Calculated and experimental electron energy-loss spectra of La2O3, La(OH)(3), and LaOF nanophases in high permittivity lanthanum-based oxide layers

Lionel Calmels (1) , Pierre-Eugène Coulon (1) , Sylvie Schamm-Chardon (1)

1 CEMES - Centre d'élaboration de matériaux et d'études structurales

Using first principles methods, the O K energy-loss near-edge structure of cubic and hexagonal La2O3, La(OH)3, and LaOF phases have been calculated. These calculations support the identification of nanocrystalline phases evidenced experimentally by electron energy-loss spectroscopy (EELS) performed in a transmission electron microscope. The nanocrystals have been observed in atomic layer deposited La2O3 thin films developed for advanced metal-oxide-semiconductor field effect transistor applications. The presence of the nanophases can be explained by the hygroscopicity and the particular reactivity with fluorine of La2O3. These calculations provide a set of EELS fingerprints which will be useful for local phase identification in La2O3-based materials.

Domaines: Physique [physics]; Science des matériaux [cond-mat.mtrl-sci]

Lionel Calmels, Pierre-Eugène Coulon, Sylvie Schamm-Chardon. Calculated and experimental electron energy-loss spectra of La2O3, La(OH)(3), and LaOF nanophases in high permittivity lanthanum-based oxide layers. Applied Physics Letters, 2011, 98 (24), pp.243116. ⟨10.1063/1.3600783⟩. ⟨hal-01745023⟩