Electrochemical Growth of Micrometer-Thick Oxide on SiC in Acidic Fluoride Solution

Dorp van, D.H. and Kooij, E.S. and Arnoldbik, W.M. and Kelly, J.J. (2009) Electrochemical Growth of Micrometer-Thick Oxide on SiC in Acidic Fluoride Solution. Chemistry of Materials, 21 (14). pp. 3297-3305. ISSN 0897-4756

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Abstract:	Anodic polarization of SiC at modest 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.
Item Type:	Article
Copyright:	© 2009 American Chemical Society
Faculty:	Science and Technology (TNW)
Research Group:	Physics of Interfaces and Nanomaterials (PIN)
Link to this item:	http://purl.utwente.nl/publications/75153
Official URL:	http://dx.doi.org/10.1021/cm900374s
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Metis ID: 258671