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Re-distribution of oxygen at the interface between γ-Al(2)O(3) and TiN

Interface of TiN electrode with γ-Al(2)O(3) layers was studied using near edge X-ray absorption fine structure, conventional X-ray photoelectron spectroscopy and photoelectron spectroscopy with high energies. Despite the atomic-layer deposited Al(2)O(3) being converted into thermodynamically-stable...

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Detalles Bibliográficos
Autores principales: Filatova, E. O., Konashuk, A. S., Sakhonenkov, S. S., Sokolov, A. A., Afanas’ev, V. V.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5495785/
https://www.ncbi.nlm.nih.gov/pubmed/28674397
http://dx.doi.org/10.1038/s41598-017-04804-4
Descripción
Sumario:Interface of TiN electrode with γ-Al(2)O(3) layers was studied using near edge X-ray absorption fine structure, conventional X-ray photoelectron spectroscopy and photoelectron spectroscopy with high energies. Despite the atomic-layer deposited Al(2)O(3) being converted into thermodynamically-stable polycrystalline cubic γ-phase by high-temperature (1000 or 1100 °C) anneal, our results reveal formation of a thin TiN(x)O(y) (≈1-nm thick) interlayer at the interface between γ-Al(2)O(3) film and TiN electrode due to oxygen scavenging from γ-Al(2)O(3) film. Formation of the TiO(2) was not observed at this interface. As environmental effect, a strong oxidation resulting in formation of a TiO(2)(1.4 nm)/TiN(x)O(y)(0.9 nm) overlayers on the top of the TiN electrode is traced. Development of O-deficiency of γ-Al(2)O(3) is observed and related to the polarization anisotropy due to the preferential orientation of spin states involved in the X-ray absorption in the plane parallel to the surface. Investigation of the TiN electrode reveals the predominantly “stretched” octahedra in its structure with the preferential orientation relative the interface with γ-Al(2)O(3). This anisotropy can be correlated with ≈200 meV electron barrier height increase at the O-deficient TiN/γ-Al(2)O(3) interface as compared to the TiN/γ-Al(2)O(3) barrier formed under abundant oxidant supply condition as revealed by internal photoemission of electrons from TiN into the oxide.