Thermal cycles were performed within, and outside of, a transmission electron microscope in order to analyze the evolution of the microstructure of Al-0.5Cu-1%Si thin films deposited onto oxidized Si substrates. It was shown that grain growth and dislocation activity began almost simultaneously, and cooperated throughout the plastic regime of the stress–temperature curve so as to generate bamboo-type grains with a low dislocation density. Precipitates of Si served as anchor-points for dislocations and grain boundaries. Thermal cycling and diffusion caused growth of the precipitates and a diminution in their number. Diffusion also played an important role with regard to plastic relaxation at the Al/SiOx interface, and at grain boundaries; where intense hillock and whisker formation was observed by scanning electron microscopy.

Impact of Thermal Cycling on the Evolution of Grain, Precipitate and Dislocation Structure in Al-0.5%Cu-1%Si Thin Films. B.Kaouache, P.Gergaud, O.Thomas, O.Bostrom, M.Legros: Microelectronic Engineering, 2003, 70[2-4], 447-54

Table 2

Interdiffusion Coefficients in Al-Based Systems at 813K