Hydrogenation of Mg-Doped InGaZnO Thin-Film Transistors for Enhanced Electrical Performance and Stability

Abstract

In this work, the hydrogenation (H) of Mg-doped amorphous InGaZnO (a-IGZO:Mg/H) thin-film transistors (TFTs) was fabricated via RF sputtering method. As a consequence, the a- IGZO:Mg/H TFT with field-effectmobility of 35.6 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /Vs, lowsub-threshold swing of 0.21 V/dec, high I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> , andsmall threshold voltage ( V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) of 0.5 V was obtained. In addition, the a- IGZO:Mg/H TFT exhibits the best stability for small V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> shifts of 1.5 (-1.7) V, 2.6 (-2.8) V, and 3.5 (-3.6) V under the conditions of gate bias, light illumination, and the temperature stress test. The X-ray photo-electron spectroscopy band structure and oxygen vacancy ( V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</sub> ) analysis indicate that the enhanced performance and stability are owing to the appropriate Mg/H co-doping concentration. This is because the Mg/H co-doped not only controlled the carrier concentration, but also reduced V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</sub> and interface trap density. Overall, the optimized Mg/H co-doped a-IGZO TFTs have provided an effective pathway to achieve high-performance oxide TFTs with superior stability.