Enhancing Performance and Reliability of Hf _1‐ <i> _x </i> Zr <i> _x </i> O ₂ Morphotropic Phase Boundary Films via Nanolaminate Structuring and Microwave Annealing

ABSTRACT Hf 1‐ x Zr 𝑥 O 2 (HZO) morphotropic phase boundary (MPB) films provide a high dielectric constant but suffer from reliability concerns stemming from phase instability and wake‐up during electrical cycling, along with variability at reduced device dimensions. A nanolaminate MPB architecture with alternating sub‐nm HZO/ZrO 2 layers that confine orthorhombic and tetragonal phase formation is reported, thereby suppressing wake‐up and preserving the MPB‐driven dielectric response under cycling. In solid‐solution MPB films, grain sizes of ≈10 nm can induce device‐to‐device variability through heterogeneous phase fractions. The nanolaminate mitigates this variability by stabilizing layer‐resolved phase partitioning. In parallel, microwave annealing (MWA) reduces interlayer intermixing relative to rapid thermal annealing, maintains sharp compositional boundaries, and improves endurance. Because nanoscale dielectric variability is difficult to measure directly, a phase distribution model calibrated to device data and extending wake‐up analysis to the MPB regime are used, revealing an endurance degradation pathway mitigated by phase confinement and preserved interfaces. Electrical measurements and structural analyses confirm that the nanolaminate with MWA preserves the high‐k response, suppresses wake‐up‐induced degradation, enhances endurance, and narrows variability relative to solid‐solution counterparts. These results outline a practical, process‐compatible route to uniform and reliable MPB dielectrics suitable for integration in advanced memory and logic technologies.