Effect of Hafnium-Based Thin Film Thickness on Microstructure and Electrical of Yttrium-Doped Hafnium Oxide Ferroelectric Devices Prepared by Magnetron Sputtering

This study employs reactive magnetron sputtering technology to fabricate TiN/Y-HfO₂/TiN multilayer thin film devices using titanium targets and yttrium-doped high-purity hafnium targets. A systematic investigation was conducted to explore the influence of hafnium-based thin film thickness on the structural and electrical properties of TiN/Y-HfO₂/TiN thin film devices. Radio frequency magnetron sputtering was utilized to deposit Y-HfO₂ films of varying thicknesses on TiN electrodes by controlling deposition time, with a yttrium doping concentration of 8.24 mol.%. The surface morphology and crystal structure of the thin films were characterized using atomic force microscopy (AFM), Raman spectroscopy, X-ray diffraction (XRD). Results indicate that as film thickness increases, surface roughness and Raman peak intensity increase correspondingly, with the tetragonal phase (t) characteristic peak being most prominent at 65 nm. DC magnetron sputtering was employed to deposit TiN top electrodes, resulting in TiN/Y-HfO₂/TiN thin film devices. Following rapid thermal annealing at 700 °C, electrical properties were evaluated using a ferroelectric tester. Leakage current density exhibited a decreasing trend with increasing film thickness, while the maximum polarization intensity gradually increased, reaching a maximum of 11.5 μC/cm² at 120 nm.