Ge ∕ Hf N x diffusion barrier for Cu metallization on Si

Abstract

The properties of Ge∕HfNx have been investigated relative to its use as a diffusion barrier for Cu metallization. The Ge∕HfNx bilayer was grown on p-Si (001) substrates by reactive sputtering, followed by in situ deposition of Cu. Individually annealed films at different temperatures (400–700°C, 1h) were characterized for evidence of Cu transport through the barrier bilayer to the Si substrate. The annealed structures were characterized by x-ray diffraction, energy-dispersive spectroscopy, and high-resolution transmission electron microscopy. The results indicate superior diffusion barrier properties of Ge∕HfNx for Cu metallization on Si compared to that for HfNx (7nm).