Study of Nitrogen High-Pressure Annealing on InGaZnO Thin-Film Transistors

We studied the effects of high-pressure annealing (HPA) on InGaZnO (IGZO) thin-film transistors (TFTs). HPA was proceeded after TFT fabrication as a post process to improve electrical performance and stability. We used N2 as the pressurized gas. The applied pressures were 1 and 3 MPa at 200 °C. For N2 HPA under 3 MPa at 200 °C, field-effect mobility and the threshold voltage shift under a positive bias temperature stress were improved by 3.31 to 8.82 cm(2)/(V s) and 8.90 to 4.50 V, respectively. The improved electrical performance and stability were due to structural relaxation by HPA, which leads to increased carrier concentration and decreased oxygen vacancy.