This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.
 

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Electromigration in Al can occur under the influence of an electric field in ICs. The electromigration induces voids, resulting in discontinuities, in the metallization runners, that causes circuit opening and/or pileups that can cause short circuit failure to adjacent conductors. The electromigration resistance of Al can be increased by alloying with copper at low concentrations, e.g. ~ 0.5%.

In situ SEM has been employed to investigate electromigration behavior. For instance, Vairagar et al. [1] used this technique to study the electromigration-induced failure in the upper and lower layers in dual-damascene Cu test structures. Their observations revealed electromigration-induced void movement along the Cu/dielectric cap interface and concluded that Cu/Si₃N₄ interface acted as the dominant electromigration path. They also observed that the void nucleation occurred in the Cu/Si₃N₄ interface at locations which were far from the cathode, and void movement along the Cu/Si₃N₄ interface in opposite direction of electron flow eventually caused void agglomeration at the via in the cathode end.

[1] A. V. Vairagar, S. G. Mhaisalkar, Ahila Krishnamoorthy, K. N. Tu, A. M. Gusak, Moritz Andreas Meyer, and Ehrenfried Zschech, In situ observation of electromigration-induced void migration in dual-damascene Cu interconnect structures, Applied Physics Letters, 85(13), 2502 (2004).