多晶硅高温压力传感器的温度特性

Research on the temperature dependence of the polysilicon high-temperature pressure sensor

讨论了改善多晶硅高温压力传感器温度特性的 3种措施 :用四甲基氢氧化铵溶液代替氢氧化钾溶液作硅杯各向异性腐蚀剂 ;优化多晶硅压敏电阻的掺杂浓度 ,实现传感器灵敏度温度漂移自补偿 ;在传感器芯片上加做温敏电阻 ,通过调节激励源的温度特性 ,进一步减小传感器灵敏度温度系数 .采用以上措施 ,使多晶硅压力传感器有良好的高温稳定性 ,灵敏度温度系数绝对值小于 2× 10 -4/℃ .

This paper mainly discusses three measures to improve the temperature dependence of polysilicon high temperature pressure sensors, which include adopting TMAH, instead of KOH, as the anisotropic etchant to fabricate the silicon cup, optimizing the doping concentration of piezoresistive resistors to realize the self compensation of output drifting, and designing a temperature sensor on the chip by regulating the temperature characteristic of the current supply to further decrease α TCS . All these ways make polysilicon pressure sensors very good in long term stability under high temperature and lower than 2× 10 -4 /℃ in absolute values of α TCS .