Electrical properties of the titanium acceptor in silicon carbide

Abstract

The transition-metal titanium (Ti) as an extrinsic impurity in the wide-band-gap semiconductor silicon carbide (SiC) is studied, applying deep-level transient spectroscopy on ${\mathrm{Ti}}^{+}$-implanted 4H and 6H SiC epitaxial layers. Two Ti centers with energy positions ${\mathrm{E}}_{\mathrm{C}}$-(117\ifmmode\pm\else\textpm\fi{}8) meV and ${\mathrm{E}}_{\mathrm{C}}$-(160\ifmmode\pm\else\textpm\fi{}10) meV, respectively, are observed in the 4H polytype. These levels are assigned to the ionized Ti acceptor ${\mathrm{Ti}}^{3+}$(${3\mathrm{d}}^{1}$) residing at hexagonal and cubic Si lattice sites. For the 6H SiC polytype, the Ti acceptor levels are assumed to be resonant in the conduction band.