Accurate analysis of carbon nanotube interconnects using transmission line model

Abstract

A new technique for analysing the time-domain response of carbon nanotube (CNT) interconnects, based on transmission line modelling, that takes the effects of both contact and fundamental (quantum) resistances into account is introduced. A new sixth-order linear parametric expression for the transfer function of these lines has been presented for the first time. For verification purposes, the step response of a driver–CNT bundle–load configuration for a 32 nm technology node, using the new technique and HSPICE simulation have been compared, with which the obtained results show an excellent match. Also the effect of contact resistance on the step response, especially the propagation delay, has been studied. The obtained results show that for the length of a CNT bundle equal to 50 µm with the diameter of each individual CNT 1 nm, the propagation delay changes from 0.138 to 5.58 ns for the contact resistance values from 1 to 50 kΩ, i.e. a variation range of 39.43 times the minimum value. The related delay variations for the length values 200 µm, 500 µm and 1000 µm, are 31.37, 22.61 and 15.42 times the minimum value, respectively.