CN215956645U - Structure and device of silicon-based cantilever beam type MEMS piezoelectric microphone - Google Patents

Abstract

The present application relates to structures and devices for silicon-based cantilever beam MEMS piezoelectric microphones, and more particularly, to the field of microphone devices; the application provides a structure of silicon-based cantilever beam formula MEMS piezoelectric microphone, the structure includes: a substrate, a first electrode layer, a piezoelectric material layer, and a second electrode layer; because the shape of this first electrode layer, piezoelectric material layer and second electrode layer is "T" shape structure, and the stub of the first electrode layer of this "T" shape structure is connected with the edge of the opening position of opening cavity structure, make this first electrode layer, piezoelectric material layer and second electrode layer have formed the cantilever beam structure, the cantilever beam structure can vibrate under the vibration's of sound effect, and then make the electric charge on the piezoelectric material layer take place to shift, make the electric charge volume on this first electrode layer and the second electrode layer change, the output of this microphone structure changes promptly, detect through exporting the signal of telecommunication, can obtain more accurate sound signal.

Description

Structure and device of silicon-based cantilever beam type MEMS piezoelectric microphone

Technical Field

The application relates to the field of microphone devices, in particular to a structure and a device of a silicon-based cantilever beam type MEMS piezoelectric microphone.

Background

A microphone is an energy conversion device that converts a sound signal into an electrical signal, and is also called a microphone or a microphone. Has been widely applied to various electronic fields, military fields, medical fields and the like. In addition, sensitivity and a lower resonant frequency will be a prerequisite.

MEMS microphones are now in widespread use in consumer electronics. With the advance of technology, piezoelectric silicon microphones are gradually developing. However, the greatest disadvantage affecting the widespread use of piezoelectric microphones, compared to capacitor microphones, is the low sensitivity of the piezoelectric microphone due to the high resonant frequency of the sensor. That is, the ability of the piezoelectric film to sense an audio signal is much lower than that of the diaphragm in the condenser microphone.

The working frequency of the microphone is generally 20-20kHz, and most manufacturers adopt a slot on the piezoelectric film in order to improve the working sensitivity of the piezoelectric microphone, but the design of the slot causes the leakage of low-frequency signals and even medium-frequency signals to be serious, so that the microphone in the prior art has low sensitivity.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to provide a structure and an apparatus of a silicon-based cantilever MEMS piezoelectric microphone, which solve the problem of the prior art that in order to lower the resonant frequency of the sensor and further improve the sensitivity of the piezoelectric microphone, most manufacturers have a slot on the piezoelectric film, but the design of the slot makes the leakage of low-frequency signals and even if intermediate-frequency signals very serious, so that the sensitivity of the prior art microphone is low. Meanwhile, the microphone has wide and flat frequency response, the key size of the microphone structure is optimized, the maximum deviation in a pass band can be within 3dB, and the microphone system is favorable for designing and realizing natural and clear sound.

In order to achieve the above purpose, the embodiment of the present invention adopts the following technical solutions:

in a first aspect, the present application provides a structure of a silicon-based cantilever beam MEMS piezoelectric microphone, the structure comprising: a substrate, a first electrode layer, a piezoelectric material layer, and a second electrode layer; the substrate is an opening cavity structure, the shapes of the first electrode layer, the piezoelectric material layer and the second electrode layer are both T-shaped structures, the short end of the first electrode layer of the T-shaped structures is connected with the edge of the opening position of the opening cavity structure, the piezoelectric material layer is arranged on one side, away from the substrate, of the first electrode layer, the second electrode layer is arranged on one side, away from the first electrode layer, of the piezoelectric material layer, the first electrode layer, the piezoelectric material layer and the second electrode layer are parallel to the horizontal plane, and the projections of the first electrode layer, the piezoelectric material layer and the second electrode layer on the horizontal plane are identical.

Optionally, the structure further includes a third electrode layer, a second piezoelectric material layer, and a fourth electrode layer, the third electrode layer is connected to an edge of the opening position of the open cavity structure, and the second piezoelectric material layer and the fourth electrode layer are sequentially disposed on a side of the fourth electrode layer away from the substrate.

