Enhancing the ferroelectricity of highly (001) oriented lanthanum-doped hafnium oxide films prepared by pulsed laser deposition

Hafnium oxide (HfO₂)-based ferroelectrics hold great promise for logic and non-volatile memory devices due to their scalability. However, the performance of most HfO₂ films is limited by a predominant (111) orientation, which yields a lower out-of-plane polarization compared to the (001) orientation. To promote the high polarization (001) orientation, we propose a synergistic interface engineering strategy utilizing non-stoichiometric cerium oxide (CeO_2−x) as both a seed and a capping layer. This approach effectively regulates the nucleation and growth of La-doped HfO₂ (HLO) films, promoting a (001)_O/(010)_O mixed preferred orientation and the formation of 90° ferroelectric domains. The film achieves a significantly enhanced remnant polarization (Pᵣ) of 37.6 μC/cm². This work provides a feasible interfacial strategy for boosting the ferroelectric performance of HfO₂-based materials, advancing their application in next-generation memory.