Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment

Effective Ohmic contact between metals and their conductive channels is a crucial step in developing high-performance Ga2O3-based transistors. Distinct from bulk materials, excess thermal energy of the annealing process can destroy the low-dimensional material itself. Given the thermal budget concer...

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Main Authors: Chen, Jinxin, Liu, Bingyan, Gu, Yang, Li, Bin
Other Authors: School of Electrical and Electronic Engineering
Format: Article
Language:English
Published: 2024
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Online Access:https://hdl.handle.net/10356/181543
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-1815432024-12-13T15:42:18Z Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment Chen, Jinxin Liu, Bingyan Gu, Yang Li, Bin School of Electrical and Electronic Engineering Engineering Ohmic contact X-ray photoemission spectroscopy Effective Ohmic contact between metals and their conductive channels is a crucial step in developing high-performance Ga2O3-based transistors. Distinct from bulk materials, excess thermal energy of the annealing process can destroy the low-dimensional material itself. Given the thermal budget concern, a feasible and moderate solution (i.e., Ar-containing plasma treatment) is proposed to achieve effective Ohmic junctions with (100) β-Ga2O3 nanosheets. The impact of four kinds of plasma treatments (i.e., gas mixtures SF6/Ar, SF6/O2/Ar, SF6/O2, and Ar) on (100) β-Ga2O3 crystals is comparatively studied by X-ray photoemission spectroscopy for the first time. With the optimal plasma pre-treatment (i.e., Ar plasma, 100 W, 60 s), the resulting β-Ga2O3 nanosheet field-effect transistors (FETs) show effective Ohmic contact (i.e., contact resistance RC of 104 Ω·mm) without any post-annealing, which leads to competitive device performance such as a high current on/off ratio (>107), a low subthreshold swing (SS, 249 mV/dec), and acceptable field-effect mobility ((Formula presented.), ~21.73 cm2 V−1 s−1). By using heavily doped β-Ga2O3 crystals (Ne, ~1020 cm−3) for Ar plasma treatments, the contact resistance RC can be further decreased to 5.2 Ω·mm. This work opens up new opportunities to enhance the Ohmic contact performance of low-dimensional Ga2O3-based transistors and can further benefit other oxide-based nanodevices. Published version This research is supported by the National Natural Science Foundation of China (Nos. 62104072 and 62174058) and the Postdoctoral Research Program of Guangzhou (No. L2230350). 2024-12-09T02:06:45Z 2024-12-09T02:06:45Z 2024 Journal Article Chen, J., Liu, B., Gu, Y. & Li, B. (2024). Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment. Electronics, 13(16), 3181-. https://dx.doi.org/10.3390/electronics13163181 2079-9292 https://hdl.handle.net/10356/181543 10.3390/electronics13163181 2-s2.0-85202662462 16 13 3181 en Electronics © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering
Ohmic contact
X-ray photoemission spectroscopy
spellingShingle Engineering
Ohmic contact
X-ray photoemission spectroscopy
Chen, Jinxin
Liu, Bingyan
Gu, Yang
Li, Bin
Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment
description Effective Ohmic contact between metals and their conductive channels is a crucial step in developing high-performance Ga2O3-based transistors. Distinct from bulk materials, excess thermal energy of the annealing process can destroy the low-dimensional material itself. Given the thermal budget concern, a feasible and moderate solution (i.e., Ar-containing plasma treatment) is proposed to achieve effective Ohmic junctions with (100) β-Ga2O3 nanosheets. The impact of four kinds of plasma treatments (i.e., gas mixtures SF6/Ar, SF6/O2/Ar, SF6/O2, and Ar) on (100) β-Ga2O3 crystals is comparatively studied by X-ray photoemission spectroscopy for the first time. With the optimal plasma pre-treatment (i.e., Ar plasma, 100 W, 60 s), the resulting β-Ga2O3 nanosheet field-effect transistors (FETs) show effective Ohmic contact (i.e., contact resistance RC of 104 Ω·mm) without any post-annealing, which leads to competitive device performance such as a high current on/off ratio (>107), a low subthreshold swing (SS, 249 mV/dec), and acceptable field-effect mobility ((Formula presented.), ~21.73 cm2 V−1 s−1). By using heavily doped β-Ga2O3 crystals (Ne, ~1020 cm−3) for Ar plasma treatments, the contact resistance RC can be further decreased to 5.2 Ω·mm. This work opens up new opportunities to enhance the Ohmic contact performance of low-dimensional Ga2O3-based transistors and can further benefit other oxide-based nanodevices.
author2 School of Electrical and Electronic Engineering
author_facet School of Electrical and Electronic Engineering
Chen, Jinxin
Liu, Bingyan
Gu, Yang
Li, Bin
format Article
author Chen, Jinxin
Liu, Bingyan
Gu, Yang
Li, Bin
author_sort Chen, Jinxin
title Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment
title_short Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment
title_full Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment
title_fullStr Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment
title_full_unstemmed Ohmic contact formation to β-Ga2O3 nanosheet transistors with Ar-containing plasma treatment
title_sort ohmic contact formation to β-ga2o3 nanosheet transistors with ar-containing plasma treatment
publishDate 2024
url https://hdl.handle.net/10356/181543
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