The kinetics and mechanism of room-temperature microstructural evolution in electroplated copper foils

The room-temperature microstructural evolution of 18 μm thick electroplated copper deposits was investigated by cross-sectional focused ion-beam microscopy. The fraction of transformed volume as a function of annealing time was measured. The transformation was found to start and nucleate from the bottom of the foils and then propagate towards the free surfaces. Based on differential scanning calorimetry results, the activation energy for grain growth is 0.85 eV atom−1. The mechanism of the grain growth is also discussed.