Control of channel resistance on metal nanowires by electromigration patterning method

A simple method for fabricating nanoscale gaps between metal electrodes, based on the break of metal nanowires induced by electromigration of metal atoms, was investigated to control the channel resistance of the nanowires. In this article, the authors studied the control of the resistance of metal nanowires by introducing a constant-voltage (CV) mode and feedback-controlled electromigration (FCE) scheme. Ni nanowires were fabricated by electron-beam lithography on Si wafers coated with SiO2. The initial resistance of the nanowires was 0.8–1.2 kΩ. In CV mode, the channel resistance of 200-nm-wide nanowires was adjusted to be 10 kΩ, but nanowires with a width greater than 300 nm were not well controlled due to Joule heating. To improve the controllability of the channel resistance, they added the CV mode to the FCE scheme, based on resistance monitoring, to control the electromigration. This procedure created a nanogap with resistance ranging from a few-atom regime to a tunneling regime. These results impl...