Conduction Mechanism of Leakage Current in Thermal Oxide on 4H-SiC

The conduction mechanism of the leakage current in thermal oxide on 4H-SiC was identified. The carrier separation current-voltage method clarified that electrons are the dominant carriers of the leakage current. The temperature dependence of the currentvoltage characteristics indicated that the conduction mechanism of the leakage current involved not only Fowler-Nordheim tunneling (FN) but also Poole-Frenkel (PF) emission. The PF emission current due to the existence of defects in the oxide increased with temperature.