Anomalous Resistance Hysteresis in Oxide ReRAM: Oxygen Evolution and Reincorporation Revealed by In Situ TEM
Anomalous Resistance Hysteresis in Oxide ReRAM: Oxygen Evolution and Reincorporation Revealed by In Situ TEM
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DOI：
10.1002/adma.201700212
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发表时间：
2017-06-20
影响因子：
29.4
通讯作者：
Dittmann, Regina
中科院分区：
文献类型：
--
作者：
Cooper, David;Baeumer, Christoph;Dittmann, Regina
基于氧化还原的忆阻器件是下一代非易失性存储器和逻辑应用的非常有吸引力的候选者，其控制和合理设计由于竞争和不太了解的切换机制而变得复杂，这可能导致具有相反电压极性的两个共存电阻器。这些竞争过程可以被定义为规则和异常电阻开关。尽管进行了大量的表征工作，但驱动异常电阻开关的复杂纳米级氧化还原过程及其对电流传输的影响仍然知之甚少。在这里，O空位浓度的横向和垂直映射过程中使用的像差校正的透射电子显微镜中的原位这样的设备的操作来解释异常的开关机制。据发现，增加（减少）的整体O空位浓度后，正（负）偏置的肖特基型电极内的设备是与电催化释放和再掺入的氧在电极/氧化物界面，是负责的电阻变化。这一基本见解为阻变过程提供了一个新的视角，并为忆阻器件的实现开辟了新的技术机会，因为现在可以选择性地抑制或故意使用异常开关来实现理想的所谓深度复位。
The control and rational design of redox-based memristive devices, which are highly attractive candidates for next-generation nonvolatile memory and logic applications, is complicated by competing and poorly understood switching mechanisms, which can result in two coexisting resistance hystereses that have opposite voltage polarity. These competing processes can be defined as regular and anomalous resistive switching. Despite significant characterization efforts, the complex nanoscale redox processes that drive anomalous resistive switching and their implications for current transport remain poorly understood. Here, lateral and vertical mapping of O vacancy concentrations is used during the operation of such devices in situ in an aberration corrected transmission electron microscope to explain the anomalous switching mechanism. It is found that an increase (decrease) in the overall O vacancy concentration within the device after positive (negative) biasing of the Schottky-type electrode is associated with the electrocatalytic release and reincorporation of oxygen at the electrode/oxide interface and is responsible for the resistance change. This fundamental insight presents a novel perspective on resistive switching processes and opens up new technological opportunities for the implementation of memristive devices, as anomalous switching can now be suppressed selectively or used deliberately to achieve the desirable so-called deep Reset.