中文摘要：

为提高微电子机械系统（Micro-electro-mechanical systems,MEMS）压电传声器的灵敏度和成品率,提出一种优化设计的圆形振动膜MEMS压电传声器。采用硼扩散方法实现振动膜的圆形支撑墙,避免由于方形支撑墙造成的四角应力集中,并通过深硼扩散技术,增加圆形围墙的厚度,避免了振动膜的＂软＂支撑问题;振动膜采用Si3N4/SiO2/Si3N4复合结构,减少振动膜的内应力;采用电极分割串联技术,传声器被分割成在声学上并联、在电学上串联的若干部分,以期提高MEMS传声器的灵敏度。在结构优化的基础上,利用MEMS技术制备压电微传声器,所制备传声器振动膜平坦、无褶皱,成品率有了明显提高。在消声室中采用同时比较法对传声器进行测量,优化设计的圆形振动膜传声器的灵敏度有了明显提高,达到0.3 mV/Pa。

英文摘要：

A improved micro-electro-mechanical systems（MEMS） piezoelectric microphone with circular diaphragm is developed to improve the sensitivity and the rate of finished product of microphone.Circular supporting wall of diaphragm is fabricated using boron-doped method to avoid stress concentration at four corners of diaphragm on rectangular supporting wall,and the deep boron-doped technique is adopted to increase the thickness of supporting wall and avert ＂softer＂ support for diaphragm;The vibrating diaphragm is composed of Si3N4/SiO2/Si3N4 composite films which reduce internal stress;The microphone is divided into some parts which are acoustical parallel connection and electrical series connection using segmenting electrodes in series method to improve the sensitivity.The microphone is fabricated by micromachined technology after structure optimization and tested by comparison method in anechoic chamber.The vibrating diaphragm is flat without wrinkling and the rate of finished product is higher.The sensitivity of microphone has great increased and achieves about 0.3 mV/Pa.