Low Subthreshold Swing and High Mobility Amorphous Indium–Gallium–Zinc-Oxide Thin-Film Transistor With Thin HfO<sub>2</sub> Gate Dielectric and Excellent Uniformity
Subhranu Samanta, Umesh Chand, Shengqiang Xu, Kaizhen Han, Ying Wu, Chengkuan Wang, Annie Kumar, Hasita Velluri, Yida Li, Xuanyao Fong, Aaron Thean, Xiao Gong
Abstract
We report high performance amorphous Indium-Gallium-Zinc-Oxide (${a}$ -IGZO) thin-film transistors (TFTs) with 10 nm atomic-layer-deposited HfO2 as the gate dielectric, achieving subthreshold swing (SS) of 70.2 mV/decade, high effective mobility ($\mu _{\textit {eff}}$ ) of 55.3cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /$\text{V}\cdot \text{s}$ at an inversion carrier density ($N_{\textit {inv}}$ ) of $5\times 10^{{12}}$ cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> , and large $I_{ON}/\text{I}_{OFF}$ of >10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> . Furthermore, very good device-to-device uniformity has been confirmed by the statistical distribution of SS and maximum transconductance (Gm, max) measured from 20 pristine TFT devices. This ${a}$ -IGZO TFT has immense potential for the ultrafast and low power electronic devices for next-generation cost-effective emissive display, image sensing, and hardware for artificial intelligence (AI).