Resonator and preparation method thereof, filter and electronic equipment

Abstract

The invention provides a resonator and a preparation method thereof, a filter and electronic equipment, and relates to the technical field of semiconductors. The bottom electrode layer located between the two adjacent cavities is provided with a groove penetrating through the bottom electrode layer, and the groove is exposed out of the surface of the piezoelectric layer. And the cut-off boundary layer between two adjacent cavities can be in contact with the bottom electrode layer and can also be in contact with the piezoelectric layer through the grooves. The material of the piezoelectric layer and the material of the cut-off boundary layer are both non-metallic materials, so that the adhesive force between the cut-off boundary layer and the piezoelectric layer is obviously greater than the adhesive force between the cut-off boundary layer and the bottom electrode layer. The cut-off boundary layer is in contact with the piezoelectric layer based on the groove in the bottom electrode layer, namely, the cut-off boundary layer and the bottom electrode layer are tightly pressed together by the contact part of the cut-off boundary layer and the piezoelectric layer, so that the problem that the bottom electrode layer and the cut-off boundary layer are layered after the cavity release process is solved; and the structural stability and the performance of the resonator are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a resonator and a preparation method thereof, a filter and an electronic device. Background Art

[0002] At present, the traditional resonator unit includes a top electrode layer, a piezoelectric layer and a bottom electrode layer. Based on the existing cofferdam structure cavity release type resonator, it is inevitable that there will be the following design, that is, the two resonator units will be connected through the top electrode layer or the bottom electrode layer. After the two resonator units connected by the bottom electrode layer are prepared, they will share a cutoff boundary layer, at which time there will be a phenomenon of direct contact between the bottom electrode layer and the cutoff boundary layer. Among them, the cutoff boundary layer is mainly used to limit the partial boundary position of the cavity of the resonator unit.

[0003] Since the cutoff boundary layer is usually a non-metallic material and the bottom electrode layer is usually a metal material, the adhesion of the area where the cutoff boundary layer and the bottom electrode layer are in direct contact is poor. After the cavity release process, the bottom electrode layer and the cutoff boundary layer will be delaminated, which will affect the structural stability and performance of the resonator. Summary of the invention

[0004] In view of the above problems, the present application provides a resonator and a method for manufacturing the same, a filter and an electronic device, wherein the cutoff boundary layer is shared in the resonator, the cutoff boundary layer is in contact with the bottom electrode layer, and is in contact with the piezoelectric layer through a groove that penetrates the bottom electrode layer, thereby improving the structural stability and performance of the resonator. The specific scheme is as follows:

[0005] In a first aspect, the present application provides a resonator, the resonator comprising:

[0006] substrate;

[0007] A cut-off boundary layer, a bottom electrode layer and a piezoelectric layer located on one side of the substrate, wherein the bottom electrode layer is located between the cut-off boundary layer and the piezoelectric layer;

[0008] The cut-off boundary layer and the piezoelectric layer form a plurality of cavities independent of each other;

[0009] The bottom electrode layer located between two adjacent cavities has a groove penetrating through the bottom electrode layer;

[0010] The cut-off boundary layer located between two adjacent cavities contacts the bottom electrode layer and contacts the piezoelectric layer through the groove.

[0011] Preferably, in the above resonator, the size of the groove in a first direction gradually increases; the first direction is perpendicular to the plane where the substrate is located, and points from the substrate to the piezoelectric layer.

[0012] Preferably, in the above resonator, the grooves are arranged in an array.

[0013] Preferably, in the above resonator, a shape of a portion of the grooves is different from a shape of another portion of the grooves.

[0014] Preferably, in the above resonator, the groove is a strip-shaped groove or an annular groove.

[0015] Preferably, in the above resonator, a portion of the grooves and another portion of the grooves have an overlapping area.

[0016] Preferably, in the above resonator, the resonator further comprises:

[0017] A plurality of top electrode layers located on a side of the piezoelectric layer facing away from the substrate;

[0018] There is a gap between two adjacent top electrode layers; the multiple top electrode layers are arranged in one-to-one correspondence with the multiple cavities.

