Polysilicon piezoresistive MEMS pressure sensor: Study of analytical solutions for diaphragm and design & simulation

Abstract

Pressure measurement is a key part of many commercial and industrial systems. Piezoresistive pressure sensors are simpler to integrate with electronics, they are inherently shielded from RF noise and their response is more linear while compared to capacitive pressure sensors. And piezoresistive devices have always dominated the pressure sensor market. The analyticals that are typically used to model the diaphragm of the pressure sensor have been analysed by many researchers. To optimize the pressure sensor for parameters like linearity and sensitivity, the Finite Element Method (FEM) is incorporated. The selection of appropriate parameters of piezoresistors such as the shape and the position of the piezoresistor on the pressure sensor diaphragm, thickness of diaphragm are important. This study shows the scope of using analytical solutions and design techniques for a piezoresistive pressure sensor.