Spatially resolved distribution of dislocations and crystallographic tilts in GaN layers grown on Si(111) substrates by maskless cantilever epitaxy

Journal Article · Fri Sep 01 04:00:00 EDT 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2234807· OSTI ID:20884676

Barabash, R I; Roder, C; Ice, G E; Einfeldt, S; Budai, J D; Barabash, O M; Figge, S; Hommel, D ^[1]

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1. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 and Center for Materials Processing, University of Tennessee, Knoxville, Tennessee 37996 (United States)

The spatial distribution of strain, misfit and threading dislocations, and crystallographic orientation in uncoalesced GaN layers grown on Si(111) substrates by maskless cantilever epitaxy was studied by polychromatic x-ray microdiffraction, high resolution monochromatic x-ray diffraction, and scanning electron microscopy. Tilt boundaries formed at the column/wing interface depending on the growth conditions. A higher lateral to vertical growth ratio suppressed sidewall deposition and was found to produce larger lattice tilts in the GaN films. Two kinds of crystallographic tilts are observed in the films. The measurements revealed that the free-hanging wings are tilted upward at room temperature in the direction perpendicular to the stripes. Finite element simulations of the thermally induced part of the wing tilt are presented. Moreover, a misorientation between the GaN(0001) and the Si(111) planes is observed in the parallel to the stripe direction. Its origin is discussed with respect to the strain of the epitaxial GaN on a miscut Si(111) surface and misfit dislocations formed at the interface.

• OSTI ID: 20884676
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 100; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH
CRYSTALLOGRAPHY
DEPOSITION
DISLOCATIONS
EPITAXY
FINITE ELEMENT METHOD
GALLIUM NITRIDES
GRAIN ORIENTATION
INTERFACES
LAYERS
MONOCHROMATIC RADIATION
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SILICON
SIMULATION
SPATIAL DISTRIBUTION
SUBSTRATES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
X-RAY DIFFRACTION