Design of Polysilicon Nano-film Pressure Sensitive Chip Structure

In order to effectively applied mechanical properties of polysilicon and piezoresistive properties of polysilicon Nano-films to pressure sensors, the sacrificial layer pressure sensor with polysilicon Nano-film piezoresistors and polysilicon diaphragm is designed and developed. The sensor structure is designed by finite element software. The cavity height is determined for overload protection. The sensor samples are developed by design structure. The samples test results show that: span is 0~2.5MPa, working temperature range is -40~200°C, full-scale output voltage is 362mV, hysteresis is 0.2%, repeatability is 0.16%, nonlinear is 0.13%, thermal zero drift is 0.01% FS/°C, thermal sensitivity drift is 0.1% FS/°C and overload capacity is more than 10MPa. A feasible way is provided for the development of high sensitivity, low temperature drift, low cost and integrated pressure sensor.