One-Step Passivation of Both Sulfur Vacancies and SiO<sub>2</sub> Interface Traps of MoS<sub>2</sub> Device.

Ahn, Byungwook; Kim, Yoonsok; Kim, Meeree; Yu, Hyang Mi; Ahn, Jaehun; Sim, Eunji; Ji, Hyunjin; Gul, Hamza Zad et al. · Nano Lett · 2023

basic_science · Level V

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Abstract

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 MoS<sub>2</sub> FET. By applying back-gate bias, protons from an H-TFSI droplet are injected into the MoS<sub>2</sub>, penetrating deeply enough to reach the SiO<sub>2</sub> gate oxide. The characterizations employing low-temperature transport and deep-level transient spectroscopy (DLTS) studies reveal that the trap density of S vacancies in MoS<sub>2</sub> drops to the lowest detection level. The temperature-dependent mobility plot on the SiO<sub>2</sub> substrate resembles that of the h-BN substrate, implying that dangling bonds in SiO<sub>2</sub> are passivated. The carrier mobility on the SiO<sub>2</sub> substrate is enhanced by approximately 2200% after the injection.