基于氮化铝薄膜的压电水听器的研制

Development of Piezoelectric Hydrophone Based on Al N Film

为将氮化铝(AlN)的压电特性与微电子机械系统(microelectro mechonical system,MEMS)的微加工技术相结合,研制基于AlN压电薄膜结构的单电极水听器。通过采用COMSOL仿真方法研究了器件在20~100 Hz低频范围内谐振特性,结果表明压电薄膜优化厚度0.8~1.0μm,振动薄膜直径100μm。给出了器件制备工艺流程,采用感应耦合等离子体(inductively coupled plasma,ICP)精准刻蚀A1N薄膜提高成品率,并对实际样品进行高静水压等环境适应性测试。单个水听器阵列结构是40×40,实际尺寸为7 mm×7 mm,可见AlN薄膜可以用来制备高性能的水听器集成系统。

To combine the piezoelectric characteristics of aluminum nitride(AlN)with the micro-fabrication technology of micro-electromechanical systems(MEMS),a single-electrode hydrophone based on AlN piezoelectric film structure was developed and the resonant characteristics of the device in a low frequency range from 20 to 100 Hz were studied by using the COMSOL simulation.The results show that the optimized thickness of the piezoelectric film was 0.8~1.0μm,and the diameter of the vibration membrane was 100μm.The flowchart of device preparation is presented.To improve the yield,inductively coupled plasma(ICP)precise etching of A1N membrane was used.The real samples were tested for their environmental adaptability under high hydrostatic pressure.The structure of a single hydrophone array was 40 by 40,the actual size was 7 mm×7 mm.It can be seen that AlN thin films can be used to fabricate high-performance integrated hydrophone systems.