  Metal-mediated exfoliation has been demonstrated as a promising approach for
obtaining large-area flakes of 2D materials to fabricate prototypical
nanoelectronics. However, several processing challenges related to organic
contamination at the interfaces of the 2D material and the gate oxide must be
overcome to realize robust devices with high yield. Here, we demonstrate an
optimized process to realize high-performance field-effect transistor (FET)
arrays from large-area (~5000 um2) 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 nanoelectronics devices
and demonstrates the need for improved engineering of the 2D material-gate
oxide interface.
