By controlling the amorphous-to-crystalline relative volume, chalcogenide phase-change memory materials can provide multi-level data storage (MLS), which offers great potential for high-density storage-class memory and neuro-inspired computing. However, this type of MLS system suffers from high power consumption and a severe time-dependent resistance increase (“drift”) in the amorphous phase, which limits the number of attainable storage levels. Here, we report a new type of MLS system in yttrium-doped antimony telluride, utilizing reversible multi-level phase transitions between three states, i.e., amorphous, metastable cubic and stable hexagonal crystalline phases, with ultralow power consumption (0.6–4.3 pJ) and ultralow resistance drift for the lower two states (power-law exponent < 0.007). The metastable cubic phase is stabilized by yttrium, while the evident reversible cubic-to-hexagonal transition is attributed to the sequential and directional migration of Sb atoms. Finally, the decreased heat dissipation of the material and the increase in crystallinity contribute to the overall high performance. This study opens a new way to achieve advanced multi-level phase-change memory without the need for complicated manufacturing procedures or iterative programming operations.

通过控制非晶到晶体的相对体积，硫族化物相变存储材料可以提供多级数据存储（MLS），这为高密度存储级存储器和神经启发计算提供了巨大潜力。然而，这种类型的 MLS 系统具有高功耗和非晶相中严重的随时间变化的电阻增加（“漂移”），这限制了可达到的存储级别的数量。在这里，我们报告了一种新型的掺钇碲化锑 MLS 系统，利用三种状态之间的可逆多能级相变，即非晶相、亚稳立方晶相和稳定六方晶相，具有超低功耗（0.6-4.3 pJ）和较低两个状态的超低电阻漂移（幂律指数 < 0.007）。亚稳立方相由钇稳定，而明显的可逆立方到六方转变归因于锑原子的连续和定向迁移。最后，材料散热的减少和结晶度的增加有助于整体的高性能。这项研究开辟了一种无需复杂的制造程序或迭代编程操作即可实现高级多级相变存储器的新途径。