Effect of the Hf content on the microstructure and ferroelectric properties of Hf _x Zr _{1− x} O ₂ thin films using an all-inorganic aqueous precursor solution

The synthesis of ferroelectric Hf_xZr_1-xO₂ (0 ≤ x ≤ 0.50) thin films by chemical solution deposition (CSD) on the surface of Si (100) substrates using all-inorganic salt precursors, is demonstrated in this study. The effects of the Hf content on the microstructure and ferroelectric properties of the films were investigated. The results showed that as the Hf component increased, the root mean square (RMS) roughness as well as the m-phase proportion gradually improved. Near the main diffraction peak of 30.7°, a phase transition from the orthorhombic to the cubic phase, and then to the tetragonal phase occurred. The best ferroelectric behaviour was obtained in the Hf_xZr_1-xO₂ film with a Hf content of 14% after 10³ field cycling. The H_0.14Z_0.86O₂ thin film exhibited the highest remanent polarization of 12.1 μC cm^-2, accompanied by a relative permittivity of 31.8.