Oxygen, Oxidation Stacking Faults, and Related Phenomena in Silicon

Abstract

ABSTRACTSome salient features of the phenomena of oxidation stacking faults (OSF) and oxidation enhanced diffusion(OED) are summarized, and some theories of OSF growth are critiqued. Then a new theory is developed which shows the growth to be reaction controlled, and the retrogrowth to be naturally a regime in the entire OSF growth process. The theory has provided an estimated bound on the activation energy of self-diffusion in silicon. It is shown that the observed power law growth kinetics can be explained quite naturally by a bimolecular annihilation process of the excess self-interstitials. A possible physical model of such an annihilation process is discussed. A number of phenomena related to the nucleation of oxygen precipitates in silicon are reported. Then a model of nucleation is presented which is shown to be consistent with all observed phenomena.In this model, the homogeneous nucleation proceeds not merely via the agglomeration of oxygen atoms, but in combination with small vacancy clusters. Evidence from the OSF and OED phenomena, and the nucleation of oxygen precipitates thus necessitates the dualism of vacancies and interstitials as thermal defects in silicon at high temperatures.