High Field Effect Mobility, Amorphous In-Ga-Sn-O Thin-Film Transistor With No Effect of Negative Bias Illumination Stress

We report a dual-gate, amorphous In-Ga-Sn-O (aIGTO) thin-film transistor (TFT) exhibiting high field-effect mobility (μFE) and very low subthreshold swing. The TFT has a bottom-gate having 5 μm overlap with source/drain (S/D) and a top-gate with 0.5 μm offset with S/D electrodes. The bottom-gate potential is swept at various top-gate voltages. The μFE of a-IGTO TFT is found to be 39.1 cm
²
V
^-1
s
^-1
which is almost independent of top-gate potential. The subthreshold swing is ~ 0.19 Vdec
^-1
and also does not change much with top-gate potential variation between -50 V and +90 V, indicating very low density of states in the gap. The a-IGTO TFT exhibits no effect of negative bias illumination stress.