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 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$5-\text{nm} \quad \text{Hf}_{0.5} \text{Zr}_{0.5} \mathrm{O}_{2}$</tex> (HZO) ferroelectric (FE) devices achieve a record-breaking energy efficiency 2Pr-to-operation voltage (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{V}_{\text {op }}$</tex>) of 43, delivering 2Pr of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$34.4 \mu \mathrm{C} / \text{cm}^{2}$</tex> at an ultra-low <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{V}_{\text {op }}$</tex> of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 0.8\mathrm{V}$</tex>, through Nb metal engineering. The Nb approach demonstrates remarkable reliability with an only <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4.5 \% 2 \text{Pr}$</tex> loss after 10 years at 85° C and an estimated 10.8 % degradation over 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> 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.