Nonvolatile Half-Loop Operation of ZrO 2 Antiferroelectric Capacitors Enabled by a TiO 2 -Rich Interfacial Layer

In this work, we demonstrate an optimization strategy toward low-thermal-budget processing for ZrO2-based antiferroelectric (AFE) capacitors, achieving nonvolatile half-loop operation at ultralow voltage. By tuning the postdeposition annealing (PDA) temperature and bottom electrode (BE) O3treatment duration, AFE capacitors with a 6-nm ZrO2layer and asymmetric electrodes are fabricated. Optimal performance is obtained with a$450~^{\circ }$C PDA and 5-min BE O3treatment, yielding a double remnant polarization ($2{P}_{\text {r}}\text {)}$of$\boldsymbol {\sim }{\!}{\!}{\!}16.29~\boldsymbol {\mu }$C/cm2, endurance$\boldsymbol {\gt }{\!}{\!}10^{{10}}$cycles, and retention$\boldsymbol {\gt }{\!}{\!}10^{{4}}$s. Structural and chemical analyses reveal that longer O3treatment forms a TiO2-rich interfacial layer that stabilizes the anti-polar orthorhombic phase and facilitates interfacial dipole-assisted half-loop centering. Density functional theory (DFT) simulations further indicate that the ZrO2/TiO2interface lowers the polarization-switching barrier. These results provide a robust pathway toward energy-efficient ZrO2-based AFE capacitors for embedded nonvolatile memory (eNVM).