Performance and noise analysis of capacitive silicon microphones using tailored system-level simulation

A fully coupled fluidic-electro-mechanical system-level model has been assembled and applied to existing and novel silicon microphone designs. Distributed and non-linear effects like fluidic damping and electrostatic forces and their impact on the overall system performance have been investigated. All relevant contributions like the package-induced acoustical effects and the electronic circuitry for biasing and read-out are included as well. Employing the fluctuation-dissipation theorem to our model we are able to predict and discriminate the noise contribution of single microphone regions in order to suggest design measures for the enhancement of the total signal-to-noise ratio (SNR) of the device. Dedicated calibration and validation of the single submodels by laser-vibrometric measurements assure the accuracy and predictive power of the presented model.

[1]  Gabriele Schrag,et al.  Modeling distributed electrostatic effects in silicon microphones and their impact on the performance , 2015, Microtechnologies for the New Millennium.

[2]  Gabriele Schrag,et al.  Mixed‐Level Approach for the Modeling of Distributed Effects in Microsystems , 2013 .

[3]  H. Callen,et al.  Irreversibility and Generalized Noise , 1951 .

[4]  Gerhard Wachutka,et al.  Experimentally validated and automatically generated multi-energy domain coupled model of a RF-MEMS switch , 2009, EuroSimE 2009 - 10th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems.

[5]  H. Nyquist.  Thermal Agitation of Electric Charge in Conductors , 1928 .

[6]  Gerhard Wachutka,et al.  System-level Modeling of Silicon Microphones Including Distributed Effects , 2014 .

[7]  Ulrich Krumbein,et al.  Design of a poly silicon MEMS microphone for high signal-to-noise ratio , 2013, 2013 Proceedings of the European Solid-State Device Research Conference (ESSDERC).