High Performance Amorphous In–Ga–Zn–O Thin-Film Transistors with Low Temperature High-k Solution Processed Hybrid Gate Insulator

Abstract

For flexible display applications, high performance amorphous In–Ga–Zn–O (a-IGZO) thin-film transistors (TFTs) fabricated by low temperature process are required. Moreover, high dielectric constant (high-k) material which enables higher mobility and lower threshold voltage while minimizing the device size are excellent candidates to replace SiO2 gate insulators in conventional oxide semiconductor TFTs. Therefore, nanocomposite material containing high-k BaTiO3 nanoparticles and transparent poly-siloxane (PSX) hybrid polymer were deposited as gate insulator in a-IGZO TFTs to facilitate the reduction of process temperature due to the high temperature requirement (>650 ºC) of BaTiO3. This paper presents the performance and analysis of a-IGZO TFTs with high-hybrid gate insulators at different ratios of BaTiO3/PSX deposited by solution process at a lower temperature (300 ºC). The TFT shows a high mobility of 35.59 cm2 V−1 s−1, low threshold voltage of 0.4 V, and gate leakage current of ∼10−10 A.