Synthesis of Large Area two-dimensional MoS2 films by Sulfurization of Atomic Layer Deposited MoO3 Thin Film for Nanoelectronic applications

In this work, the feasibility of growing atomically thin MoS2 film (down to two monolayers) on several tens of cm2 area was demonstrated by first depositing the MoO3 thin film using an atomic layer deposition and subsequent sulfurization at temperatures ranging from 500 to 1000 oC. The effects of sulfurization temperature on properties of thin MoS2 films were investigated in details. It was found that the annealing of the MoO3 film under the elemental sulfur vapor condition allows effective sulfurization from 500°C, at which the converted MoS2 film contained a rather high concentration of elemental sulfur which might reside at the boundaries between the relatively low-crystallized edge-on MoS2 grains. The increase in sulfurization temperature from 500 °C to 1000 °C results in a significant grain size growth from ~10 nm up to > ~100 nm, with the change of the edge-on grains to the flat grains with their (0001) planes being parallel to the sapphire substrate. Raman spectroscopy investigations also indicated...