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 (a- IGTO) thin-film transistor (TFT) exhibiting high field-effect mobility ( \mu _{\text {FE}} ) and very low subthreshold swing. The TFT has a bottom-gate having 5~ \mu \text{m} overlap with source/drain (S/D) and a top-gate with 0.5~\mu \text{m} offset with S/D electrodes. The bottom-gate potential is swept at various top-gate voltages. The \mu _{\text {FE}} of a-IGTO TFT is found to be 39.1 cm ^{\text {2}}\text{V}^{-\text {1}}\text{s}^{-\text {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.