In:
MRS Proceedings, Springer Science and Business Media LLC, Vol. 537 ( 1998)
Abstract:
Ambient gas effect on the epitaxial lateral overgrowth (ELO) of GaN via metalorganic vapor-phase epitaxy (MOVPE) on a MOVPE-grown GaN (0001) / sapphire (0001) substrate with a SiO 2 stripe mask has been studied by means of field-emission scanning electron microscopy (SEM) and high-resolution X-ray diffraction (XRD) analysis. Different ambient gases of nitrogen, hydrogen and their mixture (mixture ratio, hydrogen: nitrogen = 1: 1) affect the lateral overgrowth rate, the surface morphology and the crystalline tilting of ELO-GaN layers. XRD revealed that the ELO-GaN layer on the SiO 2 mask aligned along the 〈 1 1 00 〉 direction exhibited anisotropic crystalline tilting toward 〈 11 2 0 〉 . For ELO-GaN growth in nitrogen ambient, the growth rate of the (0001) facet decreases, the lateral overgrowth rate increases and the tilting of the ELO-GaN layer increases, while no smooth surface is obtained, in comparison with ELO-GaN growth in hydrogen ambient. For the mixture ambient, a smooth surface with a fast lateral overgrowth rate is achieved and the dislocation density is not more than 10 7 cm -2 , which is comparable to that in hydrogen ambient.
Type of Medium:
Online Resource
ISSN:
0272-9172
,
1946-4274
DOI:
10.1557/PROC-537-G3.1
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
1998
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