Modeling and Simulation of Carbon Nanotube Interconnect Network

The electrical properties of metallic carbon nanotubes (CNT) can rival, or even exceed, the best metals known. It is a potential candidate for future on-chip interconnect, whose performance will be dominant in the next generation integrated circuits. In this paper, a study on the modeling and simulation techniques for the CNT interconnect network is carried out. The frequency-independent models of CNT interconnects in terms of resistance, inductance and capacitance are summarized. A novel frequency-dependent circuit model is proposed for CNT for various high-frequency applications. Preliminary analysis shows a good match between numerical simulations and the compact model. The proposed modeling and simulation techniques for CNT interconnect network are expected to play an important role in the future CNT nanotechnology applications. Introduction Carbon nanotubes (CNTs) were discovered in 1991 by Sumio Iijima while working at NEC Research Laboratories in Tsukuba, Japan [1]. Since the discovery of carbon nanotubes, there has been intense activity exploring the electrical properties of these systems and their potential applications in electronics [2, 3]. Experiments and theories have shown that the electrical properties of carbon nanotubes can rival, or even exceed, the best metals and semiconductors known. Thus, the carbon nanotube-based electrical circuits are very promising for the next-generation of VLSI industry [2-5]. There exist two kinds of carbon nanotubes. Multiwall nanotubes (MWCNTs) are more common and are rolled-up stacks of graphene sheets in concentric carbon nanotubes. A single-wall carbon nanotube (SWCNT) is a rolled-up shell of graphene sheet made of benzene-type hexagonal carbon rings. SWCNT technology shows significant promise in acting as both transistors and interconnects in future generations of VLSI circuits. Compared with the conventional metal interconnections, SWCNTs can sustain a high current density without electro-migration problem. In this manner, it shows a great potential for electronic applications. In addition, the SWCNTs also overcome the high-resistance problem, often existing when the conventional metal interconnections are scaled down [3, 4]. The RLC circuit model of SWCNTs has been recently established and the equations of parameters in the circuit model have been given [5]. Yet, so far, most of the equations are frequency-independent. In various high-frequency applications, the frequency-dependent impedance models are much useful. The goal of this paper is to express the RLC parameters as a function of frequency based on existing circuit model and the experimental results [3, 4]. Therefore, new frequency-dependent models for R, L, C of SWCNT interconnects are derived for high-frequency applications. …