Superior electrical properties and ferroelectric stability of Hf0.85Ce0.15O2-ZrO2 stacks on Si and flexible mica substrates

HfO2-based ferroelectric thin films have attracted substantial attention as potential candidates for next-generation memories and logic devices due to their superior scalability and compatibility with CMOS technology. In the present study, four types of Hf0.85Ce0.15O2-ZrO2 stacks were artificially designed and successfully prepared using the economical sol-gel method. The ZrO2-HCO-ZrO2-HCO film exhibited excellent ferroelectricity with a remnant polarization (Pr) of 32.9 µC/cm2. Large orthorhombic grains promoted by the middle-ZrO2 combined with the Ce doping could be the origin of the high Pr. The bottom-ZrO2 layer and the interrupted straight grain boundaries reduced the leakage current density. Meanwhile, the well-architected film grown on a flexible Mica substrate demonstrated good endurance behavior without obvious degradation over 106 bipolar switching cycles and outstanding bending endurance. These results suggest that the combination of doping and stacking structures can effectively tune the ferroelectricity of HfO2, which provides essential insights for designing next-generation devices. © 2024 Elsevier Ltd