高灵敏度4H-SiC基高温压力传感器

High-Sensitivity 4H-SiC Based High Temperature Pressure Sensor

p型4H-SiC相较n型4H-SiC具有更高的压阻效应,p型4H-SiC正方形膜片作为弹性元件相较圆形膜片具有更高的灵敏度。基于此,设计了一种基于p型4H-SiC压阻效应的高灵敏度碳化硅压力传感器,探索了Ni/Al/Ni/Au与p型4H-SiC之间形成良好欧姆接触的条件,并制备了传感器芯片。在25~600℃空气环境中对传感器芯片的电阻进行了测试,验证了传感器在≤600℃下具有良好的电连接性。最后,在常温至250℃下对传感器进行性能测试。实验结果显示,常温环境下传感器具有较高的输出灵敏度为10.9μV/V/kPa,即使在250℃时其输出灵敏度也约为6.7μV/V/kPa。该研究为高温压阻式压力传感器发展提供了一定的技术参考。

The piezoresistive effect of p-type 4 H-SiC is more excellent than that of n-type 4 H-SiC.The p-type 4 H-SiC square diaphragm as an elastic element has higher sensitivity than the circular diaphragm.Based on this,a high sensitivity SiC pressure sensor based on the piezoresistive effect of p-type 4 H-SiC was designed,the conditions of forming good ohmic contact between Ni/Al/Ni/Au and p-type 4 H-SiC were explored,and the sensor chip was prepared.The resis-tances of the sensor chip were tested in the air at 25-600℃.It is verified that the sensor has good electrical connectivity when the temperature is no more than 600℃.Finally,the perfor-mances of the sensor were tested from room temperature to 250℃.The experimental results show that the sensor has a high output sensitivity of 10.9μV/V/kPa at room temperature and an output sensitivity of about 6.7μV/V/kPa even at 250℃.The research provides technical reference for the development of high temperature piezoresistive pressure sensors.