Fabrication and Electrical Properties of Low Temperature-Processed Thin-Film-Transistors with Chemical-Bath Deposited ZnO Layer

ZnO film was grown on ZnO quantum dot seed layer-coated substrate by a low-temperature chemical bath deposition, where sodium citrate serves as a complexing agent for Zn2+ ion. The ZnO film deposited under the optimal condition exhibited a highly uniform surface morphology with a thickness of similar to 30 nm. For the fabrication of thin-film-transistor with a bottom-gate structure, ZnO film was chemically deposited on the transparent substrate of a seed layer-coated SiNx/ITO (indium tin oxide)/glass. As-deposited ZnO channel was baked at low temperatures of 60-200 degrees C to investigate the effect of baking temperature on electrical performances. Compared to the device with 60 degrees C-baked ZnO channel, the TFT performances of one with 200 degrees C-baked channel were substantially improved, exhibiting an on-off current ratio of 3.6 x 10(6) and a saturated field-effect mobility of 0.27 cm(2)/V.s.