Article
Physics, Condensed Matter
Tingting Wang, Xiaobo Li, Taofei Pu, Shaoheng Cheng, Liuan Li, Qiliang Wang, Hongdong Li, Jin-Ping Ao
Summary: In this study, a vertical GaN Schottky barrier diode with a bevel junction termination extension was designed using Silvaco TCAD. The bevel junction termination extension effectively reduces on-resistance and suppresses electric field crowding, showing promising performance in achieving high breakdown voltage and low turn-on voltage under optimal parameters.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Engineering, Electrical & Electronic
Haiyong Wang, Wei Mao, Cui Yang, Jiabo Chen, Shenglei Zhao, Ming Du, Xiaofei Wang, Xuefeng Zheng, Chong Wang, Chunfu Zhang, Jincheng Zhang, Yue Hao
Summary: The lateral Schottky barrier diode (SBD) on p-GaN/AlGaN/GaN heterostructure with arrayed p-GaN islands termination (API-SBD) proposed in this study shows reduced reverse leakage current (I-R) and improved breakdown voltage (BV) due to the introduction of p-GaN islands termination. Compared to the counterpart SBD, the API-SBD exhibits a better trade-off between turn-on voltage (V-ON) and reverse leakage current (I-R). The capacitance of API-SBD is also approximately half of that of the traditional SBD.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Taofei Pu, Hsiang-Chun Wang, Kuang-Po Hsueh, Hsien-Chin Chiu, Xinke Liu
Summary: This paper presents the fabrication of AlGaN/GaN Schottky barrier diodes (SBDs) on free-standing GaN substrates with a Si doped barrier layer. The SBDs with doped barrier layer exhibit lower turn-on voltage, specific on resistance, faster reverse recovery time, and better low-frequency noise characteristics, which make them suitable for high power applications.
IEEE JOURNAL OF THE ELECTRON DEVICES SOCIETY
(2022)
Article
Engineering, Electrical & Electronic
Xiaolu Guo, Yaozong Zhong, Junlei He, Yu Zhou, Shuai Su, Xin Chen, Jianxun Liu, Hongwei Gao, Xiujian Sun, Qi Zhou, Qian Sun, Hui Yang
Summary: A high-performance quasi-vertical GaN Schottky barrier diode (SBD) was fabricated successfully with a high-quality n(-)-GaN drift layer and precisely-controlled n-type doping, achieving a high current on/off ratio, low specific on-resistance, and relatively high breakdown voltage. Additionally, with an Argon-implanted termination, a record high breakdown voltage of 405 V was achieved while maintaining good forward conduction characteristics for the GaN-on-Si SBD.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Physics, Multidisciplinary
Qiliang Wang, Tingting Wang, Taofei Pu, Shaoheng Cheng, Xiaobo Li, Liuan Li, Jinping Ao
Summary: In this study, a quasi-vertical GaN Schottky barrier diode with a hybrid anode structure is proposed to optimize the on-resistance and breakdown voltage. The use of a SiN dielectric and a field plate structure helps to suppress the electric field crowding effect and reduce the series resistance. The enhanced breakdown voltage is attributed to the charge-coupling effect between the insulation dielectric layer and GaN.
Article
Engineering, Electrical & Electronic
Lionel Trojman, Eliana Acurio, Brice De Jaeger, Niels Posthuma, Stefaan Decoutere, Benoit Bakeroot
Summary: A compact model based on the Lambert function is used to describe the I-V-T characteristics of Schottky Barrier Diodes (SBDs) with gated-edge termination (GET) using either SiN or SiO/AlO as GET dielectric. The obtained electrical parameters enable the assessment of Schottky barrier height (SBH). The results show that fluctuations are about 17% in both cases. Similar interface state density is obtained from the ideality factor, validating this approach as an interesting method for modeling GET-SBDs.
SOLID-STATE ELECTRONICS
(2023)
Article
Physics, Condensed Matter
Kai Liu, Chong Wang, Xuefeng Zheng, Xiaohua Ma, Yunlong He, Ang Li, Yaopeng Zhao, Wei Mao, Yue Hao
Summary: This study investigated the effect of post anode annealing on multi-channel AlGaN/GaN Schottky diodes. Both Ni and W showed low on-resistance after 300 degrees C PAA, with optimal PAA temperatures of 450 degrees C for Ni and 500 degrees C for W. Temperature-dependent characteristics were also measured, showing little effect on forward characteristics but an improvement in high-temperature stability of reverse current for Ni.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Engineering, Electrical & Electronic
Rikang Zhao, Xuanwu Kang, Yingkui Zheng, Hao Wu, Nan Wei, Shixiong Deng, Ke Wei, Xinyu Liu
Summary: A thin-barrier AlGaN/GaN Schottky barrier diode was proposed and implemented in a high-power RF limiter module, achieving better performance in terms of power capacity and frequency compared to traditional limiters.
