| 초록 |
Recently, oxide semiconductors have attracted lots of attentions as an active layer in thin film transistors. Comparing to amorphous silicon and low temperature polycrystalline silicon devices, oxide semiconductors have sufficient mobility to drive active matrix OLED, good environmental stability, low cost and high transparency for backplanes with large aperture ratio. In this research, Zinc oxide (ZnO) semiconductor thin film transistor was produced by simple sol-gel method using zinc acetate dihydrate as a precursor and ethanol amine as a chelating agent. ZnO TFT was fabricated by simple spin coating and thermal annealing process. The ZnO TFT is highly transparent (＞90% transmittance) in visible region. Property of ZnO TFT is improved as amount of chelating agent decrease. TFT characteristics are also affected by heat treatment temperature, procedure and atmosphere. The optimized ZnO TFT exhibits high field effect mobility of 1.5 cm2/Vs, positive threshold voltage. In addition, to improve the TFT characteristics fluorine was doped from Trifluoroacetic acid and it changed the stoichiometry of zinc and oxygen. As a result, we could enhance and control the TFT characteristics. |
