Abstract
A simple method for controlling the tunnel resistance of nanogap electrodes, based on electromigration induced by field emission current, is presented. In this study, we investigated the controllability of the tunnel resistance of nanogap electrodes by only adjusting the applied current. Initial planar nanogaps of Ni, typically separated by 22–44 nm, were fabricated on SiO2/Si substrates by electron-beam lithography and lift-off process. Then, a current was passed through the nanogaps at room temperature. By increasing the current from about 1 nA to 30 µA, the resistance of the nanogaps decreased, ranging from 100 TΩ to 10 MΩ. This result implies that this technique can simplify the fabrication of planar-type tunnel junction devices.