Zhang, Y., Bai, J., Hou, Y. et al. (4 more authors) (2016) Defect reduction in overgrown semi-polar (11-22) GaN on a regularly arrayed micro-rod array template. AIP Advances, 6 (2). 025201.
Abstract
We demonstrate a great improvement in the crystal quality of our semi-polar (11-22) GaN overgrown on regularly arrayed micro-rod templates fabricated using a combination of industry-matched photolithography and dry-etching techniques. As a result of our micro-rod configuration specially designed, an intrinsic issue on the anisotropic growth rate which is a great challenge in conventional overgrowth technique for semi-polar GaN has been resolved. Transmission electron microscopy measurements show a different mechanism of defect reduction from conventional overgrowth techniques and also demonstrate major advantages of our approach. The dislocations existing in the GaN micro-rods are effectively blocked by both a SiO2 mask on the top of each GaN micro-rod and lateral growth along the c-direction, where the growth rate along the c-direction is faster than that along any other direction. Basal stacking faults (BSFs) are also effectively impeded, leading to a distribution of BSF-free regions periodically spaced by BSF regions along the [-1-123] direction, in which high and low BSF density areas further show a periodic distribution along the [1-100] direction. Furthermore, a defect reduction model is proposed for further improvement in the crystalline quality of overgrown (11-22) GaN on sapphire.
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Copyright, Publisher and Additional Information: | © 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). | ||||
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Institution: | The University of Sheffield | ||||
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) | ||||
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Depositing User: | Symplectic Sheffield | ||||
Date Deposited: | 11 Oct 2017 15:23 | ||||
Last Modified: | 11 Oct 2017 15:23 | ||||
Published Version: | https://doi.org/10.1063/1.4941444 | ||||
Status: | Published | ||||
Publisher: | AIP Publishing | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1063/1.4941444 | ||||
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