耐高温压阻式压力传感器研究与进展

Study and Review of Piezoresistive High Temperature Pressure Sensor

传统的硅扩散压阻式压力传感器用重掺杂4个 P 型硅应变电阻构成惠斯顿电桥的力敏检测模式,采用 PN 结隔离,高温压阻式压力传感器取消了 PN 结隔离,与半导体集成电路平面工艺兼容,符合传感器的发展方向。根据力敏材料的分类,分别介绍了多晶硅中高温压力传感器、SiC 高温压力传感器和单晶硅 SOI(silicon on insulator)高温压力传感器的基本工作原理和国内外的发展现状,重点论述了 BESOI(bonding and etch-back SOI)、SMARTCUT 和 SIMOX(separation by implanted oxygen)技术的 SOI 晶片加工工艺,以及由此晶片微机械加工成的芯片封装的高温微型压力传感器部分特性,对此领域的发展作了展望。

The conventional piezoresistive pressure sensors were made by forming diffused or ion implanted strain gauges in a Wheatstone bridge configuration on the thin silicon diaphragm. A known limitation of these silicon-based devices using isolation by reverse biased PN-junctions is the rising junction leakage current at elevated temperatures up to 100 ~C, which makes them in unstable state, Compatible with the integrated circuit planar process, micro silicon piezoresistive high temperature pressure sensor cancelled pninsulation of the piezoresistors accords with the development of sensor, Classified with stress sensing material, the sensors whose chips were made with polysilicon, carborundum and silicon on insulator were introduced. Their basic operating principles and present research status of these high temperature piezoresistive pressure sensors were reviewed. The process technology of BESOI, SMARTCUT and SIMOX was emphasized and the sensor chips can be fabricated in the micro-machining work bay based on the technology. Part of the characteristic of high temperature pressure sensors packaged with these chips was given. The future development in this field is forecast.