Atomic Layer-by-Layer Metal-Organic Chemical Vapor Deposition of SrTiO3 Films with a Very Smooth Surface

This paper presents the investigation of single-phase SrTiO3 thin films prepared by two methods: the atomic layer-by-layer metal-organic chemical vapor deposition (ALMOCVD) method and the co-deposition MOCVD method, using third generation dipivaloylmethane chelate of strontium (Sr(DPM)2·2tetraene) and titanium tetraisopropoxide as precursors. Compared with co-deposition MOCVD, the SrTiO3 films grown by ALMOCVD on MgO substrates show higher [100] orientation with a value of the full width at half maximum as small as 0.18°, investigated by X-ray diffraction θ–2θ scan, ω-rocking curve analysis and φ scan. Observations with atomic force microscopy also show that the SrTiO3 films have a very smooth surface in which the maximum distance between peaks and valleys is 2.70 nm and the average roughness is 0.37 nm. These results demonstrate that better epitaxial SrTiO3 films, in terms of crystalline quality and surface morphology, can be obtained by ALMOCVD rather than by co-deposition MOCVD. Furthermore, we have investigated that N2O supplied during deposition influences the crystallinity and surface morphology.