基于碳化硅材料的电容式高温压力传感器的研究

Research on Capacitive High Temperature Pressure Sensor Based on SiC

针对现有的硅基高温压力传感器不满足更高温度环境(≥500℃)下测试需求的问题,设计并制备了一种基于碳化硅(SiC)材料的电容式高温压力传感器。利用ICP刻蚀工艺和直接键合工艺实现了气密性良好的敏感绝压腔结构,结合金属沉积、金属图形化等MEMS工艺制备了感压敏感芯片。搭建了压力-温度复合测试平台,完成了传感器在0~600℃环境下压力-电容响应特性的测试。测试结果表明,在0~300 kPa内,该传感器灵敏度为4.51×10-3 pF/kPa,非线性误差为2.83%;同时测试结果也表明该传感器的温度漂移效应较低,0~600℃环境下电容变化量为8.50~8.65 pF。

Aiming at the problem that the existing silicon⁃based high temperature pressure device did not meet the test re⁃quirements under higher temperature environment(≥500℃),a capacitive high temperature pressure sensor based on silicon carbide(SiC)was designed and prepared.The ICP etching process and the direct bonding process were used to realize a sensitive and absolute pressure cavity structure with good air tightness,a pressure⁃sensitive chip was fabricated by combining MEMS processes such as metal deposition and metal patterning.The pressure⁃temperature composite test platform was built,and the pres⁃sure⁃capacitance response characteristics of the sensor were tested at 0~600℃.The test results indicate that the sensitivity is 4.51×10-3 pf/kPa and the nonlinear error is 2.83%at 0~300 kPa.At the same time,test results also prove the temperature drift effect of the sensor is low and the capacitance change is 8.50~8.65 pF at 0~600℃.