Lanthanum Oxide Surface Treatment to Form Diffusion Barrier and Interface Dipoles on Ferroelectric FET

We propose a novel surface treatment technique using a few La2O3 ALD cycles to improve the performance and reliability of FeFET-based non-volatile memory devices. The interfacial layer formed by a few La2O3 ALD cycles prior to the deposition of the HfZrO (HZO) ferroelectric layer on the silicon substrate, acts as a diffusion barrier, reducing the number of trap sites in the gate stack. The La2O3 interfacial layer also creates an imprint effect by forming interface dipoles between the HZO and Si. This reduces the switching voltage (V-sw) and increases program efficiency. Compared to the conventional SiO2 interlayer (IL), this approach significantly improves performance and reliability, resulting in an increase in the memory window (MW) from 1.1 V to 2.4 V and an increase in electron mobility from 105 cm(2)/V center dot s to 382 cm(2)/V center dot s, compared to the control sample. Endurance of 3 x 10(7) cycles and improved retention characteristics were also achieved.