Wu Xiaohan, Ge Ruijing, Huang Yifu, Akinwande Deji, Lee Jack C
Microelectronics Research Center, The University of Texas at Austin Austin Texas 78758 USA
RSC Adv. 2020 Nov 19;10(69):42249-42255. doi: 10.1039/d0ra05209d. eCollection 2020 Nov 17.
MoS has been reported to exhibit a resistive switching phenomenon in a vertical metal-insulator-metal (MIM) structure and has attracted much attention due to its ultra-thin active layer thickness. Here, the resistance evolutions in the high resistance state (HRS) and low resistance state (LRS) are investigated under constant voltage stress (CVS) or constant current stress (CCS) on MoS resistive switching devices. Interestingly, compared with bulk transition metal oxides (TMO), MoS exhibits an opposite characteristic in the fresh or pre-RESET device in the "HRS" wherein the resistance will increase to an even higher resistance after applying CVS, a unique phenomenon only accessible in 2D-based resistive switching devices. It is inferred that instead of in the highest resistance state, the fresh or pre-RESET devices are in an intermediate state with a small amount of Au embedded in the MoS film. Inspired by the capability of both bipolar and unipolar operation, positive and negative CVS measurements are performed and show similar characteristics. In addition, it is observed that the resistance state transition is faster when using higher electric stress. Numerical simulations have been performed to study the temperature effect with small-area integration capability. These results can be explained by a modified conductive-bridge-like model based on Au migration, uncovering the switching mechanisms in the ultrathin 2D materials and inspiring future studies in this area.
据报道，二硫化钼（MoS）在垂直金属-绝缘体-金属（MIM）结构中表现出电阻开关现象，并且由于其超薄的有源层厚度而备受关注。在此，研究了在二硫化钼电阻开关器件上施加恒压应力（CVS）或恒流应力（CCS）时，其高电阻状态（HRS）和低电阻状态（LRS）下的电阻变化情况。有趣的是，与体相过渡金属氧化物（TMO）相比，二硫化钼在“高电阻状态”下的新器件或预复位器件中表现出相反的特性，即在施加恒压应力后，电阻会增加到更高的值，这是一种仅在基于二维材料的电阻开关器件中才会出现的独特现象。据推断，新器件或预复位器件并非处于最高电阻状态，而是处于一种中间状态，即有少量金嵌入二硫化钼薄膜中。受双极和单极操作能力的启发，进行了正向和负向恒压应力测量，结果显示出相似的特性。此外，观察到使用更高的电应力时电阻状态转变更快。已进行数值模拟以研究具有小面积集成能力的温度效应。这些结果可以通过基于金迁移的改进型类导电桥模型来解释，揭示了超薄二维材料中的开关机制，并为该领域的未来研究提供了启示。
