%0 Journal Article
%A Pampillón. María Ángela
%A Feijoo, Pedro Carlos
%A San Andrés Serrano, Enrique
%A Lucía Mulas, María Luisa
%A Prado Millán, Álvaro Del
%A Toledano-Luque, María
%T Anomalous thermal oxidation of gadolinium thin films deposited on silicon by high pressure sputtering
%D 2011
%@ 0167-9317
%U https://hdl.handle.net/20.500.14352/99145
%X Thin gadolinium metallic layers were deposited by high-pressure sputtering in pure Ar atmosphere. Subsequently, in situ thermal oxidation was performed at temperatures ranging from 150 to 750 °C. At an oxidation temperature of 500 °C the films show a transition from monoclinic structure to a mixture of monoclinic and cubic. Regrowth of interfacial SiOx is observed as temperature is increased, up to 1.6 nm for 750 °C. This temperature yields the lowest interface trap density, 4 × 1010 eV−1 cm−2, but the effective permittivity of the resulting dielectric is only 7.4. The reason of this low value is found on the oxidation mechanism, which yields a surface with located bumps. These bumps increase the average thickness, thus reducing the capacitance and therefore the calculated permittivity.
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