An efficient and novel FDTD method based performance investigation in high-speed current-mode signaling SWCNT bundle interconnect

Abstract

Carbon nanotube (CNT) has emerged as the most extensively researched area in nanoscience and amongst the frontrunners in co-triggering the nanotechnology revolution. Single-wall CNT (SWCNT) bundle is a part of CNT family and has been proposed as the future nano-wires in integrated circuits. The present paper analyzes the performance of SWCNT bundle interconnect with high-speed current-mode signaling (CMS) scheme using efficient finite-difference time-domain (FDTD) method. For the first time, FDTD based method is explored for modeling CMS SWCNT bundle interconnect incorporating practical CMOS driver gate. The CMOS gate is characterized by nth power-law model. The stability of FDTD method is ascertained by Courant condition. The proposed FDTD based method is efficient and can be used for performance analyses of future nano-wire SWCNT bundle as well as conventional copper interconnects. At the same time, this method is applicable for both traditional full-voltage swing voltage-mode signaling (VMS) and remarkable low-voltage swing CMS schemes. The various analyses in the paper reveal that CMS SWCNT bundle interconnect has higher edge over CMS copper interconnect in terms of smaller delay, lesser crosstalk induced delay and noise. The proposed analytical FDTD based method is validated using Tanner-SPICE EDA simulation tool. The maximum error between the FDTD and SPICE for the transient response in CMS SWCNT bundle interconnect for 32 nm technology node is within 3%.