Accurate Model of Capacitance for MEMS Sensors using Corrugated Diaphragm with Residual Stress

In this paper we present a new model for calculating the capacitance of MEMS sensor with corrugated diaphragm. In this work the effect of residual stress is considered on deflection of diaphragm and capacitance of sensor. First, a new analytical analyzes have been carried out to derive mathematic expressions for central deflection of corrugated diaphragm and its relationship with residual stress. Then the capacitance and sensitivity of sensor using corrugated diaphragm with residual stress are calculated under various parameters such as bias voltage and pressure. The analytical results are compared with simulation using Finite Element Method (FEM). The results show that the new analytical model is very close with simulation results.