CN113965182B - Method and structure for improving preparation yield of bulk acoustic wave filter - Google Patents
Method and structure for improving preparation yield of bulk acoustic wave filter Download PDFInfo
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- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02007—Details of bulk acoustic wave devices
- H03H9/02015—Characteristics of piezoelectric layers, e.g. cutting angles
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02007—Details of bulk acoustic wave devices
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- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezo-electric or electrostrictive material
- H03H9/56—Monolithic crystal filters
- H03H9/564—Monolithic crystal filters implemented with thin-film techniques
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- H—ELECTRICITY
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- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezo-electric or electrostrictive material
- H03H9/58—Multiple crystal filters
- H03H9/582—Multiple crystal filters implemented with thin-film techniques
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
- H03H2003/023—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks the resonators or networks being of the membrane type
Abstract
The invention provides a method and a structure for improving the preparation yield of a bulk acoustic wave filter. The structure comprises a substrate, a Bragg reflection layer, a rectangular supporting column, a stepped supporting column, a bottom electrode, a seed layer and a pentagonal top electrode; the rectangular support columns and the stepped support columns are arranged on two sides of the upper surface of the base body, and three pairs of Bragg reflecting layers with structures are arranged in grooves formed by the rectangular support columns, the stepped support columns and the upper surface of the base body; a bottom electrode is disposed on an upper surface of the bragg reflection layer, and an up-lead portion of the bottom electrode extends to the upper surface of the stepped support pillar along a stepped surface of the stepped support pillar; the seed layer extends to the upper surface of the rectangular support column; a piezoelectric layer is arranged above the seed layer; and a pentagonal top electrode with a three-region structure is arranged above the piezoelectric layer.
Description
Technical Field
The invention provides a method and a structure for improving the preparation yield of a bulk acoustic wave filter, and belongs to the technical field of thin film filters.
Background
The film bulk acoustic resonator is a new radio frequency device technology which is appeared due to the rapid development of personal wireless communication technology. The film bulk acoustic resonator has the advantages of extremely high quality factor Q value, capability of being integrated on an IC chip and the like, however, in the preparation process of the film bulk acoustic resonator, due to the fact that clutter on a transverse mode often appears in the design of a top electrode, the problem that the yield of the film bulk acoustic resonator is low is caused. Although patent CN112436819 proposes to change the boundary line of the top electrode from a straight line to an arc line, so as to reduce the generation of noise, in terms of practical application, compared with the original top electrode without a parallel line structure, the improved top electrode structure has an insignificant noise suppression effect, and the difficulty in manufacturing the top electrode is increased due to the design of the edge arc line.
Disclosure of Invention
The invention provides a method for improving the preparation yield of a bulk acoustic wave filter, which is used for solving the problem of low yield of the existing film bulk acoustic wave filter and adopts the following technical scheme:
a method of improving bulk acoustic wave filter fabrication yield, the method comprising:
step 1, depositing rectangular support columns and stepped support columns on two sides of the upper surface of a substrate respectively;
step 2, alternately forming a low-sound-wave impedance layer and a high-sound-wave impedance layer by using silicon dioxide and metal tungsten respectively through a deposition method in grooves formed on the upper surfaces of the rectangular supporting columns, the stepped supporting columns and the base body, and forming a Bragg reflection layer after finishing the combination arrangement of three pairs of low-sound-wave impedance layers and high-sound-wave impedance layers;
and 4, preparing a piezoelectric layer above the bottom electrode, and preparing a top electrode above the piezoelectric layer in a mode of combining etching and sputtering, wherein the top electrode adopts a pentagonal top electrode structure with a three-region structure.
Further, the top electrode comprises a central electrode region, a middle electrode region and an edge electrode region; the central electrode area is positioned at the central position of the pentagonal top electrode; the middle electrode area is arranged outside the edge electrode area; the edge electrode area is arranged outside the middle electrode area; the edge electrode area is provided with a plurality of metal edge areas; the metal edge regions are distributed at two ends of each straight line side of the middle electrode region, and the metal edge regions arranged at the connected straight line ends are also connected.
