1. Anomalous thermal oxidation of gadolinium thin films deposited on silicon by high pressure sputtering
- Author
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Pampillón, María Ángela, Feijoo, Pedro Carlos, Andrés, Enrique San, Lucía, María Luisa, and Toledano-Luque, María
- Subjects
Condensed Matter - Materials Science ,Physics - Applied Physics - 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., Comment: 22 pages, 7 figures, 1 table
- Published
- 2024
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