Activation of shallow boron acceptor in C∕B coimplanted silicon carbide: A theoretical study

Abstract

Ab initio supercell calculations have been carried out to investigate the complexes of boron acceptors with carbon self-interstitials in cubic silicon carbide. Based on the calculated binding energies, the complex formation of carbon interstitials with shallow boron acceptor and boron interstitial is energetically favored in silicon carbide. These bistable boron defects possess deep, negative-U occupation levels in the band gap. The theoretical results can explain the observed activation rates in carbon-boron coimplantation experiments.