Surface morphology study of a SrTiO3 thin film in a multilayer structure treated by chemical-mechanical polishing

The chemical-mechanical polishing (CMP) method was used to improve the quality and smoothness of the surface of thin films of SrTiO3 (STO) prepared by pulsed laser deposition. On thick (∼1 μm) STO films, considerable outgrowth was observed, which on further analysis was found to consist of agglomerations of (1 1 0) and (1 1 1)-oriented STO grains. The CMP method reduced the volume fraction of outgrowth, as confirmed by X-ray diffraction and the increased smoothness of the film surface. Annealing of the sample in an oxygen atmosphere after CMP further improved the surface quality of the sample through improvement of its crystallinity.