High Mobility and Improved Subthreshold Characteristics of Ultra-Thin Channel IGZTO TFTs Down to 3 nm

In this work, the electric characteristics of IGZTO thin-film transistors (TFTs) with ultra-thin channel thicknesses (T<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH</inf>) down to 3 nm were systematically investigated. As T<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH</inf> decreases, a positive shift in threshold voltage (V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf>) is observed, with the 3 nm device showing a V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf> around 0.9 V and a field-effect mobility of 30.3 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>(V·s)<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup>. The 5 nm device, featuring an appropriate V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf> of 0.36 V, achieves an optimal balance with high mobility, highlighting the potential of IGZTO TFTs in sub-10 nm process technology for low-power applications.