Fourier Transform Infrared Spectroscopy and Temperature-Programmed Desorption Mass Spectrometry Study of Surface Chemistry of Porous 6H-SiC
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- 作者：Sergei A. Alekseev ; Vladimir N. Zaitsev ; Jacques Botsoa ; Daniel Barbier
- 刊名：Chemistry of Materials
- 出版年：2007
- 出版时间：May 1, 2007
- 年：2007
- 卷：19
- 期：9
- 页码：2189 - 2194
- 全文大小：152K
- 年卷期：v.19,no.9(May 1, 2007)
- ISSN：1520-5002
文摘
Porous SiC (PSC) freestanding layers were prepared via UV light-assisted electrochemical etching ofan n-type 6H-SiC wafer. Fourier transform infrared (FTIR) spectroscopy and temperature-programmeddesorption mass spectrometry (TPD-MS) were applied to characterize functional groups on the PSCsurface and their chemical reactivity. It was shown that as-prepared PSC contains silanol groups, carboxylicacid groups, minor amounts of SiH and CHx groups, and also a carbon-rich surface phase. Annealing ofPSC in air at 673 K resulted in the oxidation of the carbon-containing surface species and the formationof a hydrated silicon oxide surface layer. Using -Si(CH3)3 groups as a model, it was demonstrated thatorganic functional groups can easily be grafted on oxidized PSC via common silanization chemistry.Treatment of oxidized PSC with HF resulted in the formation of a surface terminated with methyl groups.It confirms that the walls of the PSC pores are constituted of the (0001) "silicon" crystal face of SiC andfaces with similar atomic structure.