Simulation of the influence of the gate dielectric on amorphous indium-gallium-zinc oxide thin-film transistor reliability

Indium-gallium-zinc oxide (IGZO) thin films have attracted significant attention for application in thin-film transistors (TFTs) due to their specific characteristics, such as high mobility and transparency. The performance of a-IGZO TFTs with four different insulators (SiO2 Si3N4, Al2O3 and HfO2) is examined using a numerical simulator (Silvaco Atlas). It is found that the output performance is significantly enhanced with high relative permittivity of the insulator. HfO2 gives the best performance: lower threshold voltage 0.23 V and subthreshold 0.09 V dec−1, higher field-effect mobility 13.73 cm2 s−1 V−1 and on current (Ion) and Ion/Ioff ratio 2.81×10-6\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$2.81 \times 10^{ - 6}$$\end{document} A, 5.06×1012\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$5.06 \times 10^{12}$$\end{document}, respectively. Therefore, HfO2 gate showed high stability compared with other gate insulator materials.