Modelling and simulation of a silicon micro-diaphragm piezoresistive pressure sensor using Finite Element Analysis (FEA) tools

In this paper are presented the diaphragm deflection and output voltage obtained by applying a series of pressure loads to a silicon piezoresistive micro-diaphragm with built-in edges. Sensors of different length and thickness of diaphragms as well as various resistors lengths have been modelled and simulated using Finite Element Analysis methods. The resulting values of the membrane deflection and output vokage are compared with experimental and numerical data. The absolute value of the output voltage and its variation with respect to physical parameters are shown to depend on i.) the resistor length, ii) its placement within the diaphragm and iii.) the thickness of the diaphragm.