Kinetic influences on void formation in epitaxially regrown GaAs-based PCSELs

McKenzie, A. F. , Kyaw, A. M., Gerrard, N. D., MacLaren, D. A. and Hogg, R. A. (2023) Kinetic influences on void formation in epitaxially regrown GaAs-based PCSELs. Journal of Crystal Growth, 602, 126969. (doi: 10.1016/j.jcrysgro.2022.126969)

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Abstract

We report an investigation into the formation of crystallographic voids during the metalorganic vapour phase epitaxial regrowth of GaAs photonic crystal structures. We employ a combination of cross-sectional scanning electron microscopy and scanning transmission electron microscopy to study structures regrown with AlAs, AlGaAs and GaAs. The change in regrowth material allows the effect of adatom diffusion kinetics on the void structure to be assessed. Whilst complete grating infill is observed for GaAs, void formation is promoted for Al-containing materials, with void size increasing with Al mole fraction, in line with reduced adatom mobility. In the case of both AlAs and AlGaAs-regrown structures, a degree of asymmetry is observed in the shape of the voids within the plane of the photonic crystal. These differences are attributed to variations in group-III adatom surface mobility and the polarities of high-index crystal planes along orthogonal crystal directions. Two growth regimes of stable and dynamic faceting are observed in cross-sections containing crystal planes with A- and B-type polarities, respectively.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:McKenzie, Mr Adam and Hogg, Professor Richard and Gerrard, Dr Neil and Kyaw, Aye Su Mon and MacLaren, Dr Donald
Authors: McKenzie, A. F., Kyaw, A. M., Gerrard, N. D., MacLaren, D. A., and Hogg, R. A.
College/School:College of Science and Engineering > School of Engineering
College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
College of Science and Engineering > School of Physics and Astronomy
Journal Name:Journal of Crystal Growth
Publisher:Elsevier
ISSN:0022-0248
ISSN (Online):1873-5002
Published Online:01 November 2022
Copyright Holders:Copyright © 2022 The Authors
First Published:First published in Journal of Crystal Growth 602: 126969
Publisher Policy:Reproduced under a Creative Commons License

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