High-throughput nanogap formation is reported for simultaneous fabrication of integrated nanogap arrays. Ten series-connected nanogaps with butterfly and bottle shapes were integrated by using electromigration induced by a field emission current (“activation”). Initially, ten series-connected butterfly-shaped nickel (Ni) nanogaps were fabricated with electron-beam lithography and lift-off processes. Activation with a preset current of 300 nA reduced the separation of the gaps to <10 nm. Similar results for bottle-shaped nanogaps indicated that integration of nanogaps using activation is not dependent on nanogap shape. The activation method was also used for the mass production of 30 identical nanogaps. Overall, the distance between the Ni nanogap electrodes was completely controlled by activation.

Articles you may be interested inFabrication of planar-type Ni/vacuum/Ni tunnel junctions based on ferromagnetic nanogaps using field-emissioninduced electromigrationThe authors report on the ability to control the tunnel resistance of suspended Ni nanogaps by field-emission-induced electromigration. This method is called "activation." Suspended Ni nanogaps are ideal for investigating activation because the leakage currents flowing through the substrates are suppressed in these structures. The tips of suspended Ni nanogap electrodes are isolated from the SiO 2 substrates, so it is expected that the suspended Ni nanogaps act as isolated tunnel junctions during activation. After undergoing activation, the suspended Ni nanogaps clearly exhibited tunneling I-V properties. Furthermore, the authors were able to tune the tunnel resistance of the suspended Ni nanogaps using the activation method. When the applied voltage was swept, the device current switched between high-and low-resistance states. The results imply that activation is a viable method for modulating the electrical properties of suspended Ni nanogaps at the nanometer scale.

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