upper resonator in the circumferential direction around theentire cavity 201.

In the case where the bottom electrode of the upper resonator and the top electrode of the lower resonator are electrically connected to each other, in the structure shown in fig. 3A to 3C, the non-electrode connection end and the electrode connection end of the bottom electrode of the upper resonator and the top electrode of the lower resonator are connected to each other, that is, the electrical connection is formed around the entire circumference of thecavity 201. However, other connection means than the one shown in fig. 3A-3C are possible. For example, as described later with reference to fig. 4A, the bottom electrode of the upper resonator and the top electrode of the lower resonator may be electrically connected to each other only at a part of the non-electrode connection terminal; alternatively, as described with reference to fig. 4B, the bottom electrode of the upper resonator and the top electrode of the lower resonator may be electrically connected to each other only at the electrode connection end; or the bottom electrode of the upper resonator and the top electrode of the lower resonator may be electrically connected to each other only at all or part of the non-electrode connection terminals. These are all within the scope of the present invention.

The connection between the bottom electrode of the upper resonator and the top electrode of the lower resonator is not limited to the structures shown in fig. 3A-3C. Fig. 10 is a cross-sectional view of a resonator assembly in which upper and lower resonator active areas are acoustically isolated by a cavity, and the upper and lower resonators are electrically connected to each other in a right side view of fig. 10, according to an exemplary embodiment of the present invention.

As shown in the right sectional view of fig. 10, thepiezoelectric layer 103 is covered with thetop electrode 104, and thebottom electrode 202 is connected to thetop electrode 104 at both the electrode connection end and the non-electrode connection end. In the right side view of fig. 10, the electrode connecting end ofbottom electrode 202 overlaps the electrode connecting end oftop electrode 104, and the non-electrode connecting end ofbottom electrode 202 overlaps the non-electrode connecting end oftop electrode 104.

Process or

passivation layers

105 and 205, which may or may not be provided, are shown in fig. 10 as being provided on the top electrode upper surface.

In the structure shown in fig. 10 of the present invention, since the second electrode layer where thebottom electrode 202 is located covers the first electrode layer where thetop electrode 104 is located, the metal thickness of the bottom electrode of the upper resonator and the top electrode of the lower resonator at the electrode connection portion can be increased, which is beneficial to reducing the electrical loss.

When the maximum width of the effective area of the resonator is larger than the height of the cavity, the upper resonator and the lower resonator may be contacted in the cavity due to bending and the like, for example, the height of the cavity is

When the maximum width of the resonator effective area is larger than 100 μm, in order to ensure the complete formation of thecavity 201 in the upper and lower resonator effective areas, the stress of the lower resonator can be controlled to bend towards the lower air cavity, and/or the stress of the upper resonator can be controlled to bend towards the upper air cavity, and the top electrode of the finally formed lower resonator is concave downwards, and/or the top electrode of the upper resonator is convex upwards. Fig. 3E-3G are schematic cross-sectional views of the bulk acoustic wave resonator taken along line a-a' in fig. 2 showing that the electrodes defining thecavity 201 have an outwardly convex shape with respect to the common cavity, in particular, fig. 3E is a schematic view of the lower resonator being bent downward, fig. 3F is a schematic view of the upper resonator being bent upward, and fig. 3G is a schematic view of the lower resonator being bent downward and the upper resonator being bent upward, according to various embodiments of the present invention. On the other hand, although the upper and lower resonators are bent by adjusting the stress of their respective films, the upper resonator film is prevented from contacting with the lower resonator film due to the small thickness of the upper and lower resonators and the mechanical contact of the upper and lower resonators at the edge of the acoustic decoupling layer in the form of a cavityThe stress of the lower resonator affects the working state and performance of the lower resonator to a certain degree, and the stress of the lower resonator film affects the working state and performance of the upper resonator to a certain degree; thus, the lower the stress on the upper and lower resonator films, the better (i.e., the films do not bend, as in FIGS. 3A-3C), so that the two resonators do not affect performance; of course, if the upper and lower resonators are not in contact due to bending in the cavity, some of the resonator performance is sacrificed by adjusting the stress (as shown in fig. 3E-3G) to ensure that the two are not in contact.

