Orientation dependent ion beam mixing of Ta/Si interfaces

Ta/Si interfaces were systematically studied concerning ion beam mixing effects. Tantalum was evaporated on silicon of (1 0 0) and (1 1 1) orientation using the molecular beam epitaxy (MBE) method. The samples were then irradiated with 1.85 MeV and 6 MeV Ar, 90 keV O and 90 keV C. Rutherford backscattering spectroscopy (RBS) was used to examine mixing effects. Atomic force microscopy (AFM) was applied for investigating the surface roughness. Ballistic mixing, radiation enhanced diffusion and thermal spike effects were found in both systems. Si substrates of the orientation (1 0 0) led to smaller mixing rates at the Ta/Si interface as compared to Si(1 1 1).