The structure of dislocations in GaN grown by MBE as a function of the gallium to nitrogen ratio

MQ Baines, D Cherns, SV Novikov, MJ Manfra, CT Foxon

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

Abstract

Transmission electron microscopy (TEM) and atomic force microscopy (AFM) have been used to analyse the core structure of dislocations in GaN grown by molecular beam epitaxy (MBE) as a function of the gallium to nitrogen ratio. Ga-rich samples had a much smoother morphology; TEM observations showed that amorphous deposits decorated some dislocations and occasional surface pits, but weak beam and end-on imaging suggested that, away from the growth surface, dislocations of all types had closed core structures, in contrast to previous observations (Hsu et al, Appl. Phys. Lett. 78, 3980 (2001), Baines et al, Mat.Res.Soc.Symp.Proc. 743, L2.5 (2003)). Ga-poor samples were found to have much rougher surfaces; dislocations were often at the centers of deep surface pits but were observed to be undecorated and to have closed core structures. It is concluded that in growth under Ga-rich conditions, decoration of dislocation cores depends on the accumulation of Ga at surface pits, rather than being a fundamental property of dislocation formation.
Translated title of the contributionThe structure of dislocations in GaN grown by MBE as a function of the gallium to nitrogen ratio
Original languageEnglish
Pages (from-to)729 - 734
Number of pages6
JournalMaterial Research Society Symposium Proceedings
Volume798
Issue numberSymposium Y – GaN and Related Alloys
Publication statusPublished - 2003

Bibliographical note

Editors: Hock Min Ng, Michael Wraback, Kazumasa Hiramatsu, Nicolas Grandjean
ISBN: 1558997369
Publisher: Materials Research Society
Name and Venue of Conference: Symposium on GaN and Related Alloys held at the MRS Fall Meeting, Boston, December 2003
Conference Organiser: Materials Research Society

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