Angle-Resolved Studies of SiO_2/SiC Samples

摘要

Angle resolved studies of SiO_2/SiC samples utilizing the Si 2p and Si 1s core levels and the Si KLL Auger transitions are reported. Samples with total oxide thicknesses from ca. 5 to 118 A are investigated. The data collected show that two oxidation states only, Si~(+1) and Si~(+4), are required to explain and model recorded Si 2p, Si 1s and Si KLL spectra. For all samples investigated the intensity variations observed in the core level components versus electron emission angle are found to be well described by a layer attenuation model when assuming that the sub-oxide, Si~(+1), is located at the interface. The SiO_2 chemical shift is found to be larger in the Si 1 s level than in the Si 2p level and moreover to depend on the thickness of the oxide layer.