Self-diffusion of Si in thermally grown SiO2 was modeled taking into account the effect of SiO molecules generated at the Si/SiO2 interface and diffusing into SiO2 to enhance the self-diffusion. Based on the model, a recent self-diffusion experiment of ion-implanted 30Si in SiO2, which exhibited increasing self-diffusivity with decreasing distance between the 30Si diffusers and Si/SiO2 interface, was simulated, and the simulated results fit the experimental profiles. Furthermore, the simulation predicted that the self-diffusivity would increase for a longer annealing time because more SiO molecules should be arriving from the interface. Such time-dependent diffusivity was indeed found in follow-up experiments, and the profiles were also fitted by the simulation using a single set of parameters.

Modeling of Si Self-Diffusion in SiO2 - Effect of the Si/SiO2 Interface Including Time-Dependent Diffusivity. M.Uematsu, H.Kageshima, Y.Takahashi, S.Fukatsu, K.M.Itoh, K.Shiraishi, U.Gösele: Applied Physics Letters, 2004, 84[6], 876-8