Effect of growth temperature on structural and morphological evolution of epitaxial SrTiO3 thin films grown on LaAlO3 (001) substrates by ion beam sputter deposition

•The SrTiO3 thin films were epitaxially grown on LaAlO3 (001) substrate by IBSD.•Growth temperature has a strong influence on the evolution of crystal structure and growth mode.•The STO thin films are under in-plane compressive strain with a tetragonal distortion.•The transition from 3D island to 2D layer-by-layer growth mode occurs at ≥750 °C.

A series of epitaxial SrTiO3 (STO) thin films were grown on (001)-oriented LaAlO3 (LAO) substrates by ion beam sputter deposition (IBSD) at various growth temperatures in the range of 350–800 °C. Our results have shown that the growth temperature plays an essential role in influencing the structural and morphological evolution of the STO thin films. X-ray structural analysis demonstrates that the STO thin films are grown under in-plane compressive strain due to the effect of lattice mismatch. The out-of-plane lattice constant is found to decrease with increasing growth temperature. Atomic force microscopy observation reveals that the growth mode of STO thin films transforms from a three-dimensional island mode to a two-dimensional layer-by-layer mode at a sufficiently high growth temperature of 750 °C. We believe that high-quality epitaxial STO thin films with atomically flat surface prepared by IBSD in this study would be beneficial for the fabrication of perovskite STO-based superlattices.