Further, preparing a top electrode by a combination of etching and sputtering over the piezoelectric layer comprises:
step 401, etching central electrode areas of the top electrodes on the upper surfaces of the piezoelectric layers respectively;
step 402, etching a region range of a middle electrode region on the periphery of the middle electrode region;
step 403, etching a region range of the edge electrode region on the periphery of the middle electrode region;
step 404, etching a metal edge area at two ends of each straight line edge of the edge electrode area;
step 405, respectively preparing a central electrode area, a middle electrode area, an edge electrode area and a metal edge area corresponding to the central electrode area, the middle electrode area, the edge electrode area and the metal edge area by a sputtering method according to the positions of the central electrode area, the middle electrode area, the edge electrode area and the metal edge area.
A structure for improving the preparation yield of a bulk acoustic wave filter comprises a substrate, a Bragg reflection layer, rectangular support columns, stepped support columns, a bottom electrode, a seed layer and a pentagonal top electrode; the rectangular support columns and the stepped support columns are arranged on two sides of the upper surface of the base body, and three pairs of Bragg reflecting layers with structures are arranged in grooves formed by the rectangular support columns, the stepped support columns and the upper surface of the base body; a bottom electrode is disposed on an upper surface of the bragg reflection layer, and an up-lead portion of the bottom electrode extends to the upper surface of the stepped support pillar along a stepped surface of the stepped support pillar; the seed layer extends to the upper surface of the rectangular support column; a piezoelectric layer is arranged above the seed layer; and a pentagonal top electrode with a three-region structure is arranged above the piezoelectric layer.
Further, the pentagonal top electrode comprises a central electrode region, a middle electrode region and an edge electrode region; the central electrode area is positioned at the central position of the pentagonal top electrode; the middle electrode area is arranged outside the edge electrode area; the edge electrode area is arranged outside the middle electrode area; and the thicknesses of the central electrode area, the middle electrode area and the edge electrode area are kept consistent.
Further, the central electrode area adopts a circular electrode area structure; the middle electrode area adopts a pentagonal electrode area structure; the edge electrode area adopts a pentagonal electrode area structure with the same shape as the middle electrode area.
Further, the edge electrode region is provided with a plurality of metal edge regions; the metal edge regions are distributed at two ends of each straight line side of the edge electrode region, and the metal edge regions arranged at the connected straight line ends are also connected; the width of the metal edge area close to the linear center of the edge electrode area is smaller than the width of the metal edge area close to the linear end point.
Further, the width of the metal edge region satisfies the following condition:
wherein the content of the first and second substances,D 1representing the length of the wide side close to the position of a linear end point in the metal edge region;D 2representing the length of a wide side in the metal edge region close to the linear center position of the edge electrode region;D 01representing a linear distance between the vertex of the middle electrode area and the vertex of the edge electrode area;D 02representing a linear distance between a straight side of the middle electrode region and a straight side of the edge electrode region.
Further, the length of the metal edge region satisfies the following condition:
wherein the content of the first and second substances,L 1representing the length of the metal edge region;Lindicating the length of the straight edge of the edge electrode area.
Further, the central electrode area and the edge electrode area are made of graphene materials; the middle electrode area and the metal edge area are made of conductive metal materials.
The invention has the beneficial effects that:
according to the method and the structure for improving the preparation yield of the bulk acoustic wave filter, the Bragg reflection layer is adopted to replace the gap, so that the piezoelectric layer, the bottom electrode and the top electrode can be effectively prevented from collapsing, and the operation stability of the bulk acoustic wave filter is further effectively improved. Simultaneously, the formation of the horizontal modulus of top electrode vibration in-process can be effectively improved through the three region structure setting of top electrode and the setting of the different materials of every region structure, and then effectively restrain the clutter of top electrode in the high frequency vibration in-process and generate quantity, and then reduce the influence of top electrode vibration in-process to resonator frequency factor, the pentagon top electrode structure through this kind of three region structure's setting can effectively improve film bulk acoustic resonator operating stability and life, and then improve the yields of top bulk acoustic resonator to the at utmost.
