Analytical electron microscopy and Auger electron spectroscopy were used to study low-temperature diffusion and segregation in multi-layer thin films. Annealing (573K, 900s) led to pronounced element redistribution between the film layers. The Cu and Au diffused towards one another across the Ni layer and exhibited the most intensive redistribution, via grain boundary diffusion. The Ni layer was not effective as a diffusion barrier. Features of the measured Au and Cu depth profiles, such as the accumulation of segregating Cu atoms at the Ni–Au interface, and non-uniform Au and Cu enrichment of individual grains, were correlated with the grain structure of the film layers; which affected the effective diffusion rate.

Analytical Electron Microscopy and Auger Electron Spectroscopy Study of Low-Temperature Diffusion in Multilayer Chromium–Copper–Nickel–Gold Thin Films. M.I.Danylenko, M.Watanabe, C.Li, A.V.Krajnikov, D.B.Williams, M.A.Vasiliev: Thin Solid Films, 2003, 444[1-2], 75-84