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HL: Halbleiterphysik

HL 24: GaN: Pr
äparation und Charakterisierung I

HL 24.9: Vortrag

Dienstag, 25. März 2003, 17:15–17:30, BEY/118

Crystallographic wing tilt in laterally overgrown GaN — •Claudia Roder¹, Heidrun Heinke¹, Detlef Hommel¹, Thomas M. Katona², James S. Speck³, and Steve P. DenBaars³ — ¹Institut für Festkörperphysik, Universität Bremen, Pf. 330440 — ²Electrical and Computer Engineering Department, University of California, Santa Barbara, CA 93106, USA — ³Materials Department, University of California, Santa Barbara, CA 93106, USA

Thin uncoalesced GaN layers grown on Si(111) by maskless cantilever epitaxy have been investigated using high resolution x-ray diffraction at variable temperatures. The laterally growing wing regions of these structures commonly have a different crystallographic orientation relative to the seed region as they are tilted with respect to the surface normal in plane perpendicular to the stripe direction. This crystallographic tilt of the free-hanging wings relativ to the stripe regions of the samples was determined for different temperatures. With increased temperature the wing tilt decreased non-linearly and seemed to approach a constant value at higher temperatures. The wing tilts of two samples differing at room temperature by one order of magnitude were found to vary by less than 20% between 300 K and 1020 K. This suggests that the main part of the crystallographic wing tilt is not thermally induced for samples grown with the cantilever epitaxy technique.