Influence of copper sputtering on thermal stability of ZrN diffusion barrier

Copper film was grown by DC pulsed unbalance magnetron sputtering (UBMS) on ZrN diffusion barrier film, previously deposited by RF reactive magnetron sputtering on Si wafer surface. The Cu films were then characterized with X-ray diffraction (XRD), Auger electron spectroscopy (AES) and atomic force microscopy (AFM). The results show that UBMS-Cu film effectively restricts Cu diffusion into silicon and improves thermal stability of Cu/ZrN/Si system because of the high compactness of the Cu/ZrN layers.