Noé Pierre, Verdy Anthonin, d'Acapito Francesco, Dory Jean-Baptiste, Bernard Mathieu, Navarro Gabriele, Jager Jean-Baptiste, Gaudin Jérôme, Raty Jean-Yves
Université Grenoble Alpes, CEA, LETI, MINATEC Campus, 17 avenue des Martyrs, F-38000 Grenoble, France.
CNR-IOM-OGG c/o ESRF-The European Synchrotron, 71 rue des Martyrs, F-38043 Grenoble, France.
Sci Adv. 2020 Feb 28;6(9):eaay2830. doi: 10.1126/sciadv.aay2830. eCollection 2020 Feb.
Fifty years after its discovery, the ovonic threshold switching (OTS) phenomenon, a unique nonlinear conductivity behavior observed in some chalcogenide glasses, has been recently the source of a real technological breakthrough in the field of data storage memories. This breakthrough was achieved because of the successful 3D integration of so-called OTS selector devices with innovative phase-change memories, both based on chalcogenide materials. This paves the way for storage class memories as well as neuromorphic circuits. We elucidate the mechanism behind OTS switching by new state-of-the-art materials using electrical, optical, and x-ray absorption experiments, as well as ab initio molecular dynamics simulations. The model explaining the switching mechanism occurring in amorphous OTS materials under electric field involves the metastable formation of newly introduced metavalent bonds. This model opens the way for design of improved OTS materials and for future types of applications such as brain-inspired computing.
在发现五十周年后，硫系玻璃中观察到的独特非线性导电行为——双向阈值开关（OTS）现象，最近已成为数据存储记忆领域真正技术突破的源头。这一突破的实现得益于所谓的OTS选择器器件与创新相变记忆体的成功三维集成，二者均基于硫系材料。这为存储类记忆体以及神经形态电路铺平了道路。我们通过电学、光学和X射线吸收实验以及从头算分子动力学模拟，利用新的前沿材料阐明了OTS开关背后的机制。解释非晶OTS材料在电场作用下发生的开关机制的模型涉及新引入的变价键的亚稳形成。该模型为改进OTS材料的设计以及未来诸如受大脑启发的计算等类型应用开辟了道路。
