Enlargement of Memory Window of Si Channel FeFET by Inserting Al₂O₃ Interlayer on Ferroelectric Hf₀.₅Zr₀.₅O₂

In this work, we demonstrate the enlargement of the memory window of Si channel FeFET with ferroelectric Hf0.5Zr0.5O2 by gate-side dielectric interlayer engineering. By inserting a 3 nm Al2 O3 dielectric interlayer between TiN gate metal and ferroelectric Hf0.5Zr0.5O2, we achieve a memory window of 4.1 V with endurance of ~104 cycles and retention over 10 years. The physical origin of memory window enlargement is clarified to be charge trapping at the Al2O3/Hf0.5Zr0.5O2 interface, which has an opposite charge polarity to the trapped charges at the Hf0.5Zr0.5O2/SiOx interface.