Implantation-induced defects in silicon carbide

Abstract

The electrical activation of N and P donors in C/N-, Si/N-, C/P- and Si/P-coimplanted and subsequently annealed 4H–SiC samples is investigated by Hall effect. It turns out that doping by coimplantation, which is a process far apart from thermal equilibrium, is different from doping of SiC during growth by the chemical vapor deposition, which is largely governed by the site-competition effect. In case of N and Si coimplantation, the formation of thermally stable and electrically neutral VSi(VC)4 complexes is proposed to serve as a noticeable sink for N atoms. By illumination with photons of different energy, the electrical properties of the dominating intrinsic-related defect centers (E1/E2−/+-, Z1/Z2−/+- and Z1/Z2(3C)) are investigated in 6H–, 4H– and 3C–SiC by deep level transient spectroscopy. In 4H– and 6H–SiC, negative-U-centers are observed. The optical ionization energy of the Z1/Z2−/0-center in 4H–SiC is determined.