The CiOi(SiI)2 defect in silicon: density functional theory calculations

Abstract

Carbon–oxygen-self-interstitial defects in silicon (Si) are technologically important as they can impact the operation of devices through the concentration of intrinsic point defects. In irradiated Si the CiOi defect attracts self-interstitials (SiI’s) and leads to the formation of the CiOi(SiI). Experimental studies have determined that annealing at 150 °C results in the capturing of more SiI’s leading to the formation of the CiOi(SiI)2 defect. Recent experimental studies proposed that the CiOi(SiI)2 defect is bistable and considered possible configurations. In the present study we aim to clarify the structure of the CiOi(SiI)2 defect and use density functional theory calculations to gain insights on the formation and stability of the CiOi(SiI)2 defect in Si. It is calculated that two configurations are energetically favourable differing in energy by only 0.19 eV.