The reactions in the Si/TaC/Cu and Si/Ta2N/Cu metallisation systems were investigated by x-ray diffraction, Rutherford backscattering, scanning electron microscope and the transmission electron microscopy. The results were then combined with the assessed ternary SiTa-C, Ta-C-Cu, Si-Ta-N and Ta-N-Cu phase diagrams. It was found that both barriers ultimately failed due to diffusion of Cu through ...