Development of capacitive MEMS microphone based on slit-edge for high signal-to-noise ratio

In this paper, a capacitive MEMS microphone has been developed by using a slit membrane. This microphone is composed of a membrane with slit structures, a back-plate, a back-chamber (determining an acoustic inlet), and an air gap in-between the membrane and the back-plate. As a sound is entered on the microphone, the slit membrane is oscillating whereas the back-plate is fixed. As a result, the microphone detects a sound level by a capacitance variance between the back-plate and the membrane. The membrane is flexible because of the slit structure, and thus the MEMS microphone shows high sensitivity.