Structural and ferroelectric properties of Pr doped HfO2 thin films fabricated by chemical solution method

HfO2 thin films with different praseodymium doping contents (Pr:HfO2) were fabricated by chemical solution deposition (CSD) method at ambient conditions. The chemical bonding and the composition of Pr doped HfO2 thin film were characterized by X-ray photoelectron spectroscopy (XPS), while the structural properties were investigated by glancing incidence X-ray diffraction (GIXRD) and high resolution transmission electron microscopy (HRTEM). It is found that the ferroelectric orthorhombic phase was induced in the HfO2 based thin films by Pr doping. The combined results of P-E (polarization-electrical field) and C-V (capacitance-voltage) measurements demonstrated that the 5mol% Pr doped HfO2 film exhibited a distinct ferroelectricity, with a maximum remanent polarization (P-r) of 6.9 mu C/cm(2) and a coercive field(E-c) of 1.2MV/cm. Notably, the polarization did not show obvious degradation over 1x10(8) switching cycles, suggesting good endurance performance of the Pr doped HfO2 thin film. These results indicate that Pr dopant could effectively induce ferroelectricity in HfO2 thin films, thereby becoming a new member of dopants for HfO2 based ferroelectrics.