Grain growth in electroplated (111)-oriented nanotwinned Cu

The grain growth of pulse-plated (1 1 1)-oriented nanotwinned Cu (nt-Cu) was investigated at 200–350 °C. The results indicate that after the annealing, the nt-Cu exhibits good thermal stability, and columnar grains with a (1 1 1)-oriented nt-Cu structure are maintained up to 300 °C. The columnar grains consume the original fine-grained region at the bottom of the sample. In addition, these fine grains were converted into nanotwinned columnar grains with a (1 1 1) orientation. The electroplated Cu film possessed extremely high (1 1 1) preferred orientation after the annealing.