XPS, USXS AND PLS INVESTIGATIONS OF POROUS SILICON

X-ray photoelectron spectra (XPS) as well as ultrasoft X-ray spectra ( USXS) of porous silicon have been investigated. The samples were obtai ned by electrochemical etching of silicon plates in an alchohol soluti on of HF. Silicon 2p core states and Si 1(2,3) spectra of 'as-obtained ' samples as well as those annealed in the atmosphere were obtained. A ll the samples show an increase of oxidation in porous layers with tem perature. However, the degree of oxidation in the sample annealed at h igh temperatures for 20 sec is less than that annealed for 20 min at l ower temperatures. (C) 1998 Elsevier Science B.V.