Doping of ${\mathrm{Hf}}_{0.5}{\mathrm{Zr}}_{0.5}{\mathrm{O}}_2$ ($\mathrm{HZO}$) films with rare-earth metals during atomic layer deposition growth has been found to significantly affect their structural and functional properties. Here, we report on the structural properties of $\mathrm{Y}\text{−}$ and $\mathrm{La}$-doped polycrystalline $\mathrm{HZO}$ films as revealed by synchrotron-based near-edge x-ray absorption fine-structure (NEXAFS) technique, and complemented by x-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques for $\mathrm{Y}:\mathrm{HZO}$. In contrast to XRD and TEM, NEXAFS analysis taken near the $\mathrm{O}$ K (1s)-edge can distinguish between orthorhombic (o-) and tetragonal (t-) phases with much better accuracy and, furthermore, provides quantitative information about phase composition. In addition, the absorption spectra taken near $\mathrm{Zr}$ ${\mathrm{M}}_3$ ($3p_{3/2}$)-edge and $\mathrm{O}$ K (1s)-edge also provide reliable information about the presence of the monoclinic (m-) phase, even in the case of highly textured samples. The structural data are further correlated with the electrical properties of $\mathrm{Y}$: and $\mathrm{La}:\mathrm{HZO}$ films sandwiched in capacitor structures, which are found to depend on the dopant concentration either, suggesting that the delicate balance of different phases in doped $\mathrm{HZO}$ (revealed by NEXAFS) defines the functional properties of devices. Despite the progress in the quantitative assessment of phase composition by NEXAFS, the unambiguous prediction of the electrical response in doped $\mathrm{HZO}$ remains challenging, and calls for the use of operando NEXAFS structural analysis in functional prototype capacitor devices to directly monitor an apparent structural evolution in this class of materials upon the electrical stress.

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• Ferroelectricity
• Structural properties
• Capacitors
• Devices for digital logic, storage & processing
• Rare-earth doped crystals
• Transition metal oxides
• Ultrathin films
• X-ray absorption near-edge spectroscopy