Low-dose implantation, using various ions and doses, was used here to resolve the initial carrier loss in N-doped epitaxial layers. A strong dependence of compensation upon the N concentration was seen; thus demonstrating that N was passivated by implantation-induced point defects. An activation energy of 3.2eV was obtained for dissociation of the passivated N center.

Nitrogen Passivation by Implantation-Induced Point Defects in 4H–SiC Epitaxial Layers. D.Åberg, A.Hallén, P.Pellegrino, B.G.Svensson: Applied Surface Science, 2001, 184[1-4], 263-7