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

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.
Authors:
;  [1] ; ;  [2] ;  [3] ;  [4]
  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)
  4. (United States)
Publication Date:
OSTI Identifier:
22275784
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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