AlCu alloy films prepared by the thermal diffusion technique

Abstract 100-nm thick films of Al 1 −  x Cu x alloys were prepared on glass substrates by thermal diffusion technique. The Cu atomic concentration was varied from 10% to 90%. Alloys were prepared at different temperatures into a vacuum oven with Argon atmosphere. Two thermal processes were used: i) heating the film at 400 °C in a single step, and ii) heating the films in sequential steps at 100, 200, 300 and 400 °C. Morphology, electrical resistivity, and crystalline orientation of the alloys were studied. The electrical resistivity and surface roughness of the alloys were found to depend strongly on the atomic composition and the diffusion temperature. However, we did not find differences between samples prepared under the two thermal processes. Alloys prepared with x  = 0.6 and x  = 0.1–0.3 as Cu at concentration exhibited values on electrical resistivity and surface roughness lower than pure Al. Different phases of the Al 1 − x Cu x films were observed as a function of Cu concentration showing a good agreement with the AlCu phase diagram.