Nano-structure-controlled very low resistivity Cu wires formed by high purity electrolyte and optimized additives

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