Ferroelectricity in hafnium oxide films doped with magnesium by chemical solution deposition

In this study, a series of ∼26 nm thick hafnium oxide films doped with different concentrations of Mg were prepared by the chemical solution deposition method. With the increase of Mg concentration, the film undergoes a phase transition from monoclinic, through orthorhombic, and then to cubic. Metal–insulator–semiconductor capacitors were fabricated, and the ferroelectricity was verified for films doped with an Mg concentration of 0.4–3.7 mol. %. For the film doped with 2.3 mol. % Mg, the remanent polarization is 16.4 μC/cm2 after the wake-up process, and 76.1% of the initial 2Pr value can be maintained after 107 cycles of bipolar field cycling. All the results show that Mg is a promising dopant to stabilize the ferroelectricity of hafnium oxide films.