Ultralow Ohmic Contact in Recess-Free Ultrathin Barrier AlGaN/GaN Heterostructures Across a Wide Temperature Range

WANG Yuhao; HUANG Sen; JIANG Qimeng; WANG Xinhua; FAN Jie; YIN Haibo; WEI Ke; ZHENG Yingkui; LIU Xinyu

doi:10.23919/cje.2023.00.309

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Yuhao WANG, Sen HUANG, Qimeng JIANG, et al., “Ultralow Ohmic Contact in Recess-Free Ultrathin Barrier AlGaN/GaN Heterostructures Across a Wide Temperature Range,” Chinese Journal of Electronics, vol. 34, no. 1, pp. 1–9, 2025 doi: 10.23919/cje.2023.00.309

Citation:

Yuhao WANG, Sen HUANG, Qimeng JIANG, et al., “Ultralow Ohmic Contact in Recess-Free Ultrathin Barrier AlGaN/GaN Heterostructures Across a Wide Temperature Range,” Chinese Journal of Electronics, vol. 34, no. 1, pp. 1–9, 2025 doi: 10.23919/cje.2023.00.309

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Ultralow Ohmic Contact in Recess-Free Ultrathin Barrier AlGaN/GaN Heterostructures Across a Wide Temperature Range

doi: 10.23919/cje.2023.00.309

WANG Yuhao^{1, 2},
HUANG Sen^{1, 2
,
,},
JIANG Qimeng^{1, 2},
WANG Xinhua^{1, 2},
FAN Jie^{1, 2},
YIN Haibo^{1, 2},
WEI Ke^{1, 2},
ZHENG Yingkui^{1, 2},
LIU Xinyu^{1, 2}

1.
Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029, China
2.
Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China

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Author Bio:
Yuhao WANG received the B.S. degree in Dalian University of Technology, Dalian in 2019. He is currently pursuing the Ph.D. degree in microelectronics and solid state electronics with the Institute of Microelectronics, Chinese Academy of Sciences, Beijing

Sen HUANG received the Ph.D. degree in Peking University, Beijing in 2009. He is now a Professor with the Institute of Microelectronics, Chinese Academy of Sciences, Beijing. His current interests include advanced design, fabrication, and characterization technologies for III–V power semiconductor devices. (Email: huangsen@ime.ac.cn)

Qimeng JIANG received the Ph.D. degree from The Hong Kong University of Science and Technology, Hong Kong, China, in 2015. He is currently a professor at the Institute of Microelectronics, Chinese Academy of Sciences, Beijing. His current research interests include advanced design and fabrication technologies for power semiconductor devices and ICs

Xinhua WANG received the Ph.D. degree from the Institute of Microelectronics, Chinese Academy of Sciences, Beijing, China, in 2012. He is currently a professor with the Institute of Microelectronics, Chinese Academy of Sciences, Beijing. His current research interests include (Ultra-) wide bandgap semiconductor devices and heterogeneous integration

Jie FAN received the B.S. degree from Central Party School, Beijing, China, in 2006. She is currently a senior experimentalist at the Institute of Microelectronics, Chinese Academy of Sciences, Beijing

Haibo YIN received the Ph.D. degree from the Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China, in 2010. He is currently a senior engineer at the Institute of Microelectronics, Chinese Academy of Sciences, Beijing. His current research interests include advanced materials, device design and related equipment development for compound semiconductors

Ke WEI received the Ph.D. degree from the Institute of Microelectronics, Chinese Academy of Sciences, Beijing, China, in 2018. He is currently a professor at the Institute of Microelectronics, Chinese Academy of Sciences, Beijing. His current research interests include high frequency devices, development of high-power electronic devices, and circuits in compound semiconductors

Yingkui ZHENG received the B.S. degree from South China University of Technology, Guangzhou, China, in 1997. He is currently a senior engineer of the Institute of Microelectronics, Chinese Academy of Sciences, Beijing. His current research interests include high frequency devices, development of high-power electronic devices, and circuits in compound semiconductors

Xinyu LIU received the Ph.D. degree from the Institute of Microelectronics, Chinese Academy of Sciences, Beijing, China, in 1998. He is currently a professor at the Institute of Microelectronics, Chinese Academy of Sciences, Beijing. His current research interests include III–V compound semiconductor technology, microwave devices, and integrated circuits
Corresponding author: Email: huangsen@ime.ac.cn
Available Online: 2024-04-24

Abstract

Abstract

‘Ohmic-before-passivation’ process was implemented on ultrathin-barrier (UTB) AlGaN (<6 nm)/GaN heterostructure to further reduce the ohmic contact resistance (Rc). In this process, alloyed Ti/Al/Ni/Au ohmic metal was formed first, followed by AlN/SiN_x passivation contributed to restore 2-D Electron Gas (2DEG) in the access region. Due to the sharp change in the concentration of 2DEG at the metal edge, a reduced transfer length (L_T) consisted with lower Rc are achieved compared to that of ohmic contact on AlGaN (~20 nm)/GaN heterostructure with pre-ohmic recess process. Temperature-dependent current voltage measurements demonstrate that the carrier transport mechanism is dominated by thermionic field emission above 200 K and by field emission below 200 K. The ‘ohmic-before-passivation’ process enables the relative stability of ohmic contacts between 50~475 K and significantly improves the DC characteristics of GaN-MISHEMTs, offering a promising means for scaling down and enabling the utilization of low-voltage GaN-based power devices in extreme environmental conditions.
- AlGaN/GaN heterostructure,
- recess-free,
- ultrathin barrier (UTB),
- ohmic contact,
- transfer length,
- cryogenic temperature

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References(45)

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