Zhang Meiyun, Long Shibing, Wang Guoming, Liu Ruoyu, Xu Xiaoxin, Li Yang, Xu Dinlin, Liu Qi, Lv Hangbing, Miranda Enrique, Suñé Jordi, Liu Ming
Lab of Nanofabrication and Novel Device Integration, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, China,
Nanoscale Res Lett. 2014 Dec;9(1):2500. doi: 10.1186/1556-276X-9-694. Epub 2014 Dec 23.
A major challenge of resistive switching memory (resistive random access memory (RRAM)) for future application is how to reduce the fluctuation of the resistive switching parameters. In this letter, with a statistical methodology, we have systematically analyzed the reset statistics of the conductive bridge random access memory (CBRAM) with a Cu/HfO2/Pt structure which displays bipolar switching property. The experimental observations show that the distributions of the reset voltage (V reset) and reset current (I reset) are greatly influenced by the initial on-state resistance (R on) which is closely related to the size of the conductive filament (CF) before the reset process. The reset voltage increases and the current decreases with the on-state resistance, respectively, according to the scatter plots of the experimental data. Using resistance screening method, the statistical data of the reset voltage and current are decomposed into several ranges and the distributions of them in each range are analyzed by the Weibull model. Both the Weibull slopes of the reset voltage and current are demonstrated to be independent of the on-state resistance which indicates that no CF dissolution occurs before the reset point. The scale factor of the reset voltage increases with on-state resistance while that of the reset current decreases with it. These behaviors are fully in consistency with the thermal dissolution model, which gives an insight on the physical mechanism of the reset switching. Our work has provided an inspiration on effectively reducing the variation of the switching parameters of RRAM devices.
电阻式开关存储器（电阻随机存取存储器，RRAM）未来应用面临的一个主要挑战是如何降低电阻式开关参数的波动。在本信函中，我们采用统计方法，系统地分析了具有双极开关特性的Cu/HfO2/Pt结构的导电桥随机存取存储器（CBRAM）的复位统计数据。实验观察表明，复位电压（Vreset）和复位电流（Ireset）的分布受初始导通状态电阻（Ron）的显著影响，而初始导通状态电阻与复位过程前导电细丝（CF）的尺寸密切相关。根据实验数据的散点图，复位电压随导通状态电阻增加，电流随导通状态电阻减小。采用电阻筛选方法，将复位电压和电流的统计数据分解为几个范围，并通过威布尔模型分析它们在每个范围内的分布。结果表明，复位电压和电流的威布尔斜率均与导通状态电阻无关，这表明在复位点之前没有发生CF溶解。复位电压的比例因子随导通状态电阻增加，而复位电流的比例因子随导通状态电阻减小。这些行为与热溶解模型完全一致，该模型为复位开关的物理机制提供了深入见解。我们的工作为有效降低RRAM器件开关参数的变化提供了启示。
