Low resistivity 60 nm wide Cu wires were realized by the combination of lessening impurities through additive-free plating using high-purity plating materials and high-heating rate annealing. Resistivity values of Cu wires made with the new method were about 14% lower than those made by conventional plating with additives and high-heating rate annealing at the same temperature. The resistivity values were also found to be more than 50% lower than those for Cu wires made by plating with additives using low-purity plating materials (3N/4N) and by long-time annealing at low heating rate of 0.1 K/s in H-2 atmosphere. (C) 2013 The Electrochemical Society. All rights reserved.