ELECTRONIC-STRUCTURE OF AMORPHOUS SI3N4 - EXPERIMENT AND NUMERICAL-SIMULATION

The electronic structure of amorphous silicon nitride was studied by X PS, X-ray emission, and ELS. The partial densities of states for silic on (3s, 3p, 3d) and nitrogen (2s, 2p) atoms were determined. The resul ts of experiments were compared with the calculated electronic structu re of Si3N4. The calculations were made using quantum-chemical semiemp irical method MIND0/3 in cluster approximation. The top of the Si3N4 v alence band in terms of band structure is two-degenerated. There are S i3s,3p-N2s,2p bonding states and N2p(pi), nonbonding states at the top of valence band. The electronic structures of Si3N4 and SiO2 are simi lar. The experimentally energy of plasmon oscillations determined for Si3N4 is 23.5 eV. It was found that not only Si3s,3p, N2p orbitals of upper valence band take part into plasmon oscillations but N2s states of lower valence band, too.