[0019] A second aspect of the present application provides a method for preparing a resonator, the method comprising:

[0020] After forming the piezoelectric layer and the bottom electrode layer, processing a portion of the bottom electrode layer to form a groove penetrating the bottom electrode layer;

[0021] A cut-off boundary layer is formed, the cut-off boundary layer being in contact with the bottom electrode layer and in contact with the piezoelectric layer through the groove.

[0022] Preferably, in the above-mentioned method for preparing the resonator, after forming the piezoelectric layer and the bottom electrode layer, a partial area of ​​the bottom electrode layer is processed to form a groove penetrating the bottom electrode layer, comprising:

[0023] providing a temporary substrate;

[0024] forming a top electrode layer, the piezoelectric layer and the bottom electrode layer in sequence on the temporary substrate;

[0025] A partial area of ​​the bottom electrode layer is processed to form a groove penetrating the bottom electrode layer.

[0026] Preferably, in the above method for preparing the resonator, before forming the cutoff boundary layer, the method for preparing the resonator further comprises:

[0027] A sacrificial layer is formed and patterned based on the cavity location.

[0028] Preferably, in the above method for preparing the resonator, after forming the cutoff boundary layer, the method for preparing the resonator further comprises:

[0029] forming a bonding contact layer on a side of the cut-off boundary layer facing away from the temporary substrate;

[0030] bonding a substrate at a side of the bonding contact layer facing away from the temporary substrate;

[0031] The temporary substrate is removed, the top electrode layer is patterned, and a cavity release process is performed.

[0032] A third aspect of the present application provides a filter, comprising the resonator described in any one of the above items.

[0033] A fourth aspect of the present application provides an electronic device, the electronic device comprising the resonator described in any one of the above items;

[0034] Alternatively, the electronic device includes the filter described above.

[0035] By means of the above technical scheme, the present application provides a resonator and a preparation method thereof, a filter and an electronic device. The bottom electrode layer located between two adjacent cavities indicates that the two resonator units are connected through the bottom electrode layer, and the bottom electrode layer located between the two adjacent cavities has a groove running through itself, and the groove exposes the surface of the piezoelectric layer. Under this structure, the cut-off boundary layer located between the two adjacent cavities will contact the bottom electrode layer, and will also contact the piezoelectric layer through the groove. Since the material of the piezoelectric layer and the material of the cut-off boundary layer are both non-metallic materials, it is obvious that the adhesion between the cut-off boundary layer and the piezoelectric layer will be greater than the adhesion between the cut-off boundary layer and the bottom electrode layer. Through the cut-off boundary layer based on the groove on the bottom electrode layer, the contact between the piezoelectric layer and the piezoelectric layer is equivalent to the cut-off boundary layer and the piezoelectric layer. This part of the contact between the cut-off boundary layer and the piezoelectric layer will press the cut-off boundary layer and the bottom electrode layer tightly together, which greatly solves the problem of delamination between the bottom electrode layer and the cut-off boundary layer after the cavity release process, thereby improving the structural stability and performance of the resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.

[0037] Figure 1 A schematic diagram of a partial top view of a resonator provided by an embodiment of the present invention;

[0038] Figure 2 A method for providing an embodiment of the present invention Figure 1 Schematic diagram of the cross section along the AA' direction;

[0039] Figure 3 A method for providing an embodiment of the present invention Figure 1 Schematic diagram of the cross section along the BB' direction;

[0040] Figure 4 Another embodiment of the present invention provides Figure 1 Schematic diagram of the cross section along the BB' direction;

[0041] Figure 5 A schematic diagram of a partial top view of a bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention;

[0042] Figure 6 A schematic diagram of a partial top view of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention;

[0043] Figure 7 A schematic diagram of a partial top view structure of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention;

[0044] Figure 8 A schematic diagram of a partial top view structure of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention;

[0045] Fig. 9 A schematic diagram of a partial top view structure of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention;

[0046] Fig.10 A schematic diagram of a process for preparing a resonator provided by an embodiment of the present invention;

