Contact resistances of carbon nanotubes grown under various conditions

This paper presents an in-depth electrical characterization of contact resistance between metal and vertically aligned carbon nanotubes (CNTs) grown under various conditions. Following the bottom-up approach of interconnect fabrication processes in the nanoelectronics industry, a via test structure to extract the contact resistance is designed and fabricated. The contact resistance is extracted by measuring the resistances of CNT vias with different lengths. The extracted contact resistance dominates the total resistance of CNT vias. Further, the interface between CNT and underlayer metal is investigated using XPS to elucidate the relationship between local electronic structure and contact resistance.