Sensitivity-improved silicon condenser microphone with a novel single deeply corrugated diaphragm

A micro-machined condenser microphone, with a novel single deeply corrugated diaphragm (SDCD) for sound sensing, has been developed to improve mechanical-sensitivity by both releasing the initial stress and decreasing the mechanical stiffness of the diaphragm. Both theoretical analysis and finite-element-model (FEM) simulation results show the obvious improvement in mechanical-sensitivity of the SDCD microphone, compared with the microphones of conventional structures. The proposed microphone has been designed with a single-wafer construction and fabricated using silicon micro-machining technologies. The wafer level measurements show that the sensitivity is as high as about 10 mV/Pa under 5 V dc bias. About -3 dB bandwidth of nearly 20 kHz has been obtained by proper design of perforated holes. (C) 2001 Elsevier Science B.V. All rights reserved.