CN114890376A - Design and preparation method of flexible piezoelectric micro-processing ultrasonic transducer array - Google Patents
Design and preparation method of flexible piezoelectric micro-processing ultrasonic transducer array Download PDFInfo
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- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- 238000013461 design Methods 0.000 title claims abstract description 12
- 238000012545 processing Methods 0.000 title claims description 7
- 239000000463 material Substances 0.000 claims abstract description 68
- 229920002457 flexible plastic Polymers 0.000 claims abstract description 11
- 238000005452 bending Methods 0.000 claims abstract description 5
- 238000005530 etching Methods 0.000 claims description 38
- 238000000151 deposition Methods 0.000 claims description 33
- 238000000059 patterning Methods 0.000 claims description 30
- 229910052751 metal Inorganic materials 0.000 claims description 20
- 239000002184 metal Substances 0.000 claims description 20
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 16
- 239000000758 substrate Substances 0.000 claims description 13
- 238000007789 sealing Methods 0.000 claims description 8
- 235000012239 silicon dioxide Nutrition 0.000 claims description 8
- 239000000377 silicon dioxide Substances 0.000 claims description 8
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- 238000000034 method Methods 0.000 abstract description 11
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- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 3
- 229910052804 chromium Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
- B81C1/00134—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems comprising flexible or deformable structures
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
- B81B7/0006—Interconnects
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
- B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00436—Shaping materials, i.e. techniques for structuring the substrate or the layers on the substrate
- B81C1/00444—Surface micromachining, i.e. structuring layers on the substrate
- B81C1/00468—Releasing structures
- B81C1/00476—Releasing structures removing a sacrificial layer
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- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Mechanical Engineering (AREA)
- Transducers For Ultrasonic Waves (AREA)
Abstract
The invention relates to a design and preparation method of a flexible piezoelectric micro-machined ultrasonic transducer array, which is characterized in that N flexible plastic micro-ultrasonic transducer units are arranged into an array, two adjacent flexible plastic micro-ultrasonic transducer units are connected together by a curved interconnecting structure, the interconnecting structure is also a signal wire interconnected among the flexible plastic micro-ultrasonic transducer units, and the flexible piezoelectric micro-machined ultrasonic transducer array has a function of large-amplitude bending by utilizing the curved interconnecting structure. The method provided by the invention can be used for preparing a flexible micro-electro-mechanical system (MEMS) ultrasonic transducer (MUT) array based on a thin film material, and the array can be used for detecting and sensing environmental signals with low power consumption.
Description
Technical Field
The invention relates to a design and a preparation method of a flexible Piezoelectric Micromachined Ultrasonic Transducer (PMUT) array, belonging to the technical field of flexible miniature sensors.
Background
In recent years, with the development of science and technology, flexible electronic equipment has a huge application prospect in the fields of wearable electronic equipment, electronic skin, man-machine interaction, robots and the like. Where flexible sensors are an important unit in flexible electronic devices. The flexible sensor is formed by circuit design and assembly based on a flexible conductive composite material. Under the external stimulation of force, temperature, light, chemical signals and the like, the electrical property of the flexible sensor changes, and further the response and sensing functions to the external signals are realized.
With the more and more intensive research on flexible sensors, flexible electronics make outstanding contributions to human-computer interaction, health monitoring, wearable electronics, artificial intelligence and the like. In flexible sensor applications, numerous physical signals, such as: temperature, humidity, pressure, light, and some physiological parameters are converted into electrical signals. At present, many researches are conducted on flexible mechanical sensors (capacitors/resistors), but the limitations of low sensing sensitivity, limited testing range, low repeatability of processing and preparation processes, low repeatability of prepared sample performance and the like exist. The wide application scene makes people's requirement for flexible sensor constantly improve, and higher sensitivity is one of them requirement. In the field of flexible pressure sensors, those skilled in the art often fabricate microstructures by micromachining processes to improve sensitivity and reduce size. Initially, those skilled in the art have flexibilized the sensors by transferring the device to a flexible substrate, filling with flexible media, and the like.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the existing flexible mechanical sensor has the limitations of low sensing sensitivity, limited testing range, low repeatability of processing and preparation processes, low repeatability of prepared samples and the like.
In order to solve the technical problems, the technical scheme of the invention provides a design and preparation method of a flexible piezoelectric micro-machined ultrasonic transducer array, which is characterized in that N flexible plastic micro-ultrasonic transducer units are arranged into an array, N is more than or equal to 3, two adjacent flexible plastic micro-ultrasonic transducer units are connected together by a bent interconnection structure, the interconnection structure is also a signal line for interconnection between the flexible plastic micro-ultrasonic transducer units, and the flexible piezoelectric micro-machined ultrasonic transducer array has a function of large-amplitude bending by utilizing the bent interconnection structure.
