Process Optimization for CMOS Compatible MEMS Capacitive Acoustic Sensor

CMOS compatible MEMS capacitive acoustic sensor was designed, developed and optimized on 150mm CMOS Line. Standard LPCVD was used to develop low stress poly film for back-plate and membrane structure. Reflow process was used to solve the problem induced by high step height. Stop structure was used to avoid stiction problem during releasing process. Additional implant process was used to achieve substrate ohmic contact. And after integration process optimization, good physical profile, electrical performance and yield can be obtained which can match the sensor requirements.