Abstract: Methods of forming capacitors in memory devices include the steps of forming a first electrically insulating layer having a first conductive contact plug therein, on a semiconductor substrate, and then forming a first diffusion barrier pattern in electrical contact with the first conductive contact plug. A second electrically insulating layer having a contact hole therein is then formed on an upper surface of the first diffusion barrier pattern, to inhibit parasitic oxidation of the first diffusion barrier pattern. A lower electrode of a capacitor is then formed on the second electrically insulating layer. The lower electrode is electrically coupled to the first diffusion barrier pattern and may contact the first diffusion barrier pattern directly or may be coupled through a second diffusion barrier pattern to the first diffusion barrier pattern. A dielectric layer and upper electrode are then formed on the lower electrode.