Atomic dynamics and defect evolution during oxygen precipitation and oxidation of silicon

We report first-principles calculations in terms of which we propose a unif ied description of the atomic dynamics that underlie the nucleation and gro wth of SiO2 precipitates in Si and the oxidation of Si thin films. We ident ify a mechanism for the observed emission of Si interstitials and show that it eliminates electrically active defects without introducing dangling bon ds. The results provide an explanation for the low defect density at the Si -SiO2 interface and suggest a novel family of electrically active interface defects that are akin to the "thermal donors" in Si. (C) 1999 American Ins titute of Physics. [S0003-6951(99)04724-5].