Achieving\nQuasi Intrinsic MoS<sub>2</sub> Performance\nvia Liquid-Based Neutralization of Material and Interface Defects\nwith H<sup>+</sup> Protons

Semiconductor\nfabrication introduces imperfections such as dangling\nbonds and charge traps on channel surfaces and interfaces. Addressing\nthese defects becomes challenging with miniaturized structures and\nlow-dimensional materials, because high-energy treatments may cause\nsecondary damage. Ionized hydrogen in the liquid phase neutralizes\nnegatively charged defects through chemical reactions. The bis(trifluoromethanesulfonyl)­imide\n(H-TFSI) solution, effective in mitigating defects in MoS<sub>2</sub>, lacks verification of its mechanism and impact on device performance.\nTreating monolayer MoS<sub>2</sub> FET with H-TFSI induces simultaneous\nenhancement and degradation, complicating our understanding of the\nspecific reactions. This study employed monolayer and multilayer MoS<sub>2</sub> devices to distinguish the surface and gate dielectric interface\ninfluence. In addition to the DC measurements for device performance\nanalysis, low-frequency noise characteristics were examined to provide\na more detailed depiction of the interface traps. Treating multilayer\nMoS<sub>2</sub> with H-TFSI results in more than a 2-fold increase\nin carrier mobility, and applying a negative gate voltage to further\nenhance the hydrogen ion reaction leads to a mobility increase exceeding\n3-fold, reaching a high value of 128.3 cm<sup>2</sup>/V s compared\nto the baseline device. The interface trap density decreased, and\nthe threshold voltage shifted positively. This signifies that the\nhydrogen ions from H-TFSI validated their remarkable healing effects\non the surface and interface defects in MoS<sub>2</sub> devices by\ndemonstrating their superior performance in passivating interface\ntraps and neutralizing material defects.