We present a system-level model for fast and efficient investigations of distributed electrostatic effects in state-of-the-art silicon microphones. Combining lumped and distributed submodels it accounts for electrostatic forces and capacitive read-out, including non-linearities, fringing fields and parasitics. The derived model is calibrated using electrostatic finite element (FE) simulations and validated by measurements. The non-linearities caused by electrostatic effects have a decisive impact on the sensitivity of the microphone and the distortion of the transduced acoustical signal. Hence, the proposed model provides important insights into the operation of the device, which can be employed to optimize the microphone characteristics.

Date Published: 21 May 2015
PDF: 8 pages
Proc. SPIE 9517, Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems, 95171L (21 May 2015); doi: 10.1117/12.2180898

Published in SPIE Proceedings Vol. 9517:
Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems
José Luis Sánchez-Rojas; Riccardo Brama, Editor(s)