Investigation of band offsets and direct current leakage properties of nitrogen doped epitaxial Gd{sub 2}O{sub 3} thin films on Si

Journal Article · Tue May 14 00:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4804245· OSTI ID:22162908

Roy Chaudhuri, Ayan; Osten, H. J. ^[1]; Fissel, A. ^[2]

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1. Institute of Electronic Materials and Devices, Leibniz University of Hannover, Schneiderberg 32, D-30167 Hannover (Germany)
2. Information Technology Laboratory, Leibniz University of Hannover, Schneiderberg 32, D-30167 Hannover (Germany)

Dielectric properties of epitaxial Gd{sub 2}O{sub 3} thin films grown on Si have been found to improve significantly by incorporation of suitable dopants. However, in order to achieve optimum electrical properties from such doped oxides, it is important to understand the correlation between doping and the electronic structure of the material. In the present article, we report about the effect of nitrogen doping on the electronic structure and room temperature dc leakage properties of epitaxial Gd{sub 2}O{sub 3} thin films. Epitaxial Gd{sub 2}O{sub 3}:N thin films were grown on p-type Si (111) substrates by solid source molecular beam epitaxy technique using molecular N{sub 2}O as the nitridation agent. First investigations confirmed the presence of substitutional N in the Gd{sub 2}O{sub 3}:N layers. Incorporation of nitrogen did not affect the structural quality of the oxide layers. X ray photoelectron spectroscopy investigations revealed band gap narrowing in epitaxial Gd{sub 2}O{sub 3} due to nitrogen doping, which leads to reduction in the valence band offset of the Gd{sub 2}O{sub 3}:N layers with Si. DC leakage current measured at room temperature revealed that despite reduction in the band gap and valence band offsets due to N doping, the Gd{sub 2}O{sub 3}:N layers remain sufficiently insulating. A significant reduction of the leakage current densities in the Gd{sub 2}O{sub 3}:N layers with increasing nitrogen content suggests that doping of epitaxial Gd{sub 2}O{sub 3} thin films with nitrogen can be an effective route to eliminate the adverse effects of the oxygen vacancy induced defects in the oxide layers.

• OSTI ID: 22162908
• Journal Information: Journal of Applied Physics, Vol. 113, Issue 18; Other Information: (c) 2013 AIP Publishing LLC; 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
CORRELATIONS
CRYSTAL DEFECTS
CURRENT DENSITY
DIELECTRIC MATERIALS
DIELECTRIC PROPERTIES
DIRECT CURRENT
DOPED MATERIALS
ELECTRONIC STRUCTURE
ENERGY GAP
GADOLINIUM OXIDES
LAYERS
LEAKAGE CURRENT
MOLECULAR BEAM EPITAXY
NITROGEN ADDITIONS
NITROUS OXIDE
SILICON
SUBSTRATES
THIN FILMS
VACANCIES
X-RAY PHOTOELECTRON SPECTROSCOPY