First-principles study on barrier height of silicon emission from interface into oxide during silicon thermal oxidation

Employing first-principles calculation, the detailed energy landscape of the path for Si emission from the interface into the oxide is studied. It is found that the barrier height almost reproduces the experimental values, indicating that Si emission surely corresponds to the diffusion of SiO interstitials. It is also found that the barrier height is microscopically rate-limited by the oxygen-vacancy transfer process, which temporarily and inevitably proceeds under a large local tensile strain induced by the diffusion of SiO interstitials.