Effects of Oxidants on the Bias-Stress Instabilities of In-Ga-Zn-O Thin Film Transistors Using HfO<sub>2</sub> Gate Insulator Prepared by Atomic Layer Deposition
Se-Na Choi, Sung‐Min Yoon
Abstract
We fabricated the In-Ga-Zn-O thin-film transistors using HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gate insulator prepared by atomic-layer deposition with different oxidants of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O and O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> at 200 °C. While the device using H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O showed almost no change in threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) even after 104 s with bias-stresses, the device using O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> showed the V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> shifts of -1.4 and +1.2 V under positive and negative bias stresses, respectively. Defect-related carrier generation model was suggested as a physical origin for the anomalous bias-stress instabilities and the related mechanisms, in which the incorporated hydrogens can interact with oxygen-related defects.