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

Abstract

<p>The integration of high-quality SrTiO<small>₃</small> thin films on silicon substrates is crucial for various applications. This work investigates the use of an out-of-plane, self-oriented La<small>₂</small>O<small>₂</small>CO<small>₃</small> seed layer prepared <em>via</em> the chemical solution deposition (CSD) method as a template for SrTiO<small>₃</small> growth by pulsed laser deposition (PLD). The growth window of the SrTiO<small>₃</small> thin film was determined by <em>in situ</em> X-ray diffraction and by studying the thermal stability of the La<small>₂</small>O<small>₂</small>CO<small>₃</small> 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 SrTiO<small>₃</small> film exhibited multiple preferential orientations rather than a continuous fibre texture. Transmission electron microscopy confirmed a uniform SrTiO<small>₃</small> 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.<br></p>