Investigating the Role of Parasitic Resistance in a Class of Nanoscale Interconnects

Abstract

In nanoscale interconnects parasitic components are becoming drastically important with geometrical scaling. This work presents a comprehensive study of copper (Cu), SWCNT bundle, MWCNT, SC-MLGNR and TC-MLGNR nano interconnect in deep submicron (DSM) regime. We have extracted parasitic resistance of the above mentioned interconnects using physics based equivalent circuit models and investigated the effective resistivity of these interconnects at different technology nodes in DSM regime. It must be noted that when the dimensions of interconnect follow nanoscale, resistivity becomes the function of grain size. The nanoscale dimensions result in edge scattering and grain boundary scattering which inculcates tremendous effect on effective MFP. We examined the effect of grain size in scaled interconnects and analyzed the effect of edge and grain boundary scattering on resistivity of nanoscale interconnect. In our work we have look over five different interconnect geometries for the parasitic resistive component at 7 nm node and 14 nm node. We take Cu as a reference interconnect in our analysis. Our analysis show that the parasitic resistance of SWCNT Bundle, MWCNT, TC-MLGNR, SC-MLGNR interconnect is reduced by 77%, 84%, 59%, 80% compared to Cu interconnect at 7 nm node respectively. Our results also indicate a decrease of parasitic resistance by 70%, 80%, 35%, 60% compared to Cu interconnect at 14 nm node respectively. These calculations are valid below width of 14 nm. In this paper we have presented some Graphene counter parts which make it more promising candidate than CNT bundle interconnect apart from having greater p.u.l. resistance. We have analyzed the effects of Fermi energy and width on number of conduction channels for different technology nodes. This paper also shows comparable resistance of MWCNT and SWCNT due to reduced MFP of former interconnect.