NITROGEN-RICH TITANIUM NITRIDE SERVING as Pt-Al DIFFUSION BARRIER FOR FeRAM APPLICATION

Nitrogen-rich titanium nitride thin films are prepared by reactive sputtering using a Ti target. Distinctively, there is only N2 introduced in the reaction chamber. The obtained thin films show (111) and (200) peaks of titanium nitride, with a titanium to nitrogen ratio of 1:1.8. When applied into Pt-Al interface, such a nitrogen-rich titanium nitride layer has prevented the diffusion of Al into Pt during 450°C forming gas annealing. The contact resistance of Al/TiN x /Pt multi-structure is low enough for integrated circuit applications. While the fabrication technique of nitrogen-rich titanium nitride is simple, it still serves as a good diffusion barrier.