Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band Applications

In this study, AlGaN/GaN high-electron-mobility-transistor (HEMTs) with a small gate length were fabricated using a stepper. Additionally, a novel gate fabrication process was conducted to shrink the gate head, thus reducing the parasitic capacitance of the device to achieve high-power amplifier per...

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Main Authors: Neng-Da Li, Yueh-Chin Lin, Kai-Wen Chen, Heng-Tung Hsu, Yi-Fan Tsao, Edward Yi Chang
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Journal of the Electron Devices Society
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Online Access:https://ieeexplore.ieee.org/document/11062583/
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author Neng-Da Li
Yueh-Chin Lin
Kai-Wen Chen
Heng-Tung Hsu
Yi-Fan Tsao
Edward Yi Chang
author_facet Neng-Da Li
Yueh-Chin Lin
Kai-Wen Chen
Heng-Tung Hsu
Yi-Fan Tsao
Edward Yi Chang
author_sort Neng-Da Li
collection DOAJ
description In this study, AlGaN/GaN high-electron-mobility-transistor (HEMTs) with a small gate length were fabricated using a stepper. Additionally, a novel gate fabrication process was conducted to shrink the gate head, thus reducing the parasitic capacitance of the device to achieve high-power amplifier performance. The device performance in the research demonstrated a steady-state current density (Idss) of 975 mA/mm and a maximum transconductance (gm) of 369 mS/mm at a 20 V bias. Moreover, the cut-off frequency (fT) reached 50.6 GHz, and the maximum oscillation frequency (fmax) achieved 161 GHz as measured by S-parameter measurement. In the load-pull system, the frequency operation is under 28 GHz. For the <inline-formula> <tex-math notation="LaTeX">$2\times 50~\mu $ </tex-math></inline-formula>m device at a drain bias of 20 V, it exhibits a maximum output power density (Pout) of 2.83 W/mm with a maximum 24.97&#x0025; power-added efficiency (PAE). Additionally, for the <inline-formula> <tex-math notation="LaTeX">$8\times 50~\mu $ </tex-math></inline-formula>m device at a drain bias of 32V, it achieves a <inline-formula> <tex-math notation="LaTeX">$\mathrm { P_{out}}$ </tex-math></inline-formula> of 1.27 W (3.18 W/mm). This work demonstrates that the novel gate fabrication process of shrinking gate head by using <inline-formula> <tex-math notation="LaTeX">$\mathrm { SiN_{x}}$ </tex-math></inline-formula> shield achieves high-frequency and high-output power characteristics for Ka-band application.
format Article
id doaj-art-883a457b28cd44868930b20e01755ee2
institution Kabale University
issn 2168-6734
language English
publishDate 2025-01-01
publisher IEEE
record_format Article
series IEEE Journal of the Electron Devices Society
spelling doaj-art-883a457b28cd44868930b20e01755ee22025-08-20T03:56:05ZengIEEEIEEE Journal of the Electron Devices Society2168-67342025-01-011359359810.1109/JEDS.2025.358480911062583Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band ApplicationsNeng-Da Li0https://orcid.org/0009-0005-1590-2714Yueh-Chin Lin1Kai-Wen Chen2Heng-Tung Hsu3https://orcid.org/0000-0002-7753-5690Yi-Fan Tsao4https://orcid.org/0000-0001-6601-8308Edward Yi Chang5https://orcid.org/0000-0003-1616-5240Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, TaiwanDepartment of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, TaiwanInternational College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu, TaiwanInternational College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu, TaiwanInternational College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu, TaiwanDepartment of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, TaiwanIn this study, AlGaN/GaN high-electron-mobility-transistor (HEMTs) with a small gate length were fabricated using a stepper. Additionally, a novel gate fabrication process was conducted to shrink the gate head, thus reducing the parasitic capacitance of the device to achieve high-power amplifier performance. The device performance in the research demonstrated a steady-state current density (Idss) of 975 mA/mm and a maximum transconductance (gm) of 369 mS/mm at a 20 V bias. Moreover, the cut-off frequency (fT) reached 50.6 GHz, and the maximum oscillation frequency (fmax) achieved 161 GHz as measured by S-parameter measurement. In the load-pull system, the frequency operation is under 28 GHz. For the <inline-formula> <tex-math notation="LaTeX">$2\times 50~\mu $ </tex-math></inline-formula>m device at a drain bias of 20 V, it exhibits a maximum output power density (Pout) of 2.83 W/mm with a maximum 24.97&#x0025; power-added efficiency (PAE). Additionally, for the <inline-formula> <tex-math notation="LaTeX">$8\times 50~\mu $ </tex-math></inline-formula>m device at a drain bias of 32V, it achieves a <inline-formula> <tex-math notation="LaTeX">$\mathrm { P_{out}}$ </tex-math></inline-formula> of 1.27 W (3.18 W/mm). This work demonstrates that the novel gate fabrication process of shrinking gate head by using <inline-formula> <tex-math notation="LaTeX">$\mathrm { SiN_{x}}$ </tex-math></inline-formula> shield achieves high-frequency and high-output power characteristics for Ka-band application.https://ieeexplore.ieee.org/document/11062583/AlGaN/GaN HEMTs on SiChigh frequencySiNₓ shieldnovel gate fabrication
spellingShingle Neng-Da Li
Yueh-Chin Lin
Kai-Wen Chen
Heng-Tung Hsu
Yi-Fan Tsao
Edward Yi Chang
Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band Applications
IEEE Journal of the Electron Devices Society
AlGaN/GaN HEMTs on SiC
high frequency
SiNₓ shield
novel gate fabrication
title Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band Applications
title_full Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band Applications
title_fullStr Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band Applications
title_full_unstemmed Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band Applications
title_short Novel Gate Fabrication Process Enhancing High-Frequency Operation in AlGaN/GaN HEMTs for Ka-Band Applications
title_sort novel gate fabrication process enhancing high frequency operation in algan gan hemts for ka band applications
topic AlGaN/GaN HEMTs on SiC
high frequency
SiNₓ shield
novel gate fabrication
url https://ieeexplore.ieee.org/document/11062583/
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AT yuehchinlin novelgatefabricationprocessenhancinghighfrequencyoperationinalganganhemtsforkabandapplications
AT kaiwenchen novelgatefabricationprocessenhancinghighfrequencyoperationinalganganhemtsforkabandapplications
AT hengtunghsu novelgatefabricationprocessenhancinghighfrequencyoperationinalganganhemtsforkabandapplications
AT yifantsao novelgatefabricationprocessenhancinghighfrequencyoperationinalganganhemtsforkabandapplications
AT edwardyichang novelgatefabricationprocessenhancinghighfrequencyoperationinalganganhemtsforkabandapplications