Silicon micro piezoelectric microphone of series electrode type

An electric microphone and series technology, which is applied in piezoelectric/electrostrictive transducer microphones, sensors, piezoelectric/electrostrictive/magnetostrictive devices, etc., can solve problems such as complex processes, improve sensitivity, Sensitivity improvement and the effect of increasing the electrode distance

Inactive Publication Date: 2010-02-10
INST OF ACOUSTICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] An important method to improve the voltage sensitivity of the piezoelectric micromicrophone is to divide and connect the electrodes of the piezoelectric film in series. In theory, the sensitivity of the piezoelectric microphone can be multiplied according to the number of electrodes connected in series, such as Journal of Microelectromechanical Systems, 2, 3( 1993), p111-119, described in the article "Piezoelectric Microphone with On-chipCOMS Circuits" by Robert P.Ried, Eun Sok Kim, David M.Hong, Richard S.Muller Based on ZnO film electrode segmentation micro microphone , but due to the use of the transverse piezoelectric constant d of the piezoelectric film 31 To work, the electrodes on the upper and lower surfaces of the piezoelectric film need to be separated and connected in series, which is a complex process

Method used

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  • Silicon micro piezoelectric microphone of series electrode type
  • Silicon micro piezoelectric microphone of series electrode type
  • Silicon micro piezoelectric microphone of series electrode type

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0076] Embodiment 1, adopt the inventive method to prepare an electrode serial type silicon micro-piezoelectric microphone, its steps are as follows:

[0077] 1) Silicon wafer thermal oxidation

[0078] Clean the silicon wafer with acid cleaning solution and alkaline cleaning solution, then rinse and dry it with deionized water, put the silicon wafer into an oxidation furnace, and thermally oxidize and grow a 2 micron front high-temperature silicon dioxide layer on the front and back of the silicon wafer respectively 22 and back high temperature silicon dioxide layer 23, such as Picture 1-1 shown;

[0079] 2) Preparation of high-temperature silica circular mold layer 2

[0080] Spin-coat a positive photoresist on the front high-temperature silicon dioxide layer 22 and the back high-temperature silicon dioxide layer 23 respectively, perform photolithography on the front side of the silicon wafer, and use a buffered hydrofluoric acid solution to corrode the high-temperature s...

Embodiment 2

[0098] Embodiment 2, adopt the inventive method to prepare an electrode serial type silicon micro-piezoelectric microphone, its steps are as follows:

[0099] 1) Silicon wafer thermal oxidation

[0100] Clean the silicon wafer with acid cleaning solution and alkaline cleaning solution, then rinse and dry it with deionized water, put the silicon wafer into an oxidation furnace, and thermally oxidize and grow a 3 micron front high-temperature silicon dioxide layer on the front and back of the silicon wafer respectively 22 and back high temperature silicon dioxide layer 23, such as Picture 1-1 shown;

[0101] 2) Preparation of high-temperature silica circular mold layer 2

[0102] Spin-coat a positive photoresist on the front high-temperature silicon dioxide layer 22 and the back high-temperature silicon dioxide layer 23 respectively, and use a buffered hydrofluoric acid solution to etch the high-temperature silicon dioxide layer on the front side of the silicon wafer to form ...

Embodiment 3

[0119] Embodiment 3, adopt the method of the present invention to prepare an electrode serial type silicon micro-piezoelectric microphone, its steps are as follows:

[0120] 1) Silicon wafer thermal oxidation

[0121] Clean the silicon wafer with acid cleaning solution and alkaline cleaning solution, then rinse and dry it with deionized water, put the silicon wafer into an oxidation furnace, and thermally oxidize and grow a 3 micron front high-temperature silicon dioxide layer on the front and back of the silicon wafer respectively 22 and back high temperature silicon dioxide layer 23, such as Picture 1-1 shown;

[0122] 2) Preparation of high-temperature silica circular mold layer 2

[0123] Spin-coat a positive photoresist on the front high-temperature silicon dioxide layer 22 and the back high-temperature silicon dioxide layer 23 respectively, and use a buffered hydrofluoric acid solution to etch the high-temperature silicon dioxide layer on the front side of the silicon...

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Abstract

The invention relates to a silicon micro piezoelectric microphone of series electrode type and a manufacture method thereof. The silicon micro piezoelectric microphone comprises electrodes, an in-plane polarized ferroelectric PZT film layer, a zirconia transition layer, a vibration film layer, a high-temperature silicon-dioxide round reverse-mold layer, a bulk-silicon etching square cup and a bulk-silicon etching mask layer which are sequentially arranged from top to bottom, wherein the in-plane polarized ferroelectric PZT film layer and the electrodes are arranged in the center or / and at theedges of a round working area of the vibration film layer; the in-plane polarized ferroelectric PZT film layer is a round film layer or / and a circular film layer; the electrodes comprise arc interdigitated electrodes distributed in the circumferential direction of the in-plane polarized ferroelectric PZT film layer; and adjacent arc interdigitated electrodes are connected in series. The silicon micro piezoelectric microphone has simple manufacture process and good processing compatibility and fully utilizes the effective working area of a vibration film, and the series mode of the electrodes can improve the sensitivity of the silicon micro piezoelectric microphone by 1-2 orders of magnitude.

Description

technical field [0001] The invention relates to the field of silicon micro-piezoelectric microphones, in particular to a silicon micro-piezoelectric microphone with electrodes connected in series and a preparation method thereof. Background technique [0002] Silicon micro microphones have broad application prospects in civil and national defense (such as mobile phones, audio-visual equipment, robot language recognition, active control of noise and vibration, battlefield reconnaissance network, security interception, etc.). Microphones mainly include capacitive and piezoelectric. At present, capacitive silicon micromicrophones have entered the market. Compared with capacitive microphones, piezoelectric micromicrophones have many advantages such as no need for polarization voltage, low internal resistance, and simple preparation. , has great application prospects, but its sensitivity is low at present, and it cannot meet the practical requirements. [0003] An important meth...

Claims

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Application Information

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IPC IPC(8): H04R17/02B81B7/02H04R31/00B81C1/00
Inventor刘梦伟汪承灏李俊红
OwnerINST OF ACOUSTICS CHINESE ACAD OF SCI