Sacrificial removal of caps of aligned carbon nanotubes for interconnect application

Single-walled (SW) and multi-walled (MW) carbon nanotubes (CNTs) have excellent electrical, mechanical and thermal properties. They are considered as promising materials for future interconnect applications. MWCNTs are concentric rolls of graphene sheets. As-grown MWCNTs are typically close-ended, so the inner shells cannot be contacted to the metal electrodes and have limited contribution to the electrical conductance. Open-ended MWCNTs are preferred for interconnect applications to meet the conductance requirement. In this paper, a simple sacrificial process was developed to truncate CNTs. CNT vias were fabricated and a sacrificial process was employed to remove the CNT caps. Resistance of vias with open-ended and close-ended MWCNTs was measured using two-terminal voltage-current measurement. Via conductance was significantly increased after the MWCNTs in the vias were truncated to be open-ended using the sacrificial process.