A novel piezoresistive sensitive structure for micromachined high-pressure sensors

Abstract

A novel piezoresistive sensitive structure for micromachined high-pressure sensors is proposed. This structure employs several small cavities in a silicon bulk. When high pressure applied on all faces of the bulk, stress emerges between two cavities. The calculation for the variation of the resistance caused by stress in three-dimensional (3D) structure was discussed. According to 3D piezoresistive effect, the performance of the sensitivity and nonlinearity affected by the dimensions of cavity structure had been clarified. The simulation results show the optimized position for the resistance is in lower region. This sensitive structure is suitable for micromachined high-pressure sensors and the performance study set a guideline for designing micromachined high-pressure sensors with multi-cavities working in different range.