Article
Physics, Applied
Rui Shan Low, Joel T. Asubar, Ali Baratov, Shunsuke Kamiya, Itsuki Nagase, Shun Urano, Shinsaku Kawabata, Hirokuni Tokuda, Masaaki Kuzuhara, Yusui Nakamura, Kenta Naito, Tomohiro Motoyama, Zenji Yatabe
Summary: This study fabricates AlGaN/GaN metal-insulator-semiconductor (MIS) capacitors and high-electron-mobility transistors (MIS-HEMTs) using a 5 nm thick Al2O3 dielectric deposited by mist chemical vapor deposition (mist-CVD) technique. The results show that the mist-Al2O3/AlGaN interface has high quality, and the mist MIS-HEMTs exhibit improved performance compared to traditional HEMTs, indicating the potential of mist-CVD Al2O3 in high-performance GaN-based MIS-HEMT development.
APPLIED PHYSICS EXPRESS
(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
Materials Science, Multidisciplinary
J. Mimila-Arroyo, A. S. Arreola-Pina, F. Jomard, A. Lusson
Summary: This study investigates the effect of hydrogenation experimental parameters (plasma power, sample temperature, and duration) on the dose and distribution of hydrogen throughout the structure. The results reveal that the dose is proportional to the square of the plasma power, increases linearly with hydrogenation time, and is slightly related to the sample temperature. These findings provide insights on how to improve the performance of AlGaN/GaN HEMTs.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2023)
Article
Computer Science, Information Systems
Yuchen Li, Sen Huang, Xinhua Wang, Qimeng Jiang, Xinyu Liu
Summary: In this study, the temperature-dependent ON-state breakdown BVON of AlGaN/GaN HEMTs with an AlGaN back barrier was investigated using the gate current extraction technique. It was found that the impact ionization of acceptor-like traps is responsible for the ON-state breakdown in HEMTs when the 2DEG channel is marginally turned on. Additionally, the characteristic electric field of impact ionization was extracted and shown to have a U-shaped temperature dependence.
Article
Automation & Control Systems
Moinul Shahidul Haque, Seungdeog Choi
Summary: This article proposes a novel sparse kernel ridge regression assisted particle filter method for estimating the remaining useful life of gallium nitride field-effect transistors in emerging power electronics systems. The method aims to overcome challenges such as large variation in RUL estimation under noise uncertainty and sample degeneracy. By introducing SKRR in resampling the probability density function estimation, the method significantly enhances estimation accuracy and can effectively trace sudden changes in fault precursor trajectories.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Enrico Zanoni, Carlo De Santi, Zhan Gao, Matteo Buffolo, Mirko Fornasier, Marco Saro, Francesco De Pieri, Fabiana Rampazzo, Gaudenzio Meneghesso, Matteo Meneghini, Nicolo Zagni, Alessandro Chini, Giovanni Verzellesi
Summary: This article reviews various options for controlling short-channel effects, improving off-state characteristics, and reducing drain-source leakage current. The advantages and potential drawbacks of each proposed solution are analyzed in terms of current collapse, dispersion effects, and reliability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Wei-Min Wu, Shih-Hung Chen, Chun-An Shih, Bertrand Parvais, Nadine Collaert, Ming-Dou Ker, Tian-Li Wu, Guido Groeseneken
Summary: Gallium nitride (GaN)-on-Si technologies for advanced RF applications have been drawing attention in the semiconductor industry, along with challenges in RF electrostatic discharge (ESD) reliability. Investigating both positive and negative ESD stress polarities is equally important. In this study, four scenarios of positive and negative human body model (HBM) stresses were conducted on GaN-on-Si (MIS-HEMTs) with gate-tied-to-source and gate-tied-to-drain configurations. It was found that the negative GS MIS-HEMT exhibited a failure mechanism different from the constant-power 2DEG failure mechanism in the typical positive GS (MIS-HEMT).