Fig. 4A is a schematic cross-sectional view of the bulk acoustic wave resonator taken along line a-a' in fig. 2, in which fig. 4A, a part of the non-electrode connecting end of thebottom electrode 202 of the upper resonator in the circumferential direction is electrically connected to thetop electrode 104 of the lower resonator (shown on the right side in fig. 4A), and another part of the non-electrode connecting end of thebottom electrode 202 of the upper resonator in the circumferential direction is provided on the upper surface of thepiezoelectric layer 103 of the lower resonator (shown on the left side in fig. 4A) without being electrically connected to thetop electrode 104 of the lower resonator and outside the non-electrode connecting end of thetop electrode 104 in the lateral direction, according to an exemplary embodiment of the present invention.

Fig. 4B is a schematic cross-sectional view of the bulk acoustic wave resonator taken along line B-B' in fig. 2 according to an exemplary embodiment of the present invention, and in fig. 4B, the electrode connection end of the bottom electrode of the upper resonator is electrically connected to the electrode connection end of the top electrode of the lower resonator, but the non-electrode connection end of the bottom electrode of the upper resonator and the non-electrode connection end of the top electrode of the lower resonator are not connected to each other.

In the above embodiments, the bottom electrode of the upper resonator and the top electrode of the lower resonator are electrically connected to each other, but the present invention is not limited thereto. In the case where two bulk acoustic wave resonators stacked one above the other share an acoustic decoupling layer, the bottom electrode of the upper resonator and the top electrode of the lower resonator may also be electrically isolated from each other.

Fig. 5A is a schematic cross-sectional view of a bulk acoustic wave resonator taken along line a-a' in fig. 2 according to an exemplary embodiment of the present invention, in fig. 5A, thebottom electrode 202 of the upper resonator and thetop electrode 104 of the lower resonator are not electrically connected, and the ends of the non-electrode connection ends of thebottom electrode 202 of the upper resonator are outside thetop electrode 104 of the lower resonator and are both disposed on the upper surface of thepiezoelectric layer 103 of the lower resonator.

Fig. 5B is a schematic cross-sectional view of the bulk acoustic wave resonator taken along the line a-a' in fig. 2, in which the non-electrode connecting end of thebottom electrode 202 of the upper resonator and the non-electrode connecting end of thetop electrode 104 of the lower resonator are not electrically connected, an end of a part of the non-electrode connecting end of the bottom electrode of the upper resonator is disposed on the upper surface of thepiezoelectric layer 103 of the lower resonator (see the left side in fig. 5B) and an end of the other part is located inside the boundary of the common cavity in the lateral direction (see the right side in fig. 5B), according to an exemplary embodiment of the present invention.

Fig. 5C is a schematic cross-sectional view of the bulk acoustic wave resonator taken along the line C-C' in fig. 2, in which the non-electrode connection end of thebottom electrode 202 of the upper resonator and the non-electrode connection end of thetop electrode 104 of the lower resonator are not electrically connected, and the electrode connection end of thebottom electrode 202 of the upper resonator and the electrode connection end of thetop electrode 104 of the lower resonator are not electrically connected, according to an exemplary embodiment of the present invention.

Fig. 10 is a cross-sectional view of a resonator assembly in which upper and lower resonator active areas are acoustically isolated by a cavity, and upper and lower resonators are electrically isolated from each other in a left side view of fig. 10, according to an exemplary embodiment of the present invention.

