Improving the Electrical Performance of RF-Sputtered InSnZnO Thin-Film Transistors via Octadecylphosphonic Acid Self-Assembled Monolayer

RF-sputtered InSnZnO (ITZO) thin-film transistors (TFTs) coated with octadecylphosphonic acid (ODPA) self-assembled monolayer (SAM) is fabricated and characterized for the first time. The ODPA-treated ITZO TFTs exhibit excellent device electrical characteristics with high field-effect mobility of ~86.74 cm
²
V
^-1
s
^-1
, steep subthreshold swing of ~0.21 mV/dec, and large on/off current ratio of ~6.53x10
⁷
. The excellent device performance enhanced by introducing ODPA SAM is mainly attributed to the prevention of oxygen and water vapor into the active layer, surface doping effect and dangling bond reparation.