Low‐Power Crystallization Process in In3SbTe2 Phase Change Memory Devices with Thin Oxide Layer

Abstract

Phase change memory (PCM) technology is a strong contender for the next‐generation memory in today's data‐centric era. In3SbTe2 (IST) phase change material is recently explored due to its good thermal stability, rapid electrical switching, and significant resistance contrast for multibit storage. However, the main concern in PCM devices is the high‐energy usage during the phase switching process. Herein, a thin oxide (HfO2) layer is inserted between the IST active layer and bottom electrode in PCM device. Such a device exhibits amorphous‐to‐crystalline phase switching (crystallization or SET operation) at a lower voltage of (2.1 ± 0.1) V and 66% reduction in energy consumption compared to the device using only IST active layer. Higher temperature of 688 K is acquired in the device with the oxide layer demonstrating that the Joule heat is effectively confined by the oxide layer assisting the crystallization process in the active layer at a less voltage. Such a device also exhibits a significant resistance contrast of ≈2 orders magnitude, allowing for stable data storage. These results reveal that the switching performance of PCM device using IST phase change material is improved by the oxide layer, which is beneficial for energy‐efficient, nonvolatile data storage applications.