Point defects in Ga-implanted SiC: Experiment and theory

Abstract

We present an experimental and theoretical study of the electronic properties of Ga implanted silicon carbide (SiC). The dose of implanted Ga was selected to simulate the implant-tail region, typical of high-dose box-profile p-type doping implantation employed for device manufacture. Samples were electrically characterized by capacitance-voltage (C-V), deep level transient spectroscopy, and minority carrier transient spectroscopy. The thermal stability of the detected levels (seven majority carrier traps, five minority carrier traps) was investigated by performing an isochronal annealing prior to each characterization step. Density functional theory was employed to study both isolated (substitutional and interstitial Ga) and complex Ga-related defects (N- and vacancy-related) in order to gain more insight in the nature of the detected levels. Finally, based on the experimental and theoretical results, the possible role of Ga in the nature of the detected levels is discussed.