An atomic model was presented for the reconstructed surfaces of Si3N4 thin layers which were grown onto Si(111). Kikuchi electron holographic images clearly revealed the existence of adatoms on the Si3N4(00•1)/Si(111)-(8 x 8) surface. When compared with ab initio calculations, more than 30 symmetry-inequivalent atomic pairs in the outermost layers were identified. Scanning tunnelling microscopic images revealed diamond-shaped unit cells, with 9 adatoms in each cell. High-resolution scanning tunnelling microscopic images were in good agreement with partial charge-density distribution which were deduced from total-energy calculations.

Structure Determination of the Si3N4/Si(111)-(8 x 8) Surface: a Combined Study of Kikuchi Electron Holography, Scanning Tunnelling Microscopy and ab initio Calculations. H.Ahn, C.L.Wu, S.Gwo, C.M.Wei, Y.C.Chou: Physical Review Letters, 2001, 86[13], 2818-21