Improved RF Characteristics of Carbon Nanotube Interconnects with Deposited Tungsten Contacts

A.A. Vyas, F. Madriz, N. Kanzaki, P. Wilhite, J. Tan, T. Yamada, C.Y. Yang
Santa Clara University, US

Keywords: carbon nanofiber, tungsten, RF characteristics


Carbon Nanofibers (CNFs) grown by Plasma Enhanced Chemical Vapor Deposition (PECVD) are potential next-generation interconnect materials due to their high current capacity. We designed and fabricated a test structure for RF characterization of CNF interconnects up to 50 GHz and developed a compact circuit model based on their results. Their devices showed that the contact impedance between the CNF and the electrode contacts can be reduced to some extent by Joule heating from dc current stressing, and can be further improved if a suitable metal is deposited on the electrode contacts. we fabricated CNF interconnects with Au electrodes, and deposit W at the contacts. W deposits are produced by two techniques: Electron Beam Induced Deposition (EBID) with WF6 as the source gas, and Ion beam Induced Depositions (IBID). The electrical characteristics of these CNF interconnect test devices obtained with these two methods are compared from dc up to 50 GHz and the circuit parameters including the contact impedance are extracted.