Article
Materials Science, Multidisciplinary
Hao Wu, Xiaojun Fu, Yuan Wang, Jingwei Guo, Jingyu Shen, Shengdong Hu
Summary: The research demonstrates that both the thin GaN buffer and the step-etched GaN structure contribute to improving the breakdown voltage of the AlGaN/GaN HEMT. The optimized structure increases the breakdown voltage to 1487 V while maintaining a low on-state resistance.
RESULTS IN PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Shaocheng Li, Kuang Sheng, Shu Yang
Summary: In this study, the temperature-dependent dynamic ON-resistance (R_on) behaviors of GaN E-HEMTs with and without a p-GaN drain (PD) structure under both hard-switching (HS) and soft-switching (SS) were systematically studied and analyzed. The influences of temperature, OFF-state voltage stress, the PD structure, HS/SS, switching transients during HS, and ON-state current on dynamic R_on of GaN E-HEMTs were revealed. The findings indicate that higher temperature, higher OFF-state voltage stress, or larger ON-state current, particularly under HS, can enhance the dynamic performance of GaN E-HEMTs by facilitating the turn-on of the PD hetero-junction and enhancing hole injection.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Automation & Control Systems
Aaron Wadsworth, Matthew G. S. Pearce, Duleepa J. Thrimawithana
Summary: This article presents the design of a cryogenic gallium nitride (GaN) enhancement mode high-electron-mobility transistor (E-HEMT) synchronous buck converter, which achieves high efficiency and uses a nanocrystalline filter inductor within the cryogenic environment. The article also evaluates the selection of magnetic materials and litz wire at cryogenic temperatures. Cryogenically cooling the GaN switches reduces their losses by half compared to operating at room temperature under the same conditions.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Fang Zhang, Xuefeng Zheng, Hao Zhang, Minhan Mi, Yunlong He, Ming Du, Xiaohua Ma, Yue Hao
Summary: In this study, a linear enhancement AlGaN/GaN HEMT with high power density and high efficiency for X-band application was successfully achieved using the selective-area charge implantation (SCI) technique. The under-gate SCI technique was employed to realize device-level transconductance compensation, which significantly improved the linearity of the device. Experimental results demonstrated that SCI HEMTs have immense potential for microwave power amplifiers requiring high linearity.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Physics, Applied
Jun Hyuk Park, Sun-Kyu Hwang, Joonyong Kim, Woochul Jeon, Injun Hwang, Jaejoon Oh, Boram Kim, Younghwan Park, Dong-Chul Shin, Jong-Bong Park, Jongseob Kim
Summary: This study investigates the effect of N2O plasma treatment on the reliability of p-GaN gate AlGaN/GaN HEMTs, specifically in the AlGaN drift region. The results show that N2O plasma treatment can form a GaON/AION compound layer, reduce the number of interface traps, and protect the AIGaN surface, thereby improving the reliability of the device.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Junao Cheng, Mohammad Wahidur Rahman, Andy Xie, Hao Xue, Shahadat Hasan Sohel, Edward Beam, Cathy Lee, Hao Yang, Caiyu Wang, Yu Cao, Siddharth Rajan, Wu Lu
Summary: In this study, ScAlN/GaN dielectric superjunction high-electron-mobility transistors with high-k passivation layer BZN were demonstrated to enhance breakdown voltage. The use of SiN/BZN/SiN sandwiched passivation layer improved the average breakdown voltage while maintaining similar fT and fmax values. This work shows that high current and high breakdown voltage can be achieved simultaneously on semiconductor heterostructures with high sheet charge density by integrating high-k dielectrics.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Yuji Ando, Ryutaro Makisako, Hidemasa Takahashi, Akio Wakejima, Jun Suda
Summary: The study revealed that the epitaxial layer structure affects the electrical characteristics of AlGaN/GaN HEMTs. GaN-on-GaN HEMTs showed an improved tradeoff between maximum drain current and breakdown characteristics compared to GaN-on-SiC HEMTs. Moreover, the impact of Fe diffusion on frequency dispersion was relatively limited in GaN-on-GaN devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Ankit Soni, Mayank Shrivastava
