Diffusion in Ni/Cu bilayer films

It is shown that the diffusion of Cu into the Ni layer of a Ni/Cu bilayer film after thermal annealing is significantly reduced when the deposition temperature of the Ni layer is raised from approximately 50 to 200 °C. The effect of the deposition temperature on the physical structure of the Ni layer and the possible connection between the Ni layer physical structure and the diffusion reduction are investigated. The effect of the diffusion on the resistivity of the Cu layer is also studied.