In the left side view of fig. 10, thetop electrode 104 is in the first electrode layer, and in the left side view of fig. 10, the aforementioned first electrode layer includes thetop electrode 104 and a non-top electrode layer that is electrically isolated from the non-electrode connection end of thetop electrode 104 via the breaking structure 106 to the outside of the non-electrode connection end of the top electrode 104 (i.e., a portion to the left of the breaking structure 106 in fig. 10). In fig. 10, thebottom electrode 202 is in a second electrode layer, which, as shown in the left side view of fig. 10, includes thebottom electrode 202 and a non-bottom electrode layer that is electrically isolated from the non-electrode connecting end of thebottom electrode 202 via the breakingstructure 206 and is outside the non-electrode connecting end of the bottom electrode 202 (i.e., the right portion of the breakingstructure 206 in fig. 10). In the left side view of fig. 10, the electrode connecting end of thebottom electrode 202 covers the non-top electrode layer, which covers the electrode connecting end of thetop electrode 104.

Figures 6A-6C are cross-sectional schematic views of a bulk acoustic wave resonator assembly according to various embodiments of the present invention showing acavity 201 between the bottom electrode of the upper resonator and the top electrode of the lower resonator and asupport 401 disposed therein.

In the example shown in fig. 3E-3G, the controlling stress can reduce the probability of the upper and lower resonators contacting each other, but when the area of the resonator is larger, as shown in fig. 6A-6C, asupport 401 can be added, thesupport 401 can contact with the top or top electrode of the lower resonator, and the height of the support is less than or equal to the height of the cavity, which means the top of the support contacts with the bottom or bottom electrode of the upper resonator, and the height of the support is less than the height of the cavity, which means the top of the support does not contact with the upper resonator, and when the local thickness of the cavity is reduced due to the bending of the resonator, the top of the support contacts with the upper resonator to play a supporting role. In the structure shown in fig. 6A-6C, thesupport member 401 is in contact with both the bottom electrode of the upper resonator and the top electrode of the lower resonator.

The fabrication of the structure shown in fig. 3A is illustrated with reference to fig. 7A-7E.

First, as shown in fig. 7A, abottom electrode 102, apiezoelectric layer 103, and an electrode material layer for atop electrode 104 are formed on a substrate S, wherein the upper surface of the substrate S is also provided with a recess for forming anacoustic mirror 101, and the recess is filled with a sacrificial material. In fig. 7A-7E, passivation layers, layers of frequencies tuned to be less relevant to the concepts of the present patent are not shown.

Next, as shown in fig. 7B, a sacrificial material layer is deposited on the structure of fig. 7A, and in order to improve the growth quality of the subsequent film layer, the deposited sacrificial material layer is subjected to a surface treatment by a CMP (chemical mechanical polishing) method, and then an etching patterning process is performed on the sacrificial material layer to form asacrificial layer 301, which is removed in the subsequent process to form acavity 201. The sacrificial material may be polysilicon, amorphous silicon, silicon dioxide, doped silicon dioxide, or the like.

Again, an electrode metal layer for forming thebottom electrode 202 of the upper resonator is deposited in a sputtering or evaporation process or the like on the structure shown in fig. 7B. Next, etching is performed on the electrode metal layer corresponding to thebottom electrode 202 and the electrode metal layer corresponding to thetop electrode 104 by photolithography and etching processes to form the structure shown in fig. 7C.

Again, as shown in fig. 7D, the sacrificial material in fig. 7C is released to form thecavity 201 and theacoustic mirror cavity 101.

Finally, thepiezoelectric layer 203 and thetop electrode 204 are formed on the structure shown in FIG. 7D, resulting in the structure shown in FIG. 3A, as shown in FIG. 7E.

It is noted that in the above manufacturing process, the sacrificial material may also be released after the piezoelectric layer and the top electrode of the upper resonator are formed to form thecavity 201 and theacoustic mirror cavity 101.

Fig. 8A and 8B schematically illustrate a structure of a method of fabricating the support member of fig. 6A-6C. The structure shown in fig. 6A is manufactured differently from the structure shown in fig. 3A, in that when the structure shown in fig. 6A is manufactured, before the step corresponding to fig. 7B is performed, thesupport member 401 is required to be manufactured on the structure shown in fig. 7A, then, in the step corresponding to fig. 7B, the sacrificial material layer is deposited to cover thesupport member 401, then, the deposited sacrificial material layer is subjected to surface treatment by a CMP (chemical mechanical polishing) method, and then, an etching patterning process is performed on the sacrificial material layer to form thesacrificial layer 301 shown in fig. 8A, which is used for removing to form thecavity 201 in a subsequent process.

