Overview of Carbon Nanotube Interconnects

Abstract

At present, electronic information technology has become an important drive force that promotes social and economic progress. Integrated circuit (IC) as a core and foundation of the electronic information technology has a great influence on the daily life of human being. The semiconductor technology and IC industry have become an important symbol to embody a country’s comprehensive scientific and technological capability. In order to improve circuit’s performance and increase number of transistors on a chip, microelectronic devices have been continuously reduced in dimension according to Moore’s law [1] and scaling rule [2]. According to the 2013 International Technology Roadmap for Semiconductors (ITRS 2013), the feature size of semiconductor devices will reduce to 22 nm in 2016 and 10 nm in 2025 [3] in very large scale integrated (VLSI) circuits. For the first generation interconnect material aluminum (Al) [4], an increase in electric resistance and capacitance due to increasing wire length and decreasing wire interval as dimension scales down had led to large signal delays [5] and poor tolerance to electromigration (EM) [6]. Because of its lower resistivity, higher melting point (1083 °C versus 660 °C of Al), and longer EM lifetime [7], copper (Cu) has replaced Al as an interconnect material in the 180 nm technology node [8] and beyond. But as interconnects scale down to the 45 nm and beyond technology generations, Cu interconnect is also facing similar problems with those of Al interconnects encountered, including increase in resistivity due to size effect [9], increase in power consumption [10], delay [11], and EM distress [12].