Effects of Gate Oxide Materials on Electrical Performance of Amorphous Ingazno thin Film Transistors: An Analytical Survey

Three different oxides, including SiO2, HfLaO, and TiO2, were considered as the gate oxide (GOX) of an Amorphous Indium Gallium Zinc Oxide Thin-Film Transistor (a-IGZO TFT) and the electrical performance of the device was analytically studied using Atlas Silvaco®. The device was simulated in 2D environment and the ratio of the on- to off-state current, the subthreshold swing (SS), and the threshold voltage (Vth) of the device were investigated using individual oxides. The results are shown that significant improvements in the electrical properties in terms of a reduction in the off-state current with a large Ion/Ioff ratio of about 1015, a lowering in the subthreshold swing as low as 0.13 V/decade, and a decreasing in the threshold voltage to 0.23 V can be achieved in presence of the TiO2 as the GOX layer, compared with the other oxides.