Strain-induced phase variation and dielectric constant enhancement of epitaxial Gd{sub 2}O{sub 3}

Journal Article · Thu Jul 07 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4958301· OSTI ID:22597848

Amouyal, Y.; Eizenberg, M. ^[1]; Schwendt, D.; Wietler, T. F.; Osten, H. J. ^[2]

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1. Department of Materials Science and Engineering, Technion–Israel Institute of Technology, Haifa 32000 (Israel)
2. Institute of Electronic Materials and Devices, Leibniz University of Hannover, Schneiderberg 32, 30167 Hannover (Germany)

One of the approaches for realizing advanced high k insulators for metal oxide semiconductor field effect transistors based devices is the use of rare earth oxides. When these oxides are deposited as epitaxial thin films, they demonstrate dielectric properties that differ greatly from those that are known for bulk oxides. Using structural and spectroscopic techniques, as well as first-principles calculations, Gd{sub 2}O{sub 3} films deposited on Si (111) and Ge (111) were characterized. It was seen that the same 4 nm thick film, grown simultaneously on Ge and Si, presents an unstrained lattice on Ge while showing a metastable phase on Si. This change from the cubic lattice to the distorted metastable phase is characterized by an increase in the dielectric constant of more than 30% and a change in band gap. The case in study shows that extreme structural changes can occur in ultra-thin epitaxial rare earth oxide films and modify their dielectric properties when the underlying substrate is altered.

• OSTI ID: 22597848
• Journal Information: Journal of Applied Physics, Vol. 120, Issue 1; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CUBIC LATTICES
DEPOSITS
DIELECTRIC MATERIALS
EPITAXY
FIELD EFFECT TRANSISTORS
GADOLINIUM OXIDES
GERMANIUM
PERMITTIVITY
RARE EARTHS
SEMICONDUCTOR MATERIALS
SILICON
STRAINS
SUBSTRATES
THIN FILMS