Rutherford Scattering Studies of Diffusion in Thin Multilayer Metal Films
Interdiffusion in Ti:Pd:Au and Ti:Rh:Au thin film metallization schemes has been studied by Rutherford backscattering. Grain sizes, as a function of annealing temperature, have been measured by transmission electron microscopy. The diffusion of Au into Rh is dominated by grain boundary effects. When Rh is the intermediate layer, Au saturates the fine structured Rh grains in the as-deposited films without any heat treatment. The diffusion behavior after annealing is explained in terms of a crude model in which grain boundary diffusion is assumed to keep the Rh grain boundaries filled with Au, which subsequently diffuses into the grains by bulk diffusion. This gives Q = 1.34 eV and DO = 5×10–7 cm2/sec for bulk diffusion of Au into Rh. For equivalent annealing conditions considerably greater diffusion is observed between Pd:Au than Rh:Au.
KeywordsBoundary Diffusion Bulk Diffusion Diffusion Profile Metallization Scheme Atomic Size Effect
Unable to display preview. Download preview PDF.