Design, fabrication, and thermal zero drift compensation of a SOI pressure sensor for high temperature applications

A high-temperature piezoresistive pressure sensor based on SOI wafer was fabricated to investigate the temperature performance and thermal drift of silicon-based sensors in high-temperature environments. The Wheatstone bridge circuit structure of the pressure sensor was designed and determined through finite element simulation, and a p-type SOI based sensor was fabricated using microelectronic process technology. The temperature characteristics of silicon resistors were studied using a combination of simulation and experimental methods. At room temperature, the sensitivity of the fabricated sensor is 11.94 mV/V/MPa in the range of (0.1–1.1 MPa) with nonlinearity of 0.99 %. In order to improve the thermal zero drift of pressure sensors at high temperatures, a passive resistance compensation network was proposed in this work. The results show that the compensation network effectively reduces the thermal zero drift of the sensor, which decreases from 0.09 %FS/°C to 0.042 %FS/°C in the temperature range of 25 °C to 275 °C. The thermal hysteresis of the sensor is also reduced, which decreases from −0.059 %FS/°C to −0.026 %FS/°C. [Display omitted] •A systematic study was conducted on the design, fabrication, and thermal zero drift compensation of SOI pressure sensors.•A compensation network was proposed to compensate for thermal zero drift, and the results demonstrated its effectiveness.