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High‐quality nonpolar m ‐plane GaN substrates grown by HVPE
Author(s) -
Fujito Kenji,
Kiyomi Kazumasa,
Mochizuki Tae,
Oota Hirotaka,
Namita Hideo,
Nagao Satoru,
Fujimura Isao
Publication year - 2008
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200778709
Subject(s) - lapping , bar (unit) , materials science , surface roughness , polishing , diffraction , surface finish , epitaxy , stacking , raman spectroscopy , full width at half maximum , hydride , atomic force microscopy , analytical chemistry (journal) , crystallography , optics , optoelectronics , chemistry , nanotechnology , composite material , physics , metal , metallurgy , organic chemistry , layer (electronics) , chromatography , meteorology
Relatively large size (about 10 mm × 10 mm) m ‐plane GaN substrates are grown by hydride vapor phase epitaxy (HVPE). The high crystalline quality of the substrates was observed by X‐ray diffraction analysis. Typical full widths at half maximum values of X‐ray rocking curves measured for the (10 $ \bar 1 $ 0) and (10 $ \bar 1 $ 2) reflections were 25–35 arcsec and 30–40 arcsec, respectively. The defect density distribution was analyzed from the [10 $ \bar 1 $ 0] direction by the cathodeluminescence method. The dark spot density decreased in the growth direction and could be as low as 2.5 × 10 5 cm –2 . No stacking faults could be seen. The surface roughness after the lapping, polishing and cleaning was measured by atomic force microscopy and the RMS roughness was 0.072 nm. All of the phonon modes that the selection rules allow have been observed in polarized Raman measurements. High‐quality large‐size m ‐plane GaN substrates will enable the realization of commercial production of nonpolar devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)