Integrated circuit memory devices having memory cells therein that utilize phase-change materials to support non-volatile data retention

摘要

An integrated circuit memory device includes a semiconductor substrate and a first electrically insulating layer that extends on the semiconductor substrate and has a first contact hole extending therethrough. An electrically conductive plug is provided in the first contact hole. A phase-change material layer pattern is provided as a non-volatile storage medium. The phase-change material layer pattern has a bottom surface that is electrically connected to the electrically conductive plug. A second electrically insulating layer is provided on the phase-change material layer pattern. The second electrically insulating layer has a second contact hole therein. This contact hole exposes a portion of an upper surface of the phase-change material layer pattern. To improve data writing efficiency, the area of the exposed portion of the upper surface of the phase-change material layer pattern is less than a maximum cross-sectional area of the electrically conductive plug. A plate electrode is also provided. This plate electrode is electrically connected to the phase-change material layer pattern. Barrier layers may also be provided directly on the plug and directly on the exposed portion of the upper surface.