Graphite Carbon-Doped Sb<sub>2</sub>Te Nanostructures for Phase-Change Memory Applications
Peng Xu, Yun Meng, Zhen Li, Xiaolin Liu, Jian Zhou, Sannian Song, Zhitang Song, Zhimei Sun, Liangcai Wu
Abstract
High thermal stability, fast operation speed, low thickness variation, and low resistance drift of phase-change nanomaterials are the essential characteristics in phase-change memory (PCM) applications. In this work, we put forward a graphite carbon-doped Sb 2 Te (C-Sb 2 Te) chalcogenide with semiconductor process compatibility. Our results prove that the proposed C-Sb 2 Te has excellent thermal stability and high operation speed. More importantly, the thickness change and resistance drift are only 0.89% and 0.0149, respectively. The C-Sb 2 Te-based memory device exhibits a high switching speed to the instrument test limit (5 ns) with a large resistance ratio, low operation voltage (2 V), and low power consumption (6.9 pJ). The proposed C-Sb 2 Te nanostructure material exceeds both conventional Ge 2 Sb 2 Te 5 and transition-metal-doped Sb 2 Te materials in terms of its performance. Ab initio molecular dynamics simulations reveal that C–C and C–Sb bonds as well as C–C chains are formed in C-Sb 2 Te, and C doping constrains phase transition in a small region and refines grains of C-Sb 2 Te, thus resulting in the high performance. Our study suggests that C-Sb 2 Te is a potential candidate for high-speed, high-thermal-stability, and high-reliability PCM applications.