Dependence of SiO2 Gate Leakage Current on Annealing Temperature of Solution Processed Tin Oxide Semiconductor

In this paper, tin oxide (SnOx) semiconductor is synthesized using a sol-gel process. Thermal oxidation process is used to grow a silicon dioxide (SiO
2
) film on an n
⁺
-Si substrate as the gate dielectric layer. A significant difference in the transfer characteristics is observed for the SnOx/SiO
2
samples annealed at 200-400 °C. For the 200 °C-annealed sample, the conductivity of the SnO
x
semiconductor layer cannot be controlled by the n
⁺
-Si gate electrode. When the annealing temperature increases to 300 °C, a significant switching behavior induced by the gate bias can be obtained. However, an obvious increase in the off-sate current is found as the annealing temperature further rises to 400 °C. The leakage current of the SiO
2
gate dielectric is also found to be dependent on the concentration of the SnO
x
precursor solution. This study is helpful for developing oxide semiconductors for future flexible electronic applications.