Drawings
FIG. 1 is a flow chart of the method of the present invention;
FIG. 2 is a schematic structural diagram of a bulk acoustic wave filter according to the present invention;
FIG. 3 is a schematic view of a top electrode structure according to the present invention;
FIG. 4 is a schematic view of the structure of the metal edge region of the present invention;
(1, base; 21, rectangular support columns; 22, stepped support columns; 3, Bragg reflector; 4, bottom electrode; 5, seed layer; 6, top electrode; 7, piezoelectric layer; 61, center electrode region; 62, middle electrode region; 63, edge electrode region; 64, metal edge region).
Detailed Description
The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.
The embodiment of the invention provides a method for improving the preparation yield of a bulk acoustic wave filter, as shown in fig. 1, the method comprises the following steps:
step 1, depositing rectangular support columns and stepped support columns on two sides of the upper surface of a substrate respectively;
step 2, alternately forming a low-sound-wave impedance layer and a high-sound-wave impedance layer by using silicon dioxide and metal tungsten respectively through a deposition method in grooves formed on the upper surfaces of the rectangular supporting columns, the stepped supporting columns and the base body, and forming a Bragg reflection layer after finishing the combination arrangement of three pairs of low-sound-wave impedance layers and high-sound-wave impedance layers;
and 4, preparing a piezoelectric layer above the bottom electrode, and preparing a top electrode above the piezoelectric layer in a mode of combining etching and sputtering, wherein the top electrode adopts a pentagonal top electrode structure with a three-region structure.
Wherein the top electrode comprises a central electrode region, a middle electrode region, and an edge electrode region; the central electrode area is positioned at the central position of the pentagonal top electrode; the middle electrode area is arranged outside the edge electrode area; the edge electrode area is arranged outside the middle electrode area; the edge electrode area is provided with a plurality of metal edge areas; the metal edge regions are distributed at two ends of each straight line side of the middle electrode region, and the metal edge regions arranged at the connected straight line ends are also connected.
Specifically, the preparation of the top electrode by a combination of etching and sputtering above the piezoelectric layer comprises:
step 401, etching central electrode areas of the top electrodes on the upper surfaces of the piezoelectric layers respectively;
step 402, etching a region range of a middle electrode region on the periphery of the middle electrode region;
step 403, etching a region range of the edge electrode region on the periphery of the middle electrode region;
step 404, etching a metal edge area at two ends of each straight line edge of the edge electrode area;
step 405, respectively preparing a central electrode area, a middle electrode area, an edge electrode area and a metal edge area corresponding to the central electrode area, the middle electrode area, the edge electrode area and the metal edge area by a sputtering method according to the positions of the central electrode area, the middle electrode area, the edge electrode area and the metal edge area.
The working principle of the technical scheme is as follows: firstly, depositing rectangular support columns and stepped support columns on two sides of the upper surface of a substrate respectively; then, in grooves formed on the upper surfaces of the rectangular supporting columns, the stepped supporting columns and the base body, silicon dioxide and metal tungsten are respectively adopted to alternately form low-sound-wave impedance layers and high-sound-wave impedance layers layer by layer through a deposition method, and after the three pairs of low-sound-wave impedance layers and high-sound-wave impedance layers are assembled, a Bragg reflection layer is formed; then, a bottom electrode is arranged on the Bragg reflection layer, and a seed layer is arranged on the bottom electrode, wherein the upward leading part of the bottom electrode extends to the upper surface of the stepped support column along the stepped surface of the stepped support column; one end of the seed layer extends to the upper surface of the rectangular support column; and finally, preparing a piezoelectric layer above the bottom electrode, and preparing a top electrode above the piezoelectric layer in a combined etching and sputtering mode, wherein the top electrode adopts a pentagonal top electrode structure with a three-region structure. The substrate, the support columns, the seed layer and the piezoelectric layer are all made of materials in the prior art.