In fig. 8A, the height of thesupport member 401 is smaller than the thickness of thesacrificial layer 301, so that the upper end of thesupport member 401 is not in contact with the bottom electrode of the upper resonator in the finally formed structure, while in fig. 8B, the height of thesupport member 401 is the same as the thickness of thesacrificial layer 301, so that the upper end of thesupport member 401 is in contact with the bottom electrode of the upper resonator in the finally formed structure.

For the structure shown in fig. 7A, the fabrication process is similar to that of the structure of fig. 3A, except that in the step corresponding to fig. 7B, the fabrication of the sacrificial layer is changed to the fabrication of the acoustic reflection layer, and in the step corresponding to fig. 7D, the step of removing thesacrificial layer 301 is eliminated.

It is to be noted that, in the present invention, each numerical range, except when explicitly indicated as not including the end points, can be either the end points or the median of each numerical range, and all fall within the scope of the present invention.

In the present invention, the upper and lower are with respect to the bottom surface of the base of the resonator, and with respect to one component, the side thereof close to the bottom surface is the lower side, and the side thereof far from the bottom surface is the upper side.

In the present invention, the inner and outer are in the lateral direction or the radial direction with respect to the center of the effective area of the resonator (i.e., the effective area center), and one side or one end of a component close to the effective area center is the inner side or the inner end, and one side or one end of the component away from the effective area center is the outer side or the outer end. For a reference position, being inside of the position means being between the position and the center of the effective area in the lateral or radial direction, and being outside of the position means being further away from the center of the effective area than the position in the lateral or radial direction.

As can be appreciated by those skilled in the art, the bulk acoustic wave resonator according to the present invention may be used to form a filter or an electronic device. The electronic device includes, but is not limited to, intermediate products such as a radio frequency front end and a filtering and amplifying module, and terminal products such as a mobile phone, WIFI and an unmanned aerial vehicle.

Based on the above, the invention provides the following technical scheme:

1. a bulk acoustic wave resonator assembly comprising:

a substrate;

wherein:

2. The assembly ofclaim 1, wherein:

the first top electrode and the second bottom electrode are electrically connected to each other.

3. The assembly of claim 2, wherein:

the end of the non-electrode connection terminal of the first top electrode and the end of the non-electrode connection terminal of the second bottom electrode are connected to each other.

4. The assembly of claim 3, wherein:

the end of the non-electrode connection terminal of the first top electrode and the end of the non-electrode connection terminal of the second bottom electrode meet each other in the entire circumferential direction.

5. The assembly of claim 3, wherein:

an end portion of a part of the non-electrode connecting end of the second bottom electrode in the circumferential direction is provided on the upper surface of the first piezoelectric layer and outside the non-electrode connecting end of the first bottom electrode in the horizontal direction.

6. The assembly of claim 2, wherein:

and a conductive support member is arranged between the first top electrode and the second bottom electrode, and the first top electrode and the second bottom electrode are electrically connected with each other through the conductive support member.

7. The assembly of claim 2, wherein:

the electrode connection end of the first top electrode and the electrode connection end of the second bottom electrode are electrically connected to each other.

8. The assembly of claim 2, wherein:

the electrode connecting end of the first top electrode and the electrode connecting end of the second bottom electrode are electrically connected with each other, and the non-electrode connecting end of the first top electrode and the non-electrode connecting end of the second bottom electrode are electrically connected with each other.

10. The assembly of claim 3, wherein:

the length of a connection path where the first top electrode and the second bottom electrode are electrically connected to each other at the electrode non-connection end is less than 5 μm.

11. The assembly ofclaim 1, wherein:

the first top electrode and the second bottom electrode are electrically isolated from each other.

12. The assembly of claim 11, wherein:

an end portion of at least a part of the non-electrode connection end of the second bottom electrode in the circumferential direction or an end portion of the electrode connection end of the second bottom electrode is provided on the upper surface of the first piezoelectric layer, and the end portion is located outside the non-electrode connection end of the first top electrode in the horizontal direction.

