Room temperature fabricated transparent amorphous indium zinc oxide based thin film transistor using high-κ HfO2 as gate insulator

We report here the performance of amorphous oxide transparent thin film transistors (TFTs) fabricated using DC magnetron sputter techniques at room temperature. Amorphous indium zinc oxide (a-IZO, In2O3:ZnO, 90:10 wt.%) and high dielectric constant hafnium oxide (HfO2) films were deposited for the semiconducting channel and gate insulator under a mixture of ambient argon and oxygen gas, respectively. The reported transparent TFT structure was a bottom-gate type, consisting of indium-tin-oxide and aluminium as gate electrode and source/drain electrodes, respectively. The optical transmittance of a-IZO films in the visible region was greater than 84%. The a-IZO TFTs showed that the field effect saturation mobility, I-on/I-off ratio, sub-threshold swing, and threshold voltage were extracted to give 13.09 cm(2)/V-s, 4 x 10(5), 0.42 V/decade, and 3.54 V. respectively. The reported a-IZO TFT with high dielectric constant HfO2 gate dielectric sputtered at room temperature presents high quality characteristics, which can be used as good candidate for the application of low-temperature fabricated optoelectronic devices on organic flexible substrates. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.