Lee Inseong, Kang Mingu, Park Seohak, Park Cheolmin, Lee Hyeonji, Bae Sanggeun, Lim Hyeongjin, Kim Sungkyu, Hong Woonggi, Choi Sung-Yool
Graphene/2D Materials Research Center, School of Electrical Engineering, Graduate School of Semiconductor Technology, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
Department of Nanotechnology and Advanced Materials Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea.
Small. 2024 Jan;20(2):e2305143. doi: 10.1002/smll.202305143. Epub 2023 Sep 5.
Molybdenum disulfide (MoS ), a metal dichalcogenide, is a promising channel material for highly integrated scalable transistors. However, intrinsic donor defect states, such as sulfur vacancies (V ), can degrade the channel properties and lead to undesired n-doping. A method for healing the donor defect states in monolayer MoS is proposed using oxygen plasma, with an aluminum oxide (Al O ) barrier layer that protects the MoS channel from damage by plasma treatment. Successful healing of donor defect states in MoS by oxygen atoms, even in the presence of an Al O barrier layer, is confirmed by X-ray photoelectron spectroscopy, photoluminescence, and Raman spectroscopy. Despite the decrease in 2D sheet carrier concentration (Δn = -3.82×10 cm ), the proposed approach increases the on-current and mobility by 18% and 44% under optimal conditions, respectively. Metal-insulator transition occurs at electron concentrations of 5.7×10 cm and reflects improved channel quality. Finally, the activation energy (E ) reduces at all the gate voltages (V ) owing to a decrease in V , which act as a localized state after the oxygen plasma treatment. This study demonstrates the feasibility of plasma-assisted healing of defects in 2D materials and electrical property enhancement and paves the way for the development of next-generation electronic devices.
二硫化钼（MoS₂）作为一种金属二硫属化物，是用于高度集成可扩展晶体管的一种很有前景的沟道材料。然而，诸如硫空位（Vₛ）等本征施主缺陷态会降低沟道性能并导致不期望的n型掺杂。本文提出了一种使用氧等离子体修复单层MoS₂中施主缺陷态的方法，该方法采用氧化铝（Al₂O₃）阻挡层来保护MoS₂沟道免受等离子体处理的损伤。通过X射线光电子能谱、光致发光和拉曼光谱证实，即使存在Al₂O₃阻挡层，氧原子也能成功修复MoS₂中的施主缺陷态。尽管二维薄片载流子浓度有所降低（Δn = -3.82×10¹² cm⁻²），但该方法在最佳条件下分别使导通电流和迁移率提高了18%和44%。金属 - 绝缘体转变发生在电子浓度为5.7×10¹² cm⁻²时，这反映出沟道质量得到了改善。最后，由于氧等离子体处理后作为局域态的Vₛ减少，在所有栅极电压（V₉）下激活能（Eₐ）都降低了。这项研究证明了等离子体辅助修复二维材料中缺陷以及增强电学性能的可行性，为下一代电子器件的发展铺平了道路。
