Applications of High Diffusion Resistance Multi‐component AlCrTaTiZrRu/(AlCrTaTiZrRu)N_0.7 Film in Cu Interconnects

Herein, a multi‐component AlCrTaTiZrRu/(AlCrTaTiZrRu)N_0.7 double‐layer structure is prepared by direct current (DC) magnetron sputtering as a diffusion barrier for Cu interconnection. To verify the diffusion‐barrier properties at high temperatures, the Cu/AlCrTaTiZrRu/(AlCrTaTiZrRu)N_0.7/Si structures are annealed at 700–900 °C for 30 min in high vacuum. The barrier layer remains amorphous with few nanocrystalline structures after annealing at 800 °C. Cu particle agglomeration begins to appear on the surface, but no Cu‐silicide compound is found on the Si substrate, indicating that the layer can effectively defer the interdiffusion of Cu and Si. Under annealing at high temperature of 900 °C, Cu silicides and other intermetallic compounds are formed on the surface of the Cu film, with the film resistivity increasing significantly, indicating that the AlCrTaTiZrRu/(AlCrTaTiZrRu)N_0.7 double‐layer structures have completely failed.