文章基本信息

标题：Thickness effect of ultra-thin Ta₂O₅ resistance switching layer in 28 nm-diameter memory cell
本地全文：下载
作者：Tae Hyung Park ; Seul Ji Song ; Hae Jin Kim 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
DOI：10.1038/srep15965
出版社：Springer Nature
摘要：Resistance switching (RS) devices with ultra-thin Ta₂O₅ switching layer (0.5–2.0 nm) with a cell diameter of 28 nm were fabricated. The performance of the devices was tested by voltage-driven current—voltage (I-V) sweep and closed-loop pulse switching (CLPS) tests. A Ta layer was placed beneath the Ta₂O₅ switching layer to act as an oxygen vacancy reservoir. The device with the smallest Ta₂O₅ thickness (0.5 nm) showed normal switching properties with gradual change in resistance in I-V sweep or CLPS and high reliability. By contrast, other devices with higher Ta₂O₅ thickness (1.0–2.0 nm) showed abrupt switching with several abnormal behaviours, degraded resistance distribution, especially in high resistance state, and much lower reliability performance. A single conical or hour-glass shaped double conical conducting filament shape was conceived to explain these behavioural differences that depended on the Ta₂O₅ switching layer thickness. Loss of oxygen via lateral diffusion to the encapsulating Si₃N₄/SiO₂ layer was suggested as the main degradation mechanism for reliability, and a method to improve reliability was also proposed.