The effect of the above technical scheme is as follows: according to the bulk acoustic wave filter prepared by the method for improving the preparation yield of the bulk acoustic wave filter, the Bragg reflection layer is adopted to replace a gap, so that the piezoelectric layer, the bottom electrode and the top electrode can be effectively prevented from collapsing, and the operation stability of the bulk acoustic wave filter is further effectively improved. Simultaneously, the formation of the horizontal modulus of top electrode vibration in-process can be effectively improved through the three region structure setting of top electrode and the setting of the different materials of every region structure, and then effectively restrain the clutter of top electrode in the high frequency vibration in-process and generate quantity, and then reduce the influence of top electrode vibration in-process to resonator frequency factor, the pentagon top electrode structure through this kind of three region structure's setting can effectively improve film bulk acoustic resonator operating stability and life, and then improve the yields of top bulk acoustic resonator to the at utmost.
The embodiment of the invention provides a structure for improving the preparation yield of a bulk acoustic wave filter, which comprises a substrate, a Bragg reflection layer, a rectangular supporting column, a stepped supporting column, a bottom electrode, a seed layer and a pentagonal top electrode, and is shown in figures 2 to 4; the rectangular support columns and the stepped support columns are arranged on two sides of the upper surface of the base body, and three pairs of Bragg reflecting layers with structures are arranged in grooves formed by the rectangular support columns, the stepped support columns and the upper surface of the base body; a bottom electrode is disposed on an upper surface of the bragg reflection layer, and an up-lead portion of the bottom electrode extends to the upper surface of the stepped support pillar along a stepped surface of the stepped support pillar; the seed layer extends to the upper surface of the rectangular support column; a piezoelectric layer is arranged above the seed layer; and a pentagonal top electrode with a three-region structure is arranged above the piezoelectric layer.
Wherein the pentagonal top electrode comprises a central electrode region, a middle electrode region and an edge electrode region; the central electrode area is positioned at the central position of the pentagonal top electrode; the middle electrode area is arranged outside the edge electrode area; the edge electrode area is arranged outside the middle electrode area; and the thicknesses of the central electrode area, the middle electrode area and the edge electrode area are kept consistent. The central electrode area adopts a circular electrode area structure; the middle electrode area adopts a pentagonal electrode area structure; the edge electrode area adopts a pentagonal electrode area structure with the same shape as the middle electrode area. The edge electrode area is provided with a plurality of metal edge areas; the metal edge regions are distributed at two ends of each straight line side of the edge electrode region, and the metal edge regions arranged at the connected straight line ends are also connected; the width of the metal edge area close to the linear center of the edge electrode area is smaller than the width of the metal edge area close to the linear end point. The central electrode area and the edge electrode area are made of graphene materials; the middle electrode area and the metal edge area are made of conductive metal materials.
The working principle of the technical scheme is as follows: the central electrode area, the middle electrode area and the edge electrode area which are made of different materials and are adjacent to each other are arranged at the periphery, the middle and the central positions of the top electrode of the three-area pentagon, so that the outer edge boundary condition of the top electrode is changed through the mass load effect due to different material densities of each area in the vibration process, and clutter at the edge is further effectively inhibited. Simultaneously, the central electrode region adopts circular structure setting and graphite alkene material, because in whole top electrode, the regional area of central region is than the biggest, and at the high-frequency vibration in-process, its intensity of vibration and heat production are most obvious to the regional straight line limit of central region and edges and corners easily produce the clutter at the vibration in-process, consequently, through the setting of the circular structure of central electrode region, directly eliminate straight line limit and edges and corners, and then make the regional even vibration wave that can produce outside divergence of central electrode in the vibration process. And moreover, the central area is made of graphene materials, so that heat generated in the high-frequency high-intensity vibration process can be led out, the top electrode is prevented from being damaged due to overhigh temperature, and the running stability of the top electrode is further improved.
Meanwhile, the middle electrode area is made of metal materials, all layers of the electrodes are flexibly connected, and the middle electrode area is made of metal materials, so that the mass and the density of the middle electrode area are higher compared with those of a non-metal conductive material (graphene) in the middle electrode area. Meanwhile, in the process of high-frequency vibration of the middle electrode area made of metal, heat is generated due to energy conversion, so that the temperature generated in the middle area is transmitted outwards through the edge electrode area made of the peripheral graphene material, the temperature of the middle electrode area is reduced, and the operation stability of the top electrode is effectively improved.
