Effect of interface layer on growth behavior of atomic-layer-deposited Ir thin film as novel Cu diffusion barrier

► Growth and nucleation behavior of Ir films grown by ALD on different interfacial layers were investigated. ► The Ir film grown on the 3-nm-thick TaN surface showed the smoothest and most uniform layer for all the deposition cycles. ► Poor nucleation and three-dimensional island-type growth of the Ir layer were observed on Si, SiO2, and surface-treated TaN. ► Growth behavior of the Ir layer on different interface layer is related to the chemical bonding pattern of interface layer.