Computer security compromised by hardware failure: Difference between revisions

Revision as of 19:25, 16 January 2017

Revision as of 19:25, 16 January 2017

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Electromigration, which means to physically move the atom to new locations (to physically alter the device itself) is another type of attack.<ref name="Gut1" /> It involves the relocation of metal atoms due to high current densities, a phenomenon in which atoms are carried along by an “electron wind” in the opposite direction to the conventional current, producing voids at the negative electrode and hillocks and whiskers at the positive electrode. Void formation leads to a local increase in current density and Joule heating (the interaction of electrons and metal ions to produce thermal energy), producing further electromigration effects. When the external stress is removed, the disturbed system tends to relax back to its original equilibrium state, resulting in a backflow which heals some of the electromigration damage. In the long term though, this can cause device failure, but in less extreme cases it simply serves to alter a device’s operating characteristics in noticeable ways.

For example, the excavations of voids leads to increased wiring resistance and the growth of whiskers leads to contact formation and current leakage.<ref name="Gut1Gut10">[[#Gut1|Gutmann, 2001, p.5]]</ref> An example of a conductor which exhibits whisker growth due to electromigration is shown in the figure below:

[[File:Whisker growth.jpg|thumb|center|969px|alt=|Whisker growth due to electromigration]]