基于先进迁移率模型的4H-SiC MOSFET Spice模型研究

Spice modeling of 4H-SiC MOSFET based on advanced mobility model

提出了一种基于先进迁移率模型的4H-SiC MOSFET的Spice模型,该模型是基于MOSFET的Spice一级(Level-1)模型方程,将方程中的常数迁移率用更能准确反映4H-SiC/SiO2界面特性的迁移率模型来代替.产品数据手册验证了该模型静态特性的准确性,DC/DC Boost变换器实验也验证了该模型动态特性的准确性.利用该模型讨论了4H-SiC/SiO2的界面态密度和表面粗糙度对4H-SiC MOSFET开关特性的影响.结果表明,随着界面态密度的增加,4H-SiC MOSFET的开通延迟时间随之增加,而关断提前的时间也增加,同时器件的开关损耗也增加,但是表面粗糙度对开关特性的影响非常小.所取得的结果对4H-SiC MOSFET的应用和器件工艺都有一定的指导作用.

Spice modeling of 4 H-SiC MOSFET based on advanced mobility model has been developed.This modeling employs the Spice Level-1 model of MOSFET,but the constant mobility in the current equations has been replaced by the advanced mobility expressions,which can exactly reflect the effect of 4 H-SiC/SiO2 interface features on the characteristics of 4 H-SiC MOSFET.The transfer characteristics of the developed 4 H-SiC MOSFET model have been verified by the production datasheet,and the dynamic characteristics have been experimentally verified in DC/DC Boost converter.Based on the developed 4 HSiC MOSFET model,the effect of 4 H-SiC/SiO2 interface trap and surface roughness on the dynamic characteristics of 4 H-SiC MOSFET has been discussed.The results show that the switching loss increases with the increase in interface trap density,but surface roughness exists little impact on switching characteristics.The achieved results are very helpful to device application and device process.