As logic components shrink below 45 nm, the performance of VLSI chips are becoming increasingly limited by the interconnects which transport clock, power, and ground. Current copper interconnects cannot supply the required current densities without suffering from significant thermomechanical and electromigration reliability issues at such small scales. In the 2009 International Technology Roadmap for Semiconductors , electrically contacted bundles of carbon nanotubes (CNTs)  were touted as a viable replacement technology because of their high current-carrying capacities, heightened thermal conductivity, and enhanced resistance to electromigration. While many researchers have focused on improvements to fabrication techniques, the electrical reliability of CNT-based interconnects has been largely overlooked despite their known sensitivities to material and process variability. In the current work, we electrically test hundreds of dielectrophoretically self-assembled CNT interconnect devices. We demonstrate that CNTs can sustain high currents densities (>1 MA/cm2) for long periods of time (70+ h), but these CNT-based interconnect devices do eventually degrade over time. Under specific electrical stressing, we uncover a unique CNT failure mode, where the CNT appears physically intact but nonetheless nonconducting, that is strikingly different from the well-documented failure due to localized oxidation and resistive heating. We also find that even minimal exposure to the scanning electron microscope (SEM) beam can damage, at least temporarily, our CNT interconnect system as conductivities decrease by an order of magnitude or more, depending on exposure amount. We found the CNT device could revert to its pristine state after long periods of dormancy or with large voltage biases, we could actively repair the CNT device, a result that suggests the presence of removable trapped charges  and highlights the susceptibility of the many CNT reliability issues. Most importantly, we demonstrate that metal electrodes such as Au at the CNT-metal electrode interface can fail through void formation as large as 300 nm in diameter. We empirically determine the threshold current (¼ 1:5 mA) that is required for the formation of these voids and accompanying hillocks, which typically grow near the CNT-Au electrode interfaces where high contact resistance and potential current crowding may lead to either localized melting, thermomigration, and/or electromigration. This alarming result suggests the impressive thermal-electro-mechanical capabilities of CNTs may be underutilized in CNT-based interconnects unless all components, including the metal electrodes are thoughtfully designed for optimal performance and reliability.  “International technology roadmap for semiconductors,” Semiconductor Industry Association, San Jose, CA, 2009. <http://public.itrs.net>,  J.-H. Ting, C.-C. Chiu, and F.-Y. Huang, “Carbon nanotube array vias for interconnect applications,” J. Vac. Sci. Technol. B, vol. 27, pp. 1086–1092, 2009.  C. W. Marquardt, S. Dhem, A. Vijayaraghavan, S. Blatt, F. Hennrich, and R. Krupke, “Reversible metal-insulator transitions in metallic singlewalled carbon nanotubes,” Nano Lett., vol. 8, pp. 2767–2772, 2008.