Effects of sodium ions on trapping and transport of electrons at the SiO{sub 2}/4H-SiC interface

Journal Article · Tue Jan 21 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4861646· OSTI ID:22275784

Mooney, P. M. ^[1]; Ahyi, A. C.; Williams, J. R. ^[2]; Feldman, L. C. ^[3]

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1. Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada)
2. Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)
3. Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

Capacitance-voltage (C-V) and Deep-Level-Transient Spectroscopy (DLTS) measurements were performed on Metal-Oxide-Semiconductor (MOS) capacitors fabricated on 4H-SiC with the SiO{sub 2} layer grown by Sodium-Enhanced Oxidation. This technique has yielded 4H-SiC MOS transistors with record channel mobility, although with poor bias stability. The effects of the mobile positive charge on the C-V characteristics and DLTS spectra were investigated by applying a sequence of positive and negative bias-temperature stresses, which drifted the sodium ions toward and away from the SiO{sub 2}/4H-SiC interface, respectively. Analytical modeling of the C-V curves shows that the drift of sodium ions in the SiO{sub 2} layer during the voltage sweep can explain the temperature dependence of the C-V curves. The effects of lateral fluctuations of the surface potential (due to a non-uniform charge distribution) on the inversion layer mobility of MOS transistors are discussed within a two-dimensional percolation model.

• OSTI ID: 22275784
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CAPACITANCE
CAPACITORS
CARRIER MOBILITY
CHARGE DISTRIBUTION
DEEP LEVEL TRANSIENT SPECTROSCOPY
DIAGRAMS
ELECTRIC POTENTIAL
ELECTRONS
FLUCTUATIONS
INTERFACES
LAYERS
MOS TRANSISTORS
SEMICONDUCTOR MATERIALS
SILICON CARBIDES
SILICON OXIDES
SODIUM IONS
SURFACE POTENTIAL
TEMPERATURE DEPENDENCE