In addition, the density of the graphene material is low, the quality is low, although the boundary condition formed by the edge electrode area arranged outside the graphene material to the middle electrode area is changed and has little influence under the condition that the boundary condition of the middle electrode area is changed, a certain transverse noise is still generated under the condition that the area size of the edge electrode area is large, therefore, the metal edge area is arranged at the butt joint linear end point of the edge electrode area, the quality distribution of the edge electrode area can be changed through the arrangement of the metal edge area, the change degree of the boundary condition formed by the edge electrode area to the middle electrode area can be further reduced, the generation of the noise is reduced to the maximum extent, meanwhile, the metal connection points of the electrode and an external part can be increased, and the application compatibility of the top electrode is improved. On the other hand, because this embodiment resonator adopts the bragg reflection stratum structure, because there is not the space to dispel the heat, can lead to the resonator high temperature, adopt graphite alkene material as central electrode area can further effectively improve temperature thermal conductivity, can effectively reduce the influence of temperature to the resonator to the at utmost, improve the yields of bulk acoustic wave filter.
The effect of the above technical scheme is as follows: the Bragg reflection layer is adopted to replace a gap, so that the piezoelectric layer, the bottom electrode and the top electrode can be effectively prevented from collapsing, and the operation stability of the bulk acoustic wave filter is effectively improved. Simultaneously, the formation of the horizontal modulus of top electrode vibration in-process can be effectively improved through the three region structure setting of top electrode and the setting of the different materials of every region structure, and then effectively restrain the clutter of top electrode in the high frequency vibration in-process and generate quantity, and then reduce the influence of top electrode vibration in-process to resonator frequency factor, the pentagon top electrode structure through this kind of three region structure's setting can effectively improve film bulk acoustic resonator operating stability and life, and then improve the yields of top bulk acoustic resonator to the at utmost.
In one embodiment of the present invention, the width of the metal edge region satisfies the following condition:
wherein the content of the first and second substances,D 1representing the length of the wide side close to the position of a linear end point in the metal edge region;D 2representing the length of a wide side in the metal edge region close to the linear center position of the edge electrode region;D 01representing a linear distance between the vertex of the middle electrode area and the vertex of the edge electrode area;D 02straight sides representing the middle electrode region andthe linear distance between the straight sides of the edge electrode region.
The length of the metal edge region satisfies the following condition:
wherein the content of the first and second substances,L 1representing the length of the metal edge region;Lindicating the length of the straight edge of the edge electrode area.
The effect of the above technical scheme is as follows: the metal edge area formed by the constraint conditions can effectively reduce the change of the boundary conditions of the edge electrode area, and further effectively improve the suppression rate of transverse clutter. Meanwhile, the range size setting of the metal edge area can be adjusted by combining the actual setting size of each electrode area of the top electrode, the area forming range determining efficiency of the metal edge area in the top electrode setting with different sizes can be effectively improved in practical application, the metal edge area does not need to be tested in a large range, and the manufacturing efficiency of the top electrode is effectively improved.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (8)
1. A method for improving the preparation yield of a bulk acoustic wave filter is characterized by comprising the following steps:
step 1, depositing rectangular support columns and stepped support columns on two sides of the upper surface of a substrate respectively;
step 2, alternately forming a low-sound-wave impedance layer and a high-sound-wave impedance layer by using silicon dioxide and metal tungsten respectively through a deposition method in grooves formed on the upper surfaces of the rectangular supporting columns, the stepped supporting columns and the base body, and forming a Bragg reflection layer after finishing the combination arrangement of three pairs of low-sound-wave impedance layers and high-sound-wave impedance layers;
step 3, arranging a bottom electrode on the Bragg reflection layer, and arranging a seed layer on the bottom electrode, wherein the upward leading part of the bottom electrode extends to the upper surface of the stepped support column along the stepped surface of the stepped support column; one end of the seed layer extends to the upper surface of the rectangular support column;
step 4, preparing a piezoelectric layer above the bottom electrode, and preparing a top electrode above the piezoelectric layer in a manner of combining etching and sputtering, wherein the top electrode adopts a pentagonal top electrode structure with a three-region structure;
wherein the top electrode comprises a central electrode region, a middle electrode region, and an edge electrode region; the central electrode area is positioned at the central position of the pentagonal top electrode; the middle electrode area is arranged outside the edge electrode area; the edge electrode area is arranged outside the middle electrode area; the edge electrode area is provided with a plurality of metal edge areas; the metal edge regions are distributed at two ends of each straight line side of the middle electrode region, and the metal edge regions arranged at the connected straight line ends are also connected.
