Simulation study on the influence of metal contact and MOS interface trap states on the electrical characteristics of SiC IGBT

A 13 kV class n-channel 4H–SiC trench gate insulated bipolar transistor (IGBT) structure is designed based on Silvaco TCAD device simulator tool. The influence of metal/SiC and SiC MOS interface trap states the static dynamic characteristics IGBT devices are systematically studied. It found that electrical properties IGBTs insensitive to donor or acceptor traps at SiC/SiO2 interface. However, affect greatly. When density (Dita) up level 1012 cm−2·eV−1, turn-on voltage drop (VCEON) increased gradually with augmentation Dita. breakdown (VBR) slightly. Further study device’s turn-off shows loss (EOFF) decreased increase in Dita but a large tail current formed. mechanism may be when electrons injected from N+ source region into N− drift region, interfacial side wall capture number electrons. As result, minority carrier concentration decreased, conductance modulation effect weakened.