Sub-10 nm patterning of few-layer MoS2 and MoSe2 nanolectronic devices by oxidation scanning probe lithography

Abstract The properties of 2D materials devices are very sensitive to the physical, chemical and structural interactions that might happen during processing. Low-invasive patterning methods are required to fabricate devices at the nanoscale. Here we developed a process that combines oxidation scanning probe lithography (o-SPL) and oxygen plasma to fabricate nanoribbon field-effect transistors and nano-constrictions on few-layer MoS2 and MoSe2. The oxygen plasma has a double role in this process. First, it forms a thin, uniform oxide layer on top of the flake surface to enable o-SPL nanopatterning with full control of shape and size. Second, the oxide layer thins down the flake. Both plasma-based and o-SPL oxides are soluble in deionized H2O, which enabled etching and the definition of electrically isolated nano-constrictions and nanoribbons. The accuracy and robustness of the process was applied to pattern sub-10 nm wide constrictions and nanoribbon transistors.