Reproducible Performance Improvements to Monolayer MoS₂ Transistors through Exposed Material Forming Gas Annealing

Metal-mediated exfoliation has been demonstrated as a promising approach for obtaining large-area flakes of two-dimensional (2D) materials to fabricate prototypical nanoelectronics. However, several processing challenges related to organic contamination at the interface of a 2D material and gate oxide must be overcome to realize robust devices with high yields. Here, we demonstrate an optimized process to realize high-performance field-effect transistor (FET) arrays from large-area (∼5000 μm2), monolayer MoS2 with a yield of 85%. A central element of this process is an exposed material forming gas anneal (EM-FGA) that results in uniform FET performance metrics (i.e., field-effect mobilities, threshold voltages, and contact performance). Complementary analytical measurements show that the EM-FGA process reduces deleterious channel doping effects by decreasing organic contamination while also reducing the prevalence of insulating molybdenum oxide, effectively improving the MoS2–gate oxide interface. The uniform FET performance metrics and high device yield achieved by applying the EM-FGA technique on large-area 2D material flakes will help advance the fabrication of complex 2D nanoelectronic devices and demonstrate the need for improved engineering of the 2D material–gate oxide interface