Homogeneous dual-gate MoS2 field-effect transistors integrated by atomic layer deposition-based film synthesis

Abstract

Various synthetic approaches have been proposed and studied to grow high-quality two-dimensional (2D) transition metal dichalcogenides (TMDCs) thin films. However, most of current methods suffer from intrinsic material defects or technical limitations. Here, in this paper, large-area few-layer MoS2 thin films have been prepared on SiO2/Si substrate through sulfurizing pre-deposited MoO3 film by atomic layer deposition (ALD). Good film uniformity, crystallinity and stoichiometry have been successfully achieved. The film thickness can be precisely controlled by adjusting the ALD cycle numbers during MoO3 deposition. Field-effect transistor (FET) arrays have been further fabricated based on the large-area MoS2 film. Both back-gate and top-gate geometries have been applied and have shown excellent reproducibility in electrical performance with average electron mobility of 1.71 cm2 V−1 s−1 and 0.31 cm2 V−1 s−1 for the back-gate and top-gate FETs, respectively. Our results have enabled a promising pathway with such thickness-controlled TMD film and homogeneous FET devices towards future low-dimensional nanoelectronics applications.