Direct Transmission Electron Microscope Observation of Electrotransport in Aluminum Thin Films

The process of electrotransport in Al thin films was directly observed by transmission electron microscopy. As expected, it was seen that hole formation occured in regions where the electron flow was in the direction of increasing temperature. Hillocks and whiskers were seen to form where the electron flow was in the direction of decreasing temperature. Cine films taken of the process show the holes to grow predominately by a transverse movement of narrow fingers which ultimately coalesce and lead to a catastrophic strip burn out.