用多孔硅作牺牲层制备硅基电容式微传声器

Fabrication of Silicon Condenser Microphone Using Oxidized Porous Silicon as Sacrificial Layer

提出了一种新的硅基电容式微传声器的制备方法，即采用多孔硅牺牲层技术制备声学孔，采用聚酰亚胺膜作声学振膜，采用该方法制备出的电容式微传声器器件，开路灵敏度为107．8dB，在400～10kHz之间，频率响应较为平坦，可以实现语音通信。

A new technique to fabricate silicon condenser microphone is presented.The technique is based on the use of oxidized porous silicon as sacrificial layer for the air gap and the heavy p+-doping silicon of approximately 15μm thickness for the stiff backplate.The measured sensitivity of the microphone fabricated with this technique is in the range from -45dB(5.6mV/Pa) to -55dB(1.78mV/Pa) under the frequency from 500Hz to 10kHz,and shows a gradual increase at higher frequency.The cut-off frequency is above 20kHz.