Crystalline silicon nitride passivating the Si(111) surface: A study of the Au growth mode

Nearly-free electronlike surface resonance of aβ−Si3N4(0001)/Si(111)−8×8<

“…In this respect, a feature reported in the photoemission valence band taken at 134 eV photon energy was previously ascribed to the presence of a surface state [26]. However, that intense peak at a binding energy of −1.1 eV was never measured afterwards [7,[27][28][29]. Our data also cannot support that experimental evidence mainly on two grounds: on the one hand, angular resolved photoemission is needed to highlight the tiny feature (which is hidden if integrated in all the 075303-3 Fig.…”

“…In 2003, Kim et al [26] claimed that a feature appearing in the valence band taken at 134 eV, 1.1 eV below the Fermi level, would be related to the 8 × 8 reconstruction. However, this evidence has not been confirmed so far [7,27,28]. Indeed, at present a clear spectroscopic signature of the 8 × 8 reconstructed β-Si 3 N 4 (0001) layer has not yet been reported.…”

“…Ultrathin layers of epitaxial silicon nitride can also be grown [5] showing, at the same time, the ability to prevent the formation of silicides. Indeed, studies reporting on the interaction of this nitride layer with Au, Co, and Fe (among the most reactive elements with silicon) [6][7][8][9][10], demonstrated this ability at temperatures up to 600 K [8,11]. This is of paramount importance as metal/Si(111) ideal interfaces can now be produced without the drawbacks of the formation of interface states due to silicides.…”

“…As for the surface electronic structure, the experimental studies are limited to integrated band structures recorded at photon energies larger than 100 eV [7,[26][27][28] except for the paper by Tokumitsu et al [29] in which angle-resolved photoemission (ARPES) measurements at 32.5 and 45 eV photon energy, were reported: the authors identified the N 2p and Si 3p and 3s bands at binding energies larger than 4.5 eV, ascribing the unusual band structure to the umklapp process occurring at the interface between silicon and nitride. In 2003, Kim et al [26] claimed that a feature appearing in the valence band taken at 134 eV, 1.1 eV below the Fermi level, would be related to the 8 × 8 reconstruction.…”

Valence band offset and interface stoichiometry at epitaxial Si3N4/Si(111) heterojunctions formed by plasma nitridation

“…6,13,15 In particular, we will emphasize on the differences and advantages of the epitaxial ␤-Si 3 N 4 films prepared by N 2 -plasma nitridation. The PES experiments were performed at the 09A beamline in National Synchrotron Radiation Research Center ͑Hsinchu, Taiwan͒.…”