Calculations based on density functional theory were carried out to study interstitial generation close to the Si(100) surface with further consideration of effects related to the presence of substitutional Ge atoms on the surface. Defect structures, vacancy and Si interstitial, and associated energies were calculated. It was observed that germanium atoms tended to increase the stability of created defects, promoted the generation of interstitials through drastic structural changes and blocked the climb of Si interstitials towards the surface.

First-Principles Study of Near Surface Point Defects Stability in Si (100) and SiGe(100). S.Fetah, A.Chikouche, A.Dkhissi, A.Estève, M.D.Rouhani, G.Landa, P.Pochet: Thin Solid Films, 2010, 518[9], 2418-21