A High-Pressure Sensor With High Linearity With S-Shaped Piezoresistors

Abstract

Silicon piezoresistive pressure sensors are widely used, and the pursuit of high linearity and high accuracy of sensors is always there. In this article, through simulations and calculations, including higher order piezoresistance effects, an S-shaped piezoresistor is proposed to optimize the linearity of pressure sensors; that is, the piezoresistive connecting arms are also lightly doped silicon. Two kinds of silicon piezoresistive absolute pressure sensors with a circular diaphragm in the range of 0–60 MPa were designed and fabricated, respectively, with tri-meander-shaped piezoresistors and S-shaped piezoresistors. After measurement, the linearity of the pressure sensor with S-shaped piezoresistors is about 30% better than that of the sensor with tri-meander-shaped piezoresistors, and the linearity and accuracy can reach 0.045% FS and 0.054% FS under the voltage source.