Low-Temperature Fabrication of BiFeO3 Films on Aluminum Foils under a N2-Rich Atmosphere

To be CMOS-compatible, a low preparation temperature (<500 °C) for ferroelectric films is required. In this study, BiFeO3 films were successfully fabricated at a low annealing temperature (<450 °C) on aluminum foils by a metal–organic decomposition process. The effect of the annealing atmosphere on the performance of BiFeO3 films was assessed at 440 ± 5 °C. By using a N2-rich atmosphere, a large remnant polarization (Pr~78.1 μC/cm2 @ 1165.2 kV/cm), and a high rectangularity (~91.3% @ 1165.2 kV/cm) of the P-E loop, excellent charge-retaining ability of up to 1.0 × 103 s and outstanding fatigue resistance after 1.0 × 109 switching cycles could be observed. By adopting a N2-rich atmosphere and aluminum foil substrates, acceptable electrical properties (Pr~70 μC/cm2 @ 1118.1 kV/cm) of the BiFeO3 films were achieved at the very low annealing temperature of 365 ± 5 °C. These results offer a new approach for lowering the annealing temperature for integrated ferroelectrics in high-density FeRAM applications.