Impact of Process Variation Parameters on Propagation Delay in MLGNR VLSI Interconnects

Multi-layer graphene nanoribbons (MLGNRs) have emerged as a promising alternative to conventional copper for next-generation on-chip interconnects. This study investigates the impact of process-induced variations such as in graphene metal contact resistance, Fermi energy, mean free path, and relative permittivity on the propagation delay of MLGNR interconnect bundles at the 16 nm technology node. By employing an equivalent RLC circuit model, the propagation delay is evaluated across interconnect lengths ranging from 400 to 2000 µm. The results show that an increase in Fermi energy and mean free path leads to substantial delay improvements of 25% and 27% respectively, due to enhanced carrier transport properties and reduced electron scattering. However, variations in contact resistance and relative permittivity have a minor impact on delay performance. These results are very useful for the fabrication of graphene-based onchip interconnects.