W-deposited contacts with carbon nanofiber using focused ion and electron beams

Carbon nanofiber (CNF) is promising as a next-generation on-chip interconnect material. Understanding the temperature dependence of CNF resistance is important in evaluating its potential for such interconnect applications. In a CNF test device, contacts formed by tungsten (W) deposition using focused ion beam (FIB) is effective in minimizing the effect of unwanted parasitics, thus yielding a more accurate determination of the temperature dependence. However, FIB deposition can potentially damage devices because of its high energy. We propose to use a gas-injection system for low-energy electron-beam deposition with fine precision in a variable-pressure scanning electron microscope. The results of W-deposited CNF devices obtained using electron beam (e-beam) are compared with their FIB counterparts.