Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 29: III-V Semiconductors I (mainly Nitrides)

HL 29.8: Vortrag

Dienstag, 27. März 2012, 11:30–11:45, EW 201

Surface atomic arrangements of polar (000-1) and semipolar (11-22) InN layers. — •Daria Skuridina, Sabine Alamé, Duc Dinh, Michael Kneissl, and Patrick Vogt — TU Berlin, Institute of Solid State Physics, Hardenbergstr. 36, EW6-1, 10623 Berlin, Germany

InN surface studies and their related electronic properties still lack a fundamental understanding, despite their great technological relevance. We performed surface studies on N-polar (000-1) InN layers grown directly on (0001) sapphire and semipolar (11-22) InN layers grown on (11-22) GaN templates by MOVPE. Morphology, atomic structure and surface symmetry of InN samples were measured by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED), respectively. Moreover, Auger electron spectroscopy was used for chemical composition analysis of the layers. The oxidized surfaces were annealed at 450^∘C under UHV conditions resulting in a significant reduction of the surface carbon and oxygen contaminations. Single atomic steps were observed on the clean (000-1) InN surface. Surface reconstruction (1x1) was observed by LEED and confirmed by the atom-resolved STM image. Scanning tunneling spectroscopy showed a metallic behavior on the N-polar InN that is in good agreement with predicted metal adlayer on the surface. The atomic arrangement of (11-22) InN layers showed no evidence of dimers or adatoms on the surface but the presence of In monolayer in agreement with the calculations by Yamashita et al. [1].

[1] Yamashita et al., Jpn. J. Appl. Phys. 48, 120201, (2009)