Phase Change Heterostructure Memory with Oxygen‐Doped Sb2Te3 Layers for Improved Durability and Reliability through Nano crystalline Island Formation

Phase‐change random access memory represents a notable advancement in nonvolatile memory technology; however, it faces challenges in terms of thermal stability and reliability, hindering its broader application. To mitigate these issues, doping and structural modification techniques such as phase‐change heterostructures (PCH) are widely studied. Although doping typically enhances thermal stability, it can adversely affect the switching speed. Structural modifications such as PCH have struggled to sustain stable performance under high atmospheric conditions. In this study, these challenges are addressed by synergizing oxygen‐doped Sb2Te3 (OST) with PCH technology. This study presents a novel approach in which OST significantly improves the crystallization temperature, power efficiency, and cyclability. Subsequently, the integration of the PCH technology bolsters the switching speed and further amplifies the device's reliability and endurance by refining the grain size (≈7 nm). The resultant OST‐PCH devices exhibit exceptional performance metrics, including a drift coefficient of 0.003 in the RESET state, endurance of ≈4 × 108 cycles, an switching speed of 300 ns, and 67.6 pJ of RESET energy. These findings suggest that the OST‐PCH devices show promise for integration into embedded systems, such as those found in automotive applications and Internet of Things devices. To improve the thermal stability and reliability of Sb2Te3‐based phase‐change random access memory, oxygen doping is synergized with PCH technology. This approach utilizes oxygen doping for enhanced thermal stability and crystallization control, and PCH application to refine grain size to the nanoscale. The electrical characteristics of devices are compared based on the effect of PCH.