Performance Analysis of Mixed-MWCNT as VLSI Interconnects for Nano-Scaled Technology Nodes

Abstract

With the scaling in technology, the resistivity of the copper initially being used as an interconnect material is increasing due to surface roughness and various kind of scattering. The carbon nanotubes (CNTs) as a better choice of material for VLSI interconnects have been studied. These are further of two types single walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). The Multi-walled carbon nanotubes (MWCNTs) have become the preferred interconnect material for the nanoscale technology nodes than SWCNTs due to its longer mean free path and other properties. It is important to grow MWCNT bundle structures as interconnect for silicon chip design. In this report the performance analysis of MWCNT bundles containing several MWCNTs, with identical and different number of shells is presented. The structures are categorized into two types: MWCNT bundle (MW) which contains all the MWCNTs with same number of shells and Mixed MWCNT bundle (MMW) which contains MWCNTs having different number of shells. The Equivalent Single Conductor (ESC) model is produced by employing, Multi-conductor transmission line (MTL) model theory for all the structures. Further, by using proposed ESC model the performance on the basis of propagation delay, power dissipation and power-delay product (PDP) measurements is estimated through driver interconnect load (DIL) model for different interconnect lengths between different structures. The performance evaluation is presented for at nano-scaled technology nodes (viz. 32nm, 22nm and 16nm). It’s shown through the results that the performance of mixed MWCNT (MMW) structures is better in all aspects as compared to MWCNT (MW) for nano-scaled technology nodes.