双极性阻变效应至互补性阻变效应的可控转变及在集成器件中的应用研究

Although the crossbar is an ideal integration pattern for RRAM, the sneak current paths of the neighbor cells can result in the crosstalk of crossbar RRAM. Taking advantage of two high resistance states with the opposite polarity in complementary resistive switching (CRS) is an effective solution to suppress the crosstalk of crossbar RRAM. And how to access the stable CRS is the key issue of the nonvolatile RRAM. On basis our previous experimental results on RRAM, this project intends to achieve the controllable transformation from bipolar resistive switching (BRS) to CRS by tuning the compliance current, pulse width and other parameters. This project is also planned to interpret the intimate correlation and discrepancy of physical origin between them through investigation on the dynamic evolution of effective barrier, band structure, carriers transport behaviors, defects distribution and so on. Furthermore, the designed integrated RRAM arrays with excellent resistive switching performances would be fabricated to verify its anti-crosstalk effects of CRS. This project also provides the theoretical and experimental supports for regulated access of stable CRS and its application on crossbar integrated RRAM with non-crosstalk.

三维堆叠（Crossbar）是阻变存储器的理想集成方式，但邻近存储单元之间的漏电路径易导致信号串扰。利用互补性阻变效应不同极性的高阻态可以抑制三维堆叠集成器件的信号串扰，如何获得稳定的互补性阻变效应是阻变存储器领域当前亟需解决的关键问题。本项目拟在前期研究阻变存储器的基础上，通过控制限制电流和脉冲宽度等测试参数，实现从双极性阻变效应至互补性阻变效应的可控转变。结合有效势垒、能带结构、载流子输运特性和缺陷分布等信息的变化规律，认识双极性阻变效应与互补性阻变效应物理机制的内在关联和差异。在此基础上，设计并研制集成阻变器件阵列，研究互补性阻变效应对其信号串扰的抑制作用。本项目的完成将为互补性阻变效应的调控及其在三维堆叠集成器件上的应用提供理论和实验依据。

项目从忆阻器介质的选择、阻变性能的调控、耦合物理效应的探索及其在类脑智能领域的应用等方面开展研究。首先，构建了逆向串联结构的“ITO/Al2O3/石墨烯/Al2O3/Au”忆阻器，获得了该结构的互补性阻变特性，可用于抑制集成器件的信号串扰。其次，开展了基于量子点介质忆阻器及其柔性集成器件的性能研究：研究了基于MoS2量子点忆阻器的电致阻变特性，获得了因量子隧穿效应所产生的量子电导现象，并实现了其8*8柔性集成忆阻器；研究了CsPbBr3量子点忆阻器的光电耦合现象，实现了其电阻态与光电响应的相互调控。最后，开展了基于忆阻器的类脑神经形态研究：发现了忆阻器特殊的电阻态依赖阈值开关阻变特性，获得了类脑神经突触联想学习以及再可塑性的简易实现途径；采用具有双极性光电响应的阻变特性，模拟实现类脑系统的兴奋-抑制平衡与非平衡过程。本项目研究工作的完成，不仅丰富忆阻器阻变特性的调控方式及其微观物理机制等理论，也为基于忆阻器的类脑神经形态研究提供了实验借鉴。