spectroscopic measurements of annealed metal-oxide-Si structures. The results revealed a clear decrease in diffusivity, with increasing annealing time, which was approximately exponential. This implied a similar time-dependence of the concentration of a secondary species such as H, or a defect, which promoted diffusion; even in a nominally pure oxide.

Time-Dependent Diffusivity of Boron in Silicon Oxide and Oxynitride. K.A.Ellis, R.A.Buhrman: Applied Physics Letters, 1999, 74[7], 967-9