This investigation prepares a low-resistivity and self-passivated Cu(In) thin film. The dissociation behaviors of dilute Cu-alloy thin films, containing 1.5-5at.%In, were prepared on glass substrates by a cosputter deposition, and were subsequently annealed in the temperature range of 200-600°C for 10-30 min. Thus, self-passivated Cu thin films in the form In 2 O 3 /Cu/SiO 2 were obtained by annealing Cu(In) alloy films at an elevated temperature. Structural analysis indicated that only strong copper diffraction peaks were detected from the as-deposited film, and an In 2 O 3 phase was formed on the surface of the film by annealing the film at an elevated temperature under oxygen ambient. The formation of In 2 O 3 /Cu/SiO 2 improved the resistivity, adhesion to SiO 2 , and passivative capability of the studied film. A dramatic reduction in the resistivity of the film occurred at 500°C, and was considered to be associated with preferential indium segregation during annealing, yielding a low resistivity below 2.92 lWcm. The results of this study can be potentially exploited in the application of thin-film transistor-liquid crystal display gate electrodes and copper metallization in integrated circuits.