Direct evidence of electromigration failure mechanism in dual-damascene Cu interconnect tree structures Available to Purchase

In situ secondary electron microscope (SEM) characterizations were carried out to study electromigration failure mechanism in dual-damascene Cu interconnect tree structures, which are important for reliability assessment as well as design optimizations of on-chip interconnects. Direct evidence of electromigration-induced degradation in interconnect tree structure consisting of void nucleation and void movement in opposite direction to electron flow along the $Cu∕SiNx$ interface was unraveled. The peculiar electromigration behavior of Cu interconnect tree structures can be clearly understood based on this mechanism. Dependence of electromigration mechanism of a segment in a Cu interconnect tree on current configuration in neighboring interconnect segment is discussed in detail.