$\hbox {MoS}_{2}$ Nanoribbon Transistors: Transition From Depletion Mode to Enhancement Mode by Channel-Width Trimming

We study the channel width scaling of back-gated MoS₂ metal-oxide-semiconductor field-effect transistors from 2 μm down to 60 nm. We reveal that the channel conductance scales linearly with channel width, indicating no evident edge damage for MoS₂ nanoribbons with widths down to 60 nm as defined by plasma dry etching. However, these transistors show a strong positive threshold voltage (V_T) shift with narrow channel widths of less than 200 nm. Our results also show that transistors with thinner channel thicknesses have larger V_T shifts associated with width scaling. Devices fabricated on a 6-nm-thick MoS₂ crystal underwent the transition from depletion mode to enhancement mode.