The mechanisms of oxygen precipitation in the SiO(2) phase during rapid thermal annealing of solar-grade Cz-Si wafers at moderate temperature (850 degrees C) are analysed. A theoretical model is derived to study the kinetics of oxygen precipitate growth that takes into account a significant increase in the non-equilibrium solubility of oxygen and the increased effective diffusivity of oxygen atoms. A mechanism for the mentioned abnormal modifications of the characteristics of oxygen diffusivity and solubility is suggested based on the dominating influence of excess point defects appearing in the Si wafers during the rapid thermal anneals. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3594724] All rights reserved.