HfO<sub>2</sub>–ZrO<sub>2</sub> Superlattice Ferroelectric Field-Effect Transistor With Improved Endurance and Fatigue Recovery Performance
Yue Peng, Wenwu Xiao, Fenning Liu, Chengji Jin, Yan Cheng, Lühua Wang, Yueyuan Zhang, Xiao Yu, Yan Liu, Yue Hao, Genquan Han
Abstract
In this brief, we report that HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> –ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> superlattice (SL) ferroelectric field-effect transistors (FeFETs) demonstrate improved endurance, fatigue recovery, and retention performance compared to the HfZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> (HZO) control devices. During the program/erase (P/E) cycling and data retention, the density of interface traps is observed to increase less in the SL FeFETs than in the HZO transistors. This is due to the larger effective equivalent oxide thickness (EOT) of the SL, which reduces the electric field dropped at the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> interfacial layer (IL) in the SL transistor during P/E operations, thereby weakening the generation of interface traps and mitigating memory window (MW) degradation in SL devices. After undergoing 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> P/E cycles, the SL FeFET still achieved an MW above 500 mV with fatigue recovery.