Improvement of Stability and Performance of Amorphous Indium Gallium Zinc Oxide Thin Film Transistor by Zinc-Tin-Oxide Spray Coating
Hwayeong Lee, Suhui Lee, Youngoo Kim, Abu Bakar Siddik, Mohammad Masum Billah, Jiseob Lee, Jin Jang
Abstract
We report the effect of zinc-tin-oxide (ZTO) by spray coating on indium gallium zinc oxide (IGZO) thin-film transistor (TFT) for the improvement of both stability and performance. The IGZO/ZTO TFT exhibits the field effect mobility (μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FE</sub> ) of 18.39 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V · s, threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Th</sub> ) of 0.1 V, and subthreshold swing (SS) of 0.16V/dec. The TFT shows excellent stabilities: Δ V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Th</sub> of -1.0 V for negative bias illumination stress (NBIS) and 0.4 V for hot carrier stress. These excellent performance and stability are correlated with the built-in electric field by charge distribution at the IGZO/ZTO hetero-junction. Therefore, ZTO spray coating on IGZO semiconductor can be a good technique to improve device stability.