Optionally, the structure further comprises a fifth electrode layer and a third piezoelectric material layer, the third piezoelectric material layer is arranged on the side of the second electrode layer far away from the piezoelectric material layer, and the third electrode layer is arranged on the side of the third piezoelectric material layer far away from the second electrode layer.

Optionally, the structure further comprises a support layer disposed on a side of the substrate remote from the first electrode layer.

Optionally, the structure further comprises a silicon layer disposed on a side of the first electrode layer adjacent to the substrate.

Optionally, the structure further comprises a silicon oxide part and a device layer silicon part, the silicon oxide part is arranged at the opening position of the substrate and is consistent with the upper surface of the substrate, and the device layer silicon part is arranged on the upper part of the silicon oxide and is arranged on the side, away from the first piezoelectric layer, of the first electrode layer.

In a second aspect, the present application provides a device for a silicon-based cantilever MEMS piezoelectric microphone, where the device includes a digital-to-analog conversion device and a structure of the silicon-based cantilever MEMS piezoelectric microphone of any one of the first aspect, and positive and negative electrodes of the digital-to-analog conversion device are electrically connected to a first electrode layer and a second electrode layer of the structure, respectively, and are used to convert charge signals output by the first electrode layer and the second electrode layer into digital signals.

The utility model has the beneficial effects that:

the application provides a structure of silicon-based cantilever beam formula MEMS piezoelectric microphone, the structure includes: a substrate, a first electrode layer, a piezoelectric material layer, and a second electrode layer; the substrate is an opening cavity structure, the first electrode layer, the piezoelectric material layer and the second electrode layer are both in a T-shaped structure, the short end of the first electrode layer of the T-shaped structure is connected with the edge of the opening position of the opening cavity structure, the piezoelectric material layer is arranged on one side, far away from the substrate, of the first electrode layer, the second electrode layer is arranged on one side, far away from the first electrode layer, of the piezoelectric material layer, the first electrode layer, the piezoelectric material layer and the second electrode layer are parallel to the horizontal plane, and projections on the horizontal plane are the same. Cantilever structure microphone produces the vibration under the sound signal effect, according to piezoelectric material's piezoelectric effect, the electric charge on the piezoelectric material layer surface takes place to shift on the microphone, and then make the electric charge amount on this first electrode layer and the second electrode layer change, this microphone structure's output signal changes promptly, through detecting output charge signal, can obtain accurate sound signal, and this application is because the cantilever structure, make vibration amplitude is bigger under the effect of this cantilever structure's sound, then further reduction resonant frequency, make the low frequency sensitivity that this application's microphone structure obtained higher, the signal of telecommunication relevant with sound signal of output is more accurate stable.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating an influence of a change in a length dimension of a vibration beam of an cantilever beam type piezoelectric microphone structure on a resonant frequency of the whole microphone structure according to an embodiment of the present invention;

fig. 5 is a schematic diagram illustrating an influence of a side length change of a vibrating membrane of a cantilever beam type piezoelectric microphone on a resonant frequency of an overall microphone structure according to an embodiment of the present invention;

fig. 6 is a sensitivity diagram of an izod piezoelectric microphone according to an embodiment of the present invention;

fig. 7 is a schematic frequency response curve of a cantilever beam type piezoelectric microphone according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention.

Icon: 10-a substrate; 11-a support layer; 20-a first electrode layer; 21-a silicon layer; 30-a layer of piezoelectric material; 40-a second electrode layer; 50-a third electrode layer; 60-a second layer of piezoelectric material; 70-a fourth electrode layer; 80-a fifth electrode layer; 90-third piezoelectric material layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are one embodiment of the present invention, and not all embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In order to make the implementation of the present invention clearer, the following detailed description is made with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention; as shown in fig. 1, the present application provides a structure of a silicon-based cantilever beam MEMS piezoelectric microphone, the structure comprising: a substrate 10, a first electrode layer 20, a piezoelectric material layer 30, and a second electrode layer 40; the substrate 10 is an open cavity structure, the shapes of the first electrode layer 20, the piezoelectric material layer 30 and the second electrode layer 40 are all 'T' -shaped structures, the short end of the first electrode layer 20 of the 'T' -shaped structure is connected with the edge of the opening position of the open cavity structure, the piezoelectric material layer 30 is arranged on one side, away from the substrate 10, of the first electrode layer 20, the second electrode layer 40 is arranged on one side, away from the first electrode layer 20, of the piezoelectric material layer 30, the first electrode layer 20, the piezoelectric material layer 30 and the second electrode layer 40 are all parallel to the horizontal plane, and the projections on the horizontal plane are all the same.