[0047] Figure 11-Figure 18 for Fig.10 A partial structural schematic diagram corresponding to the preparation method of the resonator shown. DETAILED DESCRIPTION

[0048] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation method section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. It is known to those of ordinary skill in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems. It should be noted that the directional words appearing in the present invention are based on the relative position relationship shown in the drawings and cannot be used as an absolute limitation on the present application.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] refer to Figure 1 , Figure 1 A schematic diagram of a partial top view of a resonator provided in an embodiment of the present invention, referring to Figure 2 , Figure 2 A method for providing an embodiment of the present invention Figure 1 Schematic diagram of the cross section in the AA' direction, refer to Figure 3 , Figure 3 A method for providing an embodiment of the present invention Figure 1 The resonator provided by the embodiment of the present invention includes: a substrate 16.

[0051] The cut-off boundary layer 11 , the bottom electrode layer 12 and the piezoelectric layer 14 are located on one side of the substrate 16 , and the bottom electrode layer 12 is located between the cut-off boundary layer 11 and the piezoelectric layer 14 .

[0052] The cut-off boundary layer 11 and the piezoelectric layer 14 form a plurality of cavities that are independent of each other.

[0053] The bottom electrode layer 12 located between two adjacent cavities has a groove 13 penetrating the bottom electrode layer 12 .

[0054] The cut-off boundary layer 11 located between two adjacent cavities contacts the bottom electrode layer 12 , and contacts the piezoelectric layer 14 through the groove 13 .

[0055] Specifically, in the embodiment of the present invention, one cavity is set to correspond to one resonator unit. When there is a bottom electrode layer 12 between two adjacent cavities, it can be said that the two adjacent resonator units are connected through the bottom electrode layer 12. In the embodiment of the present invention, two cavities are used as an example for description, namely, the first cavity 100 and the second cavity 200. In other words, in the embodiment of the present invention, two resonator units are connected through the bottom electrode layer 12 as an example for description.

[0056] In an embodiment of the present invention, the bottom electrode layer 12 located between two adjacent cavities has a groove 13 that runs through it, and the groove 13 exposes the surface of the piezoelectric layer 14. Under this structure, the cutoff boundary layer 11 located between the two adjacent cavities will contact the bottom electrode layer 12, and will also contact the piezoelectric layer 14 through the groove 13. Since the material of the piezoelectric layer 14 and the material of the cutoff boundary layer 11 are both non-metallic materials, it is obvious that the adhesion between the cutoff boundary layer 11 and the piezoelectric layer 14 will be greater than the adhesion between the cutoff boundary layer 11 and the bottom electrode layer 12. The cutoff boundary layer 11 contacts the piezoelectric layer 14 based on the groove 13 on the bottom electrode layer 12, which is equivalent to the part of the cutoff boundary layer 11 that contacts the piezoelectric layer 14, which will press the cutoff boundary layer 11 and the bottom electrode layer 12 tightly together, which greatly solves the problem of delamination between the bottom electrode layer 12 and the cutoff boundary layer 11 after the cavity release process, thereby improving the structural stability and performance of the resonator.

[0057] Since only the bottom electrode layer 12 between two adjacent cavities is grooved and not disconnected, the two resonator units can still be connected through the bottom electrode layer.

[0058] Furthermore, the bottom electrode layer 12 between two adjacent cavities has a groove 13 running through it, indicating that a portion of the bottom electrode layer 12 at the connection between the two resonator units is cut away, thereby achieving the above-mentioned purpose while avoiding a substantial increase in the resonator resistance as much as possible, thereby reducing the impact on the resonator performance.

[0059] In an optional embodiment of the present invention, reference Figure 4 , Figure 4 Another embodiment of the present invention provides Figure 1 In the embodiment of the present invention, the size of the groove 13 in the first direction X gradually increases; the first direction X is perpendicular to the plane where the substrate 16 is located, and points from the substrate 16 to the piezoelectric layer 14.

