Super Nonlinear Electrodeposition–Diffusion-Controlled Thin-Film Selector

作者：Xinglong Ji, Li Song, Wei He, Kejie Huang, Zhiyuan Yan, Shuai Zhong, Yishu Zhang, Rong Zhao · 发表于：ACS Applied Materials & Interfaces · 年份：2018 · DOI：10.1021/acsami.7b17235 · 被引用次数：32 · 研究领域：Advanced Memory and Neural Computing、Phase-change materials and chalcogenides、Transition Metal Oxide Nanomaterials

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 (Ge 2 Sb 2 Te 5 ) 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.