1. Microstructure of InN quantum dots grown on AlN buffer layers by metal organic vapor phase epitaxy
- Author
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P. J. Huang, C. J. Tun, B. J. Pong, J. Y. Chen, Chih-Yang Chang, M. Y. Chen, S. M. Lan, M. C. Chen, C. J. Pan, Stephen J. Pearton, Fan Ren, Sheng Chun Hung, Gou-Chung Chi, and C. H. Nien
- Subjects
Crystallography ,Materials science ,Physics and Astronomy (miscellaneous) ,Transmission electron microscopy ,Quantum dot ,Phase (matter) ,Wide-bandgap semiconductor ,Analytical chemistry ,Metalorganic vapour phase epitaxy ,Epitaxy ,Microstructure ,Wetting layer - Abstract
InN quantum dots (QDs) were grown over 2in. Si (1 1 1) wafers with a 300nm thick AlN buffer layer by atmospheric-pressure metal organic vapor phase epitaxy. When the growth temperature increased from 450to625°C, the corresponding InN QDs height increased from 16to108nm while the density of the InN QDs decreased from 1.6×109cm−2to3.3×108cm−2. Transmission electron microscopy showed the presence of a 2nm thick wetting layer between the AlN buffer layer and InN QDs. The growth mechanism was determined to be the Stranski–Krastanov mode. The presence of misfit dislocations in the QDs indicated that residual strain was introduced during InN QDs formation. From x-ray diffraction analysis, when the height of the InN QDs increased from 16to62nm, the residual strain in InN QDs reduced from 0.45% to 0.22%. The residual strain remained at 0.22% for larger heights most likely due to plastic relaxation in the QDs. The critical height of the InN QDs for releasing the strain was determined to be 62nm.
- Published
- 2008