  We study field effect transistor characteristics in etched single layer MoS2
nanoribbon devices of width 50nm with ohmic contacts. We employ a SF6 dry
plasma process to etch MoS2 nanoribbons using low etching (RF) power allowing
very good control over etching rate. Transconductance measurements reveal a
steep sub-threshold slope of 3.5V/dec using a global backgate. Moreover, we
measure a high current density of 38 uA/um resulting in high on/off ratio of
the order of 10^5. We observe mobility reaching as high as 50 cm^2/V.s with
increasing source-drain bias.
