Innovative Nb Electrode Engineering for Ultra-Low-Voltage ($\mathrm{V}_{\text {op }}=0.8\mathrm{V}$) Ferroelectric Memory With Record-High Energy Efficiency: Applications in Selector-Free Feram and Neuromorphic Computing

BEOL-compatible $5-\text{nm} \quad \text{Hf}_{0.5} \text{Zr}_{0.5} \mathrm{O}_{2}$ (HZO) ferroelectric (FE) devices achieve a record-breaking energy efficiency 2Pr-to-operation voltage ($\mathrm{V}_{\text {op }}$) of 43, delivering 2Pr of $34.4 \mu \mathrm{C} / \text{cm}^{2}$ at an ultra-low $\mathrm{V}_{\text {op }}$ of $\pm 0.8\mathrm{V}$, through Nb metal engineering. The Nb approach demonstrates remarkable reliability with an only $4.5 \% 2 \text{Pr}$ loss after 10 years at 85° C and an estimated 10.8 % degradation over 10¹⁵ operation cycles. Furthermore, the Nb -integrated selector-free FeRAM exhibits nearly disturbance-free performance (1%), and outstanding potential for neuromorphic computing, characterized by superior linearity and a highly symmetric factor.