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Rui Gao, Chang Liu, Zhiyuan He, Yiqiang Chen, Yijun Shi, Xiaoling Lin, Xiaowen Zhang, Zhizhe Wang, Yunfei En, Guoguang Lu, Yun Huang
Summary: In this study, the interaction between hydrogen poisoning (HP) and bias stress in AlGaN/GaN MIS-HEMTs was explored. It was found that HP results in a threshold voltage shift and a decrease in DC resistance in the device. Additionally, passivation of interface states at the SiNx/AlGaN interface was observed due to HP.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Austin Lee Hickman, Reet Chaudhuri, Samuel James Bader, Kazuki Nomoto, Lei Li, James C. M. Hwang, Huili Grace Xing, Debdeep Jena
Summary: The shift to the aluminum nitride platform offers smarter, highly-scaled heterostructure design to improve the performance of III-nitride amplifiers, enabling maximum high-power, high-speed potential for mm-wave communication and high-power logic applications.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Computer Science, Information Systems
Gianni Bosi, Antonio Raffo, Valeria Vadala, Rocco Giofre, Giovanni Crupi, Giorgio Vannini
Summary: In this paper, we investigate the degradation effects observed on 0.15-μm GaN HEMT devices operating under realistic power amplifier conditions through experimental methods. A low-frequency load-pull characterization technique is utilized to apply power amplifier conditions to the devices under test (DUT), providing information consistent with RF operation. The experiments are conducted at different temperatures and compare the degradation effects under different power amplifier operations.
Article
Chemistry, Multidisciplinary
Jinyuan Xu, Ailing Chen, Linfeng Yu, Donghai Wei, Qikun Tian, Huimin Wang, Zhenzhen Qin, Guangzhao Qin
Summary: In this paper, the stable structure of a monolayer CuI with ultra-low thermal conductivity and an ultra-wide direct bandgap is predicted from first-principles calculations. This material shows potential applications in transparent and wearable electronics.
Article
Engineering, Electrical & Electronic
David Maria Tobaldi, Valentina Trimini, Arianna Creti, Mauro Lomascolo, Stefano Dicorato, Maria Losurdo, Adriana Passaseo, Vittorianna Tasco
Summary: The study successfully developed a remote plasma MOCVD method for epitaxial growth of high-quality GaN/AlGaN heterostructures. This method has lower growth temperature and uses remote plasma instead of ammonia, providing a cost-effective and green approach for high-quality heteroepitaxy.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Junjie Yang, Jin Wei, Yanlin Wu, Muqin Nuo, Zhenghao Chen, Xuelin Yang, Maojun Wang, Bo Shen
Summary: A 600-V p-GaN gate HEMT with a buried hole spreading channel (BHSC) is demonstrated to suppress the buffer trap related dynamic R-ON degradation. The BHSC, located between u-GaN and buried AlGaN, enables effective spreading of holes along its channel to screen the negative buffer charges injected from the gate. This spreading effect is verified by detection of hole current from the sidewall of BHSC. The proposed device exhibits immunity against buffer trapping, as demonstrated by a positive substrate stress test, achieving nearly zero buffer trap related dynamic R-ON degradation even after a 400-V substrate stress with a delay as short as approximately 20 μs.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Song Yang, Zheyang Zheng, Li Zhang, Wenjie Song, Kevin J. Chen
Summary: Surface reinforcement layer (SRL) formed in GaN MIS-HEMTs can effectively suppress device dynamic on-resistance degradation caused by long-term hot-electron stress, with enhanced thermal stability and strong immunity to energetic carriers. This suppression is further verified by electroluminescence characterizations.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Mohammad Sajid Nazir, Pragya Kushwaha, Ahtisham Pampori, Sheikh Aamir Ahsan, Yogesh Singh Chauhan
Summary: In this work, a phenomenological cryogenic model for GaN HEMTs is proposed and validated with experimental characterization results. The model accurately captures the negative threshold voltage shifts and kink effects observed at cryogenic temperatures. The impact of temperature, impact ionization, and field-dependent trapping/detrapping on performance is explored and implemented in the model to explain these phenomena.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Nicola Modolo, Carlo De Santi, Andrea Minetto, Luca Sayadi, Sebastien Sicre, Gerhard Prechtl, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: Hot electron trapping significantly affects the performance of GaN-based HEMTs during hard switching, with a logarithmic time dependence and critical operation within the first 10 microseconds. This was demonstrated through a physics-based model validated by experimental data obtained with a specially designed pulsed-drain current transient setup.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Physics, Applied
Alessandro Caria, Carlo De Santi, Matteo Buffolo, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: The degradation of InGaN-GaN LEDs under high photon densities has been studied, revealing optically-induced processes that decrease internal quantum efficiency. Measurements show a shallow level related to defects which result in an increase in yellow luminescence.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Cheng-Hung Wu, Kuan-Chi Wang, Yu-Yun Wang, Chenming Hu, Chun-Jung Su, Tian-Li Wu
Summary: The ferroelectric characteristic of a 5 nm Hf0.5Zr0.5O2 (HZO) MFIS device is enhanced through strained TiN electrode engineering. The TiN electrode with 18% N induces tensile stress in the HZO film, resulting in higher remanent polarization and larger capacitance value.
