The radiation-enhanced diffusion of implanted Au markers in amorphous Si was measured at temperatures ranging from 77 to 693K (table 8). The samples were bombarded with 2.5MeV Ar ions, and the diffusion coefficients exhibited 3 well-defined ranges. At temperatures below 400K, the diffusion was athermal and was due to ballistic mixing. At temperatures ranging from 400 to 700K, the diffusion was of Arrhenius type; with an activation energy of 0.37eV. It was considerably enhanced with respect to normal thermal diffusion. The defects which caused the enhanced diffusion arose from nuclear energy loss processes. Thermal diffusion, with an activation energy of 1.42eV, predominated at temperatures greater than 750K.

F.Priolo, J.M.Poate, D.C.Jacobson, J.Linnros, J.L.Batstone, S.U.Campisano: Applied Physics Letters, 1998, 52[15], 1213-5

Table 8

Radiation-Enhanced Diffusivity of Au in Amorphous Si