Control of microstructural phase distribution in Ge${}_2$Sb${}_2$Te${}_5$ phase change memory cells

Recently, phase change memory is one of highly developed memory products; however, further research is needed to manage intrinsic variations in switching voltage and resistance drift, which is crucial for high density memory development. Current–voltage characteristics, their temperature dependence, and voltage‐dependent resistance switching characteristics at various programming times are investigated. These data provide an indirect characterization of microstructural phase distribution in the phase change material during memory operations. Subthreshold current–voltage symmetry in phase change memory cells can be used for identifying filamentary or non‐filamentary conducting paths, both of which are controllably formed by adjusting the programming time. This work may contribute to an improved operation method to mitigate intrinsic variations in phase change memories. (© 2019 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)