Electrical Transportation Behavior of Magnetron Sputtered Al-Fe-Sn Thin Film

During the manufacturing process of Al-based thin films for electronic applications, a post-deposition annealing is required in order to achieve lower resistivity. However, the electrical transportation behavior of the magnetron sputtered Al film has been rarely investigated so far. To approach this objective, we have explored the microstructures of the films before and after annealing with emphasis on the structural features related to diffusion and interface using TEM observation. Hall-effect measurement was employed to determine the variation of carrier density and mobility brought by the evolution originating at the interface. The results demonstrate that during annealing an intimate contact is formed between the film and the substrate via diffusion, leading to a combination of high mobility and high density of the carriers. A model was proposed from the aspect of energy bands in order to explain the positive effect of the interfacial phenomenon upon electron conductivity.