Preferably, the flexible and moldable micro-ultrasonic transducer unit is prepared by the following steps:
step 1, preparing a SOIwafer.
Step 2, depositing a first releasable material layer on the SOIwafer, and then patterning the first releasable material layer into a polygonal shape through etching, wherein the first releasable material layer can be sacrificed;
step 3, depositing a second releasable material layer on the part, which is not covered by the first releasable material layer, of the SOIwafer, and then patterning the second releasable material layer into a polygonal shape by etching; the second releasable material layer is wrapped and larger than the first releasable material layer, the shape of the second releasable material layer is the same as that of the first releasable material layer, and the thickness of the second releasable material layer is smaller than that of the first releasable material layer; the second releasable material layer may be sacrificial.
Step 4, depositing a structural layer on the SOIwafer, the first releasable material layer and the second releasable material layer; the middle part of the structural layer is naturally stacked to form a bulge, and the shape and the diameter of the bulge are the same as those of the second releasable material layer;
step 5, forming holes in the structural layer to the second releasable material layer at the edges of the raised parts of the structural layer;
step 6, etching the first releasable material layer and the second releasable material layer by any processing means through the opening, and reserving the structural layer so as to form a cavity below the structural layer;
step 7, sealing the open holes on the structural layer formed in the step 5 by any means to form an open hole sealing structure;
step 8, depositing a bottom electrode-piezoelectric-upper electrode layer on the raised part in the middle of the structural layer, wherein the bottom electrode-piezoelectric-upper electrode layer is positioned between the open pore sealing structures;
step 9, depositing a metal interconnection layer on the bottom electrode-piezoelectric-upper electrode layer and the structural layer, wherein the metal interconnection layer completely covers the bottom electrode-piezoelectric-upper electrode layer and the structural layer on one side of the bottom electrode-piezoelectric-upper electrode layer, and the structural layer on the other side of the bottom electrode-piezoelectric-upper electrode layer is not covered by the metal interconnection layer; patterning the metal interconnection layer into any shape by etching;
step 10, etching the substrate Si layer of the SOIwafer from the surface by using a dry method and patterning;
and 11, removing the silicon dioxide layer of the SOIwafer and the substrate Si layer.
Preferably, when depositing the bottom electrode-piezoelectric-top electrode layer: depositing a bottom electrode layer on a structural layer, and patterning the bottom electrode layer into any shape by etching; depositing a piezoelectric layer on the bottom electrode layer, and patterning the piezoelectric layer into any shape by etching, wherein the shape of the piezoelectric layer is the same as that of the bottom electrode layer; and finally, depositing an upper electrode layer on the piezoelectric layer, and patterning the upper electrode layer into any shape by etching, wherein the shape of the upper electrode layer is the same as that of the piezoelectric layer and the bottom electrode layer.
Preferably, the flexible and moldable micro-ultrasonic transducer unit is prepared by the following steps:
step 1, preparing an SOIwafer;
step 2, after etching a shallow groove on the upper surface of the SOIwafer, transferring the bottom electrode-piezoelectric-upper electrode layer to the surface of the SOIwafer; the thickness of the shallow groove is not more than that of a top Si layer in the SOIwafer;
step 3, depositing a metal interconnection layer on the surface of the bottom electrode-piezoelectric-upper electrode layer, etching a substrate Si layer of the SOIwafer from the surface, and patterning;
and 4, removing the silicon dioxide layer and the substrate Si layer of the SOI wafer.
Preferably, when the bottom electrode-piezoelectric-upper electrode layer is formed: preparing a bottom electrode layer, and patterning the bottom electrode layer into any shape by etching; depositing a piezoelectric layer on the bottom electrode layer, and patterning the piezoelectric layer into any shape by etching, wherein the shape of the piezoelectric layer is the same as that of the bottom electrode layer; and finally, depositing an upper electrode layer on the piezoelectric layer, and patterning the upper electrode layer into any shape by etching, wherein the shape of the upper electrode layer is the same as that of the piezoelectric layer and the bottom electrode layer.
