The properties of thin film samples of the alloy were studied. When the films were annealed in Ar (400C, 0.5h), very thin protective layers of Al2O3 formed on the surface and prevented further oxidation. The Cu-Al films adhered better to SiO2 than did films of pure Cu and, unlike pure Cu, they remained microscopically smooth after annealing at temperatures of up to 700C. In addition, they exhibited no diffusion of Cu (as measured by Rutherford back-scattering spectroscopy) into SiO2 at temperatures of up to 700C.

P.J.Ding, W.A.Lanford, S.Hymes, S.P.Murarka: Journal of Applied Physics, 1994, 75[7], 3627-31