Article
Physics, Applied
Zhanyong Xing, Haochen Zhang, Yue Sun, Lei Yang, Kunpeng Hu, Kun Liang, Dawei Wang, Houqiang Fu, Haiding Sun
Summary: In this work, an enhancement-mode (E-mode) AlGaN/GaN-based high-electron-mobility transistor (HEMT) with a graded AlGaN cap layer (GACL) is proposed. The GACL is designed to produce high-concentration polarization-induced holes and negative net polarization charges to benefit the normally-OFF operation of the device. The optimized graded-AlGaN-gated metal-semiconductor HEMT achieves a large threshold voltage of 4 V, and shortening the gate length and inserting an oxide layer can suppress gate leakage current and enhance gate voltage swing.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Chia-Hao Liu, Hsien-Chin Chiu, Hsiang-Chun Wang, Hsuan-Ling Kao, Chong-Rong Huang
Summary: The study shows that DJ-HEMT exhibits higher gate voltage swing in the gate region due to the dual junction, enhancing gate performance. Compared to ST-HEMT, DJ-HEMT has higher V-TH, saturation current, I-ON/I-OFF ratio, and gate swing voltage. In addition, DJ-HEMT also has lower leakage current and longer lifetime measurement.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Shaoqian Lu, Guohao Yu, Yingfei Sun, Xu Yuan, Zhongkai Du, Bingliang Zhang, Lu Wang, Yu Li, Dongdong Wu, Zengli Huang, Zhongming Zeng, Xulei Qin, Baoshun Zhang
Summary: In this article, a method of nitrogen plasma treatment is proposed to achieve normally off p-GaN/AlGaN/GaN high-electron-mobility transistors, and the related mechanism is proposed. The nitrogen plasma treatment depletes holes in the p-GaN layer and changes the surface characteristics, resulting in the formation of a 2D electron gas at the AlGaN/GaN interface. The device shows enhanced performance with improved threshold voltage, on/off ratio, and maximum drain current.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Physics, Applied
Hong-Quan Nguyen, Thanh Nguyen, Philip Tanner, Tuan-Khoa Nguyen, Abu Riduan Md Foisal, Jarred Fastier-Wooller, Tuan-Hung Nguyen, Hoang-Phuong Phan, Nam-Trung Nguyen, Dzung Viet Dao
Summary: The study demonstrates the effect of stress or strain on the electronic characteristics of a normally off AlGaN/GaN HEMT and its potential as a highly sensitive pressure sensor with a strain sensitivity of 1250ppm(-1).
The change in drain current is most pronounced when the gate bias is near-threshold and the drain bias is slightly larger than the saturation bias.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Si-De Song, Su-Zhen Wu, Guo-Zhu Liu, Wei Zhao, Yin-Quan Wang, Jian-Wei Wu, Qi He
Summary: In this study, the degradation mechanisms of enhancement-mode p-GaN gate AlGaN/GaN high-electron mobility transistor were extensively analyzed under different stress conditions. The results showed that the device exhibited different electrical characteristics under various stress conditions, indicating excellent performance under reverse gate bias stress. These findings are significant in guiding process optimization towards a high voltage and highly reliable enhanced AlGaN/GaN high-electron mobility transistor.
Article
Physics, Applied
Changkun Zeng, Weizong Xu, Yuanyang Xia, Ke Wang, Fangfang Ren, Dong Zhou, Yiheng Li, Tinggang Zhu, Dunjun Chen, Rong Zhang, Youdou Zheng, Hai Lu
Summary: This study demonstrates the successful implementation of high-quality gate current blocking performance in GaN HEMTs through the development of dopant-free p-type polarization doping technique, improving the reliability of gate circuits.
