Patent ID: 7992283

Claim:
A miniature, surface micromachined, differential microphone, comprising: a) a silicon substrate; b) a sacrificial layer deposited upon an upper surface of said silicon substrate; c) a diaphragm material layer deposited over an upper surface of said sacrificial layer; d) said diaphragm material layer including a diaphragm isolated from a remaining portion of said diaphragm material layer by a slit adjacent to a portion of said diaphragm, and another portion comprising a supporting hinge attaching said diaphragm to said remaining portion of said diaphragm material layer; e) an enclosed back volume beneath said diaphragm having a depth defined by a thickness of said sacrificial layer, said back volume communicating with a region external thereto only via said slit; and f) a plurality of comb sense fingers disposed along at least a portion of a perimeter of said diaphragm.