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Structural characterization of AlGaN/AlN Bragg reflector grown by metalorganic chemical vapor deposition
Author(s) -
Ji X. L.,
Jiang R. L.,
Liu B.,
Xie Z. L.,
Zhou J. J.,
Li L.,
Han P.,
Zhang R.,
Zheng Y. D.,
Zheng J. G.
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.200723051
Subject(s) - chemical vapor deposition , metalorganic vapour phase epitaxy , materials science , distributed bragg reflector , optoelectronics , scanning electron microscope , auger electron spectroscopy , sapphire , raman spectroscopy , wafer , layer (electronics) , analytical chemistry (journal) , optics , wavelength , chemistry , epitaxy , laser , nanotechnology , physics , chromatography , nuclear physics , composite material
A thirty‐pair AlGaN/AlN distributed Bragg reflector (DBR) targeted at a center wavelength of 320 nm was grown on a 2‐inch sapphire substrate by metalorganic chemical vapor deposition (MOCVD). It is free of cracks in the main area of the wafer except for a ∼4 mm periphery observed under optical microscope. The measured reflectance spectrum shows a peak reflectivity of 93% at 313 nm and a bandwidth of 13 nm. Further investigation into the interfaces was performed using Auger electron spectroscopy (AES), scanning transmission electron microscope (STEM) and energy dispersive X‐ray fluorescence spectrometer (EDX). It was found that the constitutional change is abrupt when AlGaN is deposited on an AlN layer but gradual in reverse, which resulted in a stack of quasi‐three‐layer periods and high Al composition and therefore both the center reflectivity and the bandwidth were depressed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)