We investigated the effects of remote NH3 plasma passivation on the interfacial properties between 6H SiC substrate and Al2O3 gate dielectric deposited by remote-plasma atomic layer deposition in a metal-oxide-semiconductor device. X-ray photoelectron spectroscopy and Auger emission spectroscopy analysis reveal that nitrogen is clearly incorporated into the Al2O3/SiC interface. Atomic force microscopy shows negligible damage on the plasma treated SiC surface. A lower leakage current and higher breakdown voltage are attained by the remote plasma passivation. The interfacial state density of the as-deposited sample with the NH3 treatment is about 4 times lower than that of sample without nitrogen passivation and post forming gas annealing improves the interface quality further.

Keywords: SiC, ALD Al2O3, Plasma Passivation