Enhancement-mode operation of multilayer MoS_2 transistors with a fluoropolymer gate dielectric layer

摘要

Enhancement-mode multilayer molybdenum disulfide (MoS_2) field-effect transistors (FETs), which are an immensely important component toward low-power electronics based on a two-dimensional layered semiconductor, are demonstrated using the fluoropolymer CYTOP as a gate dielectric. The fabricated devices exhibit threshold voltage (V_(TH)) of ～5.7 V with field-effect mobility (μ_(FE)) of up to 82.3 cm~2/V s, and the characteristics are compared with the depletion-mode characteristics of MoS_2 FETs with the cross-linked Poly(4-vinylphenol) gate dielectric (V_(TH) ～ -7.8 V). UV photo-electron spectroscopy analysis indicates that increased surface potential due to the surface dipole effect of the fluorine group influences the positive V_(TH) shift.