Enhancing the ferroelectricity and durability in Sm doped HfO2 thin films prepared by CSD method

In this study, Sm-doped HfO 2 (Hf 1- x Sm x O 2 ) thin films on Pt/TiN/SiO 2 /Si substrates were fabricated using chemical solution deposition (CSD) method. The effects of Sm doping concentration on the microstructure and ferroelectric properties of Hf 1- x Sm x O 2 films were systematically investigated. Grazing-incidence X-ray diffraction (GIXRD) analysis and ferroelectric property measurements of the polycrystalline Sm:HfO 2 films with thicknesses ranging from 60 to 88 nm, revealed that samples doped with 2.50% Sm exhibited optimal ferroelectric characteristics with a residual polarization ( P r ) of 15.96 µC/cm 2 and a coercive field ( E c ) of 1.13 MV/cm after annealing at 800℃. Interestingly, the 2.50% Sm-doped sample also demonstrates excellent endurance and retention properties, sustaining over 10 8 switching cycles without breakdown. Furthermore, density functional theory (DFT) calculations were conducted to elucidate the regulation mechanism of doping samarium on the ferroelectric properties of HfO 2 films. The well consistency of the computational results and experimental observations, indicating that samarium doping is a feasible strategy for enhancing the ferroelectric properties of hafnium oxide films.