Improvement of electromigration reliability and diffusion of Cu films using coherent Cu(1Â 1Â 1)/Cr2O3(0Â 0Â 0Â 1) interfaces

► Cu/Cr2O3 with O-terminated interface is more stable than that with Cr-terminated one. ► The Cu-O interfaces are much stronger than the back Cu-Cu interlayers. ► Cr2O3(0 0 0 1) films greatly enhance the bonding strength at the interfaces. ► Cu atoms can hardly diffuse into the Cr vacancies. ► Cr2O3(0 0 0 1) films inhibit the diffusion of Cu atoms into the barrier layer.