An investigation was made of interstitial oxygen (Oi) diffusion in heavily As-doped Si using first-principles calculations. It was shown that it was not the As itself, but the Si vacancy (V), that trapped Oi to reduce its diffusion. The As played the role of an intermediate to activate thermal generation of As–V pairs which, in turn,trapped Oi with a large binding energy of ~1.0eV, in quantitative agreement with experiment. The results solved a long-standing puzzle concerning the atomistic mechanism underlying the retardation of Oi precipitation in heavily As-doped Si.

The Role of Vacancy on Trapping Interstitial O in Heavily As-Doped Si. G.H.Lu, Q.Wang, F.Liu: Applied Physics Letters, 2008, 92[21], 211906