School of Electrical Engineering, Korea University , Anam-dong, Seongbuk-gu, Seoul 136-701, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Dec 13;9(49):43336-43342. doi: 10.1021/acsami.7b10266. Epub 2017 Nov 28.
Crossbar arrays (CBAs) with resistive random access memory (ReRAM) constitute an established architecture for high-density memory. However, sneak paths via unselected cells increase the total power consumption of these devices and limit the array size. To eliminate such sneak-path problems, we propose a Ti/GaO/NbO/Pt structure with a self-rectifying resistive-switching (RS) behavior. In this structure, to reduce the operating voltage, we used a Ti/GaO stack to increase the number of trap sites in the RS GaO layer through interfacial reactions between the Ti and GaO layers. This increase enables easier carrier transport with reduced electric fields. We then adopted a NbO/Pt stack to add rectifying behavior to the RS GaO layer. This behavior is a result of the large Schottky barrier height between the NbO and Pt layers. Finally, both the Ti/GaO and NbO/Pt stacks were combined to realize a self-rectifying ReRAM device, which exhibited excellent performance. Characteristics of the device include a low operating voltage range (-2.8 to 2.5 V), high on/off ratios (∼20), high selectivity (∼10), high operating speeds (200-500 ns), a very low forming voltage (∼3 V), stable operation, and excellent uniformity for high-density CBA-based ReRAM applications.
交叉点数组 (CAB) 与阻变随机存取存储器 (ReRAM) 构成了高密度存储器的成熟架构。然而，未选中单元的旁路电流会增加这些器件的总功耗并限制阵列规模。为了消除这种旁路问题，我们提出了一种具有自整流电阻开关 (RS) 行为的 Ti/GaO/NbO/Pt 结构。在这种结构中，为了降低工作电压，我们使用 Ti/GaO 堆叠通过 Ti 和 GaO 层之间的界面反应在 RS GaO 层中增加陷阱数量。这一增加使得更容易通过降低电场进行载流子输运。然后，我们采用 NbO/Pt 堆叠为 RS GaO 层添加整流行为。这种行为是由于 NbO 和 Pt 层之间的大肖特基势垒高度引起的。最后，将 Ti/GaO 和 NbO/Pt 堆叠结合起来，实现了具有出色性能的自整流 ReRAM 器件。该器件的特点包括低工作电压范围（-2.8 至 2.5 V）、高导通/关断比（约 20）、高选择性（约 10）、高工作速度（200-500 ns）、非常低的形成电压（约 3 V）、稳定的操作和高密度 CBA 基 ReRAM 应用的出色均匀性。
