Wafer-Scale Uniform Growth of an Atomically Thin MoS2 Film with Controlled Layer Numbers by Metal-Organic Chemical Vapor Deposition

ACS Appl Mater Interfaces. 2021 Oct 27;13(42):50497-50504. doi: 10.1021/acsami.1c12186. Epub 2021 Oct 17.

Abstract

The growth control of a molybdenum disulfide (MoS2) thin film, including the number of layers, growth rate, and electrical property modulation, remains a challenge. In this study, we synthesized MoS2 thin films using the metal-organic chemical vapor deposition (MOCVD) method with a 2 inch wafer scale and achieved high thickness uniformity according to the positions on the substrate. In addition, we successfully controlled the number of MoS2 layers to range from one to five, with a growth rate of 10 min per layer. The layer-dependent optical and electrical properties were characterized by photoluminescence, Raman spectroscopy, differential reflectance spectroscopy, and field effect transistors. To guide the growth of MoS2, we summarized the relation between the growth aspects and the precursor control in the form of a growth map. Reference to this growth map enabled control of the growth rate, domain density, and domain size according to the application purposes. Finally, we confirmed the electrical performance of MOCVD-grown MoS2 with five layers under a high-κ dielectric environment, which exhibited an on/off current ratio of 10∼6 and a maximum field effect mobility of 8.6 cm2 V-1 s-1.

Keywords: MoS2 field effect transistors; layer control; layer dependency; metal−organic chemical vapor deposition (MOCVD); molybdenum disulfide (MoS2).