Improvement of Zr-N Diffusion Barrier Performance in Cu Metallization by Insertion of a Thin Zr Layer

Abstract

In order to increase the failure temperature of Zr-N diffusion barrier for Cu, the effect of insertion of a thin Zr layer into Zr-N film on Zr-N diffusion barrier performance in Cu metallization was investigated by means of X-ray diffraction, scanning electron microscopy, Auger electron spectroscopy, and 4-point probe technique. XRD,SEM ,AES and FPP results show that the insertion of a thin Zr layer into Zr-N film improves barrier properties significantly when the ZrN / Zr/ZrN barrier layers are deposited by RF reactive magnetron sputtering and Zr-N(10nm)/Zr (5nm)/Zr-N(10nm) barrier tolerates annealing at 700°C for 1 h without any breaking and agglomerating Cu film. This interpretes that insertion of a thin Zr layer into Zr-N film is attributed to the densification of grain boundaries in ZrN/Zr/ZrN films followed by the reduction of fast diffusion of Cu through ZrN /Zr/ ZrN multilayered films.