Article
Physics, Applied
Yuwei Zhou, Minhan Mi, Mei Yang, Yutong Han, Pengfei Wang, Yilin Chen, Jielong Liu, Can Gong, Yiwei Lu, Meng Zhang, Qing Zhu, Xiaohua Ma, Yue Hao
Summary: By regrowing Ohmic contact with a contact ledge structure, high-performance millimeter-wave InAlN/GaN HEMT is fabricated for low voltage RF applications, showing improved output current density and power-added efficiency.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Jinjin Tang, Guipeng Liu, Bangyao Mao, Guijuan Zhao, Jianhong Yang
Summary: This paper systematically elucidates the physical mechanism of the GaN interlayer for improving the 2D electron gas (2DEG) mobility in the InGaN channel using an intersub-band scattering model. The results show that introducing a GaN interlayer can significantly improve the 2DEG mobility, and this effect is closely related to scattering mechanisms such as polar optical phonon scattering and alloy disorder scattering.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Engineering, Electrical & Electronic
P. Sohi, J-F Carlin, M. D. Rossell, R. Erni, N. Grandjean, E. Matioli
Summary: This study introduces a novel high-conductivity multi-channel heterostructure design, utilizing modulation-doping to achieve higher carrier densities and electron mobilities while avoiding strong interface roughness and ionized impurity scattering. By optimizing the heterostructure design, high electron mobilities were achieved independently of the number of channels, offering a new approach to alleviate the trade-off between electron mobility and carrier density.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Vanjari Sai Charan, Rangarajan Muralidharan, Srinivasan Raghavan, Digbijoy N. Nath
Summary: In this study, InAlN/GaN-on-Si high-electron-mobility transistors (HEMTs) with an f(T)-L-G product of 20.2 GHz-mu m were demonstrated. The HEMT exhibited satisfactory performance parameters, including high peak transconductance, large I-ON/I-OFF ratio, and high on-current. Delay time analysis was carried out to evaluate various delay components and their contributions to the device's small-signal performance. The effective electron velocity in these devices was estimated, which minimized the intrinsic delay of the transistor. The factors limiting the f(T)-L-G product in deeply scaled devices were discussed using the delay analysis.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2022)
Article
Multidisciplinary Sciences
Peng Cui, Yuping Zeng
Summary: This paper investigates InAlN/GaN high-electron-mobility transistors (HEMTs) on silicon substrate, achieving high-performance parameters and predicting the scaling behavior of the device. It provides a foundation for further improvement and feasibility of this device for RF applications.
SCIENTIFIC REPORTS
(2022)
Article
Materials Science, Multidisciplinary
Jing Cai, Ruo-He Yao, Yu-Rong Liu, Kui-Wei Geng
Summary: This article proposes a physics-based threshold voltage and drain-source current model based on double-channel AlGaN/GaN HEMTs. The model takes into account the physical properties of the dual-channel HEMT and includes the influence of charges and 2DEGs distributed in lower layers on the upper channel. The accuracy of the proposed model is verified through comparison with simulations and experimental results.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Applied
Lian Zhang, Zhe Cheng, Yawei He, Jianxing Xu, Lifang Jia, Xinyuan Wang, Shiyong Zhang, Wei Tan, Yun Zhang
Summary: This study focuses on the electron concentration and mobility of SAG n(+)-GaN on InAlN/GaN HEMTs using MOCVD, revealing that the electron mobility of SAG GaN is significantly affected by thickness. A gas flow model is proposed to guide the regrowth for improving electron mobility. High mobility and low resistance are achieved in the SAG GaN, contributing to the performance of the HEMTs.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Peng Cui, Meng Jia, Hang Chen, Guangyang Lin, Jie Zhang, Lars Gundlach, John Q. Xiao, Yuping Zeng
Summary: The article investigates the improved surface properties of InAlN/GaN HEMTs after forming gas annealing and proposes a two-step forming gas/nitrogen annealing method for ohmic contact. This method can achieve lower sheet resistance, higher two-dimensional electron gas electron density, and better device performance.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Applied
