Koroleva Aleksandra A, Chernikova Anna G, Chouprik Anastasia A, Gornev Evgeny S, Slavich Aleksandr S, Khakimov Roman R, Korostylev Evgeny V, Hwang Cheol Seong, Markeev Andrey M
Moscow Institute of Physics and Technology, Institutskii Lane 9, Dolgoprudny 141700, Russian Federation.
Molecular Electronics Research Institute, 12/1 Akademika Valieva Street, Zelenograd, Moscow 124460, Russian Federation.
ACS Appl Mater Interfaces. 2020 Dec 9;12(49):55331-55341. doi: 10.1021/acsami.0c14810. Epub 2020 Nov 15.
Resistive switching (RS) device behavior is highly dependent on both insulator and electrode material properties. In particular, the bottom electrode (BE) surface morphology can strongly affect RS characteristics. In this work, Ru films with different thicknesses grown on a TiN layer by radical-enhanced atomic layer deposition (REALD) are used as an inert BE in TaO-based RS structures. The REALD Ru surface roughness is found to increase by more than 1 order of magnitude with the increase in the reaction cycle number. Simultaneously, a wide range of RS parameters, such as switching voltage, resistance both in low and high resistance states, endurance, and so forth, monotonically change. A simplified model is proposed to explain the linkage between RS properties and roughness of the Ru surface. The field distribution was simulated based on the observed surface morphologies, and the resulting conducting filament formation was anticipated based on the local field enhancement. Conductive atomic force microscopy confirmed the theoretical expectations.
电阻开关（RS）器件的行为高度依赖于绝缘体和电极材料的特性。特别是，底部电极（BE）的表面形态会强烈影响RS特性。在这项工作中，通过自由基增强原子层沉积（REALD）在TiN层上生长的不同厚度的Ru薄膜被用作基于TaO的RS结构中的惰性BE。发现随着反应循环次数的增加，REALD Ru的表面粗糙度增加超过1个数量级。同时，诸如开关电压、低电阻和高电阻状态下的电阻、耐久性等一系列RS参数也会单调变化。提出了一个简化模型来解释RS特性与Ru表面粗糙度之间的联系。基于观察到的表面形态模拟了场分布，并基于局部场增强预测了由此产生的导电细丝的形成。导电原子力显微镜证实了理论预期。