Article
Computer Science, Information Systems
Nicola Trivellin, Davide Fiorimonte, Francesco Piva, Matteo Buffolo, Carlo De Santi, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: This study reports on the reliability of recent commercial UVC LED devices and their efficacy in antiviral technologies for COVID-19. An in-depth analysis of four different state-of-the-art commercial LEDs suitable for disinfection applications indicates limited reliability possibly related to an increase in Shockley-Read-Hall (SRH) recombination. Suggestions for product design improvements will be proposed based on the results of this work.
Article
Chemistry, Analytical
Claudia Casu, Matteo Buffolo, Alessandro Caria, Carlo De Santi, Enrico Zanoni, Gaudenzio Meneghesso, Matteo Meneghini
Summary: This study investigates the defectiveness and degradation mechanisms of InGaN-based quantum wells. By designing a color-coded structure and using numerical simulations, it is found that an increase in traps in the active region is the main cause of degradation. The degradation process consists of two phases, with the first phase occurring in the quantum well closer to the p-contact. The stronger degradation in this well may be due to a lowering of injection efficiency or an increase in SRH recombination.
Article
Engineering, Electrical & Electronic
Nicola Modolo, Carlo De Santi, Andrea Minetto, Luca Sayadi, Sebastien Sicre, Gerhard Prechtl, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: The goal of this study is to investigate the impact of hard switching on the dynamic performance of GaN HEMTs. By developing a fast testing system, the researchers found that optimizing the drain node capacitance can accelerate the hard-switching transition. Through experiments at multiple frequencies, it was demonstrated that cumulative turn-on stress has a stronger effect on R-ON compared to off-state stress. By comparing devices with different LCDs, hot electrons were identified as the main mechanism in device degradation. Furthermore, comparing wafers with different processing conditions revealed the significant impact of buffer properties on the dynamic performance of devices in hard switching.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Shun-Wei Tang, Benoit Bakeroot, Zhen-Hong Huang, Szu-Chia Chen, Wei-Syuan Lin, Ting-Chun Lo, Matteo Borga, Dirk Wellekens, Niels Posthuma, Stefaan Decoutere, Tian-Li Wu
Summary: The gate current characteristics in AlGaN/GaN high electron mobility transistors (HEMTs) with a p-GaN gate were investigated to explain the threshold voltage shift. The intrinsic gate current conduction mechanisms were identified as thermionic emission (TE) in the AlGaN/GaN region at low bias range (2.5 V < V-G < 4 V) and trap-assisted tunneling (TAT) in the Schottky/p-GaN region at higher bias range (4 V < V-G < 7 V). The threshold voltage shift in the stress phase was found to be consistent with a trap level having an activation energy of E-A similar to 0.6 eV. A physical model considering TAT via hole transport was proposed to explain the negative V-TH shift.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Gao Zhan, Fabiana Rampazzo, Carlo De Santi, Mirko Fornasier, Gaudenzio Meneghesso, Matteo Meneghini, Herve Blanck, Jan Gruenenpuett, Daniel Sommer, Ding Yuan Chen, Kai-Hsin Wen, Jr-Tai Chen, Enrico Zanoni
Summary: DC characteristics of AlGaN/GaN HEMTs with different thickness values of the undoped GaN channel layer were compared. An abnormal transconductance (gm) overshoot accompanied by a negative threshold voltage (V-TH) shift was observed during IDS-V-GS sweep in devices with thinner GaN layer. At the same time, a non-monotonic increase in gate current was observed. In OFF-state, electron trapping occurs in the undoped GaN layer or at the GaN/AlN interface, leading to a positive VTH shift. When the device is turning on at a sufficiently high V-DS, electron de-trapping occurs due to trap impact-ionization; consequently, V-TH and therefore ID suddenly recovers, leading to the gm overshoot effect. These effects are attributed to electron trap impact-ionization and consequent modulation of the device's electric field.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Materials Science, Multidisciplinary
