In:
physica status solidi c, Wiley, Vol. 8, No. 7-8 ( 2011-07), p. 2063-2065
Abstract:
We report the growth of high crystal quality Al 0.3 Ga 0.7 N directly on sapphire substrates with metalorganic vapour phase epitaxy. We studied the improvements in crystal quality by introducing an in‐situ deposited SiN x interlayer. It acts as a nanomask which results in termination of the dislocations near the interface between the nanomask and epilayer. The epilayers with no SiN x interlayer have very low density of screw type dislocations evident from transmission electron microscopy (TEM) investigations confirmed by a very narrow X‐ray diffraction symmetric reflection (60”). This is a result of our oxygen doped AlN nucleation layer used to grow such epilayers. On the other hand, such epilayers have very broad XRD asymmetric reflections (typically a few thousand arcsec) indicating a high density of edge type dislocations. We could decrease the latter which are the main existing dislocations in our AlGaN epilayers. In TEM micrographs, we observed the formation of dislocation “bundles” when introducing SiN x interlayers. This phenomenon promotes the dislocation free areas on the surface of the wafer. We carried out accurate optimizations of the SiN x deposition. Consequently, we could grow high quality Al 0.3 Ga 0.7 N epilayers with much narrower XRD asymmetric peaks–782” with total sample thickness of 1.4 µm (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Type of Medium:
Online Resource
ISSN:
1862-6351
,
1610-1642
DOI:
10.1002/pssc.201001074
Language:
English
Publisher:
Wiley
Publication Date:
2011
detail.hit.zdb_id:
2105580-4
detail.hit.zdb_id:
2102966-0
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