Influence of H[sub 2]O Dipole on Subthreshold Swing of Amorphous Indium–Gallium–Zinc-Oxide Thin Film Transistors

The original influence of water on the back-channel of sol–gel derived amorphous indium–gallium–zinc-oxide thin film transistors was studied in various relative humidity environments. As humidity increased from 0 to 80%, the mobility increased from , threshold voltage decreased from , and subthreshold swing changed from . The conflicting phenomenon among the three parameters was suggested to be due to a division of the gate voltage by the water molecules which adsorbed on the thin film transistor back-channel and acted as dipoles.