The method provided by the invention can be used for preparing a flexible micro-electro-mechanical system (MEMS) ultrasonic transducer (MUT) array based on a thin film material, and the array can be used for detecting and sensing environmental signals with low power consumption. The flexible mechanical sensor prepared by the method provided by the invention has a higher sensor quality factor. In addition, the flexible mechanical sensor prepared by the method has the characteristics of higher array uniformity, small crosstalk, stress concentration, large film vibration displacement and the like due to the adoption of the material with high electromechanical coupling coefficient, namely aluminum nitride or aluminum scandium nitride and the adoption of special process design.
Drawings
FIG. 1A is a schematic diagram of one form of construction of an array of flexible piezoelectric micromachined ultrasonic transducers according to an embodiment disclosed herein;
FIG. 1B is a schematic diagram of another structural form of the flexible piezoelectric micromachined ultrasonic transducer array disclosed in the embodiment;
fig. 2A to 2K illustrate the steps of a process for manufacturing a flexible moldable micro-ultrasonic transducer unit disclosed in example 1;
fig. 3A to 3D illustrate the steps of the process for manufacturing the flexible moldable micro-ultrasonic transducer unit disclosed in embodiment 2.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
As shown in fig. 1A, the flexible piezoelectric micromachined ultrasonic transducer array disclosed in this embodiment is a 2 × 2 square array formed by four flexible moldable micro ultrasonic transducer units, two adjacent flexible moldable micro ultrasonic transducer units are connected together by an S-shaped metal wire, and the S-shaped metal wire is also a signal wire interconnected between the flexible moldable micro ultrasonic transducer units. It should be noted that the present embodiment only uses the S-shaped metal line as an example, and the present invention may adopt any interconnect structure with a curved shape instead of the S-shaped metal line in fig. 1A. The flexible plastic micro-ultrasonic transducer unit has relative freedom degree through an interconnection structure with a bending shape such as an S-shaped metal wire, so that the flexible piezoelectric micro-machined ultrasonic transducer array has a function of bending greatly.
Fig. 1A only exemplifies four flexible moldable micro-ultrasonic transducer units, and after reading this patent, a person skilled in the art should think that any number of flexible moldable micro-ultrasonic transducer units form an array to obtain a flexible piezoelectric micromachined ultrasonic transducer array, and in the array, the arrangement form of the moldable micro-ultrasonic transducer units is not limited to the square array shown in fig. 1A, and may be any shape that a person skilled in the art can think after reading this patent, such as a circle, a polygon, and the like. Fig. 1B illustrates the structure of a flexible piezoelectric micromachined ultrasonic transducer array composed of seven flexible moldable micro ultrasonic transducer units.
The flexible and moldable micro-ultrasonic transducer unit can be prepared by the process disclosed in the following embodiment 1, and also can be prepared by the process disclosed in the following embodiment 2.
Example 1
The preparation method of the flexible and moldable micro ultrasonic transducer unit disclosed by the embodiment comprises the following steps:
step 1, as shown in FIG. 2A, an SOIwafer is prepared.
Step 2, as shown in fig. 2B, a first layer of releasable material is deposited on the soi wafer, and then the first layer of releasable material is patterned into a polygonal shape by etching. The layer of releasable material may be sacrificial.
In this embodiment, the first releasable material layer is silicon dioxide, but other releasable materials may be used. The releasable material layer-may be patterned into various polygonal shapes, such as circles, squares, etc.
Step 3, as shown in fig. 2C, depositing a second layer of the releasable material on the portion of the soi wafer not covered by the first layer of the releasable material, and then patterning the second layer of the releasable material into a polygonal shape by etching. The first releasable material layer is surrounded by the second releasable material layer, the shape of the first releasable material layer is the same as that of the first releasable material layer, and the thickness of the first releasable material layer is smaller than that of the first releasable material layer. The second releasable material layer may be sacrificial.
In this embodiment, the second releasable material layer is silicon dioxide, but other releasable materials may be used. The second releasable material layer can be patterned into various polygonal shapes such as circles, squares, and the like.
Step 4, as shown in fig. 2D, a structural layer is deposited on the soi wafer, the first releasable material layer, and the second releasable material layer, wherein a protrusion is formed in the middle of the structural layer, and the shape and diameter of the protrusion are the same as those of the second releasable material layer.
In this embodiment, the structural layer is made of polysilicon or monocrystalline silicon, and has a higher selective etching ratio than the first releasable material layer and the second releasable material layer.
Step 5, as shown in fig. 2E, a hole is formed in the structural layer to the second releasable material layer at the edge of the raised portion of the structural layer.
Step 6, as shown in fig. 2F, the first releasable material layer and the second releasable material layer are etched away by any processing means through the opening, and the structural layer is remained, so that a cavity is formed under the structural layer.