O. Ambacher, B. Christian, M. Yassine, M. Baeumler, S. Leone, R. Quay
Summary: The electrical properties of pseudomorphic MeAl1-xN/GaN, MeAl1-xN/AlN, and MeAl1-xN/InN heterostructures and devices are significantly influenced by the piezoelectric and spontaneous polarization of wurtzite ScxAl1-xN, GaxAl1-xN, and InxAl1-xN ternary compounds. Predictions of polarization-induced interface charges and comparisons of different heterostructures suggest superior potential in ScAlN/GaN-based structures for high electron mobility transistors in high-frequency and power electronic applications.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Mei Ge, Yi Li, Youhua Zhu, Dunjun Chen, Zhiliang Wang, Shuxin Tan
Summary: The improved e-mode AlGaN/GaN HEMT with a gate stack beta-Ga2O3/p-GaN structure outperforms the conventional p-GaN gate HEMT, mainly due to the use of the beta-Ga2O3 layer which reduces the electric field strength in the gate region and decreases off-state leakage current. Additionally, there is a trade-off between the thickness of the beta-Ga2O3 layer and the performance of the device.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Mohamed Aniss Mebarki, Ragnar Ferrand-Drake Del Castillo, Alexey Pavolotsky, Denis Meledin, Erik Sundin, Mattias Thorsell, Niklas Rorsman, Victor Belitsky, Vincent Desmaris
Summary: The successful integration of superconducting niobium gate electrodes into cryogenic gallium nitride-based high-electron-mobility transistors is reported. The superconductivity of the gate is tested using various measurements methods, and the impact of different gate materials on the cryogenic microwave noise performances is compared.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Applied
Markus Wohlfahrt, Michael J. Uren, Felix Kaess, Oleg Laboutin, Hassan Hirshy, Martin Kuball
Summary: AlGaN/GaN High Electron Mobility Transistors (HEMTs) exhibit a UV-induced persistent photoconductivity (PPC) effect, which is related to changes in electronic band bending in the buffer layer. This effect is significant only in p-type buffers and allows for quantification of deep-level doping density, with recovery times extending to several days.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Coatings & Films
Stefan Schmult, Pascal Appelt, Claudia Silva, Steffen Wirth, Andre Wachowiak, Andreas Grosser, Thomas Mikolajick
Summary: Inconsistencies in the concentrations of unintentional donor impurities and free charge carriers in GaN/AlGaN layer stacks containing a two-dimensional electron gas (2DEG) can be explained by the measurement procedure and the method of extracting the free charge carrier concentration. When the 2DEG acts as the bottom electrode in capacitance versus voltage measurements, unphysically low concentrations of free charges are calculated due to the depletion of the 2DEG and the disappearance of the bottom electrode. It is shown that, for the case of a defined (non-vanishing) bottom electrode, the levels of donor impurities and resulting free charges consistently match.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Chemistry, Physical
Hsin-Ying Lee, Day-Shan Liu, Jen-Inn Chyi, Edward Yi Chang, Ching-Ting Lee
Summary: A double-channel Al0.83In0.17N/GaN/Al0.18Ga0.82N/GaN heterostructured-MOSHEMTs with superior gate control capability and low noise power density was fabricated using laser interference photolithography and vapor cooling condensation systems.
Article
Engineering, Electrical & Electronic
Yawei He, Lian Zhang, Zhe Cheng, Chengcheng Li, Jiaheng He, Shujie Xie, Xuankun Wu, Chang Wu, Yun Zhang
Summary: This paper reports on a scaled In0.17Al0.83N/GaN high-electron-mobility transistor (HEMT) fabricated on a sapphire substrate. The device has a T-gate length of 47 nm, a source-drain distance of 300 nm, and selective area regrown n(+)-GaN. It exhibits cutoff frequencies f(T)/f(max) of 190/301 GHz and a record sqrt (f(T) x f(max)) = 239 GHz, surpassing previous Ga-polar GaN-on-sapphire HEMTs. The device demonstrates excellent current density, external direct current transconductance, I-on/I-off ratio, and other characteristics.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)