双外延基区4H-SiC BJTs的高温特性研究

基于4H-SiC的材料特性及双外延基区BJTs的工作原理，依据漂移扩散及复合理论，求解在考虑4种复合机制下的双极晶体管直流增益，并通过二维仿真模型对其在高温条件下的工作特性进行了计算分析。结果表明，随着温度的升高，基区离化率的增加会导致发射极注入效率下降，从而降低器件的直流增益。同时，SiC/SiO2 界面态及钝化层的质量会影响器件的表面复合速度，从而造成大电流下直流增益的显著下降。

High temperature characterization of double base epilayer 4H-SiC BJTs

Based on the material characteristics and the operational principle of the double base epilayer BJTs, and according to the drift--diffusion and the carrier recombination theory, the common emitter current gain is calculated considering four recombination processes. Then its performance is analyzed under high temperature conditions. The results show that the emitter injection efficiency decreases due to an increase in the base ionization rate with increasing temperature. Meanwhile, the SiC/SiO₂ interface states and the quality of the passivation layer will affect the surface recombination velocity, and make an obvious current gain fall-off at a high collector current.