Thick crack-free AlGaN films deposited by facet-controlled epitaxial lateral overgrowth

R Liu, A Bell, FA Ponce, H Amano, I Akasaki, D Cherns

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

Thick crack-free AlGaN films have been grown on inclined-facet GaN templates. Light emitting diodes with = 323 nm has been achieved on these epilayers. The GaN template was grown at a low temperature in order to obtain triangle-facet growth fronts. Subsequent growth of AlGaN on this template involving a lateral overgrowth process exhibits interesting properties. The microstructure and optical characterizations were done using transmission electron microscopy and cathodoluminescence. At the AlGaN/GaN interface, a high density of dislocations was created due to lattice mismatch strain. Another unexpected set of triangular boundaries was observed inside the AlGaN layer, which grew without any change of the growth parameters. These boundaries were found to arise from domains grown in different directions. Mono-chromatic cathodoluminescence images indicate that Al content is different between the vertically-grown and the laterally-grown domains, suggesting that lattice mismatch strain exists between them. Dislocations were created at these mismatched boundaries to relax the strain.
Translated title of the contributionThick crack-free AlGaN films deposited by facet-controlled epitaxial lateral overgrowth
Original languageEnglish
Pages (from-to)2136 - 2140
Number of pages5
Journalphysica status solidi (c)
Volume0(7)
Publication statusPublished - 2003

Bibliographical note

Publisher: Wiley Interscience

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