Epitaxial ferroelectric thin films of Bi-layered perovskites on silicon-based epitaxial oxide heterostructures by large area pulsed laser deposition

Ferroelectric thin films of Bi₄Ti₃O₁₂ and SrBi₂Ta₂O₉, the most studied Bi-layered perovskites, have been deposited by the so-called off-axis Pulsed Laser Deposition (PLD) technique. This technique allows deposition with a good uniformity onto entire silicon or silicon-based 3-inch wafers. In order to promote epitaxial growth, the Bi₄Ti₃O₁₂ and SrBi₂Ta₂O₉ thin films have been deposited onto epitaxial thin film templates of CeO₂/YSZ and on the conductive oxide (La_1−xSr_xCoO₃ (LSCO), itself deposited on a CeO₂/YSZ epitaxial template. These electrode and buffer layers have been deposited by off-axis PLD as well. The thickness and composition uniformity of the ferroelectric films, electrodes and buffer layers are important parameters with regard to their possible application in integrated microelectronics; uniformities achieved are in the range of 5 % to 15% of the mean thickness, depending on the material and deposition conditions.