Numerous investigations have recently been performed on quantitative analysis of the SiC surface. However, compositional changes at the silicon carbide surface due to low energy argon ion bombardment are not well understood up to date. Surface enrichment of silicon, restored stoichiometry and also carbon enriched surfaces have been reported. Therefore, reliable quantitative surface analysis of ion-bombarded SiC is highly desirable.
We examined here the influence of the low-energy Ar+ ion bombardment on the surface composition of polycrystalline and monocrystalline SiC samples. Surface composition of the samples was monitored by XPS. The XPS experiments were performed with the MICROLAB 350 [1] and ESCALAB-210 [2] spectrometers. During successive XPS experiments performed using the MICROLAB 350, the SiC surface was sputtered with 1-3 keV argon ions at an incidence angle of 67.5° with respect to surface normal. In the case of the ESCALAB-210, SiC samples were bombarded by Ar+ ions of energy 1-5 keV at an angle of 50° with respect to the surface normal. Quantitative XPS analysis was based on the C 1s, Si 2p and O 1s photoelectron spectra. This analysis was separately performed with the use of the AVANTAGE program and the multiline method.
XPS showed using the AVANTAGE procedure that polycrystalline SiC samples had slightly C-rich compositions in the surface region after bombardment with 1 keV Ar+.
The results obtained here as well as the procedures of their determination were discussed and compared with those published in the literature. We concluded that the SiC surface composition was strongly dependent on the ion bombardment conditions, structural properties and procedures of quantitative evaluation of XPS spectra.
Acknowledgements
One of the authors (A.J.) would like to acknowledge partial support by the Foundation for Polish Science.
[1] M. Krawczyk, A. Kosiñski, A. Jablonski A. Mycielski, Surf. Sci. 600 (2006) 3744.
[2] M. Krawczyk, L. Zommer, A. Kosiñski, J. W. Sobczak, A. Jablonski, Surf. Interface Anal. 38 (2006) 644.
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