Controlled Growth of a Single Palladium Nanowire between Microfabricated Electrodes

We report a novel electrochemical method for dimensionally controlled growth of a single palladium nanowire between premicrofabricated electrodes. In this method, the dimensions of the nanowire are defined by the dimensions of the e-beam-patterned channel between the microfabricated gold electrodes. The formation of the nanowire is confirmed by both optical and scanning electron microscopy imaging in addition to the electrical measurement using the two terminal current-voltage (I-V) characteristics of the nanowire. Fabrication of a single localized palladium nanowire with controlled dimensions is demonstrated for 100 nm, 500 nm, and 1 (mu)m wide and 2.5 (mu)m long channels (length-to-diameter ratio ~2.5-25). The growth profile, confinement, resistance, and morphology of the nanowires were strongly influenced by the deposition conditions. A current of -100 nA was found to provide well-confined, stable nanowires with ohmic contact with the gold electrodes.