The demonstration of high-performance multilayer BaTiO₃/BiFeO₃ stack MIM capacitors

Multilayer BaTiO₃/BiFeO₃ (BTO/BFO) stack structures were prepared on the Pt/TiO₂/SiO₂/Si (100) substrate via highly accurate magnetron sputtering process. The cubic to the tetragonal phase transition of BTO was confirmed by both the X-ray diffraction and Raman spectroscopy after the process of rapid thermal anneal. An 74.1% increase of the relative permittivity was observed with the increasing thickness of BFO in the metal-insulator-metal capacitor. On the other hand, we also demonstrate that the leakage current density and the relative permittivity are found to have 20-50 times reduction and 26.6% improvement, respectively, with the additional cap of the BTO layer.