Embodiments of a semiconductor device having storage nodes include an interlayer insulating layer disposed on a semiconductor substrate; a conductive pad disposed in the interlayer insulating layer to contact with a predetermined portion of the substrate, an upper portion of the conductive pad protruding above the interlayer insulating layer; an etch stop layer disposed on the conductive pad and the interlayer insulating layer; and storage nodes penetrating the etch stop layer and disposed on the conductive pad. A penetration path of wet etchant is completely blocked during the wet etch process that removes the mold oxide layer. Therefore, inadvertent etching of the insulating layer due to penetration of wet etchant is prevented, resulting in a stronger, more stable, storage node structure.