An X-ray absorption study of Si_xO_yN_z films.

摘要

Thin Si_xO_yN_z films, fabricated by ion implantation of N_2O~+ molecular ions into Si substrates, ar stuided with near edge x-ray absorption fine structure (NEXAFS) spectroscopy. The N and O depth profiles are determiined by nuclear reaction analysis using the reactions ~(15)N(p, alpha gamma )~(12) and ~(18)O(p, alpha ~(15)N. The NEXAFS spectra are characterized by two resonance lines, which appear at 400.3 and 402eV, i.e. 1.2eV below and 0.5eV above the absorption edge, respoectively. These resonance lines appear due to electron dipole transitions of 1s electron to empty defect states with p character. The resonance at 400.3 eV is characteristic of funderstoichimetric oxynitrides and is attributed to the N pair defect. The resonance at 402 eV is characteristic of N-rich samples and its is the signature of N dangling bonds in the NEXAFS spectra of Si_xO_yN_z.