An investigation was made of the critical voltage for electromigration in atomic-scale Cu nanojunctions by using electromigration spectroscopy. The critical voltage was determined to be 0.35V from the peak of the obtained electromigration spectrum, which was close to the atom diffusion potential for clean Cu surfaces. It was also demonstrated that ballistic Cu nanojunctions could support current densities on the order of 10GA/cm2, as long as the junctions were biased below the critical voltage. The results suggested that both high current densities and high electromigration reliabilities could be achieved when the dimension of the metal interconnects was reduced to several tens of atoms.

Critical Voltage for Atom Migration in Ballistic Copper Nanojunctions and Its Implications to Interconnect Technology for Very Large Scale Integrated Circuits. S.Sakata, A.Umeno, K.Yoshida, K.Hirakawa: Applied Physics Express, 2010, 3[11], 115201