Current mechanisms in n-SiC/p-Si heterojunctions

Current-voltage characteristics of 3C-SiC/Si heterojunction diodes are presented with reverse breakdown voltage exceeding 200 V, leakage current of 1.3 mAcm^-2 at 200 V, and a +/-1V rectification ratio of 200,000. The reverse leakage current was observed to have both temperature and field dependence and hence a model is presented to explain this observation based on a trap assisted tunneling-thermal emission mechanism located at the SiC/Si interface. With further improvements in the SiC crystal quality at the silicon interface, trap concentrations and thus reverse bias leakage currents will be reduced.