Finite element simulations combined with statistical analysis of variance: Exploring the potential of piezoelectric MEMS microphones

Finite Element Analysis (FEA) has successfully been combined with the statistical “analysis of variance” (ANOVA) method to explore the potential of different piezoelectric microphone designs. The impact of the relevant design parameters on the overall microphone performance (sensitivity and frequency response) has been investigated, leading to an optimized design with a sensitivity of 1.64 mV/Pa (without amplification). This is much higher than reported for any other piezoelectric microphone variants in literature. Furthermore, the novel membrane design has been optimized with respect to robustness against thermally induced intrinsic stress variations, which is crucial in all layered membrane structures. The underlying FEA models have been calibrated on the basis of measurements on dedicated test structures.