Influence of feedback parameters on resistance control of metal nanowires by stepwise feedback-controlled electromigration.

We propose a stepwise feedback-controlled electromigration (SFCE) approach to control the channel resistance of metal nanowires at room temperature. SFCE procedure finely divides a conventional feedback-controlled electromigration (FCE) scheme into several FCE cycles. This approach effectively removes thermal instability caused by large current passing through a metal nanowire, because process time of each FCE cycle can be successfully reduced. Using the SFCE approach, a wide-range control of the channel resistance of Ni nanowires was achieved ranging from the order of 10(2) omega to 10(5) omega at room temperature, without catastrophic breaks of the nanowires. Furthermore, total process time of the SFCE procedure was considerably shortened without degradation of the controllability of the resistance of the nanowires. The channel resistance of a Ni nanowire was precisely controlled from 0.2 to 600 k(omega) for 20 min at room temperature, which is 3000 times larger than the initial resistance of the channel. These results clearly indicate that a wide-range control of the channel resistance of metal nanowires can be achieved with a shortened process time using SFCE scheme.