The effect of Cu interlayers on grain size and stress in sputtered Fe–Cu multilayered thin films

The stress states of magnetron sputtered Fe–Cu multilayered films are studied using X-ray diffraction, in particular with respect to the relation between stress and morphology. It is suggested that the deposition of copper interlayers between layers of iron can lead to the formation of body-centered cubic Cu which keeps the orientation of iron crystallites unchanged through the whole thickness of a multilayer. Copper interlayers also are effective in controlling grain size and eventually stresses. Tensile stress is observed to increase substantially as a result of annealing up to 200 °C, which is suggested to be the result of the elimination of voids.