Behavior of (1 1 1) grains during the thermal treatment of copper film studied in situ by electron back-scatter diffraction

An annealed Cu blanket film was investigated in situ at high temperature using electron back-scatter diffraction (EBSD). The primary aim of the experiment was to study the changes in the (1 1 1) texture in the Cu film where the microstructure was already stabilized by previous annealing treatment. Two separate investigations were carried out at the same location of the film for better statistical reliability of data. It was found that the (1 1 1) planes got increasingly inclined to the specimen surface with increasing temperature. Additionally, a change in the strength of {1 1 1}〈1 1 0〉 and {1 1 1}〈1 1 2〉 texture components was observed with increasing temperature. Absence of these phenomena in freestanding Cu film indicates the impact of substrate on the behavior of (1 1 1) grains. The effect of substrate on the peculiar behavior of the (1 1 1) grains has been explained by a model which describes the contribution of both dislocations and diffusion to the observed phenomenon. The tilting of the (1 1 1) grains is discussed with reference to the recently reported Bauschinger effect in the Cu films.