Summary: | 碩士 === 國立交通大學 === 電子研究所 === 100 === In this paper, we have successfully developed a high performance thin film transistor (TFT) with indium gallium zinc oxide (IGZO) active layer deposited by atmospheric pressure plasma jet (APPJ). IGZO films show amorphous phase in XRD analysis. IGZO films have over 80% transmittance of visible light and band gap energy 3.78eV. Therefore, IGZO films deposited by APPJ are suitable for transparent devices. Wide band gap can release the issue of photo-excited leakage current. We deposited IGZO thin films on silicon wafer which was covered with SiO2 and studied the effect of thermal annealing on IGZO films quality and properties of TFTs with IGZO as active layer. In this work, we discussed the IGZO films properties including surface morphology, roughness, structure and crystallinity by analysis equipments including SEM, AFM, XRD, TEM and XPS. We also used Agilent 4156C to analyze IGZO TFTs electrical characteristic. At the final, we substituted high-k material for SiO2 as gate dielectric for decreasing Vth and S.S. And the IGZO TFT with Al2O3 as gate dielectric shows excellent performance of μ = 8.6 cm2/V-s, Vth = 0.75 V, SS = 0.28V/dec, Ion/Ioff ratio of 1.04×108.
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