Ferroelectricity in Ce0.2-HfO2 films around 500 nm in thickness

CeO2-HfO2 solid solution thin films (Hf1-xCexO2) were deposited on Pt(111)/TiO2/SiO2/Si(100) substrates using the chemical solution deposition method. This study investigates the influence of CeO2 content and annealing temperature on the structure and ferroelectric properties of Hf1-xCexO2 films. Ferroelectric behavior is demonstrated in polycrystalline Hf0.80Ce0.20O2 films with thicknesses ranging from 163 to 524 nm. And the structure of the films is analyzed using glancing incidence X-ray diffraction. The comprehensive results indicate that Hf0.80Ce0.20O2 films annealed at 850 °C exhibit excellent ferroelectricity. Square hysteresis loops associated with the ferroelectric orthorhombic phase are observed, even in the 524-nm-thick film. The remnant polarization (Pr) and coercive field (Ec) range from 16 to 18 μC/cm2 and 1100–1250 kV/cm, respectively, under a maximum applied electric field of 2 MV/cm for all Hf0.80Ce0.20O2 films. Furthermore, the film presents thickness-insensitive characteristic. The current work paves the new way to design high-performance thick HfO2-based ferroelectric films.