Preparation and properties characterization of gradient α-Ta(N)/TaN bi-layer diffusion barrier

An ultra-low nitrogen atmosphere strategy of magnetron sputtering deposition with dynamic regulation of sputtering atmosphere was developed to prepare gradient α-Ta(N)/TaN bi-layer films, which have lower resistivity and high thermal stabilization. This deposition method can avoid effectively the high resistivity of bi-layer barrier films resulted from the N integration and the introduction of heterogeneous elements for the transformation of α-Ta phase. X-ray diffraction spectra (XRD), Four-point probe (FPP) measurement and Transmission electron microscopy (TEM) were used for characterization of the film microstructure. The results show that the as-deposited gradient α-Ta(N)/TaN bi-layer films have lower resistivity and good crystallinity, and the gradient α-Ta(N)/TaN bi-layer films have good structure stability even annealed at 600°C for 60 min in vacuum.