The Effect of Interlayer Distance and Doping on the Performance of Multilayer Graphene Nano Ribbons as VLSI Interconnects

Abstract

Graphene nanoribbons are considered as a potential VLSI interconnect material. Performance of deep sub micron circuits is deeply impacted by the interconnect due to reduced pitch size. The impact of interlayer distance on the performance in terms of propagation delay, power dissipation and power delay product (PDP) of multilayer GNR interconnect material is studied. Propagation delay is estimated for different interconnect length as well by using ESC model for GNR interconnects. This analysis is performed on 16nm technology node. It is found that for a doped multilayer GNR VLSI interconnects, the approximate optimum interlayer distance is 0.575nm at which MLGNR provides the optimum delay, power and PDP, other than this value the delay, power dissipation and power delay product is in increasing order. The similar analysis is also performed on 22nm technology node and found the same optimum interlayer distance around 0.575nm. But the propagation delay, power dissipation and power delay product are reduced as compare to the 16nm technology node. Impact of conductance of GNR interconnects is also studied. Resistance per unit length for different GNR versus interconnect cross-sectional width for interconnects length larger than its mean free path is also plotted. Further, the impact of fermi energy on propagation delay and power dissipation is studied for different technology nodes. As the scaling continues, the propagation delay and power dissipation of MLGNR interconnect increases. A suitable number of repeaters are inserted to obtain the performance analysis of GNR interconnect. The results so obtained show the performance of graphene nano ribbons with increased doping. Thus MLGNR with suitable Fermi energy has a potential to replace copper at global interconnect lengths.