Integration of Vertical Carbon Nanotube Bundles for Interconnects

Abstract

Carbon nanotubes (CNTs) are considered a promising material for interconnects for future generation microchips. The integration of vertical CNT in a processing environment is evaluated in this work. Extrapolated performances of CNT-based interconnects are compared with existing technologies at different hierarchy levels including the limitations of present deposition methods for copper and tungsten. For practical implementation, CNT bundles were selectively grown into contact holes using physical vapor deposited and electrochemical deposited cobalt or nickel catalysts. A polishing step was used to control the CNT length after embedding the CNT into an oxide matrix. A CNT metal decoration method based on electrodeposition is presented, which can be used to assess the yield of electrically conductive CNT as well as to form top contacts for electrical characterization. Finally, the importance of having suitable and robust structures for evaluating the integration process is highlighted after the electrical characterization of CNT in a nanoprober station.