What is "electromigration"

n. 1 (context physics English) the transport of small particles under the influence of an electric charge 2 (context chemistry English) the separation of ions of isotopes by this method

Electromigration is the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is important in applications where high direct current densities are used, such as in microelectronics and related structures. As the structure size in electronics such as integrated circuits (ICs) decreases, the practical significance of this effect increases.