Protection of Cu from Oxidation by Ta Capping Layer

X-ray reflectometry (XRR) and photoelectron spectroscopy (XPS) measurements (core levels valence bands) were made of Cu thin films that prepared coated by capping Ta layers with different thicknesses (5, 10, 15, 20, 30 Å), are presented. The XRR XPS 4f-spectra revealed a complete oxidation the protective layer up to thickness 10 Å. From 15 Å, pure Ta-metal line appeared in 4f-spectrum, contribution which increased 2p-spectra underlying copper formation CuO Ta-layer Starting from protection against was ensured during exposure ambient atmosphere.