Evolution of internal stress and microstructure in Ti50Cu50 alloy films: influence of substrate temperature and composition

Annealing of low-temperature alloy films gives rise to irreversible tensile stress changes indicating restructuring of the films. The stress change measured when annealing a superstructured γ-TiCu film is compressive and is assigned to the transformation of the metastable superstructure to polycrystalline γ-TiCu. The magnitude of this compressive stress contribution is strongly dependent on the copper concentration, i.e., copper vacancy concentration.