One-Step Passivation of Both Sulfur Vacancies and SiO₂ Interface Traps of MoS₂ Device

Transition metal dichalcogenides (TMDs) benefit electrical devices with spin-orbit coupling and valley- and topology-related properties. However, TMD-based devices suffer from traps arising from defect sites inside the channel and the gate oxide interface. Deactivating them requires independent treatments, because the origins are dissimilar. This study introduces a single treatment to passivate defects in a multilayer MoS₂ FET. By applying back-gate bias, protons from an H-TFSI droplet are injected into the MoS₂, penetrating deeply enough to reach the SiO₂ gate oxide. The characterizations employing low-temperature transport and deep-level transient spectroscopy (DLTS) studies reveal that the trap density of S vacancies in MoS₂ drops to the lowest detection level. The temperature-dependent mobility plot on the SiO₂ substrate resembles that of the h-BN substrate, implying that dangling bonds in SiO₂ are passivated. The carrier mobility on the SiO₂ substrate is enhanced by approximately 2200% after the injection.