Nitrogen Implantation - An Alternative Technique to Reduce Traps at SiC/SiO2-Interfaces

A near-surface Gaussian nitrogen (N) profile is implanted into the Si- or C-face of n-/ptype 4H-SiC epilayers prior to a standard oxidation process. The corresponding MOS capacitors are investigated by conductance and internal photoemission spectroscopy. The effect of N-implantation on the density of interface traps Dit is studied and a model is proposed, which consistently explains the observed results.