用于压电和电容微麦克风的体硅腐蚀相关研究

用溶胶-凝胶法制备的锆钛酸铅压电薄膜的微麦克风和纹膜电容式微麦克风都是基于微电子机械系统技术的硅基单片微麦克风。在其工艺制作过程中,在表面硅微加工之后进行体硅的湿法腐蚀,由此产生了硅片的正面保护和体硅腐蚀的控制等新的工艺问题。从各种正面保护方法和体硅腐蚀自停止技术两方面对这一问题进行了研究和解决。保持了微麦克风具有20~40 mV/Pa的开路灵敏度,并且使圆片级成品率达到70%以上。

Research on Bulk Silicon Etching for Piezoelectric Miniature Microphone and Capacitive Miniature Microphone

Both miniature microphone with PZT Piezoelectric thin films prepared by Sol-Gel method and the one with capacitive corrugated diaphragms are silicon-based single-chip miniature microphone based on MEMS.Bulk silicon etching is executed after surface micromachining processes in the fabrication of silicon microphone,which causes new fabrication problems of the protection for the front side of the wafer and control of bulk silicon etching.These are researched and resolved by several methods of protection for the front side of the wafer and techniques of self-halt for etching.An open circuit sensitivity of 20~40 mV/Pa in audio frequency has been achieved,and fabrication runs have been conducted with the yield reaching upon 70%