The vacancy contribution to self-diffusion in Si, recently revealed by a study by Shimitzu et al., was analyzed in order to demonstrate that the pre-exponential term, as well as the enthalpy term, accurately matched that of the isolated neutral vacancy, as determined many years earlier at cryogenic temperatures by using electron paramagnetic resonance and deep level transient spectroscopy. The persistent suggestion of a so-called extended vacancy with very different migrational properties at elevated temperatures was therefore incorrect. There was only one vacancy.

The Vacancy in Silicon - Identical Diffusion Properties at Cryogenic and Elevated Temperatures. G.D.Watkins: Journal of Applied Physics, 2008, 103[10], 106106