X-ray diffraction analysis and scanning micro-Raman spectroscopy of structural irregularities and strains deep inside the multilayered InGaN/GaN heterostructure

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Semiconductors

DOI:https://doi.org/10.1134/S1063782610090174· OSTI ID:21562220

Kladko, V P; Avramenko, E A; Kolomys, O F; Safryuk, N V; Konakova, R V ^[1]; Valakh, M Ya; Machulin, V F; Belyaev, A E ^[1]

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1. National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine)

High-resolution X-ray diffraction analysis and scanning confocal Raman spectroscopy are used to study the spatial distribution of strains in the In{sub x}Ga{sub 1-x}N/GaN layers and structural quality of these layers in a multilayered light-emitting diode structure produced by metal-organic chemical vapor deposition onto (0001)-oriented sapphire substrates. It is shown that elastic strains almost completely relax at the heterointerface between the thick GaN buffer layer and In{sub x}Ga{sub 1-x}N/GaN buffer superlattice. It is established that the GaN layers in the superlattice are in a stretched state, whereas the alloy layers are in a compressed state. In magnitude, the stretching strains in the GaN layers are lower than the compressive strains in the InGaN layers. It is shown that, as compared to the buffer layers, the layers of the superlattice contain a smaller number of dislocations and the distribution of dislocations is more randomly disordered. In micro-Raman studies on scanning through the thickness of the multilayered structure, direct evidence is obtained for the asymmetric gradient distributions of strains and crystal imperfections of the epitaxial nitride layers along the direction of growth. It is shown that the emission intensity of the In{sub x}Ga{sub 1-x}N quantum well is considerably (more than 30 times) higher than the emission intensity of the GaN barrier layers, suggesting the high efficiency of trapping of charge carriers by the quantum well.

• OSTI ID: 21562220
• Journal Information: Semiconductors, Vol. 44, Issue 9; Other Information: DOI: 10.1134/S1063782610090174; Copyright (c) 2010 Pleiades Publishing, Ltd.; ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
CHARGE CARRIERS
CHEMICAL VAPOR DEPOSITION
CRYSTALS
DISLOCATIONS
EMISSION
EPITAXY
GALLIUM NITRIDES
LAYERS
LIGHT EMITTING DIODES
ORGANOMETALLIC COMPOUNDS
QUANTUM WELLS
RAMAN SPECTROSCOPY
SAPPHIRE
SPATIAL DISTRIBUTION
STRAINS
SUBSTRATES
SUPERLATTICES
THICKNESS
X-RAY DIFFRACTION
CHEMICAL COATING
COHERENT SCATTERING
CORUNDUM
CRYSTAL DEFECTS
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
DEPOSITION
DIFFRACTION
DIMENSIONS
DISTRIBUTION
GALLIUM COMPOUNDS
LASER SPECTROSCOPY
LINE DEFECTS
MINERALS
NANOSTRUCTURES
NITRIDES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
OXIDE MINERALS
PNICTIDES
SCATTERING
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SPECTROSCOPY
SURFACE COATING