| Abstract Scope |
As the development of high end technology devices, it requires much more transistors under the same dimension than before, which leads to narrower and thinner Cu redistribution lines (RDLs). Consequently, the electromigration reliability issue becomes an important issues.
In previous studies, the columnar nano-twinned Cu has highly <111>-oriented surface, which has better performance for resisting oxidation while comparing to random-oriented Cu. Also, the surface electromigration could be inhibited by the triple junctions which consisted of twin boundaries and the free surface. In this study, we successfully prepare 2μm wide and 2μm thick nano-twinned Cu lines covered with PI passivation layer, and apply 10^6 A/cm^2 at 180℃ for electromigration tests. The results show that the nano-twinned Cu lines possess a higher electromigration lifetime than the regular Cu lines. |