Study of the Au Schottky contact formation on oxygen plasma treated n-type SnO{sub 2} (101) thin films

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3298467· OSTI ID:21476127

Nagata, Takahiro ^[1]; Bierwagen, Oliver; White, Mark E; Speck, James S ^[1]; Tsai, Min-Ying ^[2]

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1. Department of Materials, University of California, Santa Barbara, California 93106-5050 (United States)
2. Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106-9560 (United States)

As-grown and oxygen plasma treated n-type tin dioxide (SnO{sub 2}) (101) thin films were investigated regarding the properties of Au contacts, surface structure, and band bending. The plasma treatment was performed in a conventional oxygen plasma cleaning system with maximum oxygen ion energies of 400 eV. Whereas the as-deposited SnO{sub 2} film formed non-Schottky contacts with Au, the oxygen plasma treated films formed Schottky contacts with Au. Capacitance-voltage and differential Hall measurements indicated the introduction of bulk electron traps up to several 100 nm below the surface due to the oxygen plasma treatment. Angle resolved x-ray photoelectron spectroscopy (AR-XPS) revealed a surface accumulation layer on the as-grown film that was absent after the plasma treatment. These measurements further revealed chemical differences between the as-deposited and the plasma treated SnO{sub 2} surfaces. All SnO{sub 2} films had Sn{sup 2+}-O bonds. The AR-XPS Sn{sup 2+}-O signal intensity increased after plasma treatment, indicating that the oxygen plasma damaged the SnO{sub 2} surface. Additionally, an O{sub 2} adlayer was formed due to the oxygen plasma treatment. The damaged layer due to oxygen ion bombardment, oxygen adsorption layer, and possibly bulk traps depleted the surface carriers which enabled the formation of a Schottky contact with Au.

• OSTI ID: 21476127
• Journal Information: Journal of Applied Physics, Vol. 107, Issue 3; Other Information: DOI: 10.1063/1.3298467; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ADSORPTION
CAPACITANCE
CHEMICAL BONDS
CRYSTAL STRUCTURE
ELECTRONS
EV RANGE
GOLD
LAYERS
N-TYPE CONDUCTORS
OXYGEN IONS
PLASMA
SURFACES
THIN FILMS
TIN IONS
TIN OXIDES
X-RAY PHOTOELECTRON SPECTROSCOPY
CHALCOGENIDES
CHARGED PARTICLES
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
FERMIONS
FILMS
IONS
LEPTONS
MATERIALS
METALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
SEMICONDUCTOR MATERIALS
SORPTION
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TIN COMPOUNDS
TRANSITION ELEMENTS