INTEGRATED CAPACITIVE TRANSDUCER

摘要

An electroacoustic transducer, such as a microphone, which may be integrated into a semiconductor chip and a method of fabrication. The semiconductor (10) is etched to produce a membrane (11) having a sufficiently small thickness and an area so as to vibrate at audio frequencies. Electrodes (12, 17) are provided in relation to the membrane so that an electrical output signal can be derived from the audio frequencies, or vice versa, due to variable capacitance. Preferably, the sensitivity of the device is made to be an approximately linear function of sound pressure level to be compatible with amplification.