On the basis of a network defect model for B diffusion in this oxide, it was proposed that B diffused via a peroxy linkage defect whose concentration varied according to the processing conditions. It was found that, as the oxide was reduced to less than 8nm in thickness, chemical processes acted so as to increase the B diffusivity and decrease its activation energy as a function of the distance from the SiO2/Si interface. For a 1.5nm oxide sample, the B diffusivity at 900C was decreased by a factor of 24 with respect to diffusion in a 10nm oxide.

R.B.Fair: IEEE Electron Device Letters, 1996, 17[5], 242-3