Molecular Beam Epitaxy Scalable Growth of Wafer‐Scale Continuous Semiconducting Monolayer MoTe2 on Inert Amorphous Dielectrics

• Published in: Advanced materials (Weinheim) 2019-08, Vol.31 (32), p.e1901578-n/a
• Main Authors: 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
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Carrier transport; Circuits; Continuity (mathematics); Dielectrics; Electronics; Epitaxial growth; Island growth; layer‐by‐layer growth; Materials science; Miniaturization; Molecular beam epitaxy; Molybdenum compounds; monolayer MoTe2; Monolayers; monolithic integration; Nucleation; Optoelectronics; phonon scattering; Semiconductor devices; Silicon dioxide; Substrates; Tellurides; Transistors; Transition metal compounds
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201901578

Monolayer MoTe2, 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‐MoTe2 films on inert SiO2 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‐MoTe2 with 100% monolayer coverage is successfully grown on inert 2 in. SiO2/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‐MoTe2 on atomic‐layer‐deposited Al2O3 dielectric. With the breakthrough in growth of wafer‐scale continuous 2H‐MoTe2 monolayers on device compatible dielectrics, batch fabrication of high‐mobility monolayer 2H‐MoTe2 field‐effect transistors and the three‐level integration of vertically stacked monolayer 2H‐MoTe2 transistor arrays for 3D circuitry are successfully demonstrated. This work provides novel insights into the scalable synthesis of monolayer 2H‐MoTe2 films on universal substrates and paves the way for the ultimate miniaturization of electronics. Two‐inch atomically flat 2H‐MoTe2 monolayers with tunable coverage from 40 to 100% are directly grown on inert SiO2 dielectrics by molecular beam epitaxy. A single‐step nucleation and growth strategy is developed to promote lateral growth under low Mo‐flux. The effective layer‐by‐layer growth is controlled solely by the molecular beam dynamics rather than the assistance of catalysts, seeding promoters, and epitaxial templates.