Ultrafast Threshold Switching Dynamics in Phase-Change Materials

Discovery of electrical switching in chalcogenide glasses by S.R. Ovshinsky paves a new path for developing high-speed nonvolatile electronic memory and high-performance computing solutions. This article presents a review on the systematic understanding of threshold switching (TS) properties in various chalcogenide materials, Ovonic threshold switching (OTS) and Ovonic memory switching (OMS), the nature of TS, voltage-dependent transient characteristics, and the role of TS in governing the programming speed based on research efforts over the last six decades. Furthermore, realization of TS in picosecond timescale, the commonalities between OTS and OMS, and the possible underlying mechanism has been explored. Furthermore, a scheme of material classification based on TS dynamics for ultrafast yet energy-efficient programming has been proposed for phase-change memory with SRAM-like programming speed for future electronics.