Preparation and atomic structure of reconstructed (0001) InGaN surfaces

Journal Article · Wed Aug 01 04:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4743000· OSTI ID:22089374

Friedrich, C.; Biermann, A.; Kneissl, M.; Vogt, P. ^[1]; Hoffmann, V. ^[2]; Esser, N. ^[1]

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1. Institut fuer Festkoerperphysik EW6-1, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)
2. Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany)

The preparation and surface structure of high quality group-III-polar (0001) InGaN layers grown by metal-organic vapor phase epitaxy have been investigated. In order to obtain a clean and well-ordered surface we studied the preparation by annealing at various temperatures under ultra high vacuum and nitrogen-rich conditions in nitrogen-plasma. We show that different InGaN surface reconstructions such as (1 Multiplication-Sign 1), (1 + 1/6), (2 Multiplication-Sign 2), and ({radical}(3) Multiplication-Sign {radical}(3))R30 Degree-Sign can be obtained as observed by low energy electron diffraction. Dependent on the annealing temperature and nitrogen supply these surfaces exhibit significant differences in stoichiometry and morphology as determined by Auger electron spectroscopy and atomic force microscopy measurements. The (1 Multiplication-Sign 1), (2 Multiplication-Sign 2), and ({radical}(3) Multiplication-Sign {radical}(3))R30 Degree-Sign superstructures are terminated by single group-III-adatoms, whereas the (1 + 1/6) exhibits a incommensurate overlayer of group-III-atoms. We show that the (2 Multiplication-Sign 2) and ({radical}(3) Multiplication-Sign {radical}(3))R30 Degree-Sign an In depletion in the first group-III layer and In or Ga adatoms in ontop position. Strain-relaxation is suggested to explain this structure formation.

• OSTI ID: 22089374
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 112; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
ATOMIC FORCE MICROSCOPY
ATOMS
AUGER ELECTRON SPECTROSCOPY
ELECTRON DIFFRACTION
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LAYERS
NITROGEN COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PLASMA
RELAXATION
SEMICONDUCTOR MATERIALS
STOICHIOMETRY
STRAINS
SURFACE CLEANING
SURFACES
VAPOR PHASE EPITAXY