Lattice distortion analysis of nonpolar a-plane $$(11\bar 20)$$ GaN films by using a grazing-incidence X-ray diffraction technique
In: Journal of the Korean Physical Society, Jg. 66 (2015-02-01), S. 607-611
Online
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Zugriff:
This work examines the anisotropic microstructure and the lattice distortions of nonpolar a-plane \((11\bar 20)\) GaN (a-GaN) films by using the grazing-incidence X-ray diffraction technique. Faulted a-GaN films typically exhibit an in-plane anisotropy of the structural properties along the X-ray in-beam directions. For this reason, the anisotropic peak broadenings of the X-ray rocking curves (XRCs) were observed for various angle (phi) rotations for a-GaN films with and without SiNx interlayers. Analysis revealed the peak widths of the XRCs displayed an isotropic behavior for a nonpolar a-GaN bulk crystal. Thus, the in-plane anisotropy of the XRC peak widths for nonpolar a-GaN films apparently originates from the heteroepitaxial growth of the a-GaN layer on a foreign substrate. The lattice distortion analysis identified the presence of compressive strains in both the two in-plane directions (the c- and the m-axis), as well as a tensile strain along the normal growth direction. In addition, the observed frequency shifts in the Raman E2 (high) mode for the a-GaN films showed the existence of considerable in-plane compressive strain on both a-GaN films, as confirmed by the lattice distortion analysis performed using the grazing-incidence XRD method.
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Lattice distortion analysis of nonpolar a-plane $$(11\bar 20)$$ GaN films by using a grazing-incidence X-ray diffraction technique
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Autor/in / Beteiligte Person: | Kwang Hyeon Baik ; Kim, Ji-Hoon ; Kim, Jihyun ; Hwang, Sung-Min ; Jang, Soohwan ; Yong Gon Seo ; Kim, Heesan |
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Zeitschrift: | Journal of the Korean Physical Society, Jg. 66 (2015-02-01), S. 607-611 |
Veröffentlichung: | Korean Physical Society, 2015 |
Medientyp: | unknown |
ISSN: | 1976-8524 (print) ; 0374-4884 (print) |
DOI: | 10.3938/jkps.66.607 |
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