Current conduction mechanisms in thermal nitride and dry gate oxide grown on 4H-silicon carbide (SiC)

Current conduction mechanisms of SiC metal-oxide-semiconductor (MOS) capacitors on n-type 4H-SiC with or without NO annealing have been investigated in this work. It has been revealed that Fowler-Nordheim (FN) tunneling is the dominating current conduction mechanism in high electrical fields, with barrier height of 2.67 and 2.54 eV respectively for samples with NO and without NO annealing. A higher barrier height for NOannealed sample indicates the effect of N element on the SiC/ SiO2 interface quality. In the intermediate oxide field, instead of trap-assisted tunneling (TAT), Poole-Frenkel (PF) emission play the key role in this region. A combination of C-V characteristics also show us the advantages of NO annealing on the SiC/SiO2 characteristics.