Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT
A dual Al<sub>2</sub>O<sub>3</sub> MIS gate structure is proposed to enhance the DC and RF performance of enhancement-mode GaN high-electron mobility transistors (HEMTs). As a result, the proposed MOS-HEMT with a dual recessed MIS gate structure offers 84% improvements in cut...
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MDPI AG
2025-06-01
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| author | Yuan Li Yong Huang Jing Li Huiqing Sun Zhiyou Guo |
| author_facet | Yuan Li Yong Huang Jing Li Huiqing Sun Zhiyou Guo |
| author_sort | Yuan Li |
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| description | A dual Al<sub>2</sub>O<sub>3</sub> MIS gate structure is proposed to enhance the DC and RF performance of enhancement-mode GaN high-electron mobility transistors (HEMTs). As a result, the proposed MOS-HEMT with a dual recessed MIS gate structure offers 84% improvements in cutoff frequency (f<sub>T</sub>) and 92% improvements in maximum oscillation frequency (f<sub>max</sub>) compared to conventional HEMTs (from 7.1 GHz to 13.1 GHz and 17.5 GHz to 33.6 GHz, respectively). As for direct-current characteristics, a remarkable reduction in off-state gate leakage current and a 26% enhancement in the maximum saturation drain current (from 519 mA·mm<sup>−1</sup> to 658 A·mm<sup>−1</sup>) are manifested in HEMTs with new structures. The maximum transconductance (g<sub>m</sub>) is also raised from 209 mS·mm<sup>−1</sup> to 246 mS·mm<sup>−1</sup>. Correspondingly, almost unchanged gate–source capacitance curves and gate–drain capacitance curves are also discussed to explain the electrical characteristic mechanism. These results indicate the superiority of using a dual Al<sub>2</sub>O<sub>3</sub> MIS gate structure in GaN-based HEMTs to promote the RF and DC performance, providing a reference for further development in a miniwatt antenna amplifier and sub-6G frequencies of operation. |
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| language | English |
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| series | Micromachines |
| spelling | doaj-art-4422f166b35848c1a21f63d80e7b1d9c2025-06-25T14:11:39ZengMDPI AGMicromachines2072-666X2025-06-0116668710.3390/mi16060687Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMTYuan Li0Yong Huang1Jing Li2Huiqing Sun3Zhiyou Guo4Institute of Semiconductor Science and Technology, South China Normal University, 55 Zhongshan Avenue, Tianhe District, Guangzhou 510631, ChinaGuangdong Industrial Training Center, Guangdong Polytechnic Normal University, Guangzhou 510665, ChinaSchool of Information and Engineering, Nanjing XiaoZhuang University, Nanjing 211171, ChinaInstitute of Semiconductor Science and Technology, South China Normal University, 55 Zhongshan Avenue, Tianhe District, Guangzhou 510631, ChinaInstitute of Semiconductor Science and Technology, South China Normal University, 55 Zhongshan Avenue, Tianhe District, Guangzhou 510631, ChinaA dual Al<sub>2</sub>O<sub>3</sub> MIS gate structure is proposed to enhance the DC and RF performance of enhancement-mode GaN high-electron mobility transistors (HEMTs). As a result, the proposed MOS-HEMT with a dual recessed MIS gate structure offers 84% improvements in cutoff frequency (f<sub>T</sub>) and 92% improvements in maximum oscillation frequency (f<sub>max</sub>) compared to conventional HEMTs (from 7.1 GHz to 13.1 GHz and 17.5 GHz to 33.6 GHz, respectively). As for direct-current characteristics, a remarkable reduction in off-state gate leakage current and a 26% enhancement in the maximum saturation drain current (from 519 mA·mm<sup>−1</sup> to 658 A·mm<sup>−1</sup>) are manifested in HEMTs with new structures. The maximum transconductance (g<sub>m</sub>) is also raised from 209 mS·mm<sup>−1</sup> to 246 mS·mm<sup>−1</sup>. Correspondingly, almost unchanged gate–source capacitance curves and gate–drain capacitance curves are also discussed to explain the electrical characteristic mechanism. These results indicate the superiority of using a dual Al<sub>2</sub>O<sub>3</sub> MIS gate structure in GaN-based HEMTs to promote the RF and DC performance, providing a reference for further development in a miniwatt antenna amplifier and sub-6G frequencies of operation.https://www.mdpi.com/2072-666X/16/6/687GaN HEMTAl<sub>2</sub>O<sub>3</sub> dielectricMIS structureTCAD simulation |
| spellingShingle | Yuan Li Yong Huang Jing Li Huiqing Sun Zhiyou Guo Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT Micromachines GaN HEMT Al<sub>2</sub>O<sub>3</sub> dielectric MIS structure TCAD simulation |
| title | Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT |
| title_full | Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT |
| title_fullStr | Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT |
| title_full_unstemmed | Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT |
| title_short | Effect of Dual Al<sub>2</sub>O<sub>3</sub> MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT |
| title_sort | effect of dual al sub 2 sub o sub 3 sub mis gate structure on dc and rf characteristics of enhancement mode gan hemt |
| topic | GaN HEMT Al<sub>2</sub>O<sub>3</sub> dielectric MIS structure TCAD simulation |
| url | https://www.mdpi.com/2072-666X/16/6/687 |
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