Properties and preparation of high quality, free-standing GaN substrates and study of spontaneous separation mechanism
| Autor: | Jan Misiewicz, P.R. Hageman, Robert Kudrawiec, Jarosław Serafińczuk, Jan L. Weyher, Hina Ashraf |
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| Rok vydání: | 2010 |
| Předmět: |
Applied Materials Science
Photoluminescence Materials science business.industry Hydride Gallium nitride Condensed Matter Physics Epitaxy Inorganic Chemistry chemistry.chemical_compound Template reaction Optics chemistry Materials Chemistry Sapphire Optoelectronics Dislocation business Layer (electronics) |
| Zdroj: | Journal of Crystal Growth, 312, 4, pp. 595-600 Journal of Crystal Growth, 312, 595-600 |
| ISSN: | 0022-0248 |
| DOI: | 10.1016/j.jcrysgro.2009.11.043 |
| Popis: | High quality free-standing (FS) GaN layers of thickness ∼600 μm were prepared by exploiting spontaneous separation mechanism. Study of the mechanism revealed that the separation took place inside the GaN layer and not from the sapphire substrate. The abrupt changes in growth conditions during the deposition process and thermal mismatch between GaN and sapphire are discussed as possible causes of such spontaneous separation of GaN layers. The substrates were prepared by overgrowing GaN templates using the HCl based hydride vapor phase epitaxy (HVPE). The obtained FS-GaN substrates had a dislocation density (DD) in the order of 106 cm−2. Low temperature photoluminescence (PL) and reflection spectroscopy showed that the FS-GaN have good optical quality. The substrates were nearly stress free as revealed by X-ray diffraction (XRD), PL, and reflection spectroscopy. |
| Databáze: | OpenAIRE |
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