Impact of nitridation on negative and positive charge buildup in SiC gate oxides

In conclusion, we observe that nitrogen passivation of gate oxides on 4H-SiC suppresses interface state generation during electron injection but is responsible for an increase in hole traps. These phenomena are thought to be correlated with the bonding of nitrogen atoms in the interfacial layer. Our results highlight an undesired effect of SiC gate oxide nitridation. It suggests refining the processing steps to optimize both the interface state density and the amount of hole traps.