Fabrication of First-Level Carbon Nanotube Interconnect Via Structures by Thermal Chemical Vapor Deposition

As devices continue to scale down to the 50 nm technology node, current Cu/low k interconnect technology will face a number of challenges including reduced current carrying capabilities, decreased thermal conductivity, and reliability problems due to electromigration at large current densities. Carbon nanotubes (CNTs) with their unique structural, thermal and electrical transport properties have been suggested as a promising candidate as interconnect structures for future microelectronics. In this study we have demonstrated the growth of vertically aligned, highly dense CNT arrays by thermal chemical vapor deposition (CVD). It was found that a thin layer of tantalum (Ta), which was originally used as the barrier layer in copper interconnects, may enhance a uniform growth and better vertical alignments of CNT arrays. We have also developed a nanofabrication process of the first-level CNT via structures.