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arXiv · 2402.10925

Anomalous thermal oxidation of gadolinium thin films deposited on silicon by high pressure sputtering

María Ángela Pampillón·Pedro Carlos Feijoo·Enrique San Andrés·María Luisa Lucía·María Toledano-Luque
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Abstract

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 $^\circ$C. At an oxidation temperature of 500 $^\circ$C the films show a transition from monoclinic structure to a mixture of monoclinic and cubic. Regrowth of interfacial SiO$_x$ is observed as temperature is increased, up to 1.6 nm for 750 $^\circ$C. This temperature yields the lowest interface trap density, 4e10 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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María Ángela Pampillón, Pedro Carlos Feijoo, Enrique San Andrés, María Luisa Lucía, María Toledano-Luque. 2024-01-29. Anomalous thermal oxidation of gadolinium thin films deposited on silicon by high pressure sputtering. https://doi.org/10.1016/j.mee.2011.04.058

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