A Unified Delay, Power and Crosstalk Model for Current Mode Signaling Multiwall Carbon Nanotube Interconnects

Multiwall carbon nanotube (MWCNT) has been investigated as a potential interconnect material for future advanced technology nodes. The present paper analyzes performance of MWCNT interconnects using current mode signaling (CMS) scheme. The novelty of the present work can be stated as: Firstly, a unified model is proposed for both copper and MWCNT interconnects using finite-difference time-domain (FDTD) technique. Secondly, this model is applicable for both the conventional voltage mode signaling and more versatile CMS schemes. Furthermore, the presented FDTD-based model is valid for single as well as M-line coupled interconnects in integrated circuits. The model also incorporates CMOS gate as driver for MWCNT interconnect. Thirdly, power model using FDTD technique is investigated for the first time. Accurate formulation and computation of power dissipation in CMS MWCNT interconnects are presented in the paper. Propagation delay, power dissipation and power_delay_product (PDP) are the performance metrics considered for single-line CMS MWCNT interconnect. Crosstalk is analyzed for 2-Line and 5-Line coupled interconnects. It is investigated that CMS scheme leads to about 4 times lesser propagation delay and 2.5 times reduced PDP in MWCNT interconnect than the conventional copper interconnect for interconnect length of 4500 μ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}m. The technology node considered is 32 nm. The response of the system is accurately computed using the proposed FDTD-based model. The maximum percentage error between results obtained by the proposed analytical model and SPICE simulation model is <3% for the various test cases.