2. The method of claim 1, wherein preparing a top electrode by a combination of etching and sputtering over the piezoelectric layer comprises:
step 401, etching central electrode areas of the top electrodes on the upper surfaces of the piezoelectric layers respectively;
step 402, etching a region range of a middle electrode region on the periphery of the middle electrode region;
step 403, etching a region range of the edge electrode region on the periphery of the middle electrode region;
step 404, etching a metal edge area at two ends of each straight line edge of the edge electrode area;
step 405, respectively preparing a central electrode area, a middle electrode area, an edge electrode area and a metal edge area corresponding to the central electrode area, the middle electrode area, the edge electrode area and the metal edge area by a sputtering method according to the positions of the central electrode area, the middle electrode area, the edge electrode area and the metal edge area.
3. A structure for improving the preparation yield of a bulk acoustic wave filter is characterized by comprising a substrate, a Bragg reflection layer, a rectangular support column, a stepped support column, a bottom electrode, a seed layer and a pentagonal top electrode; the rectangular support columns and the stepped support columns are arranged on two sides of the upper surface of the base body, and three pairs of Bragg reflecting layers with structures are arranged in grooves formed by the rectangular support columns, the stepped support columns and the upper surface of the base body; a bottom electrode is disposed on an upper surface of the bragg reflection layer, and an up-lead portion of the bottom electrode extends to the upper surface of the stepped support pillar along a stepped surface of the stepped support pillar; the seed layer extends to the upper surface of the rectangular support column; a piezoelectric layer is arranged above the seed layer; a pentagonal top electrode with a three-region structure is arranged above the piezoelectric layer; wherein the content of the first and second substances,
the pentagonal top electrode comprises a central electrode area, a middle electrode area and an edge electrode area; the central electrode area is positioned at the central position of the pentagonal top electrode; the middle electrode area is arranged outside the edge electrode area; the edge electrode area is arranged outside the middle electrode area; and the thicknesses of the central electrode area, the middle electrode area and the edge electrode area are kept consistent.
4. The structure of claim 3, wherein the central electrode region adopts a circular electrode region structure; the middle electrode area adopts a pentagonal electrode area structure; the edge electrode area adopts a pentagonal electrode area structure with the same shape as the middle electrode area.
5. The structure of claim 3, wherein the edge electrode region is provided with a plurality of metal edge regions; the metal edge regions are distributed at two ends of each straight line side of the edge electrode region, and the metal edge regions arranged at the connected straight line ends are also connected; the width of the metal edge area close to the linear center of the edge electrode area is smaller than the width of the metal edge area close to the linear end point.
6. The structure of claim 5, wherein the width of the metal edge region satisfies the following condition:
wherein the content of the first and second substances,D 1representing the length of the wide side close to the position of a linear end point in the metal edge region;D 2representing the length of a wide side in the metal edge region close to the linear center position of the edge electrode region;D 01representing a linear distance between the vertex of the middle electrode area and the vertex of the edge electrode area;D 02representing a linear distance between a straight side of the middle electrode region and a straight side of the edge electrode region.
7. The structure of claim 5, wherein the length of the metal edge region satisfies the following condition:
wherein the content of the first and second substances,L 1representing the length of the metal edge region;La linear side length representing the edge electrode region;D 1representing the length of the wide side close to the position of a linear end point in the metal edge region;D 2representing the length of a wide side in the metal edge region close to the linear center position of the edge electrode region;D 01representing a linear distance between the vertex of the middle electrode area and the vertex of the edge electrode area;D 02represents a straight line between a straight line of the middle electrode region and a straight line of the edge electrode regionThe line distance.
8. The structure of claim 3, wherein the central electrode region and the edge electrode region are made of graphene material; the middle electrode area and the metal edge area are made of conductive metal materials.
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