Investigation of reactive phase formation in the Al–Cu thin film systems

This work is an investigation on the phase formation in Al–Cu thin film systems. This investigation was carried out on eight samples with different Cu/Al thickness ratios (0.29, 0.56, 0.71, 0.87, 1.07, 1.26, 1.58 and 2.38). The corresponding compositions of these samples are 29, 44, 50, 55, 60, 64, 69 and 77 at.% Cu. The samples were prepared by sputtering and characterized using in situ resistance measurements, and in-situ X-ray Diffraction (XRD). The sequence of phase formation was evidenced from this study. In addition, the energies of activation of Al2Cu and Al4Cu9 were calculated using simulations of the XRD and resistivity results, and the resistivity values of AlCu, Al2Cu3 and Al4Cu9 were determined at room temperature.