Capacitive out of plane large stroke MEMS structure

Abstract

This paper introduces a way to increase the airgap of a capacitive MEMS sensor or actuator. Usually, a thicker sacrificial layer composed of silicon dioxide is used to increase the distance between two parallel plates. In our case, both poly-silicon planes are being produced with a small gap filled with silicon dioxide. Corrugation grooves lined with highly tensile silicon nitride cause a stress induced displacement of the stator after the release etch was done. We will present first results, gained from FEM-simulations and fabricated wafers. An insight into the optimization of the deflection profile and the mechanical stability of the buckling electrode is discussed.