Electric-Field-Induced Mass Movement of Ge_2Sb_2Te_5 in Bottleneck Geometry Line Structures

摘要

We report an electric-field-induced directional mass movement of Ge_2Sb_2Te_5 in bottleneck geometry. Under high-electric-stress circumstances (>10~6 A cm~-2), a mass of Ge_2Sb_2Te_5 tends to move toward the cathode (—) by the remaining mass depletion at the anode (+). The high electric stress induces an asymmetric compositional separation such that Sb is distributed toward the cathode (—) whereas Te is distributed toward the anode (+). Ionicity in Ge_2Sb_2Te_5 at high temperature and high electric stress can be one of the origins of the asymmetric behavior. The electric-field-induced mass movement may provide insight on the device reliability of phase-change random access memory.