Filatova, E.O.; Sokolov, A.A.; Egorova, Yu.V.; Konashuk, A.S.; Vilkov, O.Yu.; Gorgoi, M.; Pavlychev, A.A.: X-ray spectroscopic study of SrTiOx films with different interlayers. Journal of Applied Physics 113 (2013), p. 224301/1-8
Air-exposed systems SrTiOx/B/Si with different film thickness (7 nm and 15 nm) and different interlayers (ILs) (B: SiO2, Si3N4, and HfO2) grown by the atomic layer deposition (ALD) technique were studied using near edge x-ray absorption fine structure (NEXAFS), soft x-ray photoelectron spectroscopy (XPS), and hard x-ray photoelectron spectroscopy (HAXPES). It was established that the material of the IL influences strongly the lowest unoccupied bands and local atomic structure of the SrTiO3 film. In the case of SiO2 IL, the SrTiO3 film is characterized by nearly ideal cubic structure. The Si3N4 IL supports the Sr-enrichment of the air-exposed film. Presumably the enrichment of Sr occurs predominantly in the near surface range of the film. The HfO2 IL promotes the violation of the structure creating numerous defects inside the film. The surfaces of all the investigated SrTiOx films are carbonate-rich surfaces in the form of SrCO3. The SrCO3 content is minimal/maximal in the film grown on the SiO2/HfO2 IL.