Unified Phase-Field Framework for Antiferroelectric, Ferroelectric and Dielectric Phases: Application to HZO Thin Films

초록

Hafnia-based thin films used in metal-insulator-metal capacitors often exhibit mixed phases: ferroelectric (FE), antiferroelectric (AFE), and dielectric (DE). A theoretical framework linking polycrystalline microstructure to ferroic switching in such mixed-phase systems remains lacking. Here, we develop a three-dimensional (3D) phase-field model that resolves grain topology, and evolves coupled macroscopic and staggered polarization order parameters under self-consistent electrostatics. In single-layer films, FE-AFE proximity, rather than long-range percolation, controls AFE switching. Vertical phase architecture provides a deterministic lever on the coercive field , decomposing it into structural and electrostatic contributions: , arising from interlayer gradient coupling and bound charges, respectively. The saturation electrostatic energy density emerges as the dominant predictor of MV/cm and . This shared dependence creates a trade-off between and , defining a Pareto frontier that identifies the best-balanced architecture. These findings establish vertical phase architecture as a design parameter to reduce in such films.

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