Abstract: Disclosed is a metal-metal oxide resistive memory device including a lower conductive layer pattern disposed in a substrate. An insulation layer is formed over the substrate, including a contact hole to partially expose the upper surface of the lower conductive layer pattern. The contact hole is filled with a carbon nanotube grown from the lower conductive layer pattern. An upper electrode and a transition-metal oxide layer made of a 2-components material are formed over the carbon nanotube and the insulation layer. The metal-metal oxide resistive memory device is adaptable to high integration and operable with relatively small power consumption by increasing the resistance therein.

Abstract: An integrated circuit device includes a storage cell including an upper electrode and a lower electrode on a substrate, and a conductive hard mask pattern directly on the upper electrode of the storage cell opposite the lower electrode. The upper electrode is formed of a metal softer than the conductive hard mask pattern. The device further includes an interlayer on the substrate having an alignment key recess therein. The alignment key recess extends towards the substrate beyond a depth of the upper electrode. An alignment key pattern may extend towards the substrate beyond the depth of the upper electrode on opposing sidewalls and on a surface therebetween of the alignment key recess. The alignment key pattern may have a distinct step difference between portions thereof on the opposing sidewalls and portions thereof on the surface therebetween. Related methods are also discussed.