Liu Cheng, Zheng Yonghui, Xin Tianjiao, Zheng Yunzhe, Wang Rui, Cheng Yan
Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China.
Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401120, China.
Nanomaterials (Basel). 2023 Jan 31;13(3):582. doi: 10.3390/nano13030582.
Phase-change random-access memory (PCRAM) holds great promise for next-generation information storage applications. As a mature phase change material, GeSbTe alloy (GST) relies on the distinct electrical properties of different states to achieve information storage, but there are relatively few studies on the relationship between electron transport and microstructure. In this work, we found that the first resistance dropping in GST film is related to the increase of carrier concentration, in which the atomic bonding environment changes substantially during the crystallization process. The second resistance dropping is related to the increase of carrier mobility. Besides, during the cubic to the hexagonal phase transition, the nanograins grow significantly from ~50 nm to ~300 nm, which reduces the carrier scattering effect. Our study lays the foundation for precisely controlling the storage states of GST-based PCRAM devices.
相变随机存取存储器（PCRAM）在下一代信息存储应用中具有巨大潜力。作为一种成熟的相变材料，GeSbTe合金（GST）依靠不同状态下独特的电学性质来实现信息存储，但关于电子输运与微观结构之间关系的研究相对较少。在这项工作中，我们发现GST薄膜中的首次电阻下降与载流子浓度的增加有关，其中在结晶过程中原子键合环境发生了显著变化。第二次电阻下降与载流子迁移率的增加有关。此外，在立方相到六方相转变过程中，纳米晶粒从约50纳米显著生长到约300纳米，这降低了载流子散射效应。我们的研究为精确控制基于GST的PCRAM器件的存储状态奠定了基础。
