Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 4: GaN: Preparation and Characterization I (mainly Optics)
HL 4.3: Vortrag
Montag, 26. März 2012, 10:00–10:15, EW 201
Angle resolved XPS for investigation of surface band-bending of III-nitrides — •Robert Metzner1, Bernd Garke1, Martin Feneberg1, Stephanie Fritze2, Armin Dadgar2, Alois Krost2, and Rüdiger Goldhahn1 — 1Otto-von-Guericke-Universität Magdeburg, Institut für Experimentelle Physik, Abteilung Materialphysik — 2Otto-von-Guericke-Universität Magdeburg, Institut für Experimentelle Physik, Abteilung Halbleiterepitaxie
Due to surface donor states, III-nitrides suffer from Fermi level pinning at the surface leading to band-bending. To investigate this effect we establish angle resolved X-ray Photoelectron Spectroscopy (XPS) for determining size and direction of this fields. Variation of observation angles leads to different sampling depths and finally to a shift of the XPS peaks. With direction and size of these shifts, band-bending at the surface can be estimated. Samples which are expected to employ different surface band-bendings are investigated, especially c-oriented polar InN and GaN samples with various bulk doping levels. The measurements are finally compared to model calculations showing the principal applicability of the method.