Step 7, as shown in fig. 2G, the opening in the structural layer formed in step 5 is sealed by any means to form an open-cell sealing structure.
And 8, as shown in fig. 2H, depositing a bottom electrode-piezoelectric-upper electrode layer on the raised part in the middle of the structural layer, wherein the bottom electrode-piezoelectric-upper electrode layer is positioned between the open pore sealing structures. Deposition of bottom electrode-piezoelectric-top electrode layer: depositing a bottom electrode layer on the structural layer, wherein the bottom electrode layer can be Pt or Au and the like, and patterning the bottom electrode layer into any shape by etching; depositing a piezoelectric layer on the bottom electrode layer, wherein the piezoelectric layer can be aluminum nitride, aluminum scandium nitride, PZT or lithium niobate and the like, and patterning the piezoelectric layer into any shape by etching, and the shape of the piezoelectric layer is the same as that of the bottom electrode layer; and finally, depositing an upper electrode layer on the piezoelectric layer, wherein the upper electrode layer can be Pt, Au or Cr and the like, and patterning the upper electrode layer into any shape by etching, and the shape of the upper electrode layer is the same as that of the piezoelectric layer and the bottom electrode layer.
Step 9, as shown in fig. 2I, a metal interconnection layer is deposited on the bottom electrode-piezoelectric-top electrode layer and the structural layer, the metal interconnection layer completely covers the bottom electrode-piezoelectric-top electrode layer and the structural layer on one side of the bottom electrode-piezoelectric-top electrode layer, and the structural layer on the other side of the bottom electrode-piezoelectric-top electrode layer is not covered by the metal interconnection layer. The metal interconnection layer may be formed of Au, Al, or the like, and may be patterned into any shape by etching.
Step 10, shown in FIG. 2J, the base Si layer to the SOIwafer is etched from the surface and patterned by any means.
Step 11, as shown in fig. 2K, the silicon dioxide layer of the soi wafer and the base Si layer are removed by any means, such that the upper device layer and the lower base layer are detached, and the upper device layer remains.
Example 2
The preparation method of the flexible and moldable micro ultrasonic transducer unit disclosed by the embodiment comprises the following steps:
step 1, as shown in FIG. 3A, a SOIwafer is prepared.
Step 2, as shown in fig. 3B, after etching a shallow trench on the soi wafer surface, the bottom electrode-piezoelectric-top electrode layer is transferred to the soi wafer surface.
The shallow trench has a thickness no greater than the thickness of the top Si layer in the soi wafer.
When the bottom electrode-piezoelectric-top electrode layer is formed: preparing a bottom electrode layer, wherein the bottom electrode layer can be Pt or Au and the like, and patterning the bottom electrode layer into any shape by etching; depositing a piezoelectric layer on the bottom electrode layer, wherein the piezoelectric layer can be aluminum nitride, aluminum scandium nitride, PZT or lithium niobate and the like, and patterning the piezoelectric layer into any shape by etching, and the shape of the piezoelectric layer is the same as that of the bottom electrode layer; and finally, depositing an upper electrode layer on the piezoelectric layer, wherein the upper electrode layer can be Pt, Au or Cr and the like, and patterning the upper electrode layer into any shape by etching, and the shape of the upper electrode layer is the same as that of the piezoelectric layer and the bottom electrode layer.
And step 3, as shown in fig. 3C, depositing a metal interconnection layer on the surface of the bottom electrode-piezoelectric-upper electrode layer, etching the substrate Si layer of the soi wafer from the surface by any means, and patterning the substrate Si layer.
Step 4, as shown in fig. 3D, the silicon dioxide layer and the substrate Si layer of the SOI wafer are removed by any means, so that the upper device layer and the lower substrate layer are separated, and the upper device layer is remained.
Claims (5)
1. A design and preparation method of a flexible piezoelectric micro-machined ultrasonic transducer array is characterized in that N flexible plastic micro-ultrasonic transducer units are arranged into an array, N is larger than or equal to 3, two adjacent flexible plastic micro-ultrasonic transducer units are connected together through a bent interconnection structure, the interconnection structure is also a signal line interconnected among the flexible plastic micro-ultrasonic transducer units, and the flexible piezoelectric micro-machined ultrasonic transducer array has a function of large-amplitude bending by utilizing the bent interconnection structure.
2. The design and preparation method of flexible piezoelectric micromachined ultrasonic transducer array according to claim 1, wherein the flexible moldable micromachined ultrasonic transducer unit is prepared by the following steps:
step 1, preparing a SOIwafer.
