Effect of Sc<sub>2</sub>O<sub>3</sub> Passivation Layer on the Electrical Characteristics and Stability of InSnZnO Thin-Film Transistors
Wei Zhong, Liangyun Kang, Sunbin Deng, Lei Lü, Ruohe Yao, Linfeng Lan, Hoi Sing Kwok, Rongsheng Chen
Abstract
We measure the electrical performance and stability of indium tin zinc oxide (ITZO) thin-film transistors (TFTs), respectively, covered with a passivation layer (PVL) of aluminum oxide (Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) or scandium oxide (Sc <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) prepared by pulsed laser deposition (PLD). The devices with the Sc <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> PVL exhibit both satisfactory electrical performance and stability with a field effect mobility of 16.4 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /Vs, threshold voltage of 1.0 V, subthreshold swing of 0.09 V/decade, and especially, a minimum threshold voltage shift of 0.7 and −1.6 V under negative bias temperature stress (NBTS) and positive bias temperature stress (PBTS), respectively. This may be attributable to the suppression of oxygen vacancy formation and excellent capacity to protect the channel from environmental effects. Although the devices with the Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> PVL show similar electrical performance, their stability is worse than that of the devices with Sc <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> . This shows the excellent potential of Sc <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> thin films as a PVL.