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Identification of ferroelectric HfZrO2 from the distinct signature of O 1s spectra in polar and non-polar sublattices

Marius Adrian Husanu, Lucian Dragos Filip, Cristina Florentina Chirila, and Dana Georgeta Popescu*

  • *Contacy author: dana.popescu@infim.ro
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Phys. Rev. Materials 10, 034401 – Published 2 March, 2026

DOI: https://doi.org/10.1103/h2lj-slbg

Abstract

HfZrO2(HZO) is a promising ferroelectric material compatible with CMOS technology, retaining functionality at nanometer-scale thicknesses. Its ferroelectricity arises from metastable polar phases—orthorhombic (Pca21) and rhombohedral (R3m)–coexisting with the thermodynamically stable, non-polar monoclinic phase (P21/c). Accurate quantification of these coexisting phases is essential for optimizing device performance. Here, we use first-principles calculations to estimate core-level shifts in the O 1s X-ray photoelectron spectroscopy (XPS) peak, revealing a distinct, up to 0.84 eV higher binding energy component for oxygen atoms in the polar sublattice compared to those in non-polar environments. These shifts incorporate both initial and final state effects in photoemission. Experimental validation through X-ray diffraction (XRD) and XPS on HZO films with varying phase composition confirms our predictions. Our findings provide a clear, spectroscopically accessible fingerprint to distinguish polar and non-polar phases in HZO via O 1s XPS analysis, offering a practical tool for phase quantification and enabling targeted integration of ferroelectricity in advanced nanoelectronic devices.

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Phys. Rev. Materials 10, 034401– Published 2 March, 2026
  • Received 25 June 2025
  • Accepted 29 January 2026
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