Enhanced Tunneling Electro-Resistance Ratio for Ferroelectric Tunnel Junctions by Engineering Metal Work Function
Yi-Fan Chen, Lee-Wen Hsu, Chia-Wei Hu, Guan-Ting Lai, Yung‐Hsien Wu
Abstract
The structure of metal electrode/HfZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> (HZO)/AlON/n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -Si was employed as the platform to study how the effective work function (EWF) of the electrode affects the characteristics of the FTJ devices. By introducing TiAl into the conventional TiN electrode, the EWF is reduced which leads to a higher tunnel electroresistance (TER) ratio of 30 due to the improved LRS current arising from the lower barrier height for thermionic emission. In addition, the TiAl-based device also displays high switching speed of 500 ns and robust endurance up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> , showing competitive advantages compared to others. Furthermore, the implementation of long-term plasticity is also demonstrated, implying potential applications for neuromorphic computing. The prominent properties make TiAl-based electrode as a compelling enabler for FTJ devices with even higher performance.