Preferentially oriented SrTiO3 thin films grown on lanthanide-assisted Si(001) via pulsed laser deposition

Abstract

The integration of high-quality SrTiO₃ thin films on silicon substrates is crucial for various applications. This work investigates the use of an out-of-plane, self-oriented La₂O₂CO₃ seed layer prepared via the chemical solution deposition (CSD) method as a template for SrTiO₃ growth by pulsed laser deposition (PLD). The growth window of the SrTiO₃ thin film was determined by in situ X-ray diffraction and by studying the thermal stability of the La₂O₂CO₃ film. This study resulted in crack-free films with preferential but not exclusive (001) out-of-plane orientation when using one-step PLD deposition at 750 °C. Further in-depth X-ray diffraction analysis revealed that the SrTiO₃ film exhibited multiple preferential orientations rather than a continuous fibre texture. Transmission electron microscopy confirmed a uniform SrTiO₃ film without interfacial reactions and a homogeneous composition. These findings highlight the key role of deposition conditions in controlling crystallinity and orientation, enabling the integration of high-quality perovskite oxide on silicon.