篇題：Charge Storage of Isolated Monolayer Molybdenum Disulfide in Epitaxially Grown MoS2/Graphene Heterostructures for Memory Device Applications
文章出處：ACS Applied Materials & Interfaces, vol. 13, no. 38, pp. 45864-45869, 29 Sept. 2021. DOI10.1021/acsami.1c12064
作者：Tsai, Po-Cheng, Huang, Chun-Wei, Chang, Shoou-Jinn, Chang, Shu-Wei, Lin, Shih-Yen
任職單位及部門：成功大學電機系微電子工程所
We epitaxially grew bilayer molybdenum disulfide (MoS2) on monolayer graphene by sulfurizing a molybdenum-trioxide film (MoO3) which was deposited with thermal evaporation. The Hall mobilities of graphene before and after the growth of MoS2 are similar, indicating that the underlying 2D layer was little affected during the deposition and sulfurization. Through the atomic-layer etching, the topmost layer of MoS2 is isolated from the source and drain electrodes. The top-gate transistor with the isolated monolayer MoS2 on top of the graphene channel exhibits hysteresis of drain current as the gate voltage varies. This may be due to the weak tunneling through 2D layers bonded by the van der Waals force in the absence of an external electric field. The long retention time of the device features robust charge storage around the isolated MoS2 layer. The one-transistor-zero-capacitor memory module based on this thin heterostructure of 2D materials can be advantageous for applications in dynamic random access memories with reduced thickness.
文章摘要：
本研究由熱蒸鍍系統在單層石墨稀上沉積一層三氧化鉬薄膜，並對該薄膜進行硫化過程，以磊晶的方式在石墨稀上成長雙層二硫化鉬。其中在沉積二硫化鉬前後其石墨稀的霍爾遷移率均為相似，表明該底層的2D層在沉積與硫化的過程中並無受到太大影響。透過原子層蝕刻，將最頂層的二硫化鉬與源極和汲極隔離。在上閘極電晶體的部分，隨著閘極電壓的變化，石墨稀通道上的單層二硫化鉬電晶體表現出汲極電流遲滯現象。這可能是由於在凡德瓦力在沒有外部電場的情況下這二維層鍵合產生弱隧穿現象。另外該元件在二硫化鉬層的周圍有強大的電賀儲存能力，代表著該元件具有很長的保留時間。基於這種薄的二維材料異質結構的單電晶體零電容記憶儲存模塊有利於應用減小動態隨機存取存儲器的厚度。