梯度掺杂对SiC LTT短基区少子输运增强研究

A 10 kV 4H-SiC photo-triggered thyristor (LTT) with a gradient-doped short base region is investigated by theoretical analysis and numerical simulation. The donor impurities in the short-base region are distributed in a gradient, and an induced electric field is generated in the longitudinal direction when the impurity is not depleted, which improves the oligon transport in the short-base region from a single diffusion mode to a combination of diffusion and drift, and promotes the longitudinal transport of the oligons in the short-base region. The simulation results show that the gradient-doped short-base region has stronger oligon transport efficiency, and the turn-on delay time of SiC LTT with gradient-doped short-base region is shortened by 36% compared with that of conventional SiC LTT.

通过理论分析与数值仿真的方法对具有梯度掺杂短基区的10 kV 4H-SiC光触发晶闸管(LTT)进行了研究。短基区的施主杂质呈梯度分布,未耗尽时会在纵向产生感生电场,使短基区的少子输运从单一的扩散方式改善为扩散与漂移相结合的方式,促进短基区少子的纵向输运。仿真结果显示,梯度掺杂短基区具有更强的少子传输效率,相比于常规SiC LTT,具有梯度掺杂短基区的SiC LTT开通延迟时间缩短了36%。