Dresden 2014 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 32: Transport II - Microstructure/Grain boundaries

MM 32.4: Talk

Tuesday, April 1, 2014, 16:30–16:45, IFW B

Lattice degradation in bi-crystalline Ag wires during reversible electromigration — •Simon P. Sindermann, Michael Horn-von Hoegen, Günter Dumpich, and Frank-J. Meyer zu Heringdorf — Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE) University of Duisburg-Essen, D-47057 Duisburg, Germany

Electromigration is known as the reversible mass transport occuring at high electric current densities. We use well controlled bi-crystalline Ag test structures [1] to study the interaction of electromigration driven voids with the crystal lattice by in-situ scanning electron microscopy (SEM).

Previously we have shown that the void shape is strongly influenced by the lattice symmetry [2], and we observed an increased number of additional voids in the motion path of voids [3].

Here, we present our observation of void motion at the reversal of the electric current direction. We find that a void exactly retraces its previous path. The test structure remembers where a void has passed through it. Electron backscatter diffraction (EBSD) shows that this kind of memory effect is caused by a permanent lattice degradation. Electromigration is thus not reversible with respect to the microstructure.

[1] S. Sindermann et al. RSI 82, 123907 (2011)

[2] A. Latz et al. PRB 85, 035449 (2012)

[3] S. P. Sindermann et al. JAP 113, 134505 (2013)