Study of Carbon in Thermal Oxide Formed on 4H-SiC by XPS
In this work, we present results on the study of bonding and concentration of carbon in 4H-SiC MOS structure by x-ray photoelectron spectroscopy (XPS). The XPS spectra were fitted by several Gaussian lineshape functions. It is found that the so-called carbon clusters (C-C bonds) appear at the interface of SiO2/SiC, but are not seen in the oxide bulk. However, there are still some SiOxCy and Si-C bonds inside the oxide and the integrated area ratio of SiOxCy/Si-C bonds increases when further away from the SiO2/SiC interface. These observations can be interpreted in terms of the dynamic oxidation process that transforms Si-C bonds into SiOxCy bonds, which are then further oxidized to form SiO2 bonds.
Roberta Nipoti, Antonella Poggi and Andrea Scorzoni
P. Zhao et al., "Study of Carbon in Thermal Oxide Formed on 4H-SiC by XPS", Materials Science Forum, Vols. 483-485, pp. 653-656, 2005