Ding Xiangxiang, Feng Yulin, Huang Peng, Liu Lifeng, Kang Jinfeng
Institute of Microelectronics, Peking University, Beijing, 100871, China.
Nanoscale Res Lett. 2019 May 9;14(1):157. doi: 10.1186/s11671-019-2956-4.
Resistive random-access memory devices with atomic layer deposition HfO and radio frequency sputtering TiO as resistive switching layers were fabricated successfully. Low-power characteristic with 1.52 μW set power (1 μA@1.52 V) and 1.12 μW reset power (1 μA@1.12 V) was obtained in the HfO/TiO resistive random-access memory (RRAM) devices by controlling the oxygen content of the TiO layer. Besides, the influence of oxygen content during the TiO sputtering process on the resistive switching properties would be discussed in detail. The investigations indicated that "soft breakdown" occurred easily during the electrical forming/set process in the HfO/TiO RRAM devices with high oxygen content of the TiO layer, resulting in high resistive switching power. Low-power characteristic was obtained in HfO/TiO RRAM devices with appropriately high oxygen vacancy density of TiO layer, suggesting that the appropriate oxygen vacancy density in the TiO layer could avoid "soft breakdown" through the whole dielectric layers during forming/set process, thus limiting the current flowing through the RRAM device and decreasing operating power consumption.
成功制备了以原子层沉积HfO和射频溅射TiO作为电阻开关层的电阻式随机存取存储器器件。通过控制TiO层的氧含量，在HfO/TiO电阻式随机存取存储器（RRAM）器件中获得了低功耗特性，其设置功率为1.52 μW（1 μA@1.52 V），复位功率为1.12 μW（1 μA@1.12 V）。此外，将详细讨论TiO溅射过程中的氧含量对电阻开关特性的影响。研究表明，在TiO层氧含量高的HfO/TiO RRAM器件的电形成/设置过程中容易发生“软击穿”，导致高电阻开关功率。在TiO层具有适当高氧空位密度的HfO/TiO RRAM器件中获得了低功耗特性，这表明TiO层中适当的氧空位密度可以避免在形成/设置过程中通过整个介电层发生“软击穿”，从而限制流过RRAM器件的电流并降低工作功耗。
