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The elastic moduli of amorphous and crystalline atomic layer-deposited Hf1-xZrxO2 (HZO, x = 0, 0.31, 0.46, 0.79, 1) films prepared with TaN electrodes on silicon substrates were investigated using picosecond acoustic measurements. The moduli of the amorphous films were observed to increase between 211 ± 6 GPa for pure HfO2 and 302 ± 9 GPa for pure ZrO2. In the crystalline films, it was found that the moduli increased upon increasing the zirconium composition from 248 ± 6 GPa for monoclinic HfO2 to 267 ± 9 GPa for tetragonal ZrO2. Positive deviations from this increase were observed for the Hf0.69Zr0.31O2 and Hf0.54Zr0.46O2 compositions, which were measured to have moduli of 264 ± 8 GPa and 274 ± 8 GPa, respectively. These two compositions contained the largest fractions of the ferroelectric orthorhombic phase, as assessed from polarization and diffraction data. The biaxial stress states of the crystalline films were characterized through sin2( ψ) x-ray diffraction analysis. The in-plane stresses were all found to be tensile and observed to increase with the increasing zirconium composition, between 2.54 ± 0.6 GPa for pure HfO2 and 5.22 ± 0.5 GPa for pure ZrO2. The stresses are consistent with large thermal expansion mismatches between the HZO films and silicon substrates. These results demonstrate a device-scale means to quantify biaxial stress for investigation on its effect on the ferroelectric properties of hafnia-based materials.

We introduce an Atomic Layer Deposition (ALD) technique referred to here as Sequential, No-Atmosphere Processing (SNAP) to fabricate ferroelectric Hf0.5Zr0.5O2 capacitors in Metal–Ferroelectric–Metal (MFM) structures. SNAP involves the ALD of each layer sequentially while maintaining the sample under vacuum process conditions without ambient exposure during the entire sequential deposition processes. We first use plasma enhanced ALD to fabricate 002-textured TiN films and study the degree of texture and quality of the film by X-ray Diffraction (XRD), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and transmission electron microscopy. Building upon the textured TiN film, we fabricate MFM capacitors with 10-nm-thick Hf0.5Zr0.5O2 via SNAP deposition and observe an unexpectedly large remanent polarization (2Pr = 54.2 μC/cm2). We report that annealing at T

We report on the thermal resistances of thin films (20 nm) of hafnium zirconium oxide (Hf1–xZrxO2) with compositions ranging from 0 ≤ x ≤ 1. Measurements were made via time-domain thermoreflectance and analyzed to determine the effective thermal resistance of the films in addition to their associated thermal boundary resistances. We find effective thermal resistances ranging from 28.79 to 24.72 m2 K GW−1 for amorphous films, which decreased to 15.81 m2 K GW−1 upon crystallization. Furthermore, we analyze the heat capacity for two compositions, x = 0.5 and x = 0.7, of Hf1–xZrxO2 and find them to be 2.18 ± 0.56 and 2.64 ± 0.53 MJ m−3 K−1, respectively.