A method is presented for forming a semiconductor structure. The method includes depositing an insulating layer over a semiconductor substrate, etching the insulating layer to form trenches for receiving a metal, depositing one or more sacrificial layers, and etching portions of the one or more sacrificial layers to expose a top surface of the metal of one or more of the trenches. The method further includes selectively depositing an electrode over the top surface of the exposed metal and nitridizing the electrode to form a diffusion barrier between chip components and the metal.