Electron transport properties of antimony doped SnO{sub 2} single crystalline thin films grown by plasma-assisted molecular beam epitaxy

Journal Article · Sun Nov 01 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3254241· OSTI ID:21361907

White, M E; Bierwagen, O; Speck, J S ^[1]; Tsai, M Y ^[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)

By antimony doping tin oxide, SnO{sub 2}:Sb (ATO), below 1.0% Sb concentration, controllable n-type doping was realized. Plasma-assisted molecular beam epitaxy has been used to grow high quality single crystalline epitaxial thin films of unintentionally doped (UID) and Sb-doped SnO{sub 2} on r-plane sapphire substrates. A UID thickness series showed an electron concentration of 7.9x10{sup 18} cm{sup -3} for a 26 nm film, which decreased to 2.7x10{sup 17} cm{sup -3} for a 1570 nm film, whereas the mobility increased from 15 to 103 cm{sup 2}/V s, respectively. This series illustrated the importance of a buffer layer to separate unintentional heterointerface effects from the effect of low Sb doping. Unambiguous bulk electron doping was established by keeping the Sb concentration constant but changing the Sb-doped layer thickness. A separate doping series correlated Sb concentration and bulk electron doping. Films containing between 9.8x10{sup 17} and 2.8x10{sup 20} Sb atoms/cm{sup 3} generated an electron concentration of 1.1x10{sup 18}-2.6x10{sup 20} cm{sup -3}. As the atomic Sb concentration increased, the mobility and resistivity decreased from 110 to 36 cm{sup 2}/V s and 5.1x10{sup -2} to 6.7x10{sup -4} OMEGA cm, respectively. The Sb concentration was determined by secondary ion mass spectrometry. X-ray diffraction and atomic force microscopy measurements showed no detrimental effects arising from the highest levels of Sb incorporation. Temperature dependent Hall measurements established a lower limit for the Sb electron activation energy of 13.2 meV and found that films with greater than 4.9x10{sup 19} electrons/cm{sup 3} were degenerately doped. Within experimental uncertainties, 100% donor efficiency was determined for Sb-doped SnO{sub 2} in the range studied.

• OSTI ID: 21361907
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 9; Other Information: DOI: 10.1063/1.3254241; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ANTIMONY
ATOMIC FORCE MICROSCOPY
CRYSTAL GROWTH
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRON DENSITY
ELECTRON MOBILITY
ELECTRONS
HALL EFFECT
MASS SPECTRA
MASS SPECTROSCOPY
MOLECULAR BEAM EPITAXY
MONOCRYSTALS
SAPPHIRE
SEMICONDUCTOR MATERIALS
TEMPERATURE DEPENDENCE
THIN FILMS
TIN OXIDES
X-RAY DIFFRACTION
CHALCOGENIDES
COHERENT SCATTERING
CORUNDUM
CRYSTAL GROWTH METHODS
CRYSTALS
DIFFRACTION
ELECTRICAL PROPERTIES
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
EPITAXY
FERMIONS
FILMS
LEPTONS
MATERIALS
METALS
MICROSCOPY
MINERALS
MOBILITY
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE MOBILITY
PHYSICAL PROPERTIES
SCATTERING
SPECTRA
SPECTROSCOPY
TIN COMPOUNDS