[0060] Specifically, in the embodiment of the present invention, the size and other parameters of the groove 13 are designed so that the size of the groove 13 in the first direction X gradually increases, thereby increasing the contact area between the cutoff boundary layer 11 and the piezoelectric layer 14 through the groove 13, and further improving the adhesion of the cutoff boundary layer 11 based on the contact between the groove 13 on the bottom electrode layer 12 and the piezoelectric layer 14, thereby maximizing the structural stability and performance of the resonator.

[0061] In an optional embodiment of the present invention, referring to 5, Figure 5The schematic diagram of a partial top view of a bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention is shown in FIG.

[0062] Specifically, in the embodiment of the present invention, the positions of the grooves 13 are limited by an array arrangement, so that more grooves 13 can be set in the limited space between two adjacent cavities, thereby greatly improving the adhesion force between the cutoff boundary layer 11 based on the contact between the grooves 13 on the bottom electrode layer 12 and the piezoelectric layer 14, thereby maximizing the structural stability and performance of the resonator.

[0063] In an optional embodiment of the present invention, reference Figure 6 , Figure 6 A schematic diagram of a partial top view of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention. The shape of a portion of the grooves 13 is different from the shape of another portion of the grooves 13 .

[0064] Specifically, in the embodiments of the present invention, Figure 6 As shown, a part of the grooves 13 are in the shape of quadrilaterals, and a part of the grooves 13 are in the shape of triangles. By designing grooves 13 of different shapes, the cut-off boundary layer 11 based on the grooves 13 on the bottom electrode layer 12 and the piezoelectric layer 14 have different contact areas, so as to improve the adhesion of the cut-off boundary layer 11 based on the grooves 13 on the bottom electrode layer 12 and the piezoelectric layer 14 to a greater extent, thereby maximizing the structural stability and performance of the resonator.

[0065] In an optional embodiment of the present invention, reference Figure 7 , Figure 7 A schematic diagram of a partial top view of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention, referring to Figure 8 , Figure 8 A schematic diagram of a partial top view of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention, referring to Fig. 9 , Fig. 9 A schematic diagram of a partial top view of another bottom electrode layer located between two adjacent cavities provided in an embodiment of the present invention. The groove 13 is a strip groove or an annular groove. A portion of the groove 13 overlaps with another portion of the groove 13.

[0066] Specifically, in the embodiments of the present invention, Figure 7 When the grooves 13 are strip-shaped grooves, they can be arranged in a comb-tooth shape. Figure 8 As shown, the groove 13 is an annular groove. When a portion of the groove 13 overlaps with another portion of the groove 13, as shown in FIG. Fig. 9As shown, there is an overlapping area between the two annular grooves, forming an integrated large-sized groove structure, which can achieve a larger-sized contact between the cutoff boundary layer 11 and the piezoelectric layer 14 based on the integrated large-sized groove structure on the bottom electrode layer 12, so as to further improve the adhesion between the cutoff boundary layer 11 and the piezoelectric layer 14 based on the groove 13 on the bottom electrode layer 12, thereby maximizing the structural stability and performance of the resonator.

[0067] In an optional embodiment of the present invention, the arrangement density of the grooves 13 at a position close to the cavity is greater than the arrangement density of the grooves 13 at a position far from the cavity.

[0068] Specifically, in the embodiment of the present invention, since the position close to the cavity can be understood as the edge position where the cutoff boundary layer 11 contacts the bottom electrode layer 12, when the arrangement density of the grooves 13 at the position close to the cavity is greater than the arrangement density of the grooves 13 at the position far from the cavity, the adhesion force between the cutoff boundary layer 11 at this position based on the contact between the grooves 13 on the bottom electrode layer 12 and the piezoelectric layer 14 can be greatly improved, which can greatly solve the problem of stratification between the bottom electrode layer 12 and the cutoff boundary layer 11 after the cavity release process, thereby improving the structural stability and performance of the resonator.

[0069] In an optional embodiment of the present invention, Figure 2 , Figure 3 or Figure 4 As shown, the resonator provided by the embodiment of the present invention also includes:

[0070] A plurality of top electrode layers 15 are located on a side of the piezoelectric layer 14 facing away from the substrate 16 .

