Deng, Y. orcid.org/0000-0002-8804-9428, Xie, N., Hu, W. orcid.org/0000-0003-0254-8363 et al. (17 more authors) (2023) Atomic plane misorientation assisted crystalline quality improvement in epitaxial growth of AlN on a nanopatterned sapphire (0001) surface for deep ultraviolet photoelectric devices. ACS Applied Nano Materials, 6 (6). pp. 4262-4270. ISSN 2574-0970
Abstract
The atomic-layer misorientation during the growth of a 5 μm thick AlN thin film on a patterned (0001) sapphire substrate was investigated by the scan rotation approach using a probe aberration-corrected scanning transmission electron microscope at a nanometer scale. Through the geometrical phase analysis of the resulting twisted atomic structure at different depths below the top surface, it is shown that over 10% of local tensile and compressive strain is balanced in a 1.6° twist of the c-planes within the first micron of AlN growth. As a consequence, the formation of threading dislocations is reduced. The in-plane twist is seen to decrease toward the layer surface down to 0.5°. Finally, growth has adopted the conventional step flow mechanism with a reduced density of emerging dislocations by the thickness of 5 μm. Our finding forecasts the possibility of understanding the relationship between atomic bilayer twist and local strain accommodation at a nanometer scale, which could provide guidance for achieving better crystal quality of AlN thin films on patterned substrates during epitaxy.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2023 American Chemical Society. This is an author-produced version of a paper subsequently published in ACS Applied Nano Material. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | strain relaxation; strain accommodation; moire fringes; misorientation; scan rotation; scanning transmission electron microscopy |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 16 Jun 2023 09:15 |
Last Modified: | 09 Mar 2024 01:13 |
Status: | Published |
Publisher: | American Chemical Society (ACS) |
Refereed: | Yes |
Identification Number: | 10.1021/acsanm.2c05372 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:200474 |