Sub-10 nm Tunable Hybrid Dielectric Engineering on MoS2 for Two-Dimensional Material-Based Devices

The successful realization of high-performance 2D-materials-based nanoelectronics requires integration of high-quality dielectric films as a gate insulator. In this work, we explore the integration of organic and inorganic hybrid dielectrics on MoS2 and study the chemical and electrical properties of these hybrid films. Our atomic force microscopy, X-ray photoelectron spectroscopy (XPS), Raman, and photoluminescence results show that, aside from the excellent film uniformity and thickness scalability clown to 2.5 nm, the molecular layer deposition of octenyltrichlorosilane (OTS) and Al2O3 hybrid films preserves the chemical and structural integrity of the MoS2 surface. The XPS band alignment analysis and electrical characterization reveal that through the inclusion of an organic layer in the dielectric film, the band gap and dielectric constant can be tuned from similar to 7.00 to 6.09 eV and similar to 9.0 to 4.5, respectively. Furthermore, the hybrid films show promising dielectric properties, including a high breakdown field of similar to 7.8 MV/cm, a low leakage current density of similar to 1 X 10(-6) A/cm(2) at 1 MV/cm, a small hysteresis of similar to 50 mV, and a top gate subthreshold voltage swing of similar to 79 mV/dec. Our experimental findings provide a facile way of fabricating scalable hybrid gate dielectrics on transition metal dichalcogenides for 2D-material-based flexible electronics applications.