NEXAFS and XPS studies of porous silicon

By ultra-soft x-ray spectroscopy methods with the use of synchrotron radiation, porous layers of silicon with various types of conductivity were investigated. The effective thickness of the oxide on the surface of a silicon skeleton was determined and the interface structure at the silicon/silicon oxides interface was studied. It was shown that the fine structure of the Si 2p absorption spectra of the silicon skeleton is identical to that of the spectrum of crystalline silicon, and the thickness of the oxide layer on the surface of porous silicon is 1.8-2.4 nm for various samples.The parameter x in the stoichiometric formula SiOх of silicon oxide is in the range of 1,66-1,82.