Research On Electrical Characteristics Of Carbon Nanotube Interconnects

When the feature size of interconnects shrinks into nanoscale in integrated circuit (IC), copper (Cu) wire will be challenged seriously. It is necessary to search a new interconnect material for IC chips. Since carbon nanotube (CNT) has been found, there are many interconnect advantages for interconnects. It has been suggested as next-generation interconnect material to replace Cu wire. Under such backgrounds, in order to implement its interconnect applications, we must explore its electrical characteristics.In this paper, electrostatic capacitance of each individual CNT in the bundle will be extracted by analytical software of electromagnetic field based on the equivalent circuit of distributed parameter. The total electrostatic capacitance of the bundle by approximate formula is larger than that of this method, which will affect the results and cannot calculate electrostatic capacitance of each individual CNT in the bundle. The ratio of electrostatic capacitance in the bundle becomes larger with the decrease of technology nodes. The electrical performances are affected by electrostatic capacitance obviously. Therefore, electrostatic capacitance should be extracted accurately for CNT interconnects, On this basis, the electrical characteristics are studied as follows:The electrical characteristics of single-walled CNT (SWCNT) are analysed. The in?uences of the length, diameter and contacting resistance on the stability, crosstalk and latency of SWCNT interconnects are discussed respectively, especially proposing several approaches of the stability analysis in frequency domain. Bode diagram reflecting the frequency performance of interconnect system is adopted to analyse the stability of CNT interconnects, which can display the stable margin clearly and give the quantitative analysis of the electrical stability. It is beneficial for the analysis of CNT interconnect performances in high frequency. The length, diameter, contacting resistance and packing density dominate the electrical characteristics of CNT interconnects for the practical applications.The electrical characteristics and equivalent circuit of multi-walled CNT (MWCNT) are analysed based on those of SWCNT. The relations between the electrical characteristics and the length, diameter, contacting resistance and packing density are discussed respectively. The electrical performances of MWCNT interconnects are better than those of SWCNT interconnects by comparations.