SiO2 clusters are found to be excellent sink for metallic impurities in Si crystals. Experiments have shown that SiO2clusters can be formed inside Si owing to oxygen precipitation at defect (dangling bond) sites Curing prolonged heating of Si if the Si is supersaturated with oxygen at the heating temperature.
Super saturation means that the oxygen concentration is higher than the maximum solubility at the observation temperature. Suppose that an SiO2cluster is formed at 1 μm below the Si surface.
How long does the SiO2 cluster disappear-Into the Si surface at room (300K) and how long is the maximum shelf storage (125C) temperatures of an Si diode or transistor? Use given Figure to extrapolate or use the equation in the figure to calculate the oxygen diffusivity in Si at 300K and 125C.
