Physical properties of MOD derived Bi₄Ti₃O₁₂/Bi₂SiO₅/Si structures

Bismuth titanate (Bi₄Ti₃O₁₂) thin films were fabricated on (100)-oriented silicon substrates with bismuth silicate (Bi₂SiO₅) buffer layer by metal organic decomposition (MOD) method. It was confirmed that the resultant films were single-phase Bi₄Ti₃O₁₂ with c-axis dominant orientation. Thickness of Bi₄Ti₃O₁₂ and Bi₂SiO₅ layer were approximately 50 nm and 5 nm, respectively. The fabricated metal-ferroelectric-insulator-semiconductor (MFIS) structures, have relatively superior leakage current density of approximately 10^-9 A cm^-2 and high break-down applied voltage of approximately 10 V. From the above result, it is confirmed that the crystallinity and surface morphology of Bi₄Ti₃O₁₂ thin films are greatly dependent on the existence of a Bi₄SiO₅ layer. Therefore, we consider that the Bi₄Ti₃O₁₂ thin film characteristics may be improved by Bi₂SiO₅ buffer layer.