Do, H.-B., Zhou, J. and De Souza, M.M. orcid.org/0000-0002-7804-7154 (2022) Origins of the Schottky barrier to a 2DHG in a Au/Ni/GaN/AlGaN/GaN heterostructure. ACS Applied Electronic Materials, 4 (10). pp. 4808-4813. ISSN 2637-6113
Abstract
We report the influence of thickness of an undoped GaN (u-GaN) layer on current transport to a 2DHG through the metal/p++GaN contact in a GaN/AlGaN/GaN heterostructure. The current is dominated by an internal potential barrier of 0.2–0.27 eV at the p+ GaN/u-GaN, which increases with thickness from 5 to 15 nm and remains constant thereafter due to Fermi pinning by a defect at ∼0.6 eV from the top valence band. We also report a nonideality factor, n, between 6 and 12, for the combined tunneling current through the p+GaN/u-GaN to the 2DHG. Our contact resistivity of 5.3 × 10–4 Ω cm2 and hole mobility, μ, of ∼15.65 cm2/V s are the best-in-class for this metal stack on a GaN/AlGaN/GaN heterostructure, reported to date.
Metadata
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Copyright, Publisher and Additional Information: | © 2022 The Authors. Published by American Chemical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. | ||||
Keywords: | p-type contact to GaN; Ni/Au; Schottky contact; 2DHG; thermionic field emission; Mg traps in u-GaN | ||||
Dates: |
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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) | ||||
Funding Information: |
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Depositing User: | Symplectic Sheffield | ||||
Date Deposited: | 10 Oct 2022 11:52 | ||||
Last Modified: | 07 Nov 2022 16:48 | ||||
Status: | Published | ||||
Publisher: | American Chemical Society (ACS) | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1021/acsaelm.2c01138 |