中文摘要：

通过商用半导体模拟器MEDICI对700 V 4H-SiC晶闸管开通特性进行了模拟研究。模拟结果表明阳极电压小于100 V时,开通过程符合扩散模型,电压更高时,开通时间随阳极电压升高而迅速下降,符合场开通机制。不同于Si及GaAs晶闸管,SiC晶闸管p型耐压层中浅能级杂质Al使得其开通时间随温度的升高而降低。较厚的基区使得电导调制效应只发生在发射区与基区边界一个范围之内,随着温度的升高,其余部分的载流子数目指数增加,压降指数减小。开通时间随着门极触发电流的加大而逐渐缩短,减小到一定程度时,减小速度明显变缓。

英文摘要：

The steady-state current-voltage characteristics and turn-on process of 700 V 4H-SiC thyristors were simulated with commercial simulator MEDICI.The simulation results indicate the turn-on process is consistent with diffusion model at low voltage（100 V）,but the turn-on time decreases with the increase of voltage（100 V）,which obeys the field mechanism of the turn-on process.Different from Si and GaAs thyristors,the dopant aluminum served as shallow energy impurity in p-type SiC voltage sustaining layer,makes turn-on time be decreased with temperature.The relatively thick base region enables the conductivity modulation effect only to be active in a region far from the emitter.Meanwhile,the carrier concentration increases exponentially（voltage decreases exponentially） in other regions when the temperature is enhanced.It is also found that the turn-on time is a strong function of the gate current and decreases with increasing of the current.