13. The assembly ofclaim 12, wherein:

an end of a part of the non-electrode connecting end of the second bottom electrode in the circumferential direction or an end of the electrode connecting end of the second bottom electrode is provided on the upper surface of the first piezoelectric layer, and an end of another part of the non-electrode connecting end of the second bottom electrode in the circumferential direction is located inside a boundary of the acoustic decoupling layer in the horizontal direction.

14. The assembly ofclaim 13, wherein:

the assembly comprises a first electrode layer and a second electrode layer;

the first electrode layer includes a first top electrode and a non-top electrode layer electrically isolated from the non-electrode connection end of the first top electrode to be outside the non-electrode connection end of the first top electrode;

the second electrode layer includes a second bottom electrode and a non-bottom electrode layer electrically isolated from the non-electrode connection end of the second bottom electrode and located outside the non-electrode connection end of the second bottom electrode;

the electrode connecting end of the second bottom electrode covers the non-top electrode layer, and the non-bottom electrode layer covers the electrode connecting end of the first top electrode.

15. The assembly ofclaim 1, wherein:

at least one of the first top electrode and the second bottom electrode has a convex shape away from the cavity; or

The portion of the first top electrode defining the lower side of the cavity and the portion of the second bottom electrode defining the upper side of the cavity each have a straight shape.

16. The assembly of claim 15, wherein:

the assembly is provided with a support between the first top electrode and the second bottom electrode.

17. The assembly of claim 2, wherein:

the resonant frequency of the lower resonator is more than 0.5GHz, and the thickness of the first top electrode is less than

And/or

The resonant frequency of the upper resonator is more than 0.5GHz, and the thickness of the second bottom electrode is less than

18. The assembly of claim 17, wherein:

the resonant frequency of the lower resonator is more than 3GHz, and the thickness of the first top electrode is less than

And/or

The resonant frequency of the upper resonator is more than 3GHz, and the thickness of the second bottom electrode is less than

19. A bulk acoustic wave resonator assembly comprising:

at least two resonators which are adjacently stacked from bottom to top in the thickness direction of the assembly are bulk acoustic wave resonators, the at least two resonators comprise a first resonator and a second resonator, an acoustic decoupling layer in a cavity mode is arranged between a top electrode of the first resonator and a bottom electrode of the second resonator, and the acoustic decoupling layer serves as an acoustic mirror of the second resonator.

20. The assembly ofclaim 1 or 19, wherein:

the at least two resonators include a first resonator, a second resonator, and a third resonator stacked in a thickness direction;

the first acoustic decoupling layer is arranged between the top electrode of the first resonator and the bottom electrode of the second resonator, the second acoustic decoupling layer in the form of a cavity is arranged between the top electrode of the second resonator and the bottom electrode of the third resonator, and the second acoustic decoupling layer forms an acoustic mirror of the third resonator.

21. The assembly of claim 20, wherein:

the boundary of the second acoustic decoupling layer is outside the boundary of the first acoustic decoupling layer in the horizontal direction.

22. A method of manufacturing a bulk acoustic wave resonator assembly, comprising:

23. The method of claim 22, wherein:

in step 2, further comprising providing a support in the layer of sacrificial material.

24. A filter comprising a bulk acoustic wave resonator assembly according to any one of claims 1-21.

25. An electronic device comprising the filter of 24 or the bulk acoustic wave resonator assembly of any one of claims 1-21.

Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

Translated fromChinese

1.一种体声波谐振器组件，包括：1. A bulk acoustic wave resonator assembly comprising:

基底；base;

至少两个谐振器，所述至少两个谐振器为体声波谐振器且在基底的一侧在基底的厚度方向上叠置，所述至少两个谐振器包括第一谐振器和第二谐振器，第二谐振器在第一谐振器的上方，第一谐振器具有第一顶电极、第一压电层、第一底电极和第一声学镜，第二谐振器具有第二顶电极、第二压电层、第二底电极和第二声学镜，at least two resonators, the at least two resonators are bulk acoustic wave resonators and are stacked on one side of the substrate in the thickness direction of the substrate, the at least two resonators include a first resonator and a second resonator , the second resonator is above the first resonator, the first resonator has a first top electrode, a first piezoelectric layer, a first bottom electrode and a first acoustic mirror, and the second resonator has a second top electrode, a second piezoelectric layer, a second bottom electrode and a second acoustic mirror,

其中：in:

第一顶电极与第二底电极之间设置有空腔形式的声学解耦层，所述声学解耦层作为所述第二声学镜。An acoustic decoupling layer in the form of a cavity is disposed between the first top electrode and the second bottom electrode, and the acoustic decoupling layer serves as the second acoustic mirror.

2.根据权利要求1所述的组件，其中：2. The assembly of claim 1, wherein:

第一顶电极与第二底电极彼此电连接。The first top electrode and the second bottom electrode are electrically connected to each other.

3.根据权利要求2所述的组件，其中：3. The assembly of claim 2, wherein:

第一顶电极的非电极连接端的端部与第二底电极的非电极连接端的端部彼此相接。The end of the non-electrode connection end of the first top electrode and the end of the non-electrode connection end of the second bottom electrode are in contact with each other.

4.根据权利要求3所述的组件，其中：4. The assembly of claim 3, wherein:

第一顶电极的非电极连接端的端部与第二底电极的非电极连接端的端部在整个周向方向上彼此相接。The end of the non-electrode connection end of the first top electrode and the end of the non-electrode connection end of the second bottom electrode are in contact with each other in the entire circumferential direction.

5.根据权利要求3所述的组件，其中：5. The assembly of claim 3, wherein:

第二底电极的非电极连接端的在周向方向上的一部分的端部设置于第一压电层的上表面且在水平方向上位于第一底电极的非电极连接端的外侧。An end portion of a portion of the non-electrode connection end of the second bottom electrode in the circumferential direction is provided on the upper surface of the first piezoelectric layer and is located outside the non-electrode connection end of the first bottom electrode in the horizontal direction.

6.根据权利要求2所述的组件，其中：6. The assembly of claim 2, wherein:

第一顶电极与第二底电极之间设置导电支撑件，第一顶电极与第二底电极通过所述导电支撑件彼此电连接。A conductive support member is disposed between the first top electrode and the second bottom electrode, and the first top electrode and the second bottom electrode are electrically connected to each other through the conductive support member.

7.根据权利要求2所述的组件，其中：7. The assembly of claim 2, wherein:

第一顶电极的电极连接端与第二底电极的电极连接端彼此电连接。The electrode connection terminal of the first top electrode and the electrode connection terminal of the second bottom electrode are electrically connected to each other.

8.根据权利要求2所述的组件，其中：8. The assembly of claim 2, wherein:

第一顶电极的电极连接端与第二底电极的电极连接端彼此电连接，且第一顶电极的非电极连接端与第二底电极的非电极连接端彼此电连接。The electrode connection end of the first top electrode and the electrode connection end of the second bottom electrode are electrically connected to each other, and the non-electrode connection end of the first top electrode and the non-electrode connection end of the second bottom electrode are electrically connected to each other.

9.根据权利要求3所述的组件，其中：9. The assembly of claim 3, wherein:

第一顶电极与第二底电极在电极非连接端彼此电连接的连接路径的长度小于5μm。The length of the connection path where the first top electrode and the second bottom electrode are electrically connected to each other at the non-connecting ends of the electrodes is less than 5 μm.

10.根据权利要求1所述的组件，其中：10. The assembly of claim 1, wherein:

第一顶电极与第二底电极彼此电学隔离。The first top electrode and the second bottom electrode are electrically isolated from each other.

11.根据权利要求10所述的组件，其中：11. The assembly of claim 10, wherein:

第二底电极的非电极连接端的在周向方向上的至少一部分的端部或者第二底电极的电极连接端的端部设置于第一压电层的上表面，且所述端部在水平方向上位于第一顶电极的非电极连接端的外侧。The end of at least a part of the non-electrode connection end of the second bottom electrode in the circumferential direction or the end of the electrode connection end of the second bottom electrode is provided on the upper surface of the first piezoelectric layer, and the end is in the horizontal direction is located outside the non-electrode connection end of the first top electrode.

