氮离子注入提高4H-SiC n-MOSFET沟道迁移率的分析（英文）

Analysis of Nitrogen Implantation to Improve the Channel Mobility of 4H-SiC n-MOSFET

氮离子注入提高4H-SiC MOSFET的沟道迁移率来自两方面的原因:一是减小了界面态密度,另一个是反掺杂。本文详细研究了这两方面的原因。结果表明,当氮的反掺杂浓度和P型衬底的掺杂浓度可以相比较的时候,氮离子注入提高4H-SiC MOSFET的迁移率来自于界面态密度的减小;随着反掺杂浓度的增加,反掺杂在氮离子注入提高沟道迁移率的贡献越来越多,同时,在这种情况下,限制沟道迁移率的机制是表面粗糙度散射。

The reasons that nitrogen implantation can improve the channel mobility of 4H-SiCn-MOSFET are from two aspects.One is the decreasing density of interface traps,another one is the counter doping.In this paper,detailed investigation on the improvement of channel mobility of 4H-SiC n-MOSFET from the two aspects was reported.When the counter doping concentration was comparable to the doping concentration of p-type substrate,the contribution of the channel mobility improvement was mainly from the decreasing density of interface traps.With the increasing counter doping concentration,the counter doping made more and more contribution to the improvement of channel mobility,and at the same time,the dominating mechanism of limiting channel mobility in this case was the surface roughness scattering.