Outstanding Performance as Cu Top Gate IGZO TFT With Large Trans-Conductance Coefficient by Adopting Double-Layered Al2O3/SiNx Gate Insulator

Abstract

Gate insulator (GI) materials in top gate structured InGaZnO thin-film transistor (TFT) with copper gate electrode are examined for the application to the large area display. To overcome the problems with hydrogen diffusion, which can influence the number of carriers in oxide semiconductor and to gain large trans-conductance coefficient, a double-layered GI of 30nm Al2O3/120nm SiN(x)is adopted. The TFT showed field-effect mobility, V-on, SS, and hysteresis of 12.8cm(2)V(-1)s(-1), -0.7V, 0.17V decade(-1), and almost 0V, respectively, and the Von under the positive bias stress of 20V and negative bias stress of -20V at 60C for 10000s are +0.1 and -0.4V, respectively.