The shape and size of the substrate 10 are set according to actual needs, and are not specifically limited herein, in practical application, the shape of the substrate 10 is a rectangular parallelepiped structure, the interior of the rectangular parallelepiped is a cavity structure, and one surface of the cavity structure of the rectangular parallelepiped is open, the size of the open position is set according to actual needs, for convenience of description, the size of the opening on the substrate 10 is equal to the size of the top surface of the substrate 10, the edge position of the open position of the substrate 10 is provided with the first electrode layer 20, the piezoelectric material layer 30 and the second electrode layer 40 in sequence, and the shapes of the first electrode layer 20, the piezoelectric material layer 30 and the second electrode layer 40 are completely the same and are all "T" -shaped structures, that is, the cantilever beam structure composed of the first electrode layer 20, the piezoelectric material layer 30 and the second electrode layer 40 includes a long end and a short end, wherein the width of the long end is greater than the width of the short end, and the short end of the first electrode layer 20 is connected with the edge position of the opening position of the substrate 10, so that the first electrode layer 20 is parallel to the bottom surface of the substrate 10, the piezoelectric material layer 30 is disposed on the upper surface of the first electrode layer 20, and the second electrode layer 40 is disposed on the upper surface of the piezoelectric material layer 30. Due to the effect of inverse piezoelectric effect, the piezoelectric material layer 30 generates directional movement of charges under the effect of pressure, and due to the second electrode layer 40 disposed on the upper surface and the first electrode layer 20 disposed on the lower surface of the piezoelectric material layer 30, when the piezoelectric material layer 30 vibrates or deforms under the effect of pressure, the amount of charges on the upper and lower surfaces of the piezoelectric material layer 30 changes, so that the voltages detected by the first electrode layer 20 and the second electrode layer 40 change.

In practical applications, the microphone structure of the present application is used for collecting a sound signal, and since the sound signal is generated by vibration, the sound signal is also a transmission process of vibration in a transmission process, and when a vibration signal corresponding to the sound signal acts on the cantilever, the cantilever is also vibrated, so that the piezoelectric material layer 30 is also vibrated, so as to change a voltage between the first electrode layer 20 and the second electrode layer 40, which is equivalent to converting vibration information of the sound signal into a voltage signal, it should be noted that the vibration information of the sound signal and the voltage signal have a corresponding relationship, in practical applications, the cantilever structure can vibrate under the vibration of sound, so that charges on the piezoelectric material layer 30 are transferred, so that charges on the first electrode layer 20 and the second electrode layer 40 are changed, the output voltage of this microphone structure changes promptly, through detecting output voltage signal, can obtain accurate sound signal, and this application is because the cantilever beam structure, make vibration amplitude is bigger under the effect of this cantilever beam structure's sound, because the amplitude is negative correlation with this vibration frequency, then further reduction resonant frequency, make the sensitivity that this application's microphone structure obtained higher, the voltage signal relevant with sound signal of output is more accurate stable, the size relation between the long end and the short end of this cantilever beam sets up according to actual need, do not specifically limit here.

Generally, the larger the size ratio of the long end to the short end is, the smaller the resonance frequency of the cantilever beam is, so that the acquired sound information is clearer. According to the simulation result, in practical application, the size ratio of the long end and the short end of the cantilever beam is controlled to control the resonant frequency of the cantilever beam to be 40kHz-60kHz, at the moment, the output of the microphone in the working frequency band is higher, the sensitivity is highest, the flatness of the receiving frequency of the microphone is higher, and the sound signal received by the microphone is further guaranteed not to be distorted, so that the stability and the accuracy of the sound signal received and transmitted by the microphone are higher. The piezoelectric material has good dynamic characteristics and abundant vibration modes, the acoustic emission frequency spectrum of various materials almost covers the whole frequency band, and the piezoelectric material can quickly respond to external force by virtue of excellent electromechanical coupling effect. The piezoelectric material in this patent may be selected from aluminum nitride, which has the same or higher performance than other MEMS piezoelectric materials (e.g., zinc oxide, lead zirconate titanate) and has better compatibility than either material. In addition, lithium niobate and the like can be selected as the piezoelectric material.