12.根据权利要求11所述的组件，其中：12. The assembly of claim 11, wherein:

第二底电极的非电极连接端的在周向方向上的一部分的端部或者第二底电极的电极连接端的端部设置于第一压电层的上表面，第二底电极的非电极连接端的在周向方向上的另一部分的端部在水平方向上位于声学解耦层的边界的内侧。A part of the end of the non-electrode connection end of the second bottom electrode in the circumferential direction or the end of the electrode connection end of the second bottom electrode is provided on the upper surface of the first piezoelectric layer, and the end of the non-electrode connection end of the second bottom electrode is provided on the upper surface of the first piezoelectric layer. The end of the other portion in the circumferential direction is located inside the boundary of the acoustic decoupling layer in the horizontal direction.

13.根据权利要求12所述的组件，其中：13. The assembly of claim 12, wherein:

所述组件包括第一电极层和第二电极层；the assembly includes a first electrode layer and a second electrode layer;

第一电极层包括第一顶电极以及与第一顶电极的非电极连接端电学隔离而处于第一顶电极的非电极连接端的外侧的非顶电极层；The first electrode layer includes a first top electrode and a non-top electrode layer that is electrically isolated from the non-electrode connection end of the first top electrode and located outside the non-electrode connection end of the first top electrode;

第二电极层包括第二底电极以及与第二底电极的非电极连接端电学隔离而处于第二底电极的非电极连接端的外侧的非底电极层；The second electrode layer includes a second bottom electrode and a non-bottom electrode layer that is electrically isolated from the non-electrode connection end of the second bottom electrode and located outside the non-electrode connection end of the second bottom electrode;

第二底电极的电极连接端覆盖所述非顶电极层，所述非底电极层覆盖所述第一顶电极的电极连接端。The electrode connection end of the second bottom electrode covers the non-top electrode layer, and the non-bottom electrode layer covers the electrode connection end of the first top electrode.

14.根据权利要求1所述的组件，其中：14. The assembly of claim 1, wherein:

第一顶电极与第二底电极中的至少一个具有远离所述空腔的凸出形状；或者At least one of the first top electrode and the second bottom electrode has a convex shape away from the cavity; or

所述第一顶电极的限定所述空腔的下侧的部分以及所述第二底电极的限定所述空腔的上侧的部分均具有平直形状。The portion of the first top electrode defining the lower side of the cavity and the portion of the second bottom electrode defining the upper side of the cavity each have a straight shape.

15.根据权利要求14所述的组件，其中：15. The assembly of claim 14, wherein:

所述组件在第一顶电极与第二底电极之间设置有支撑件。The assembly is provided with a support between the first top electrode and the second bottom electrode.

16.根据权利要求2所述的组件，其中：16. The assembly of claim 2, wherein:

所述下谐振器的谐振频率大于0.5GHz，第一顶电极的厚度小于

和/或The resonant frequency of the lower resonator is greater than 0.5GHz, and the thickness of the first top electrode is less than

and / or所述上谐振器的谐振频率大于0.5GHz，第二底电极的厚度小于

The resonant frequency of the upper resonator is greater than 0.5GHz, and the thickness of the second bottom electrode is less than

17.根据权利要求16所述的组件，其中：17. The assembly of claim 16, wherein:

所述下谐振器的谐振频率大于3GHz，第一顶电极的厚度小于

和/或The resonant frequency of the lower resonator is greater than 3GHz, and the thickness of the first top electrode is less than

and / or

所述上谐振器的谐振频率大于3GHz，第二底电极的厚度小于

The resonant frequency of the upper resonator is greater than 3GHz, and the thickness of the second bottom electrode is less than

18.一种体声波谐振器组件，包括：18. A bulk acoustic wave resonator assembly comprising:

