Department of Engineering Product Design , Singapore University of Technology and Design , 8 Somapah Road , 487372 , Singapore.
College of Information Science Electronic Engineering , Zhejiang University , Hangzhou 310027 , China.
ACS Appl Mater Interfaces. 2018 Mar 28;10(12):10165-10172. doi: 10.1021/acsami.7b17235. Epub 2018 Mar 15.
Selector elements with high nonlinearity are an indispensable part in constructing high density, large-scale, 3D stackable emerging nonvolatile memory and neuromorphic network. Although significant efforts have been devoted to developing novel thin-film selectors, it remains a great challenge in achieving good switching performance in the selectors to satisfy the stringent electrical criteria of diverse memory elements. In this work, we utilized high-defect-density chalcogenide glass (GeSbTe) in conjunction with high mobility Ag element (Ag-GST) to achieve a super nonlinear selective switching. A novel electrodeposition-diffusion dynamic selector based on Ag-GST exhibits superior selecting performance including excellent nonlinearity (<5 mV/dev), ultra-low leakage (<10 fA), and bidirectional operation. With the solid microstructure evidence and dynamic analyses, we attributed the selective switching to the competition between the electrodeposition and diffusion of Ag atoms in the glassy GST matrix under electric field. A switching model is proposed, and the in-depth understanding of the selective switching mechanism offers an insight of switching dynamics for the electrodeposition-diffusion-controlled thin-film selector. This work opens a new direction of selector designs by combining high mobility elements and high-defect-density chalcogenide glasses, which can be extended to other materials with similar properties.
具有高非线性的选择器元件是非易失性存储器和神经形态网络高密度、大规模、3D 可堆叠结构的不可或缺的部分。尽管人们已经做出了巨大的努力来开发新型薄膜选择器，但在满足各种存储元件严格的电气标准的情况下，在选择器中实现良好的开关性能仍然是一个巨大的挑战。在这项工作中，我们利用具有高密度缺陷的硫属化物玻璃（GeSbTe）和高迁移率的 Ag 元素（Ag-GST）来实现超非线性的选择开关。一种新型的基于 Ag-GST 的电沉积-扩散动态选择器表现出优异的选择性能，包括优异的非线性(<5 mV/dev)、超低漏电流(<10 fA)和双向操作。通过固态微观结构证据和动态分析，我们将选择性开关归因于电场下玻璃状 GST 基质中 Ag 原子的电沉积和扩散之间的竞争。提出了一种开关模型，对选择性开关机制的深入理解为电沉积-扩散控制的薄膜选择器提供了开关动力学的见解。这项工作通过结合高迁移率元件和高密度缺陷硫属化物玻璃为选择器设计开辟了一个新的方向，这可以扩展到具有类似特性的其他材料。
