This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY 1 A Multiresolution Time Domain (MRTD) Method for Crosstalk Noise Modeling of CMOS-Gate-Driven Coupled MWCNT Interconnects Shashank Rebelli , Student Member, IEEE, and Bheema Rao Nistala Abstract—In this paper, the multiresolution time domain (MRTD) method with its unique features is tailored for modeling interconnects. To build further credence to this and its profound existence in the recent state-of-the-art, simulations for inclusive crosstalk noise, on complementary metal-oxide semiconductor gate-driven mutually coupled multi-walled carbon nanotube interconnect lines, using MRTD method and conventional finite- difference time-domain (FDTD) model for 32-nm technology are executed. The results demonstrate the dominance of MRTD model over conventional FDTD in terms of accuracy with respect to recursive simulations of Synopsys HSPICE tool. An average error of less than 0.2% is observed in the estimation of dynamic crosstalk noise analysis. The proposed method is used to model interconnects with two and three mutually coupled lines and can be extended for N-coupled lines. The results of the transient analysis prove the efficiency of MRTD method over HSPICE with respect to computational time. The proposed method can also be used to address the issues of electromagnetic compatibility and electromagnetic interference of on-chip interconnects. Index Terms—Complementary metal-oxide semiconductor (CMOS), crosstalk, finite-difference time-domain (FDTD), HSPICE, multiresolution time-domain (MRTD), multi-walled car- bon nanotube (MWCNT). I. INTRODUCTION O NE of the traditional interconnect materials used in deep- submicron very large scale integrated (VLSI) circuits is copper (Cu). The scaling down of interconnect dimensions has made surface scattering and grain boundary scattering more prominent, resulting in increased resistivity of Cu material [1]. In addition to this, the skin effect, electromigration effect, low thermal and electrical conductivity, small mean free path (MFP), and limited current density also degrade the performance of an IC [2], [4]. Therefore, the requirements of new and reliable ma- terials for integrated circuit (IC) interconnects have increased. In the recent times, carbon nanomaterials such as carbon nan- otubes (CNTs) and graphene nanoribbons (GNRs) form one of the most promising candidates proposed as a substitute for Cu interconnects in advanced VLSI circuits [5], [6]. CNTs, with Manuscript received September 28, 2018; revised January 24, 2019; accepted February 21, 2019. (Corresponding author: Shashank Rebelli.) The authors are with the Department of Electronics and Communica- tion Engineering, National Institute of Technology, Warangal India (e-mail:, s.rebelli@gmail.com; nbr.rao@gmail.com). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TEMC.2019.2903728 their outstanding thermal and electrical properties, such as high melting point (3800 K), higher thermal stability, large MFPs, and the maximum current density (10 10 A/cm 2 ) outperform the conventional Cu interconnect [7]. Based on the physical properties, CNTs are classified into two types: single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs) [8], [9]. The MWCNTs have few concentric shells of rolled-up graphene sheets with their diameter ranging from few nanometers to tens of nanometers. Based on the chi- rality of graphene sheets, the SWCNT exhibits either metallic or semiconducting behavior, whereas the MWCNT exhibits only metallic behavior [6]. Due to the large diameter and consider- ing all the shells adequately connected to the metal contacts, MWCNTs have long electron MFPs and a great number of con- ducting channels compared to SWCNTs. Although the MWC- NTs provide similar current-carrying capability as SWCNTs, they are simpler to fabricate due to their greater control over the growth process [10]. Therefore, in the present state-of-the- art, MWCNT has been considered as interconnect to analyze the signal integrity issues of driver-interconnect-load (DIL) system. To analyze the signal integrity issues, such as functional crosstalk and dynamic crosstalk effects, the MWCNT intercon- nect is evaluated using an equivalent single conductor (ESC) model [11], [12]. In the recent past, for the analysis of the crosstalk effects in graphene-based interconnects, many models have considered a simple linear resistor as a replacement to the nonlinear CMOS (complementary metal-oxide semiconductor) driver [13], [15]. This leads to a discrepancy in the results as about half of the operating time of MOSFET is in the saturation region, whereas the other half is divided between the cutoff and the linear regions [16]. Several methods, such as analytical and SPICE solutions, have been proposed to model a DIL system as reported in [17]. However, in the present state of the art, most of the researchers rigorously studied the crosstalk effects based on the conventional finite-difference time-domain (FDTD) algo- rithm due to its accuracy [18], [26]. Li et al. [18] and Vob- ulapuram et al. [19] extended the FDTD method to a non- linear CMOS driver by considering α-power law model and n-th-power law model, respectively, to analyze the crosstalk effects in Cu interconnects. Agrawal and Chandel [20] have performed crosstalk analysis in current-mode signaling (CMS)- coupled resistance-inductance-capacitance (RLC) interconnects driven by a CMOS-gate driver using the FDTD model. 0018-9375 © 2019 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications standards/publications/rights/index.html for more information.