The hydrostatic pressure dependence of the diffusivity of P in compressively strained Si0.93Ge0.07 and unalloyed Si was measured. In both cases the diffusivity was almost independent of pressure, characterized by an activation volume V* of +0.09 times the atomic volume for the unalloyed Si, and +0.01 times the atomic volume for Si0.93Ge0.07. The results were used in conjunction with the reported effect of biaxial strain on diffusion normal to the surface to test the prediction for an interstitialcy-based mechanism of the Aziz phenomenological thermodynamic treatment of diffusion under uniform non-hydrostatic stress states. The prediction agreed well with measured behavior, lending additional support to the interstitial-based mechanism and the non-hydrostatic thermodynamic treatment.

Activation Volume for Phosphorus Diffusion in Silicon and Si0.93Ge0.07. Y.Zhao, M.J.Aziz, N.R.Zangenberg, A.Nylandsted Larsen: Applied Physics Letters, 2005, 86[14], 141902 (3pp)