Nano-Structure-Controlled Very Low Resistivity Cu Wires Formed by High Purity and Optimized Additives

Resistivity increase in nano-level Cu wires is becoming a critical issue for high speed ULSIs. We have established a new manufacturing process utilizing very high purity 9N electrolyte and optimized additives to control nano-structures of Cu wires, and we realized Cu wires for practical use with 50% lower resistivity than those made with the conventional process. Using STEM analyses and phase field simulation, we also ascertained the reason for getting the very low resistivity Cu wires.