Fully room-temperature IGZO thin film transistors adopting stacked gate dielectrics on flexible polycarbonate substrate

Abstract

This study demonstrates the feasibility of producing an InGaZnO thin-film transistor (TFT) using a high-kappa germanium oxide (GeO2)/titanium oxide (TiO2)/GeO2 gate stack on a flexible polycarbonate substrate. The flexible TFT exhibited a small sub-threshold swing of 0.132 V/decade, an acceptable field effect mobility of 8 cm(2)/(V s), and a robust I-on/I-off ratio of 2.4 x 10(7). The improved device performance can be attributed to the combined effect of high-kappa TiO2 and the large band gap of GeO2 that exhibits a tendency to remain in a Ge4+ oxidation state at room temperature. (C) 2013 Elsevier Ltd. All rights reserved.