The electromigration and stress migration of Cu interconnects is significantly reduced by forming a composite capping layer comprising a layer of \u03b2-Ta on the upper surface of the inlaid Cu, a layer of tantalum nitride on the \u03b2-Ta layer and a layer of \u03b1-Ta on the tantalum nitride layer. The SCU also includes at least two electrodes coupled to means for delivering electrical stimulation to a patient within whom the device is implanted, and may also include a reservoir for holding one or more drugs and a driver means for delivering the drug to the patient. The toner container with this configuration surely prevents the developer from leaking when the developer container is dismounted from an image forming apparatus.