Deposition and characterization of electroless Ni–Co–P alloy for diffusion barrier applications

Electroless deposited NiP and NiCoP thin films were studied for their diffusion barrier properties for copper wiring in ultra-large scale integration (ULSI) technology. The thermal stability of the Si/NiP/Cu and Si/NiCoP/Cu structures was evaluated by X-ray diffractometer (XRD), four probe method and field emission-scanning electron microscope (FE-SEM). Results indicated that both structures, i.e. Si/NiP/Cu and Si/NiCoP/Cu are thermally stable up to 500 °C. Further annealing results in formation of various silicided phases.