Dynamic observation of Al thin films plastically strained in a TEM

Aluminum thin films deposited onto oxidized silicon substrates were deforme d using the difference in thermal expansion coefficients between the two ma terials. Stresses in the Al films were measured by the wafer curvature meth od. The stress-temperature behavior is explained by cross-sectional TEM stu dies which revealed grain growth and dislocation exhaustion. In order to tr ack down finer dislocation mechanisms, in situ cross-sectional samples were heated from room temperature up to 450 degreesC in a TEM. Dynamic observat ions demonstrated that the Al/SiOx-Si interface acts as a sink for dislocat ions and grain boundaries. (C) 2001 Elsevier Science B.V. All rights reserv ed.