Phase change memory cell employing a gebite layer as a phase change material layer, phase change memory device including the same, electronic system including the same and method of fabricating the same

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 (A(Ge, Bi, Te), A(Ge, Bi, Te), A(Ge, Bi, Te) and A(Ge, Bi, Te)) represented by coordinates on a triangular composition diagram having vertices of germanium (Ge), bismuth (Bi) and tellurium (Te). The doped GeBiTe layer contains an impurity and has a composition ratio within a range surrounded by four points (D(Ge, Bi, Te), D(Ge, Bi, Te), D(Ge, Bi, Te) and D(Ge, Bi, Te)) represented by coordinates on the triangular composition diagram.