Phase identification of self-forming Cu–Mn based diffusion barriers on p-SiOC:H and SiO2 dielectrics using x-ray absorption fine structure

X-ray absorption fine structure spectroscopy has been used to study the chemical and structural properties of self-forming diffusion barrier layers from Cu-8 at. % Mn alloy films on porous low-k and thermally grown SiO2 dielectrics. For the porous low-k/Cu(Mn) system, we provide evidence that the interface is composed of MnSiO3 and MnO with near complete Mn segregation from the alloy film; however, we find that the self-forming process does not go to full completion on thermally grown SiO2 substrates.