Multi-layered film stack models to simulate X-ray reflectivity of TaN and Ta thin films

X-ray reflectivity (XRR) study is performed on single and multi-stacked TaN/Ta thin films. A model using single or multiple layers for TaN and Ta gives a good fit between the experimental and simulation results. The effect of PVD etch-back process on the density of Ta and TaN films is discussed in the paper.