Thermal effect of annealing-temperature on solution-processed high-k ZrO(2) dielectrics

In this paper, a solution-processed zirconium oxide (ZrO(2)) dielectric was deposited by spin coating with varying pre-annealing temperatures and post-annealing temperatures. The thermal effect of the pre-annealing and post-annealing process on the structural and electrical properties of ZrO(2) films was investigated. The result shows that the pre-annealing process had a significant impact on the relative porosity and internal stress of ZrO(2) film. A pre-annealing process with a low temperature could not effectively remove the residual solvent, while a high pre-annealing temperature would lead to large internal stress. As for post-annealing temperature, it was found that the post-annealing process can not only reduce internal defects of the ZrO(2) dielectric, but also optimize the interface between the semiconductor and dielectric by lowering the surface defects of the ZrO(2) film. Finally, the TFT with a pre-annealing temperature of 200 °C and post-annealing temperature of 400 °C showed optimized performance, with a mobility of 16.34 cm(2) (V s)(−1), an I(on)/I(off) of 2.08 × 10(6), and a subthreshold swing (SS) of 0.17 V dec(−1).