The diffusivity was studied using both inert (nitrogen) and oxidizing (nitrogen + steam + air) atmospheres at between 1000 and 1200C. The experimental data were analyzed using the Kato-Nishi model which took account of redistribution effects occurring at the moving oxide/Si interface. This showed that the diffusion coefficient was markedly affected by the nature of the atmosphere. Thus, the activation energy was found to be 3.5eV in the case of an inert atmosphere, and 2.5eV in the case of an oxidizing atmosphere. It was concluded that the results confirmed the P diffusion mechanism based upon E-centers in the case of an inert atmosphere. A different mechanism was required in the case of an oxidizing atmosphere.

G.Masetti, S.Solmi, G.Soncini: Solid State Electronics, 1973, 16, 1419-21