Abstract
Anodic polarization of SiC atmodest potential in dilute fluoride solution of pH 3 surprisingly gives
rise to the growth of micrometer-thick surface layers, clearly revealed with scanning electron
microscopy. The reaction occurs at p-type SiC in the dark and at n-type SiC under (supra)bandgap
illumination. The surface layer was shown by Rutherford backscattering spectrometry (RBS) to
consist of silicon dioxide and to contain excess oxygen. Elastic recoil detection (ERD) indicated only
a low level of carbon and fluoride in the layer but a considerable content of hydrogen. The growth
kinetics was characterized in situ by spectroscopic ellipsometry and electrical impedance spectroscopy.
The results suggest the formation of a duplex layer: a thin inner dielectric oxide and a thick
hydrated outer oxide. The latter must have a considerable degree of porosity to allow diffusion/
migration of reactants and products during oxide growth.
Original language | Undefined/Unknown |
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Pages (from-to) | 3297-3305 |
Number of pages | 9 |
Journal | Chemistry of Materials |
Volume | 21 |
Issue number | 14 |
Publication status | Published - 2009 |