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 andcapacitance of sensor. First, a new analytical analyzes have been carried out to derive mathematicexpression 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 bias voltage and pressure. The analytical results are compared with simulation using aFinite Element Method (FEM). The results show that the new analytical model is very close with simulation results.

Keywords:

Residual Stress , Capacitance , Corrugated Diaphragm , Sensor Sensitivity