Modeling of Micromachined Piezoresistive Pressure Sensors

Abstract

This paper presents a model for piezoresistive pressure sensor. The model assumes a plane stress condition and it accounts for the finite stiffness of the step up support, which is represented by elastically restrained boundary condition. Variation of stress due to thermal mismatch between silicon and dielectrics and change in piezoresistance due to temperature and dopant concentration of the silicon piezoresistors is also taken into account. Finite difference method has been used to implement the model and results are verfied by comparing with the results available in the literature.

Indexing terms:

• Piezoresistive solid state pressure sensor
• elastically restrained
• thermal mismatch