Three examples were given, which showed that ion implantation and electron irradiation could drastically modify the electrical properties of SiC and SiC-based MOS capacitors. (1) It was demonstrated that S ions (S+) implanted into 6H-SiC act as double donors with ground states ranging from 310 to 635meV below the conduction band-edge. (2) Co-implantation of N+ – and Si+ – ions into 4H-SiC led to a strong deactivation of N donors. Additional experiments with electron (e−)-irradiated 4H-SiC samples (E(e−) = 200keV) supported the idea that this deactivation was due to the formation of an electrically neutral (Nx–VC, y)-complex. (3) Implantation of a surface-near Gaussian profile into n-type 4H-SiC followed by a standard oxidation process leads to a strong reduction of the density of interface traps Dit close to the conduction band-edge in n-type 4H-SiC/SiO2 MOS capacitors.

Defect-Engineering in SiC by Ion Implantation and Electron Irradiation. G.Pensl, F.Ciobanu, T.Frank, D.Kirmse, M.Krieger, S.Reshanov, F.Schmid, M.Weidner, T.Ohshima, H.Itoh, W.J.Choyke: Microelectronic Engineering, 2006, 83[1], 2006, 146-9