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Domagała J.Z.♦, Morelhão S.L.♦, Sarzyński M.♦, Maździarz M., Dłużewski P., Leszczyński M.♦, Hybrid reciprocal lattice: application to layer stress determination in GaAlN/GaN(0001) systems with patterned substrates,
JOURNAL OF APPLIED CRYSTALLOGRAPHY, ISSN: 1600-5767, DOI: 10.1107/S1600576716004441, Vol.49, No.3, pp.798-805, 2016Streszczenie: Epitaxy of semiconductors is a process of tremendous importance in applied science and in the optoelectronics industry. The control of defects introduced during epitaxial growth is a key point in manufacturing devices of high efficiency and durability. In this work, it is demonstrated how useful hybrid reflections are for the study of epitaxial structures with anisotropic strain gradients due to patterned substrates. High accuracy in detecting and distinguishing elastic and plastic relaxations is one of the greatest advantages of measuring this type of reflection, as well as the fact that the method can be exploited in a symmetric reflection geometry on a commercial high-resolution diffractometer. Słowa kluczowe: optoelectronics, Group III-nitride semiconductors, epitaxial growth, X-ray multiple diffraction, interface defects Afiliacje autorów:
Domagała J.Z. | - | Institute of Physics, Polish Academy of Sciences (PL) | Morelhão S.L. | - | University of Sao Paulo (BR) | Sarzyński M. | - | Military University of Technology (PL) | Maździarz M. | - | IPPT PAN | Dłużewski P. | - | IPPT PAN | Leszczyński M. | - | inna afiliacja |
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Kret S.♦, Dłużewski P., Szczepańska A.♦, Żak M.♦, Czernecki R.♦, Kryśko M.♦, Leszczyński M.♦, Maciejewski G., Homogenous indium distribution in InGaN/GaN laser active structure grown by LP-MOCVD on bulk GaN crystal revealed by transmission electron microscopy and X-ray diffraction,
NANOTECHNOLOGY, ISSN: 0957-4484, DOI: 10.1088/0957-4484/18/46/465707, Vol.18, No.46, pp.465707-0, 2007Streszczenie: We present transmission electron microscopy (TEM) and x-ray quantitative studies of the indium distribution in InxGa1−xN/GaN multiple quantum wells (MQWs) with x = 0.1 and 0.18. The quantum wells were grown by low-pressure metalorganic chemical vapour deposition (LP-MOCVD) on a bulk, dislocation-free, mono-crystalline GaN substrate. By using the quantitative TEM methodology the absolute indium concentration was determined from the 0002 lattice fringe images by the strain measurement coupled with finite element (FE) simulations of surface relaxation of the TEM sample. In the x-ray diffraction (XRD) investigation, a new simulation program was applied to monitor the indium content and lateral composition gradients. We found a very high quality of the multiple quantum wells with lateral indium fluctuations no higher than ΔxL = 0.025. The individual wells have very similar indium concentration and widths over the whole multiple quantum well (MQW) stack. We also show that the formation of 'false clusters' is not a limiting factor in indium distribution measurements. We interpreted the 'false clusters' as small In-rich islands formed on a sample surface during electron-beam exposure. Afiliacje autorów:
Kret S. | - | Institute of Physics, Polish Academy of Sciences (PL) | Dłużewski P. | - | IPPT PAN | Szczepańska A. | - | inna afiliacja | Żak M. | - | inna afiliacja | Czernecki R. | - | inna afiliacja | Kryśko M. | - | inna afiliacja | Leszczyński M. | - | inna afiliacja | Maciejewski G. | - | IPPT PAN |
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