Diffusion barrier performance of Zr-N/Zr bilayered film in Cu/Si contact system

Zr-N/Zr bilayered film as a diffusion barrier between Cu and Si is evaluated. The thermal stability of the diffusion barrier is investigated by annealing the Cu/Zr-N/Zr/Si samples in N-2 for an hour. XRD, SEM and AES results for the above contact systems after annealing at 700 degrees C show that Cu film has preferential (111) crystal orientation and no diffraction peaks of Cu3Si and a Cu-Zr-Si ternary compound are observed for all Cu/Zr-N/Zr/Si contact systems. In addition, the atomic distribution of Zr and Si is evident and grows with increasing temperature up to 700 degrees C, which corresponds to the Zr-Si phase having low contact resistivity. Low contact resistivity and high thermal stability diffusion barrier can be expected by the application of the Zr-N/Zr bilayered film as a diffusion barrier between Cu and Si. (C) 2008 Published by Elsevier Ltd.