【作者】 耿青涛；

【导师】 孙以材；

【作者基本信息】 河北工业大学 ， 微电子学与固体电子学， 2007， 硕士

【摘要】 高温压力传感器因其特殊的应用环境而日益受到人们的重视。在石油，化工，冶金，航空航天等领域，对高温环境下的压力测试是必要的。多晶硅高温压力传感器和SOI高温压力传感器是目前传感器市场上，用于在高温压力测量领域中替代普通扩散硅压力传感器的理想产品。本文论述了一种新型多晶硅-AlN薄膜高温压力传感器的研制，它综合考虑了多晶硅高温压力传感器和SOI高温压力传感器的优点，并结合了MEMS制作工艺技术。其要点是在力敏电阻条与硅弹性膜之间利用氮化铝进行绝缘隔离。氮化铝与硅的热膨胀系数接近，附着力高，耐击穿性好。又具有高化学稳定性，高热导率，对于压力传感器的电桥散热特别有利，可解决压力传感器启动时的零点时漂。由于无p－n结，力敏电阻无反向漏电，依此制造的压力传感器的特性好（零点电漂移及热漂移小、非线性小）。力敏电阻条由多晶硅构成。利用Al诱导退火能使溅射得到的非晶硅在600℃时转化成为多晶硅。利用湿法刻蚀电阻图形，并采用各向异性腐蚀技术制作硅杯，最后使用PbO-ZnO-B2O3低温玻璃封接技术进行封接。多晶硅-AlN薄膜结构的压力传感器制作工艺与传统的CMOS制作工艺兼容，易于实现集成化。所以这是一种性能理想的高温压力传感器。此外，利用工程上较为流行的软件ANSYS对高温压力传感器进行了模拟，得出其在高温环境下工作时的温度分布情况。比较了AlN, 2 SiO与2 3 Al O分别作为绝缘散热层时模型的温度分布，并且比较了散热层不同厚度时力敏电阻中心点的温度。更多还原

【Abstract】 Pressure sensor used for high temperature is regarded highly by people for its specialapplications. It is necessary for us to make a pressure measure in high temperature environmentsuch as the field of petroleum, chemical industry, aeronautics and astronautics . Polysilicon hightemperature pressure sensor and SOI high temperature pressure sensor are the ideal product forreplacing the ordinary diffusion silicon pressure sensor in the high temperature pr essure measureat present market.A polysilicon-AlN film pressure sensor used for high temperature is developed in this paper.It is designed by the characteristic of polysilicon high temperature pressure sensor, SOI hightemperature pressure sensor as wel l as MEMS technology. The essential is using AlN film toseparate piezo-resistors from silicon elastic film. The expansion coefficient of AlN is close tothat of silicon with a good stiffness and high break -down voltage as well as good chemical steady.It is benefit to thermal dissipation for bridge with its high thermal conductivity. That can solvethe problem of drift of offset with time when starting and powering sensors. The properties(electric and thermal drift for offset, non -linearity) of pressure sensors fabricated by thesesubstrates are particularly excellent. Piezo -resistors consist of nano-polycrystal silicon, which ismade from sputtering amorphous silicon by Al induced crystallization at temperature of 600℃.The silicon cup is prepared with anisotropyically etching the substrate and the resistance isprepared with plasma etching. Packaging of this device is also prepared by PbO -ZnO-B2O3process.It is easy to realize the integration because the process of polysilicon-AlN thin film pressuresensor is compiled with the traditional CMOS process. So it is an ideal high temperature pressuresensor with good performance.Also,the temperature distribution in the model was simulated essentially by using ANSYSsoftware, respectively comparing the temperature distribution among AlN, 2 SiO , 2 3 Al O as heatdispersion-layer, and the temperatures at resistor center for different thickness of these heatdispersion-layers .更多还原