Enhanced and wafer-dependent oxygen diffusion in CZ-Si at 500–700 °C

Abstract

Oxygen diffusivity in silicon in the intermediate temperature range 500–650 °C has, for the first time, been directly measured. Oxygen diffusion in this temperature range is enhanced relative to the normal diffusion of interstitial oxygen. The degree of enhancement increases with decreasing temperature, with the enhancement factor reaching >102 at ≤550 °C. The diffusivity at 550–750 °C is found to vary among Si wafers by as much as 10×. Oxygen diffusivity generally decreases with increasing annealing time but does not vary proportionally with oxygen concentration as expected from a molecular oxygen model.