MEMS acoustic sensor using PMN-PT single-crystal diaphragm

Abstract

The MEMS (micro-electro-mechanical systems) microphone enables the manufacturing of small mechanical components on the surface of a silicon wafer. The MEMS microphones are less susceptible to vibration because of the smaller diaphragm mass and an excellent candidate for chip-scale packaging. The PMN-PT materials itself exhibit extremely high piezoelectric coefficients and other desirable properties for an acoustic sensor. In this paper, we present a piezoelectric MEMS microphone based on PMN-PT single crystal diaphragm. The fabrication process including dry etching conditions and scale-factored prototype is presented. In particular, this paper introduces the design of a PMN-PT single crystal diaphragm with interdigitated electrode.