the present invention provides a method for fabricating a capacitor , comprising the steps of forming a trench in a substrate , forming a layer of a first material selected from the group consisting of titanium and titanium nitride in the trench , filling the trench with a conductive material to form a plug , planarizing the substrate , patterning the substrate to expose the first material , forming an electrode material layer over the substrate , and patterning the electrode material layer , whereby the first material is substantially encapsulated by the electrode material layer .