绝缘体上硅高温压力传感器研究

Study on High-Temperature Piezoresistive Pressure Sensors Based on Silicon on Insulator

采用有限元分析工具ANSYS完成了一种矩形弹性膜绝缘体上硅(SOI)高温压力传感器的优化设计,制作出样品,并与相同结构、工艺的多晶硅压力传感器进行了对比测试.结果表明:1∶2的膜片宽长比可以使SOI压力传感器的灵敏度达到220mV/MPa,远大于多晶硅压力传感器的灵敏度(约50mV/MPa).此外,该传感器能够工作在200℃的高温环境中,有良好的长期稳定性,30d内的零点时间漂移为0 12%.

With the help of finite element analysis tool, ANSYS, a high-temperature piezoresistive pressure sensor based on silicon on insulator was designed. The aspect ratio of the rectangular strain diaphragm was determined to 1∶2 to get larger output and smaller chip size. Samples were fabricated and measured compared to polysilicon piezoresistive pressure sensors with the same structure and fabrication process. The results show that the sensitivity of the pressure sensor reaches 220mV/MPa, much higher than that of polysilicon pressure sensor (about 50mV/MPa). Moreover, it can work at 200℃, and has good performance on long-term stability. The offset drift is 0.12% full scale in 30 days.