Piezoresistive Pressure Sensors Fabricated Based on in-Situ Doping Technology Exhibits Outstanding Performance at High Temperatures

The zero drift is a key factor affecting the measurement accuracy of the piezoresistive pressure sensor at 500° C. This report presents for the first time the high-temperature piezoresistive pressure sensor fabricated by in-situ doping technology. Device layers of appropriate concentration are directly grown through in-situ doping technology. There is no need to perform ion implantation or thermal diffusion of new impurity elements into the silicon of the device layer again. At 500° C for 8 hours, the zero drift of the sensor has reached an outstanding$218 \mu \mathrm{V}$. After linear temperature compensation, the pressure measurement error within the entire temperature range reached$\pm 1.83 \%$FS. The in-situ doping type pressure sensor not only improves the temperature stability at high temperatures, but also promotes the development of MEMS high-temperature pressure sensors towards the direction of high performance.