Recently, Cu-1 at.% Sn thin film alloy has been found to exhibit good electromigration resistance. Electromigration behavior is strongly affected by the alloy's microstructure and in turn, by grain growth kinetics. In this work, we report the grain growth behavior of non-cold-rolled pure Cu, cold-rolled pure Cu and cold-rolled Cu-2 at.% Sn alloy in bulk samples. The non-cold-rolled pure Cu shows a monomodal grain size distribution and normal grain growth. The cold-rolled pure Cu shows the temporary appearance of a bimodal grain size distribution which, with sufficient annealing in the temperature range of 700 to 900°C for 24 h, eventually returns to a monomodal distribution. However, the cold-rolled Cu(Sn) alloy shows a monomodal grain size distribution similar in behavior to the non-cold-rolled Cu. The influence of the strain energy owing to cold-rolling and the presence of Sn solute on the grain growth is discussed.
- Bimodal grain size distribution
- Cu(Sn) alloys
- Grain growth