Evolution of the mosaic structure in InGaN layer grown on a thick GaN template and sapphire substrate
Author
Arslan, E.
Ozturk, M. K.
Cakmak, H.
Demirel, P.
Ozcelik, S.
Özbay, Ekmel
Date
2013-08-08Source Title
Journal of Materials Science: Materials in Electronics
Print ISSN
0957-4522
Publisher
Springer
Volume
24
Issue
11
Pages
4471 - 4481
Language
English
Type
ArticleItem Usage Stats
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Abstract
The InxGa1-xN epitaxial layers, with indium (x) concentration changes between 0.16 and 1.00 (InN), were grown on GaN template/(0001) Al2O3 substrate by metal organic chemical vapour deposition. The indium content (x), lattice parameters and strain values in the InGaN layers were calculated from the reciprocal lattice mapping around symmetric (0002) and asymmetric (10-15) reflection of the GaN and InGaN layers. The characteristics of mosaic structures, such as lateral and vertical coherence lengths, tilt and twist angle and heterogeneous strain and dislocation densities (edge and screw dislocations) of the InGaN epilayers and GaN template layers were investigated by using high-resolution X-ray diffraction (HR-XRD) measurements. With a combination of Williamson-Hall (W-H) measurements and the fitting of twist angles, it was found that the indium content in the InGaN epilayers did not strongly effect the mosaic structures' parameters, lateral and vertical coherence lengths, tilt and twist angle, or heterogeneous strain of the InGaN epilayers.
Keywords
X-ray-diffractionEpitaxial GaN
Threading dislocations
Physical - properties
Defect structure
Films
Diffractometry
Spread