Sequential pulsed laser deposition of homoepitaxial SrTiO${}_3$ thin films

Abstract

Control of thin film stoichiometry is of primary relevance to achieve desired functionality. Pulsed laser deposition ablating from binary-oxide targets (sequential deposition) can be applied to precisely control the film composition, offsetting the importance of growth conditions on the film stoichiometry. In this work, we demonstrate that the cation stoichiometry of SrTiO${}_3$ thin films can be finely tuned by sequential deposition from SrO and TiO${}_2$ targets. Homoepitaxial SrTiO${}_3$ films were deposited at different substrate temperatures and Ti/Sr pulse ratios, allowing the establishment of a growth window for stoichiometric SrTiO${}_3$. The growth kinetics and nucleation processes were studied by reflection high-energy electron diffraction and atomic force microscopy, providing information about the growth mode and the degree of off-stoichiometry. At the optimal (stoichiometric) growth conditions, films exhibit atomically flat surfaces, whereas off-stoichiometry is accommodated by crystal defects, 3D islands and/or surface precipitates depending on the substrate temperature and the excess cation. This technique opens the way to precisely control stoichiometry and doping of oxide thin films.

arXiv comment6 pages, 5 figures

References in corpus (6)

• Recent advances in pulsed-laser deposition of complex-oxides
• Dramatic Mobility Enhancements in Doped SrTiO3 Thin Films by Defect Management
• Measurements of Surface Diffusivity and Coarsening During Pulsed Laser Deposition
• Fabricating Superconducting Interfaces between Artificially-Grown LaAlO${}_3$ and SrTiO${}_3$ Thin Films
• Chemistry and structure of homoepitaxial SrTiO${}_3$ films and their influence on oxide-heterostructure interfaces
• In-situ Investigation of the Early Stage of TiO2 epitaxy on (001) SrTiO3