Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET Fabrication
In this study, we conducted an optimization of a low-damage selective etching process utilizing inductively coupled plasma-reactive ion etch (ICP-RIE) with a fluorine-based gas mixture. This optimization was carried out for the fabrication of p-GaN gated AlGaN/GaN enhancement-mode (E-mode) heterojun...
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MDPI AG
2023-10-01
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| Series: | Electronics |
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| Online Access: | https://www.mdpi.com/2079-9292/12/20/4347 |
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| author | Hyeon-Ji Kim Jun-Hyeok Yim Hyungtak Kim Ho-Young Cha |
| author_facet | Hyeon-Ji Kim Jun-Hyeok Yim Hyungtak Kim Ho-Young Cha |
| author_sort | Hyeon-Ji Kim |
| collection | DOAJ |
| description | In this study, we conducted an optimization of a low-damage selective etching process utilizing inductively coupled plasma-reactive ion etch (ICP-RIE) with a fluorine-based gas mixture. This optimization was carried out for the fabrication of p-GaN gated AlGaN/GaN enhancement-mode (E-mode) heterojunction field-effect transistors (HFETs). The optimum process conditions resulted in an etch selectivity of 21:1 (=p-GaN:Al<sub>0.2</sub>Ga<sub>0.8</sub>N) with a p-GaN etch rate of 5.2 nm/min and an AlGaN etch rate of 0.25 nm/min. In comparison with an oxygen-based selective etching process, the fluorine-based selective etching process demonstrated reduced damage to the etched surface. This was confirmed through current–voltage characteristics and surface roughness inspections. The p-GaN gated AlGaN/GaN E-mode device, fabricated using the optimized fluorine-based selective etching process, achieved a high threshold voltage of 3.5 V with a specific on-resistance of 5.3 mΩ.cm<sup>2</sup> for the device and with a gate-to-p-GaN gate distance of 3 μm, a p-GaN gate length of 4 μm, and a p-GaN gate-to-drain distance of 12 μm. The catastrophic breakdown voltage exceeded 1350 V. |
| first_indexed | 2024-03-10T21:18:10Z |
| format | Article |
| id | doaj.art-fd5426e6feeb4911bafcb88cc94558e3 |
| institution | Directory Open Access Journal |
| issn | 2079-9292 |
| language | English |
| last_indexed | 2024-03-10T21:18:10Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Electronics |
| spelling | doaj.art-fd5426e6feeb4911bafcb88cc94558e32023-11-19T16:20:26ZengMDPI AGElectronics2079-92922023-10-011220434710.3390/electronics12204347Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET FabricationHyeon-Ji Kim0Jun-Hyeok Yim1Hyungtak Kim2Ho-Young Cha3School of Electronic and Electrical Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of KoreaSchool of Electronic and Electrical Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of KoreaSchool of Electronic and Electrical Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of KoreaSchool of Electronic and Electrical Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of KoreaIn this study, we conducted an optimization of a low-damage selective etching process utilizing inductively coupled plasma-reactive ion etch (ICP-RIE) with a fluorine-based gas mixture. This optimization was carried out for the fabrication of p-GaN gated AlGaN/GaN enhancement-mode (E-mode) heterojunction field-effect transistors (HFETs). The optimum process conditions resulted in an etch selectivity of 21:1 (=p-GaN:Al<sub>0.2</sub>Ga<sub>0.8</sub>N) with a p-GaN etch rate of 5.2 nm/min and an AlGaN etch rate of 0.25 nm/min. In comparison with an oxygen-based selective etching process, the fluorine-based selective etching process demonstrated reduced damage to the etched surface. This was confirmed through current–voltage characteristics and surface roughness inspections. The p-GaN gated AlGaN/GaN E-mode device, fabricated using the optimized fluorine-based selective etching process, achieved a high threshold voltage of 3.5 V with a specific on-resistance of 5.3 mΩ.cm<sup>2</sup> for the device and with a gate-to-p-GaN gate distance of 3 μm, a p-GaN gate length of 4 μm, and a p-GaN gate-to-drain distance of 12 μm. The catastrophic breakdown voltage exceeded 1350 V.https://www.mdpi.com/2079-9292/12/20/4347p-GaNAlGaN/GaN heterojunctionenhancement modeselective etchingfluorine |
| spellingShingle | Hyeon-Ji Kim Jun-Hyeok Yim Hyungtak Kim Ho-Young Cha Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET Fabrication Electronics p-GaN AlGaN/GaN heterojunction enhancement mode selective etching fluorine |
| title | Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET Fabrication |
| title_full | Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET Fabrication |
| title_fullStr | Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET Fabrication |
| title_full_unstemmed | Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET Fabrication |
| title_short | Fluorine-Based Low-Damage Selective Etching Process for E-Mode p-GaN/AlGaN/GaN HFET Fabrication |
| title_sort | fluorine based low damage selective etching process for e mode p gan algan gan hfet fabrication |
| topic | p-GaN AlGaN/GaN heterojunction enhancement mode selective etching fluorine |
| url | https://www.mdpi.com/2079-9292/12/20/4347 |
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