Fig. 2 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention; as shown in fig. 2, optionally, the structure further includes a third electrode layer 50, a second piezoelectric material layer 60, and a fourth electrode layer 70, the third electrode layer 50 is connected to an edge of an opening position of the open cavity structure, and the second piezoelectric material layer 60 and the fourth electrode layer 70 are sequentially disposed on a side of the fourth electrode layer 70 away from the substrate 10.

The third electrode layer 50, the second piezoelectric material layer 60 and the fourth electrode layer 70 form a second cantilever beam, the second cantilever beam is arranged at the edge of the opening position of the open cavity structure and connected, the third electrode layer 50, the second piezoelectric material layer 60 and the fourth electrode layer 70 in the second cantilever beam are sequentially far away from the substrate 10, the second cantilever beam and the narrow end and the wide end of the cantilever beam are respectively far away, the size is consistent, a square structure is formed, the cantilever beams are all located on the cavity, the edge is fixed on the substrate and are respectively located at two corresponding sides. The design of the array is adopted, the output response and the sensitivity of the microphone are improved, and the two cantilever beam structures adopt point symmetry design and supplement each other, so that the smooth response effect of the microphone structure in the working frequency band is better.

Optionally, the microphone structure may further include a plurality of cantilever beams, the plurality of cantilever beams are arranged at intervals, and the design of the array is adopted to improve the output of the microphone, so that the accuracy and stability of the sound signal obtained by the microphone are higher.

Fig. 3 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention; as shown in fig. 3, optionally, the structure further includes a fifth electrode layer 80 and a third piezoelectric material layer 90, the third piezoelectric material layer 90 is disposed on a side of the second electrode layer 40 away from the piezoelectric material layer 30, and the third electrode layer is disposed on a side of the third piezoelectric material layer 90 away from the second electrode layer 40.

This second electrode layer 40's upper portion is provided with third piezoelectric material layer 90, this third piezoelectric material layer 90's upper portion is provided with fifth electrode layer 80, this piezoelectric material layer 30 and third piezoelectric material layer 90 all can produce the vibration under sound signal's effect, even the thickness of the cantilever beam that makes this application obtains the thickening, and then make under the effect of the same sound signal, the output signal of electricity of this cantilever beam is higher, and the flatness in the passband has also obtained further promotion, thereby make the degree of accuracy of the sound information that this application acquireed obtain further improvement, and then make the quality of the sound information that the microphone structure of this application acquireed higher. Meanwhile, the reliability of the microphone is further improved due to the increase of the thickness of the piezoelectric structure.

