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

摘要

This study demonstrates the feasibility of producing an InGaZnO thin-film transistor (TFT) using a high-K germanium oxide (GeO_2)/titanium oxide (TiO_2)/GeO_2 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 × 10~7. The improved device performance can be attributed to the combined effect of high-k TiO_2 and the large band gap of GeO_2 that exhibits a tendency to remain in a Ge~(4+) oxidation state at room temperature.