First-principles design of high speed nanoscale interconnects based on GaN nanoribbons

Abstract

Investigation of efficient interconnects for upcoming nano-electronic devices is an active area of research. In the present work, we gauged the effect of O-passivation on zigzag GaN nanoribbons (ZGaNNR) as well as armchair GaN nanoribbons (AGaNNR) for interconnect applications. Various possible configurations of O-passivation were considered and the findings thus obtained were compared. It is reported that O-passivated ZGaNNR nanoribbons exhibit metallic character unlike H-passivated counterparts. On the other hand, the magnitude of band gap for AGaNNR is drastically reduced upon O-passivation. It is also noticed that replacing H with O for passivation purpose also enhances the structural stability of the ribbons making them preferable. The non equilibrium Green’s formalism coupled with density functional theory was employed to study the transport properties. The obtained current–voltage (I-V) characteristics confirm maximum current for O@both-edges while minimum current has been obtained for O@Ga-edge. The small-signal dynamic performance parameters such as $R_Q$, $C_Q$, and $L_K$ are derived using the two-probe model for the interconnect modeling. The O@N-edge functionalized ZGaNNR has the lowest values of $R_Q$ (12.9 K$\Omega$), $C_Q$ (8.60 pF/$\mu$m), $L_K$ (358.511 nH/$\mu$m), and quantum latency ${\tau }_p$ (0.111 ms) and higher Fermi velocity. Our work paves the way for the realization of low-power nanoscale high-speed interconnect applications.