在所述组件的厚度方向上自下而上相邻叠置的至少两个谐振器，所述至少两个谐振器为体声波谐振器，所述至少两个谐振器包括第一谐振器和第二谐振器，其中，第一谐振器的顶电极与第二谐振器的底电极之间设置有空腔形式的声学解耦层，所述声学解耦层作为所述第二谐振器的声学镜。At least two resonators stacked adjacently from bottom to top in the thickness direction of the component, the at least two resonators are bulk acoustic wave resonators, the at least two resonators include a first resonator and a second resonator Two resonators, wherein an acoustic decoupling layer in the form of a cavity is provided between the top electrode of the first resonator and the bottom electrode of the second resonator, and the acoustic decoupling layer acts as an acoustic mirror of the second resonator .

19.根据权利要求1或18所述的组件，其中：19. The assembly of claim 1 or 18, wherein:

所述至少两个谐振器包括在厚度方向上叠置的第一谐振器、第二谐振器和第三谐振器；the at least two resonators include a first resonator, a second resonator, and a third resonator stacked in a thickness direction;

第一谐振器的顶电极与第二谐振器的底电极之间具有所述第一声学解耦层，第二谐振器的顶电极与第三谐振器的底电极之间具有空腔形式的第二声学解耦层，第二声学解耦层构成第三谐振器的声学镜。There is the first acoustic decoupling layer between the top electrode of the first resonator and the bottom electrode of the second resonator, and there is a cavity form between the top electrode of the second resonator and the bottom electrode of the third resonator. The second acoustic decoupling layer constitutes an acoustic mirror of the third resonator.

20.根据权利要求19所述的组件，其中：20. The assembly of claim 19, wherein:

第二声学解耦层的边界在水平方向上处于第一声学解耦层的边界的外侧。The boundary of the second acoustic decoupling layer is horizontally outside the boundary of the first acoustic decoupling layer.

21.一种体声波谐振器组件的制造方法，包括：21. A method of manufacturing a bulk acoustic wave resonator assembly, comprising:

步骤1：在基底的表面上形成用于第一体声波谐振器的第一结构，所述第一体声波谐振器包括第一声学镜、第一底电极、第一压电层、第一顶电极；Step 1: Form a first structure for a first bulk acoustic wave resonator on the surface of the substrate, the first bulk acoustic wave resonator including a first acoustic mirror, a first bottom electrode, a first piezoelectric layer, a first top electrode;

步骤2：在步骤1形成的第一结构上设置图形化的牺牲材料层；Step 2: setting a patterned sacrificial material layer on the first structure formed in step 1;

步骤3：在步骤2的结构上形成用于第二体声波谐振器的第二结构，第二体声波谐振器包括第二声学镜、第二底电极、第二压电层以及第二顶电极，所述牺牲材料层在基底的厚度方向上位于第一顶电极与第二底电极之间；Step 3: forming a second structure for a second bulk acoustic wave resonator on the structure of step 2, the second bulk acoustic wave resonator includes a second acoustic mirror, a second bottom electrode, a second piezoelectric layer and a second top electrode , the sacrificial material layer is located between the first top electrode and the second bottom electrode in the thickness direction of the substrate;

步骤4：释放所述牺牲材料层以形成空腔，所述空腔构成第二体声波谐振器的第二声学镜。Step 4: Release the sacrificial material layer to form a cavity that constitutes a second acoustic mirror of the second BAW resonator.

22.根据权利要求21所述的方法，其中：22. The method of claim 21, wherein:

在步骤2中，还包括在牺牲材料层中设置支撑件。In step 2, a support member is further included in the sacrificial material layer.

23.一种滤波器，包括根据权利要求1-20中任一项所述的体声波谐振器组件。23. A filter comprising the bulk acoustic wave resonator assembly of any of claims 1-20.

24.一种电子设备，包括根据权利要求23所述的滤波器或根据权利要求1-20中任一项所述的体声波谐振器组件。24. An electronic device comprising the filter of claim 23 or the bulk acoustic wave resonator assembly of any of claims 1-20.