Mass transport-induced failure in direct copper (Cu) bonding interconnects for 3-D integration

This paper presents the first complete electromigration study (EM tests, failure analyses, statistical analyses with lifetime extrapolation) for direct copper bonding interconnects. This study reveals excellent performances, comparable to BEoL interconnects. Nevertheless, the results show that it will be interesting to increase the precision of alignment to maximize the Cu-Cu interface in comparison of the Cu-SiO
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to ensure high activation energy and at the end a high electromigration resistance.