High-Mobility Amorphous InGaZnO Thin-Film Transistors With Nitrogen Introduced via Low-Temperature Annealing

In this letter, the carrier mobility of amorphous InGaZnO (a-IGZO) thin-film transistor (TFT) was remarkably enhanced by the introduction of nitrogen and the formation of Zn ₃ N ₂ , in which the saturation field-effect mobility ( $\mu _{\text {sat}}$ ) was 61.6 cm ² /Vs. Annealing temperature plays a key role on the enhancement of carrier mobility. When the annealing temperature was increased to 400 °C, $\mu _{\text {sat}}$ was reduced to 4.1 cm ² /Vs, which was proposed to be due to the formation of defective Zn _x N _y based on X-ray photoelectron spectroscopy results. In addition, the a-IGZO TFT with enhanced mobility did not exhibit persistent photoconductivity behavior. The high carrier mobility could expand the application of a-IGZO TFTs to functional circuits in active-matrix displays.