1. The motion of ions in a metal conductor within an integrated circuit, typically in aluminum surfaces in response to high current passage.

It causes voids (empty spaces) in the conductor that can grow until current flow is blocked.

Its destructive effects are aggravated at high temperature and high-current flow, but these effects can be minimized by limiting current densities and alloying the aluminum with copper or titanium.

2. A detrimental effect occurring in transistors employing aluminum metallization schemes.

Electromigration of aluminum results from the mass transportation of metal by momentum exchanges between thermally activated metal ions and conduction electrons.

When it occurs, the ideally uniform aluminum film reconstructs to form thin conductor regions and extruded-like hillocks (hills or bumps) that may cause the transistor's destruction.