He Qingyuan, Li Pengji, Wu Zhiheng, Yuan Bin, Luo Zhongtao, Yang Wenlong, Liu Jie, Cao Guoqin, Zhang Wenfeng, Shen Yonglong, Zhang Peng, Liu Suilin, Shao Guosheng, Yao Zhiqiang
State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.
Process Research R&D Array Technology Department, Visionox Technology Co., Ltd., Gu'an New Industry Park, Langfang, 065500, P. R. China.
Adv Mater. 2019 Aug;31(32):e1901578. doi: 10.1002/adma.201901578. Epub 2019 Jun 14.
Monolayer MoTe , with the narrowest direct bandgap of ≈1.1 eV among Mo- and W-based transition metal dichalcogenides, has attracted increasing attention as a promising candidate for applications in novel near-infrared electronics and optoelectronics. Realizing 2D lateral growth is an essential prerequisite for uniform thickness and property control over the large scale, while it is not successful yet. Here, layer-by-layer growth of 2 in. wafer-scale continuous monolayer 2H-MoTe films on inert SiO dielectrics by molecular beam epitaxy is reported. A single-step Mo-flux controlled nucleation and growth process is developed to suppress island growth. Atomically flat 2H-MoTe with 100% monolayer coverage is successfully grown on inert 2 in. SiO /Si wafer, which exhibits highly uniform in-plane structural continuity and excellent phonon-limited carrier transport behavior. The dynamics-controlled growth recipe is also extended to fabricate continuous monolayer 2H-MoTe on atomic-layer-deposited Al O dielectric. With the breakthrough in growth of wafer-scale continuous 2H-MoTe monolayers on device compatible dielectrics, batch fabrication of high-mobility monolayer 2H-MoTe field-effect transistors and the three-level integration of vertically stacked monolayer 2H-MoTe transistor arrays for 3D circuitry are successfully demonstrated. This work provides novel insights into the scalable synthesis of monolayer 2H-MoTe films on universal substrates and paves the way for the ultimate miniaturization of electronics.
单层碲化钼（MoTe₂）在钼基和钨基过渡金属二硫属化物中具有约1.1电子伏特的最窄直接带隙，作为新型近红外电子学和光电子学应用的有前途候选材料，已引起越来越多的关注。实现二维横向生长是在大规模上均匀控制厚度和性能的必要前提，但目前尚未成功。在此，报道了通过分子束外延在惰性二氧化硅（SiO₂）电介质上逐层生长2英寸晶圆级连续单层2H-MoTe薄膜。开发了一种单步钼通量控制的成核和生长过程以抑制岛状生长。在惰性2英寸SiO₂/Si晶圆上成功生长出具有100%单层覆盖率的原子级平整的2H-MoTe，其在平面内具有高度均匀的结构连续性和优异的声子限制载流子输运行为。动力学控制的生长方法也扩展到在原子层沉积的Al₂O₃电介质上制备连续单层2H-MoTe。随着在与器件兼容的电介质上晶圆级连续2H-MoTe单层生长的突破，成功展示了高迁移率单层2H-MoTe场效应晶体管的批量制造以及用于3D电路的垂直堆叠单层2H-MoTe晶体管阵列的三级集成。这项工作为在通用衬底上可扩展合成单层2H-MoTe薄膜提供了新见解，并为电子学的最终小型化铺平了道路。
