The analysis and structural design of micro SOI pressure sensors

A kind of micro piezoresistive pressure sensor with stable performances under high temperature is designed based on the silicon on insulator (SOI). Through analyzing the stress distribution of diaphragm by finite element method (FEM), the model of structure was established. The fabrication operated on SOI wafer, which can be used in extreme high temperature environments, and applied the technology of anisotropy chemical etching. Performances of this kind of SOI piezoresistive sensor, including size, sensitivity, and temperature were investigated. The result shows that the precision is 0.57% FS. Therefore, this kind of design not only has smaller size, simplicity preparation but also has high sensitivity, temperature coefficient and accuracy.