Carbon Nanotubes Interconnects for Nanoelectronics Circuits

In this chapter, the electrodynamics of the conduction electrons on the surface of a generic CNT is described via a simple and physically meaningful model. The model is based on a semiclassical transport equation and describes the motion of the conduction electrons, seen as a fluid moving under the influence of the collective field and of the interaction with the fixed ion lattice. A frequency-domain constitutive equation is given, describing the electrical behavior of the CNT in terms of a nonlocal Ohm’s law. The conductivity is strongly influenced by two parameters, which account for the electron inertia and the quantum pressure. The conductivity, as well as all the most relevant parameters of the model, may be expressed in terms of the effective number of conducting channels, a parameter that counts the number of subbands significantly involved in the conduction. By coupling the above CNT constitutive equations to Maxwell equations, two different models are derived. The first is an electromagnetic model, to be used when analyzing the scattering properties of CNT, that is, when CNTs are intended as absorbing materials or as antennas. The second is a circuit model, derived in the frame of the TL theory, which allows easy analysis of the behavior of nanointerconnects made by bundles of CNTs.