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 .