Study of bulk and interface defects in silicon oxide with X-ray absorption spectroscopy

We show in this work a detailed study of the SiO2/Si interface by means of X-ray absorption spectroscopy (XAS). The Si2p absorption edge was measured for both a thick (50 nm) oxide layer and a native (1.5 nm) oxide. From the comparison between these two spectra we can address XAS features to bulk defects in SiO2 and to interface defects in the native oxide. We demonstrate the capability of XAS of achieving information about interface defects and suggest its use in more complex systems.