Abstract: A phase change memory cell includes an interlayer insulating layer formed on a semiconductor substrate, and a first electrode and a second electrode disposed in the interlayer insulating layer. A phase change material layer is disposed between the first and second electrodes. The phase change material layer may be an undoped GeBiTe layer, a doped GeBiTe layer containing an impurity or a doped GeTe layer containing an impurity. The undoped GeBiTe layer has a composition ratio within a range surrounded by four points (A1(Ge21.43, Bi16.67, Te61.9), A2(Ge44.51, Bi0.35, Te55.14), A3(Ge59.33, Bi0.5, Te40.17) and A4(Ge38.71, Bi16.13, Te45.16)) represented by coordinates on a triangular composition diagram having vertices of germanium (Ge), bismuth (Bi) and tellurium (Te).

Abstract: In a semiconductor memory device and a method of manufacturing the same, an insulating layer is formed on a substrate having a logic region on which a first pad is provided and a cell region on which a second pad and a lower electrode are subsequently provided. The insulating layer is etched to be a first insulating layer pattern having a first opening exposing the first pad. A first plug is formed in the first opening. The first insulating layer pattern where the first plug is formed is etched to be a second insulating layer pattern having a second opening exposing the lower electrode. A second plug including a phase-changeable material is formed in the second opening. A conductive wire and an upper electrode are formed on the first plug and the second plug, respectively.