Tailoring the ferroelectric properties of ZrO2 ultrathin films by interfacial engineering

The ferroelectric and antiferroelectric properties of ZrO2 ultrathin films (~12 nm in thickness) prepared by atomic layer deposition (ALD) were tailored by introducing sub-nanometer interfacial layers between the ZrO2 ultrathin film and top and bottom Pt electrodes. In terms of polarization switching ability, the ferroelectricity of ZrO2 ultrathin films was significantly enhanced by an HfO2 interfacial layer (i.e., a Pt/HfO2/ZrO2/HfO2/Pt layered arrangement). While, a TiO2 interfacial layer (i.e., a Pt/TiO2/ZrO2/TiO2/Pt layered arrangement) led to a transition from ferroelectricity to antiferroelectricity. The modulation of ferroelectricity and antiferroelectricity of ZrO2 ultrathin films by the interfacial layers can be achieved without post-annealing.