Fast analytical design of MEMS capacitive pressure sensors with sealed cavities

This paper presents a fast design strategy for MEMS capacitive pressure sensors with sealed cavities. Based on circular Kirchhoff-Love plate theory and the perfect gas law, the underlying analytical model allows for a rapid and accurate evaluation of the sensitivity of the sensors, crucial for improving their design in function of the reference pressure applied in the sealed cavities. The accuracy of the new model is demonstrated by comparing its predictions with more computationally expensive simulation techniques (high-order parametric element and three-dimensional finite element models) and with experimental measurements performed on a 300 µm diameter membrane fabricated using the Poly-SiGe platform developed at imec.