Fig. 4 is a schematic diagram illustrating an influence of a change in a length dimension of a vibration beam of a cantilever beam type piezoelectric microphone structure on a resonant frequency of the whole microphone structure according to three embodiments of the present invention; fig. 5 is a schematic diagram illustrating an influence of a side length change of a vibrating membrane of a cantilever beam type piezoelectric microphone on a resonant frequency of an overall microphone structure according to three embodiments of the present invention; fig. 6 is a sensitivity diagram of a cantilever beam type piezoelectric microphone according to three embodiments of the present invention; fig. 7 is a schematic frequency response curve of a cantilever beam type piezoelectric microphone according to three embodiments of the present invention; the device in the embodiment comprises two cantilever beam structures, and the arrangement is such that by optimizing the critical dimensions of the device, including the dimensions and thicknesses of the first electrode layer 20, the second electrode layer 40, the third electrode layer 40, the fourth electrode layer 70, the piezoelectric material layer 30 and the second piezoelectric material layer 60, the device of the present application can realize the function which can be realized only by a larger dimension under the condition of a smaller dimension, so that the final resonant frequency of the device of the present application can be reduced to the range of 5-350kHz, the structure can be obtained to reach a lower frequency range, and the device has great potential in the design and preparation aspects of low-frequency piezoelectric devices. Parametrically scanning the side length of the cantilever beam structure, as shown in fig. 4, the abscissa represents the length of the cross section of the beam, the ordinate represents the resonant frequency of the structure, and the length of the beam is changed, and the beam comprises a first electrode layer 20, a first piezoelectric material layer 30, a second electrode layer 40, a third piezoelectric material layer 90 and a fifth electrode layer 80, wherein according to a data schematic diagram, under the condition of given width, the resonant frequency of the device is reduced by increasing the length of the cantilever beam, so that the sensitivity of the microphone structure is influenced; as shown in fig. 5, the abscissa represents the side length of the section of the square edge of the diaphragm, the ordinate represents the resonant frequency of the piezoelectric microphone, and the change of the side length of the square edge of the diaphragm of the whole microphone can obtain that the resonant frequency of the microphone gradually decreases with the increase of the side length, the amplitude of the decrease is from fast to slow, the frequency can be decreased to below 20kHz and reach 8kHz, and from the simulation result, the cantilever beam type structure has great potential in the application aspect of very low frequency devices. Meanwhile, the structure can be obtained by performing multi-physical field coupling simulation, as shown in fig. 6, the abscissa represents frequency, and the ordinate represents the sensitivity of the structure, i.e., the proportional relation between the output voltage and the input sound pressure, and the schematic diagram can represent the variation of the sensitivity of the microphone along with the vibration frequency, so that the sensitivity of the structure can reach 0.1mV/Pa, and the sensitivity can be further improved by further optimizing the key size of the cantilever beam and combining the optimization of materials. In addition, fig. 7 is a frequency response curve of the microphone structure according to the three embodiments of the present invention, which shows the relationship between the output and input frequencies of the structure, and it can be seen that in the frequency range of 20-20kHz, the unevenness of the structure is about 1.1dB, the maximum unevenness is far within 3dB, and the flatness of the frequency response curve is high.

Fig. 8 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention; as shown in fig. 8, the structure optionally further comprises a support layer 11, the support layer 11 being arranged on a side of the substrate 10 remote from the first electrode layer 20.

The supporting layer 11 is disposed on a side of the substrate 10 away from the first electrode layer 20, the supporting layer 11 is used for supporting the substrate 10 to prevent the piezoelectric material layer 30 from breaking, and when the cantilever beam structure vibrates, the supporting layer 11 can play a role in protecting the structure from breaking when overloaded. Therefore, in practical applications, the support layer 11 on the bottom of the substrate 10 is generally prepared using a Si — Si bonding process.

Fig. 9 is a schematic structural diagram of another silicon-based cantilever MEMS piezoelectric microphone according to an embodiment of the present invention; as shown in fig. 9, the structure optionally further comprises a silicon layer 21, the silicon layer 21 being disposed on a side of the first electrode layer 20 close to the substrate 10.

The silicon layer 21 is used for supporting the first electrode layer 20, the piezoelectric material layer 30 and the second electrode layer 40, so as to increase the thickness of the cantilever beam, and further make the cantilever beam under the action of the sound signal with the same strength, so as to improve the resonant frequency of the device, and further make the deformation amount of the piezoelectric material layer 30 become small under the action of the sound signal with the same strength, that is, the voltage information output by the piezoelectric material layer 30 is correspondingly changed, so that the accuracy of the sound information obtained by the application is further improved, and further the flatness in the frequency band of the microphone is further improved, and thus the quality of the obtained sound information is higher.

Optionally, the structure further includes a silicon oxide portion and a device layer silicon portion, the silicon oxide portion is disposed above the substrate 10, is consistent with the upper surface of the substrate 10, and has the same opening position, and the device layer silicon portion is disposed on the upper portion of the silicon oxide portion and is disposed on the side of the first electrode layer away from the first piezoelectric layer.

