Characterization of self-heating and current-carrying capacity of intercalation doped graphene-nanoribbon interconnects

As VLSI technology node scales down beyond 14 nm, the current carrying capacity of metal interconnects decreases rapidly and will not meet the increasing circuit performance driven current density requirements. FeCl
₃
intercalation doped multilayer (ML-) graphene-nanoribbon (GNR) interconnect has been recently demonstrated to surpass nanoscale Cu interconnects, in terms of performance, reliability, and energy-efficiency. Doped ML-GNRs, unlike conventional metals (such as Cu) do not exhibit any gradual time-dependent degradation of resistance due to electromigration. In the DC current stress/breakdown tests, doped ML-GNR breakdown showed a strong dependency on GNR temperature induced by self-heating, indicating that the major breakdown mechanism is self-heating induced thermal decomposition. A detailed self-heating model is developed and calibrated with experimental measurements on doped ML-GNR interconnects to explain the thermally activated breakdown of such interconnects. Moreover, ML-GNR thinning by thermal decomposition was observed near the breakdown, which started from the top-most GNR layer. Overall, our doped ML-GNR interconnect shows excellent current carrying capacity (>200 MA/cm
²
), w.r.t. Cu (<;5 MA/cm
²
), indicating their feasibility as likely replacement for Cu in next-generation ICs.