[0071] There is a gap between two adjacent top electrode layers 15 ; the multiple top electrode layers 15 are arranged in one-to-one correspondence with the multiple cavities.

[0072] The resonator provided by the embodiment of the present invention further includes: a bonding contact layer 17 located between the substrate 16 and the cut-off boundary layer 11 , for realizing a bonding connection between the substrate 16 and the cut-off boundary layer 11 .

[0073] The resonator provided by the embodiment of the present invention further includes: a sacrificial layer 18 , which is the sacrificial layer 18 remaining after the cavity release process.

[0074] Based on the above embodiment of the present invention, another embodiment of the present invention further provides a method for preparing a resonator, referring to Fig.10 , Fig.10 A schematic flow chart of a method for preparing a resonator provided in an embodiment of the present invention. The method for preparing a resonator provided in an embodiment of the present invention comprises:

[0075] S101: Figure 11-13 As shown, after the piezoelectric layer 14 and the bottom electrode layer 12 are formed, a partial area of ​​the bottom electrode layer 12 is processed to form a groove 13 penetrating the bottom electrode layer 12 .

[0076] Specifically, Fig.11 and Fig.12 As shown, after forming the piezoelectric layer and the bottom electrode layer, a partial area of ​​the bottom electrode layer is processed to form a groove passing through the bottom electrode layer, including: providing a temporary substrate 19; sequentially forming a top electrode layer 15, the piezoelectric layer 14 and the bottom electrode layer 12 on the temporary substrate 19; and processing a partial area of ​​the bottom electrode layer 12 to form a groove passing through the bottom electrode layer 12.

[0077] In other words, if Fig.11 As shown, a top electrode layer 15, a piezoelectric layer 14 and a bottom electrode layer 12 are sequentially formed on a temporary substrate 19. The material of the top electrode layer 15 includes but is not limited to Mo materials and the like, the material of the piezoelectric layer 14 includes but is not limited to AlN materials, AlScN materials or PZT materials and the like, and the material of the bottom electrode layer 12 includes but is not limited to Mo materials and the like. Fig.12 As shown, based on the design requirements of the groove 13 of the technical solution of the present application, the bottom electrode layer 12 is etched so that the bottom electrode layer 12 subsequently located between two adjacent cavities has a groove 13 penetrating the bottom electrode layer 12 .

[0078] like Fig.13 As shown, before forming the cutoff boundary layer 11, the method for preparing the resonator further includes: forming a sacrificial layer 18, and patterning the sacrificial layer 18 based on the cavity position. In other words, the sacrificial layer 18 is deposited and the sacrificial layer pattern is made based on the cavity position. The material of the sacrificial layer 18 includes but is not limited to SiO2, P-doped SiO2 or B-doped SiO2 and other materials.

[0079] S102: Figure 14-18 As shown, a cut-off boundary layer 11 is formed, and the cut-off boundary layer 11 is in contact with the bottom electrode layer 12 , and is in contact with the piezoelectric layer 14 through the groove 13 .

[0080] Specifically, Fig.14 As shown, a cut-off boundary layer 11 is deposited. The material of the cut-off boundary layer 11 includes but is not limited to materials such as Poly-Si or AlN.

[0081] like Figure 2 as well as Figure 15-18As shown, after forming the cutoff boundary layer 11, the resonator preparation method further includes: forming a bonding contact layer 17 on the side of the cutoff boundary layer 11 away from the temporary substrate 19; bonding the substrate 16 on the side of the bonding contact layer 17 away from the temporary substrate 19; removing the temporary substrate 19, patterning the top electrode layer 15, and performing a cavity release process. In other words, Fig.15 As shown, a bonding contact layer 17 is deposited, and a surface of the bonding contact layer 17 facing away from the temporary substrate 19 is planarized. The material of the bonding contact layer 17 includes but is not limited to SiO2, P-doped SiO2 or B-doped SiO2. Fig.16 As shown, the bonding substrate 16. Fig.17 As shown, the temporary substrate 19 is removed. Fig.18 As shown, based on the design requirements and the location of the cavity, the top electrode layer 15 is etched to form a plurality of independent top electrode layers 15. Figure 2 As shown, a cavity releasing process is performed to form the cavity required for the resonator unit.

