Free standing GaN layers with GaN nanorod buffer layer

Autor: Hiroki Goto, S. W. Lee, Hyunjae Lee, Hyo-Jong Lee, Takafumi Yao, M. W. Cho, Jun-Seok Ha
Rok vydání: 2007
Předmět:
Zdroj: physica status solidi c. 4:2268-2271
ISSN: 1610-1642
1862-6351
DOI: 10.1002/pssc.200674858
Popis: Thick GaN films were grown by HVPE (Hydride Vapor Phase Epitaxy) on c-sapphire substrates with GaN nano-rod buffer layers. Lateral epitaxial growth mode was adapted to grow GaN thick films on nano-structure buffer. Thick GaN films were self-separated during cooling down by thermal stress caused by the difference of thermal expansion coefficient (TEC) between GaN and sapphire. Since the nano-rod buffer consists of nano-rods and voids, it is mechanically weaker than planar GaN layers and contributes to the self-separation of GaN thick films. 200 μm-thick free-standing GaN substrates show smooth surface morphology without any microcracks. The full width at half maximum (FWHM) of (0002) X-ray rocking curve is 619 [arcsec]. Donor-bound exciton emission is observed at 3.4718 eV in low-temperature photoluminescence spectra, which is nearly the same peak position as bulk GaN. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Databáze: OpenAIRE
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