Remote NH3 plasma passivation on the interface between the remote plasma Al2O3 atomic layer deposited and 6H SiC substrate

Abstract

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.