Summary: This study investigated the impact of various charge sources on the electric field distribution and breakdown mechanism of HEMTs, revealing strong correlations between different charges and breakdown voltage. Insights were developed to explain the dependence of HEMT breakdown on surface states, polarization charge, and buffer traps, aiding in the design of efficient surface passivation schemes.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Materials Science, Multidisciplinary
V. Hemaja, D. K. Panda
Summary: An n-polar GaN MIS-HEMT based biosensor is proposed for label-free detection of various bio-molecules by immobilizing the analytes in the underlap region to alter the electrostatic properties of the device, resulting in a significant increase in drain current and output conductance with the addition of different biomolecules in the nanocavity, with a maximum shift in threshold voltage observed for uricase due to its low dielectric constant.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Hao Wu, Xiaojun Fu, Jingwei Guo, Tao Liu, Yuan Wang, Jun Luo, Zhiyong Huang, Shengdong Hu
Summary: The research investigated the total ionizing dose and annealing effects on Schottky type p-GaN gate Al0.2Ga0.8N/GaN HEMTs. It was found that the threshold voltage shifts are caused by the accumulation of positive charges at the interface of p-GaN/AlGaN. After performing both high temperature and room temperature annealing processes, the shifted threshold voltage recovered, with high temperature accelerating the recovery process. Experiment results suggest that the total ionizing dose effect is recoverable.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Bo Yi, Yi Xu, Junji Cheng, Haimeng Huang, Moufu Kong, Hongqiang Yang
Summary: In this article, a CB-MIS-HEMT was proposed, in which a thick AlxGa(1-x)N is implemented in the gate region to achieve high V-th and high electron mobility. A Al0.25Ga0.75N/AlN is set on the AlxGa(1-x)N-layer to maintain high 2DEG density in the access region. The thick AlxGa(1-x)N reduces mobility degradation effects and combined with small Al mol fraction design, it achieves low Ron,sp and high Vth simultaneously. An analytical model is presented to predict the electron density and Vth, which matches well with TCAD simulation. For a 600-V design, the CB-MIS-HEMT shows improved electron mobility and reduced R-on,R-sp compared to a conventional recess-gate MIS-HEMT.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Physics, Applied
Chih-Yao Chang, Yao-Luen Shen, Shun-Wei Tang, Tian-Li Wu, Wei-Hung Kuo, Suh-Fang Lin, Yuh-Renn Wu, Chih-Fang Huang
Summary: In this study, a novel etching buffer layer was designed and incorporated into the p-GaN/AlGaN/GaN high electron mobility transistor structure to improve the etching process. The results showed that the device with the buffer layer exhibited improved process uniformity and device performance.
APPLIED PHYSICS EXPRESS
(2022)
Article
Chemistry, Analytical
Idriss Abid, Youssef Hamdaoui, Jash Mehta, Joff Derluyn, Farid Medjdoub
Summary: We report on the fabrication and electrical characterization of AlGaN/GaN normally off transistors on silicon designed for high-voltage operation. The normally off configuration was achieved with a p-gallium nitride (p-GaN) cap layer below the gate, enabling a positive threshold voltage higher than +1 V. The buffer structure was based on AlN/GaN superlattices (SLs), delivering a vertical breakdown voltage close to 1.5 kV with a low leakage current all the way to 1200 V.
Article
Energy & Fuels
Surya Elangovan, Edward Yi Chang, Stone Cheng
Summary: This study investigates the degradation characteristics of E-mode GaN HEMTs with a p-GaN gate through negative gate bias stress experiments, revealing the significance of electron trapping effects in the gradual degradation of electrical parameters, and identifying the degradation mechanism mainly caused by hole deficiency in the p-GaN region and the trapping process at the p-GaN/AlGaN hetero-interface.
Article
Physics, Applied
Xin Chen, Yaozong Zhong, Shumeng Yan, Xiaolu Guo, Hongwei Gao, Xiujian Sun, Haodong Wang, Fangqing Li, Yu Zhou, Meixin Feng, Ercan Yilmaz, Qian Sun, Hui Yang
Summary: The characteristics of an AlGaN/GaN high-electron-mobility transistor buffer structure are studied and optimized by employing an AlN/GaN superlattice (SL) structure. The influence of buffer traps on carrier transport behaviors and electrical performance for SL buffer structures under a high electric field is analyzed. The AlN/GaN SL buffer structures are further optimized with various AlN/GaN thickness ratios and their total thickness, achieving a high breakdown voltage and suppressing the buffer trapping effect.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
