Single-chip condenser miniature microphone with a high sensitive circular corrugated diaphragm

A novel single-chip condenser miniature microphone with a circular corrugated diaphragm for residual stress releasing has been proposed, fabricated and tested. The condenser microphone consists of a rigid single-crystal backplate and a flexible circular corrugated diaphragm using induced couple plasma (ICP) etching. An electrostatic-structural coupling finite element analysis (FEA) was performed for design optimization. A sensitivity of 40 mv/Pa up to 15 KHz has been achieved under a low bias voltage of 14 V, which is among the best in the presented reports.