Design And Simulation Analysis Of MEMS Piezoelectric Hydrophone Based On Aluminum Nitride Film

Sonar is the main equipment for underwater information collection and communication.Underwater acoustic transducer is an important part of sonar system.The receiving transducer in the transducer is also called hydrophone.Its performance will directly affect the performance of sonar.MEMS technology is a cutting-edge research field developed on the basis of microelectronics technology.Combining MEMS technology with hydrophones is conducive to miniaturization design and array integration.Aluminum nitride material is a new type of piezoelectric sensitive material,which has the compatibility of semiconductor batch manufacturing process.The FOM value of aluminum nitride is higher than piezoelectric ceramics,and the surface acoustic wave velocity of aluminum nitride film is all inorganic nonferroelectric Among the piezoelectric materials,the application of aluminum nitride piezoelectric materials in MEMS systems has attracted widespread attention in recent years and has shown outstanding advantages,such as high sensitivity and high signal-to-noise ratio.Based on the outstanding advantages of aluminum nitride materials,this paper refers to the MEMS piezoelectric hydrophone developed by the Jinghui Xu team,designed a silicon micro piezoelectric hydrophone based on aluminum nitride piezoelectric film,using a typical elastic sensitive structure to derive The quantitative formula of the hydrophone voltage sensitivity is determined,and the structure is optimized according to the finite element simulation software.The structure size of the sensitive chip is determined.The size of the sensitive chip of the aluminum nitride piezoelectric hydrophone is ?5×0.05 mm.183.3d B;In order to verify the high sensitivity advantages of the new aluminum nitride material applied to the sensor,this article designed and fabricated two similar structures of aluminum nitride piezoelectric accelerometer and piezoelectric ceramic accelerometer,aluminum nitride piezoelectric acceleration The piezoelectric conversion element of the meter is a square diaphragm with a side length of 10 mm,and the ceramic diaphragm is a round diaphragm with a radius of 7 mm.In this paper,the vibration method is used to test the voltage sensitivity of the piezoelectric accelerometer.The experimental test verifies that the aluminum nitride piezoelectric sensor has the advantage of high voltage sensitivity compared to the traditional piezoelectric ceramic sensor.The voltage sensitivity of the piezoelectric ceramic accelerometer is measured.It is 52 m V/g,and the voltage sensitivity of the aluminum nitride accelerometer is 135 m V/g.