An improvement of membrane structure of MEMS piezoresistive pressure sensor

This paper describes an improvement of the membrane structure of MEMS piezoresistive(PZR) pressure sensor. Finite element method (FEM) is applied to design and optimize the property of PZR the membrane structure and piezoresistors stress analysis is performed under the rated pressure. An equation that transfers the simulation stress data into output voltage is proposed in this paper according to the Wheatstone bridge principle and piezoresisitive effect in silicon. In order to achieve better sensor performance, several kinds of output voltage curve of the membrane structure were contrasted to obtain a suitable membrane structure. The design parameters of the pressure sensor include membrane size and shape and the location of piezoresistance. After that the pressure-output characteristic, the nonlinear error of the optimization sensor and the mechanical stability were analyzed. The results confirmed that the optimization structure has good sensitivity and linearity. It is a kind of high stability, high sensitivity, and low linear error of MEMS PZR pressure sensor.