Diffusion barrier performance of W/Ta–W–N double layers for Cu metallization

In this work, the properties of Cu/W/Ta–W–N/Si film stacks were studied. Adding a thin W layer to a stable Ta–W–N diffusion barrier significantly affected the whole metallization system. The introduction of a thin W interlayer caused a significant change of the system while increasing the stability of the film. The tandem barrier was demonstrated to be stable up to 800 °C by the performed analytical barrier tests.