The substrate layer structure adopts an SOI substrate, and the process procedures can be reduced and the reliability of process preparation can be improved by adopting the SOI substrate. The SOI bottom layer silicon and the SOI silicon oxide part are used as a supporting layer 11, meanwhile, the bottom layer silicon and the silicon oxide part both adopt an opening structure shown by a cantilever beam substrate 10, and the SOI top layer device layer silicon is used for a piezoelectric structure layer, is placed on one side of a first electrode layer far away from a first piezoelectric layer and is consistent with the upper surface of the structure of the electrode layer and the piezoelectric layer. The thickness of the whole cantilever beam is increased due to the existence of SOI top device layer silicon, the reliability of the device is improved, and the resonant frequency of the device is relatively improved, so that the flatness in the frequency band of the microphone is further improved, and the quality of the obtained sound information is higher.

Alternatively, the preparation method of the present application: preparing a silicon chip, sputtering electrode materials/piezoelectric materials/electrode materials on a silicon chip substrate in sequence, patterning the electrode materials/piezoelectric materials/electrode materials from top to bottom in sequence, completing etching of an electrode pad, and finally performing back cavity etching to etch an opening cavity of the substrate.

The device comprises a digital-to-analog conversion device and any one of the structures of the silicon-based cantilever beam type MEMS piezoelectric microphone, wherein the positive electrode and the negative electrode of the digital-to-analog conversion device are respectively electrically connected with a first electrode layer 20 and a second electrode layer 40 of the structure and are used for converting voltage signals output by the first electrode layer 20 and the second electrode layer 40 into digital signals.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A structure of a silicon-based cantilever beam MEMS piezoelectric microphone, the structure comprising: a substrate, a first electrode layer, a piezoelectric material layer, and a second electrode layer; the substrate is an opening cavity structure, the first electrode layer the piezoelectric material layer with the shape of second electrode layer is "T" shape structure, and "T" shape structure the stub of first electrode layer with the edge connection of opening position of opening cavity structure, the piezoelectric material layer sets up first electrode layer is kept away from one side of substrate, the second electrode layer sets up the piezoelectric material layer is kept away from one side of first electrode layer, just first electrode layer the piezoelectric material layer with the second electrode layer all is parallel with the horizontal plane, and the projection on the horizontal plane is all the same.

2. The structure of a silicon-based cantilever beam MEMS piezoelectric microphone according to claim 1, further comprising a third electrode layer, a second piezoelectric material layer, and a fourth electrode layer, wherein the third electrode layer is connected to the edge of the opening position of the open cavity structure, and the second piezoelectric material layer and the fourth electrode layer are sequentially disposed on the side of the fourth electrode layer away from the substrate.

3. A structure for a silicon-based cantilever MEMS piezoelectric microphone according to claim 2, wherein the structure further comprises a fifth electrode layer and a third piezoelectric material layer, the third piezoelectric material layer being disposed on a side of the second electrode layer remote from the piezoelectric material layer, the third electrode layer being disposed on a side of the third piezoelectric material layer remote from the second electrode layer.

4. A structure for a silicon-based cantilever beam MEMS piezoelectric microphone according to claim 3, wherein the structure further comprises a support layer disposed on a side of the substrate remote from the first electrode layer.

5. The structure of a silicon-based cantilever beam MEMS piezoelectric microphone according to claim 4, wherein the structure further comprises a silicon layer disposed on a side of the first electrode layer remote from the piezoelectric layer.

6. The structure of a silicon-based cantilever beam MEMS piezoelectric microphone according to claim 5, further comprising a silicon oxide part and a device layer silicon part, wherein the silicon oxide part is disposed on a side of the substrate close to the first electrode layer, and the silicon part is disposed on a side of the silicon oxide part far from the substrate silicon and on a side of the first electrode layer far from the first piezoelectric layer.

7. A silicon-based cantilever beam type MEMS piezoelectric microphone device, characterized in that, the device comprises a digital-to-analog conversion device and the structure of the silicon-based cantilever beam type MEMS piezoelectric microphone as claimed in any one of claims 1 to 6, wherein the positive and negative electrodes of the digital-to-analog conversion device are respectively electrically connected with the first electrode layer and the second electrode layer of the structure, and are used for converting the voltage signals output by the first electrode layer and the second electrode layer into digital signals.

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