[0082] Based on the above embodiments of the present invention, a filter is provided in another embodiment of the present invention. The filter includes the resonator described in any of the above embodiments.

[0083] Based on the above embodiments of the present invention, another embodiment of the present invention provides an electronic device, which includes the resonator described in any of the above embodiments.

[0084] Alternatively, the electronic device includes the filter described in the above embodiment.

[0085] The resonator and its preparation method, filter and electronic device provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

[0086] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0087] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device that includes a series of elements is inherent to the elements, or also includes elements inherent to these processes, methods, articles or devices. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0088] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A resonator, characterized in that: The resonator comprises: substrate; A cut-off boundary layer, a bottom electrode layer and a piezoelectric layer located on one side of the substrate, wherein the bottom electrode layer is located between the cut-off boundary layer and the piezoelectric layer; The cut-off boundary layer and the piezoelectric layer form a plurality of cavities independent of each other; The bottom electrode layer located between two adjacent cavities has a groove penetrating through the bottom electrode layer; The cut-off boundary layer located between two adjacent cavities contacts the bottom electrode layer and contacts the piezoelectric layer through the groove.

2. The resonator according to claim 1, characterized in that The size of the groove gradually increases in a first direction; the first direction is perpendicular to the plane where the substrate is located, and points from the substrate to the piezoelectric layer.

3. The resonator according to claim 1, characterized in that The grooves are arranged in an array.

4. The resonator according to claim 1, characterized in that The shape of a portion of the grooves is different from the shape of another portion of the grooves.

5. The resonator according to claim 1, characterized in that The groove is a strip-shaped groove or an annular groove.

6. The resonator according to claim 5, characterized in that A portion of the grooves overlaps with another portion of the grooves.

7. The resonator according to any one of claims 1 to 6, characterized in that: The resonator further comprises: A plurality of top electrode layers located on a side of the piezoelectric layer facing away from the substrate; There is a gap between two adjacent top electrode layers; the multiple top electrode layers are arranged in one-to-one correspondence with the multiple cavities.

8. A method for preparing a resonator, characterized in that: The preparation method of the resonator comprises: After forming the piezoelectric layer and the bottom electrode layer, processing a portion of the bottom electrode layer to form a groove penetrating the bottom electrode layer; A cut-off boundary layer is formed, the cut-off boundary layer being in contact with the bottom electrode layer and in contact with the piezoelectric layer through the groove.

9. The method for preparing a resonator according to claim 8, characterized in that: After forming the piezoelectric layer and the bottom electrode layer, processing a portion of the bottom electrode layer to form a groove penetrating the bottom electrode layer comprises: providing a temporary substrate; forming a top electrode layer, the piezoelectric layer and the bottom electrode layer in sequence on the temporary substrate; A partial area of ​​the bottom electrode layer is processed to form a groove penetrating the bottom electrode layer.

10. The method for preparing a resonator according to claim 9, characterized in that: Before forming the cutoff boundary layer, the method for preparing the resonator further comprises: A sacrificial layer is formed and patterned based on the cavity location.

11. The method for preparing a resonator according to claim 10, characterized in that: After forming the cutoff boundary layer, the method for preparing the resonator further comprises: forming a bonding contact layer on a side of the cut-off boundary layer facing away from the temporary substrate; bonding a substrate at a side of the bonding contact layer facing away from the temporary substrate; The temporary substrate is removed, the top electrode layer is patterned, and a cavity release process is performed.

12. A filter, characterized in that: The filter comprises the resonator according to any one of claims 1-7.

13. An electronic device, characterized in that: The electronic device comprises the resonator according to any one of claims 1 to 7; Or, the electronic device comprises the filter according to claim 12.

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