Formulation of Geometrically Nonlinear Numerical Model for Design of MEMS-Based Piezoresistive Pressure Sensor Operating in the Low-Pressure Range

Micro-fabricated pressure sensors are presently one of the most used micro-electromechanical system devices in the industry. Notably, they have gained popularity in medical, automotive and aeronautical applications. In the present work, a sensor operating in the low-pressure range with piezoresistive sensing and having a bossed-diaphragm structure has been designed. The structure has been characterized through numerical simulations using a custom-made software featuring geometrically nonlinear 2D elements. This simulation tool enables fast iterative design along with capturing key features related to the drift in sensitivity with respect to doping concentration and temperature. The simulation results show that the designed sensor has a full scale output of 2.2 mu V/V/Pa, a linear error of 0.05% over its operating range of 5 kPa and a thermal sensitivity shift of - 0.1%/C-o.