Characterization of Ge22Sb22Te56 and Sb-excess Ge15Sb47Te38 chalcogenide thin films for phase-change memory applications

A phase-change memory device that utilizes an antimony (Sb)-excess Ge15Sb47Te38 chalcogenide thin film was fabricated and its electrical properties were measured and compared with a similar device that uses Ge22Sb22Te56. The resulting electrical characteristics exhibited I-reset values of 14 mA for Ge22Sb22Te56 and 10.6 mA for Ge15Sb47Te38. Also, the set operation time (t(set)) for the device using Ge15Sb47Te38 films was 140 ns, which was more than twice as fast as the Ge22Sb22Te56 device. The relationship between the microstructure and the improved electrical performance of the device was examined by means of transmission electron microscopy (TEM).