APPLIED PHYSICS EXPRESS
(2022)
Article
Engineering, Electrical & Electronic
Xing Wei, Xiaodong Zhang, Chi Sun, Wenxin Tang, Chunhong Zeng, Fu Chen, Tao He, Guohao Yu, Liang Song, Wenkui Lin, Xuan Zhang, Desheng Zhao, Wei Huang, Yong Cai, Baoshun Zhang
Summary: In this article, normally-OFF etching-free p-GaN stripe array gate AlGaN/GaN high-electron-mobility-transistors (PSAG-HEMTs) are designed and experimentally demonstrated through hydrogen plasma treatment. A unique threshold voltage modulation technique is proposed based on the PSAG structure, allowing continuous V-TH shift by tuning the widths of p-GaN and hydrogenatedp-GaN stripes. By extending the PSAG to the drain side based on 3-D simulation results, improvements in breakdown voltage and enhanced conductivity effect are observed, resulting in a low ON-resistance. The fabricated PSAG-HEMT exhibits significant improvements over Reference single-gate E-mode and D-mode devices, showcasing a promising architecture for future high voltage normally-OFF p-GaN HEMT devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Yunlong He, Qing He, Minhan Mi, Meng Zhang, Chong Wang, Ling Yang, Xiaohua Ma, Yue Hao
Summary: This article describes the fabrication of fully removed AlGaN barrier recessed-gate normally off AlGaN/GaN HEMTs with N2O plasma treatment, achieving devices with excellent characteristics and demonstrating a high breakdown electric field value.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Crystallography
Xiaobiao Han, Wang Lin, Qiliang Wang, Shaoheng Cheng, Liuan Li, Liang He
Summary: In this paper, a novel p-GaN/AlGaN/GaN HFET with re-grown AlGaN is designed using Silvaco TCAD. The thin AlGaN barrier beneath the p-GaN positively shifts the threshold voltage to achieve normally-off operation, but it reduces the drain current due to low 2DEG concentration. The re-grown AlGaN barrier in the access regions partially recovers the 2DEG concentration and enhances the drain current. Furthermore, the field plate structure formed during the AlGaN re-growth process effectively suppresses electric field crowding and premature breakdown. By optimizing device parameters, a normally-off p-GaN/ AlGaN/GaN HFET with balanced output current, threshold voltage, and breakdown voltage is designed.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Engineering, Electrical & Electronic
Lin-Qing Zhang, Zhi-Yan Wu, Peng-Fei Wang
Summary: In this paper, a novel semi-floating gate (SFG) AlGaN/GaN HEMT with 20 nm Al2O3 as the control gate capacitance for normally-off operation was reported. This technique avoids the gate recess process which may damage the 2DEG channel and allows for programming of the threshold voltage (V-th) by adjusting the control gate voltage (V-CGP). Experimental results demonstrate the successful fabrication of E-mode AlGaN/GaN HEMTs using this technique.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Kai Liu, Runhao Wang, Chong Wang, Xuefeng Zheng, Xiaohua Ma, Junchun Bai, Bin Cheng, Ruiyu Liu, Ang Li, Yaopeng Zhao, Yue Hao
Summary: This paper investigates the influence of a lightly doped p-GaN cap layer on p-GaN/AlGaN/GaN high electron mobility transistors (HEMTs). The results show that the p(-)-GaN cap layer optimizes the gate characteristics, significantly reduces the gate leakage voltage, and increases the gate forward breakdown voltage and continuous operating voltage. Furthermore, simulation results demonstrate that the p(-)-GaN cap layer disperses the electric field and alleviates the electric peak, thereby suppressing impact ionization and carrier injection.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Yun-Long He, Fang Zhang, Kai Liu, Yue-Hua Hong, Xue-Feng Zheng, Chong Wang, Xiao-Hua Ma, Yue Hao
Summary: A novel p-GaN Schottky hybrid gate AlGaN/GaN HEMT has been proposed and simulated, showing higher current density and lower on-resistance compared to traditional p-GaN HEMTs, with a faster switching speed.
Article
Engineering, Electrical & Electronic
Jingyu Shen, Chao Yang, Liang Jing, Jingwei Guo, Ping Li, Hao Wu, Shengdong Hu
Summary: In this study, an enhancement mode p-GaN gate HEMT with selective regrowth and strain engineering has been proposed. The device shows improved 2DEG density and surface electric field distribution, leading to significant improvements in ON-resistance and breakdown voltage.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Energy & Fuels
Gwen Rolland, Christophe Rodriguez, Guillaume Gomme, Abderrahim Boucherif, Ahmed Chakroun, Meriem Bouchilaoun, Marie Clara Pepin, Faissal El Hamidi, Soundos Maher, Richard Ares, Tom MacElwee, Hassan Maher
Summary: This paper presents a Normally-OFF GaN HEMT device with a p-doped GaN barrier layer regrown by CBE, achieving a V-th of 1.5 V with 4E17 cm(-3) p doping. The impact of p doping on device performance was investigated using a TCAD simulator. The breakdown of the fabricated device was examined, and the cause of device failure was identified.
Article
Computer Science, Information Systems
Xiaoyu Ding, Xu Yuan, Tao Ju, Guohao Yu, Bingliang Zhang, Zhongkai Du, Zhongming Zeng, Baoshun Zhang, Xinping Zhang
Summary: A technique called ion implantation was used to passivate p-GaN and create a normally off p-GaN/AlGaN/GaN HEMT. Through experiments, it was determined that an ion implantation energy of 20 keV and a dosage of 1.5 x 10(13) cm(-2) were required for passivation. Annealing at 400 degrees C was found to be ideal for obtaining a normally off p-GaN HEMT with desirable electrical properties.