Diffusion barrier performance of chemically vapor deposited TiN films prepared using tetrakis-dimethyl-amino titanium in the Cu/TiN/Si structure

We investigated diffusion barrier performance of chemical vapor deposition (CVD) TiN films prepared using tetrakis-dimethyl-amino titanium, Ti[N(CH3)2]4, to copper in the Cu/TiN/Si structure. The in situ treatment of the TiN films using N2/H2 plasma was found to significantly improve barrier performance against copper diffusion. The plasma-treated TiN films were stable up to 650 °C but as-deposited TiN films showed an evidence of copper diffusion into silicon even after annealing at 550 °C. The causes of the different effectiveness as a copper diffusion barrier of the two types of the CVD TiN films were discussed.