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

ABSTRACT

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 Al2 O3 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.