A single-chip silicon condenser microphone with a single deeply corrugated diaphragm (SDCD) has been developed. The fundamental characteristics, including mechanical sensitivity, resonance frequency, zero-pressure offset and temperature dependence of the diaphragm, are simulated using a finite element model (FEM). An analytical model is presented to validate that the higher mechanical sensitivity of the SDCD compared with the flat diaphragm with clamped edges is achieved by both releasing the residual stress and reducing the effective mechanical constant of the diaphragm structure. The electrostatic–structural coupling FEM analysis is used in combination with equivalent circuits to evaluate and understand the mechanical, electrostatic and acoustic performances of the microphone. The measurements show reasonable agreements with the theoretical predictions.

In this paper, single deeply corrugated diaphragms (SDCDs) with various corrugation depths and initial stresses are studied extensively for applications to micromachined high-sensitivity devices. Finite-element model simulation results show that significant improvement in mechanical sensitivity can be achieved using a SDCD with larger corrugation depth. The diaphragm has been applied to the fabrication of a high-sensitivity microphone. The measurements show that the SDCD structure is promising in its applications to high-sensitivity devices.