In situ transmission electron microscope studies of the kinetics of abnormal grain growth in electroplated copper films

We have performed in situ transmission electron microscopy studies of abnormal grain growth in electroplated copper films at room temperature and 55 °C, starting minutes after the plating process by electroplating directly onto electron-transparent membranes. A kinetic analysis indicates that the grains that grow abnormally, reject impurities as they grow, so that the impurities accumulate in (and must diffuse through) the untransformed matrix. This suggests that while impurities impair normal grain growth, impurity rejection contributes to the energetics that drive abnormal grain growth. This result also indicates that removal of impurities from the film can control the kinetics of the transformation to large-grained structures.