Removal of near-interface traps at SiO2/4H–SiC (0001) interfaces by phosphorus incorporation

Effective removal of near-interface traps (NITs) in SiO2/4H–SiC (0001) structures through phosphorus incorporation is demonstrated in this paper. Low-temperature capacitance-voltage and thermal dielectric relaxation current measurements were employed to investigate NITs in oxides prepared by dry oxidation, NO annealing, and POCl3 annealing. Both the measurements revealed that the density of electrons trapped in NITs in POCl3-annealed oxide is smaller than that in dry and NO-annealed oxides. The drastic elimination of NITs lowers the interface state density and increases the channel mobility in 4H–SiC metal-oxide-semiconductor field-effect transistors.