Intergranular Diffusion-Assisted Liquid-Phase Chemical Vapor Deposition for Wafer-Scale Synthesis of Patternable 2D Semiconductors

Abstract

2D semiconductors have attracted considerable interest in the quest to overcome some of the challenges associated with 3D bulk semiconductors. The application of 2D semiconductors in transistor-based electronic devices requires a reliable patterning technology with thickness controllability for continued transistor scaling. In this study, a facile synthesis approach is developed that allows direct patterning of transition metal dichalcogenides (TMDs) with thickness controllability at the wafer scale through intergranular diffusion-assisted liquid-phase chemical vapor deposition using a sacrificial metal layer. By depositing a liquid-phase transition metal precursor onto the pre-patterned polycrystalline Ni/SiO2 substrate, a directly patterned transition metal layer can be formed on SiO2 via intergranular diffusion through the Ni grain boundaries, enabling the growth of patternable TMDs with a controllable thickness. The as-synthesized directly patterned WS2 transistor exhibits typical n-type transport behavior with a stable photoswitching performance. The proposed patterning technique can make the application of 2D semiconductors in advanced electronic devices more viable.