Three-Dimensional Restricted C/C–Sb₂Te Heterostructure for Phase-Change Memory Applications

Conventional single-layer phase-change film in phase-change memory (PCM) tends to form large grains during phase transition, resulting in reduced operation speed, endurance, and increased resistance drift, density change. In this work, we propose a carbon/carbon-doped Sb2Te (C/CST) heterostructure thin film consisting of alternating sublayers of CST and pure C to realize 3-D restricted phase transition to achieve high performance of PCM. The C/CST heterostructure-based PCM device exhibits a rapid phase-change speed of 6 ns, a stable SET/RESET resistance ratio of about $5\times 10^{5}$ cycles, an ultralow-resistance drift coefficient of 0.0010, and only 0.75% thickness variations during phase transition. These results demonstrate that the 3-D restricted C/CST heterostructure would be an effective strategy for high-performance PCM applications.