Sensitivity enhancement of piezoresistive pressure sensor with meander shape piezoresistor

Abstract

Amongst various transduction principles of pressure sensor, piezoresistive method provides high sensitivity and linear operation over a wide range of pressure. In this paper, piezorestive transduction mechanism is employed for design of a pressure sensor. The diaphragm of the proposed sensor is designed using n-type of Si with copper material used as a connecting arms for the p-type meander shaped piezoresistors placed on the surface of the diaphragm in a Wheatstone bridge configuration at the high strain region of the diaphragm. Meander shape piezoresistors of different length are simulated, in order to find out the best configuration for high sensitivity and linearity. The proposed design is analysed to study the deflection of the diaphragm and output voltage across the bridge. Results reveal that the 50 μm length of piezoresistors is found to have the best sensitivity.