Step 2, depositing a first releasable material layer on the SOIwafer, and then patterning the first releasable material layer into a polygonal shape through etching, wherein the first releasable material layer can be sacrificed;
step 3, depositing a second releasable material layer on the part, which is not covered by the first releasable material layer, of the SOIwafer, and then patterning the second releasable material layer into a polygonal shape by etching; the first releasable material layer surrounds the second releasable material layer, the shape of the first releasable material layer is the same as that of the first releasable material layer, and the thickness of the first releasable material layer is smaller than that of the first releasable material layer; the second releasable material layer may be sacrificial.
Step 4, depositing a structural layer on the SOIwafer, the first releasable material layer and the second releasable material layer; a bulge is formed in the middle of the structural layer, and the shape and the diameter of the bulge are the same as those of the second releasable material layer;
step 5, forming holes in the structural layer to the second releasable material layer at the edges of the raised parts of the structural layer;
step 6, etching the first releasable material layer and the second releasable material layer by any processing means through the opening, and reserving the structural layer so as to form a cavity below the structural layer;
step 7, sealing the open holes on the structural layer formed in the step 5 by any means to form an open hole sealing structure;
step 8, depositing a bottom electrode-piezoelectric-upper electrode layer on the raised part in the middle of the structural layer, wherein the bottom electrode-piezoelectric-upper electrode layer is positioned between the open pore sealing structures;
step 9, depositing a metal interconnection layer on the bottom electrode-piezoelectric-upper electrode layer and the structural layer, wherein the metal interconnection layer completely covers the bottom electrode-piezoelectric-upper electrode layer and the structural layer on one side of the bottom electrode-piezoelectric-upper electrode layer, and the structural layer on the other side of the bottom electrode-piezoelectric-upper electrode layer is not covered by the metal interconnection layer; patterning the metal interconnection layer into any shape by etching;
step 10, etching the substrate Si layer of the SOIwafer from the surface and patterning;
and 11, removing the silicon dioxide layer of the SOIwafer and the substrate Si layer.
3. The design and preparation method of flexible piezoelectric micromachined ultrasonic transducer array according to claim 2, wherein when depositing bottom electrode-piezoelectric-top electrode layer: depositing a bottom electrode layer on a structural layer, and patterning the bottom electrode layer into any shape by etching; depositing a piezoelectric layer on the bottom electrode layer, and patterning the piezoelectric layer into any shape by etching, wherein the shape of the piezoelectric layer is the same as that of the bottom electrode layer; and finally, depositing an upper electrode layer on the piezoelectric layer, and patterning the upper electrode layer into any shape by etching, wherein the shape of the upper electrode layer is the same as that of the piezoelectric layer and the bottom electrode layer.
4. The design and preparation method of the flexible piezoelectric micromachined ultrasonic transducer array according to claim 1, wherein the flexible plastic micromachined ultrasonic transducer unit is prepared by the following steps:
step 1, preparing a SOIwafer;
step 2, after etching a shallow groove on the upper surface of the SOIwafer, transferring the bottom electrode-piezoelectric-upper electrode layer to the surface of the SOIwafer; the thickness of the shallow groove is not more than that of a top Si layer in the SOIwafer;
step 3, depositing a metal interconnection layer on the surface of the bottom electrode-piezoelectric-upper electrode layer, etching a substrate Si layer of the SOIwafer from the surface, and patterning;
and 4, removing the silicon dioxide layer of the SOIwafer and the substrate Si layer.
5. The design and preparation method of flexible piezoelectric micromachined ultrasonic transducer array according to claim 4, wherein when forming bottom electrode-piezoelectric-top electrode layer: preparing a bottom electrode layer, and patterning the bottom electrode layer into any shape by etching; depositing a piezoelectric layer on the bottom electrode layer, and patterning the piezoelectric layer into any shape by etching, wherein the shape of the piezoelectric layer is the same as that of the bottom electrode layer; and finally, depositing an upper electrode layer on the piezoelectric layer, and patterning the upper electrode layer into any shape by etching, wherein the shape of the upper electrode layer is the same as that of the piezoelectric layer and the bottom electrode layer.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116965825A (en) * | 2023-09-22 | 2023-10-31 | 武汉高芯科技有限公司 | Flexible needle tip electrode and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116965825A (en) * | 2023-09-22 | 2023-10-31 | 武汉高芯科技有限公司 | Flexible needle tip electrode and preparation method thereof |
| CN116965825B (en) * | 2023-09-22 | 2024-02-06 | 武汉高芯科技有限公司 | Flexible needle tip electrode and preparation method thereof |
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