Nicola Trivellin, Francesco Piva, Davide Fiorimonte, Matteo Buffolo, Carlo De Santi, Enrico Zanoni, Gaudenzio Meneghesso, Matteo Meneghini
Summary: This study reports on the reliability of commercial ultraviolet-C (UV-C) light-emitting diodes (LEDs) under constant current stress. Electrical, optical, and spectral analyses were conducted on UV-C LEDs with a peak emission at 275 nm and a nominal power of 12 mW at 100 mA. Degradation tests were performed at maximum rated current, double the maximum, and three times the maximum. The results show that LED lifetime is inversely proportional to the stress current density, potentially due to high-energy electrons from Auger-Meitner recombination.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Chemistry, Analytical
Yao-Luen Shen, Chih-Yao Chang, Po-Liang Chen, Cheng-Chan Tai, Tian-Li Wu, Yuh-Renn Wu, Chih-Fang Huang
Summary: In this study, AlGaN/GaN light-emitting HEMTs with different locations of a single quantum well are fabricated and analyzed. The experiment demonstrates that confining the radiative recombination in the quantum well significantly shifts the light-emitting wavelength. Epi B, with a quantum well above the AlGaN barrier layer, shows superior intensity and uniformity in light-emitting compared to Epi A, which has a quantum well underneath the barrier.
Editorial Material
Materials Science, Multidisciplinary
Michael Kneissl, Juergen Christen, Axel Hoffmann, Bo Monemar, Tim Wernicke, Ulrich Schwarz, Asa Haglund, Matteo Meneghini
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Nicola Modolo, Carlo De Santi, Giulio Baratella, Andrea Minetto, Luca Sayadi, Sebastien Sicre, Gerhard Prechtl, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
Summary: Ideally, the emission profile in semiconductors should follow a pure exponential decay, but complex devices often exhibit a strongly stretched exponential shape. Conventional methodologies for mapping capture/emission time constants may lead to inaccuracies. In this article, a new methodology based on the double inverse Laplace transform is introduced to accurately extract the capture-emission time map of defects. The proposed approach is compared with conventional approximations, providing insight into the accuracy of simplified methods. The method is tested on custom-generated functions and successfully applied to extract the capture/emission time map from a power GaN HEMT subjected to positive bias instability test.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Computer Science, Information Systems
Alexander Herzog, Simon Benkner, Babak Zandi, Matteo Buffolo, Willem D. Van Driel, Matteo Meneghini, Tran Quoc Khanh
Summary: This study reports on the degradation mechanisms and dynamics of silicone encapsulated high-power ultraviolet A (UV-A) light-emitting diodes (LEDs) with a peak wavelength of 365 nm. Stress tests were conducted for 8665 hours at forward currents ranging from 350 mA to 700 mA and junction temperatures up to 132 degrees C. The results showed a significant decrease in optical power, with faster degradation at higher operating conditions. The degradation mechanisms were analyzed, and a degradation model was proposed to estimate the device lifetime under different operating parameters. Additional stress test data was used to validate the accuracy of the model's lifetime predictions.
Proceedings Paper
Computer Science, Hardware & Architecture
G. Gupta, M. Kanamura, B. Swenson, D. Bisi, B. Romanczyk, C. Neufeld, S. Wienecke, T. Ogino, Y. Miyazaki, K. Imanishi, J. Ikeda, M. Kamiyama, J. Guerrero, S. Yea, M. Labrecque, R. Prejdova, B. Cruse, J. Mckay, G. Bolante, Z. Wang, T. Hosoda, Y. Wu, P. Parikh, R. Lal, U. Mishra
Summary: The article presents results on 1200V GaN switches made with HEMTs on sapphire substrates, showing high performance under high voltages, high efficiency, and excellent switching characteristics. This technology can be very competitive in the 1200V power device market.
2022 IEEE 34TH INTERNATIONAL SYMPOSIUM ON POWER SEMICONDUCTOR DEVICES AND ICS (ISPSD)
(2022)