发表机构
Kyushu University; The University of Osaka; University of Tsukuba; Pohang University of Science and Technology (POSTECH); Kumamoto University; National Institute of Advanced Industrial Science and Technology (AIST)（九州大学; 大阪大学; 筑波大学; 浦项科技大学; 熊本大学; 国立产业技术综合研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出一种化学气相沉积方法，在蓝宝石表面逐层生长高度排列的MoS2纳米带阵列，可控制层数至四层，双层器件性能显著提升，为TMD纳米带晶体管提供可扩展途径。
AI 中文摘要
一维过渡金属二硫化物（TMD）纳米带（NRs）为纳米级晶体管中激进的沟道宽度缩放提供了一条有前景的途径。然而，控制其层数（器件性能的关键决定因素）一直难以实现。在此，我们展示了一种化学气相沉积（CVD）方法，用于在低对称性蓝宝石表面上逐层生长MoS$_2$纳米带。该方法能够实现具有2H堆叠构型的单晶双层纳米带的定向生长，同时保持宽度低于20纳米。研究发现，增加MoO$_3$前驱体供应对于促进第二层及后续层的生长至关重要。通过控制生长时间和前驱体供应，MoS$_2$纳米带的层数可以增加到四层。该方法还可扩展到垂直MoS$_2$/WS$_2$异质纳米带的生长。双层纳米带场效应晶体管（FETs）的平均载流子迁移率和电流密度分别比单层对应物高出两倍和三倍，并且双层纳米带FET达到了86.7 cm$^2$V$^{-1}$s$^{-1}$的最大迁移率。这些结果突出了层数作为优化纳米带器件性能的关键参数。我们的厚度控制生长策略为基于TMD纳米带的晶体管提供了增强可扩展性和性能的通用途径。
英文摘要
One-dimensional transition metal dichalcogenides (TMD) nanoribbons (NRs) offer a promising route to aggressive channel-width scaling in nanoscale transistors. However, controlling their layer number, a key determinant of device performance, has remained elusive. Here, we demonstrate a chemical vapor deposition (CVD) approach for layer-by-layer growth of MoS$_2$ NRs on a low-symmetry sapphire surface. This approach enables the oriented growth of single-crystalline bilayer NRs with a 2H stacking configuration, while maintaining widths below 20 nm. Increasing the MoO$_3$ precursor supply was found to be crucial for promoting the growth of the second and subsequent layers. By controlling the growth time and precursor supply, the layer number of MoS$_2$ NRs can be increased up to four layers. This method can also be extended to the growth of vertical MoS$_2$/WS$_2$ hetero-NRs. The average carrier mobility and current density of bilayer NR field-effect transistors (FETs) are two- and three-times higher than those of monolayer counterparts, respectively, and a maximum mobility of 86.7 cm$^2$V$^{-1}$s$^{-1}$ was attained with a bilayer NR-FET. These results highlight layer number as a key parameter for optimizing NR device performance. Our thickness-controlled growth strategy provides a general route towards TMD NR-based transistors with enhanced scalability and performance.
Comments30 pages, 6 figures
