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HL: Fachverband Halbleiterphysik
HL 17: Interfaces and surfaces
HL 17.5: Vortrag
Montag, 11. März 2013, 16:00–16:15, H15
From surface dimers to Si—P bonds at the GaP/Si(100) heterointerface — •Oliver Supplie1,2, Sebastian Brückner1,3, Henning Döscher1,3,4, Peter Kleinschmidt1,5, and Thomas Hannappel1,4,5 — 1Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe — 2Humboldt-Universität zu Berlin, Institut für Physik — 3TU Ilmenau, Institut für Physik, Fachgebiet Photovoltaik — 4NREL, Golden, CO, USA — 5CiS Forschungsinstitut für Mikrosensorik und Photovoltaik, Erfurt
Dimerized (100) surfaces of cubic crystals often exhibit characteristic reflection anisotropy (RA) spectra, as reported for both monohydride [1] and As [2] terminated Si(100), as well as for P-rich GaP(100) [3]. This allows in situ control during metalorganic vapor phase epitaxy which is essential, in particular, directly before III-V nucleation since preparation routes strongly vary with offcut and desired surface termination. Given the polarity of the GaP film and the dimer orientation of the substrate prior to nucleation, a simplistic model [4] allows to conclude whether Si—III or Si—V bonds are preferred at the heterointerface. Since GaP polarity corresponds to orientation of P-dimers at the P-rich GaP/Si(100) surface, we can deduce the preferred bonding from in situ RA spectra only. We find that P-polar GaP was grown both on As-terminated Si(100) and H-terminated, B-type Si(100) while Ga-polar GaP grew on H-terminated A-type Si(100). In all three cases, Si—V bonds established preferentially.
[1] Brückner et al., PRB 86:195310. [2] Kipp et al., PRL 76:2810.
[3] Töben et al., Surf.Sci. 494:755. [4] Beyer et al., JAP 111:083534.