Dynamic observation of Al thin films plastically strained in a TEM

Aluminum thin films deposited onto oxidized silicon substrates were deformed using the difference in thermal expansion coefficients between the two materials. Stresses in the Al films were measured by the wafer curvature method. The stress-temperature behavior is explained by cross-sectional TEM studies which revealed grain growth and dislocation exhaustion. In order to track down finer dislocation mechanisms, in situ cross-sectional samples were heated from room temperature up to 450°C in a TEM. Dynamic observations demonstrated that the Al/SiOx–Si interface acts as a sink for dislocations and grain boundaries.