New evidence for enhanced O diffusion in Czochralski material at 450 to 650C was obtained from O precipitation during prolonged annealing at 750C following a variety of pre-treatments involving slow ramping annealing or single-step annealing. The two previously proposed fast-diffusing species of O-vacancy and O-Si-interstitial, for understanding enhanced O diffusion at low temperatures, were questioned. Moreover, the reason why significant O precipitation could occur at such a low temperature as 750C was clarified; based upon the enhanced O diffusion at low temperatures.

Enhanced Oxygen Diffusion in Czochralski Silicon at 450-650C. C.Cui, X.Ma, D.Yang: Physica Status Solidi A, 2008, 205[5], 1148-51