Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7887599 | Ceramics International | 2018 | 24 Pages |
Abstract
High-k oxide dielectric films have attracted intense interest for thin-film transistors (TFTs). However, high-quality oxide dielectrics were traditionally prepared by vacuum routes. Here, amorphous high-k alumina (Al2O3) thin films were prepared by the simple sol-gel spin-coating and post-annealing process. The microstructure and dielectric properties of Al2O3 dielectric films were systematically investigated. All the Al2O3 thin films annealed at 300-600â¯Â°C are in amorphous state with ultrasmooth surface (RMS ~ 0.2â¯nm) and high transparency (above 95%) in the visible range. The leakage current of Al2O3 films gradually decreases with the increase of annealing temperature. Al2O3 thin films annealed at 600â¯Â°C showed the low leakage current density down to 3.9â¯Ãâ¯10â7 A/cm2 at 3â¯MV/cm. With the increase of annealing temperature, the capacitance first decreases then increases to 101.1â¯nF/cm2 (at 600â¯Â°C). The obtained k values of Al2O3 films are up to 8.2. The achieved dielectric properties of Al2O3 thin films are highly comparable with that by vapor and solution methods. Moreover, the fully solution-processed InZnO TFTs with Al2O3 dielectric layer exhibit high mobility of 7.23â¯cm2 Vâ1 sâ1 at the low operating voltage of 3â¯V, which is much superior to that on SiO2 dielectrics with mobility of 1.22â¯cm2/Vâ1 sâ1 at the operating voltage of 40â¯V. These results demonstrate that solution-processed Al2O3 thin films are promising for low-power and high-performance oxide devices.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Wenwen Xia, Guodong Xia, Guangsheng Tu, Xin Dong, Sumei Wang, Rui Liu,