IEEE MICROWAVE AND WIRELESS TECHNOLOGY LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Xuanwu Kang, Yingkui Zheng, Hao Wu, Ke Wei, Yue Sun, Guoqi Zhang, Xinyu Liu
Summary: In this study, novel AlGaN/GaN Schottky barrier diodes (SBDs) with high device uniformity were fabricated using thin-barrier (5 nm) AlGaN/GaN heterostructures. By combining a gated-edge termination (GET) design and high-quality SiN (x) deposition, low reverse leakage current and high reverse breakdown voltage were achieved. The proposed diode process flow is also compatible with AlGaN/GaN high-electron-mobility transistors, showing promise for integration in the smart GaN platform.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Genzhuang Li, Yuan Ren, Wang Lin, Qiliang Wang, Liang He, Liuan Li
Summary: A novel quasi-vertical GaN-on-sapphire MPS diode is fabricated by using the p-NiO/n-GaN heterojunction. The MPS diode exhibits a higher turn-on voltage and on-resistance compared to the Ni-anode SBD. The depletion regions at the heterojunction interface effectively enhance the reverse breakdown voltage.
Article
Engineering, Electrical & Electronic
Xiaolu Guo, Yaozong Zhong, Yu Zhou, Shuai Su, Xin Chen, Shumeng Yan, Jianxun Liu, Xiujian Sun, Qian Sun, Hui Yang
Summary: This study presents a novel Nitrogen-implanted guard ring technology for GaN-on-Si Schottky barrier diodes, significantly improving their performance and high-temperature operation capability compared to traditional designs. Through detailed simulations and precise design, the breakdown voltage was enhanced while maintaining excellent characteristics.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Hao Wu, Xuanwu Kang, Yingkui Zheng, Ke Wei, Rikang Zhao, Yafei Yuan, Xinyu Liu, Guoqi Zhang
Summary: In this study, we investigated the soft breakdown (BD) behavior in thin-barrier (TB) AlGaN/GaN Schottky barrier diode (SBD) with carbon-doped GaN buffer. The soft BD behavior is a result of multiple mechanisms coupling together. In the off-state, ionized carbon (C) acceptors cause electric field (E-field) crowding at the cathode and induce impact ionization. The holes generated by impact ionization compensate for the ionized C acceptors, suppressing E-field crowding and preventing further avalanche BD. Residual holes flow to and accumulate under the anode, leading to a continuous increase in the Schottky E-field and Schottky leakage, eventually causing the soft BD. Schottky leakage is highly sensitive to the Schottky E-field in the TB structure due to the tunneling effect, resulting in an abnormally high leakage rise rate during soft BD.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
S. Niranjan, R. Muralidharan, Prosenjit Sen, Digbijoy N. Nath
Summary: This article reports on the electrical performance of AlGaN/GaN high-electron mobility transistors (HEMTs) fabricated using an Au-free process on flexible Kapton tape. The flexible HEMT shows a slightly higher ON-current when bent, while the OFF-state performance remains unaffected. The electrical characteristics of the transferred devices indicate a reduction in 2-DEG concentration and ON-current compared to the original HEMTs.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Physics, Applied
Hao Wu, Xuanwu Kang, Yingkui Zheng, Ke Wei, Yue Sun, Pengfei Li, Xinyu Liu, Guoqi Zhang
Summary: This letter reports the reverse leakage mechanism of thin-barrier AlGaN/GaN Schottky barrier diode for the first time, revealing trap-assisted tunneling and Schottky edge leakage as dominant mechanisms. Thinning the barrier was found to effectively suppress Schottky edge leakage.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Juraj Priesol, Alexander Satka, Ales Chvala, Steve Stoffels, Brice De Jaeger, Stefaan Decoutere
Summary: The study successfully localized electrically stressed regions in AlGaN/GaN-on-Si Schottky barrier diode structures using scanning electron microscopy and electron beam induced current measurements, revealing the formation of local microavalanches under high voltages. Simulations based on electro-physical modeling and finite element method demonstrated the variation of local electric field intensity in the SBD.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Applied
A. Minj, M. Zhao, B. Bakeroot, K. Paredis
Summary: The current state of dopant assessment for the optimization of III-nitride-based heterostructures relies heavily on quantitative chemical analysis techniques, however, limitations exist due to poor activation of Mg, presence of O impurities, and amphoteric nature of carbon impurities. Exploitation of nanosize metal-semiconductor junction formed between the metallic scanning probe microscopy probe and III-nitride surface shows promise for carrier determination, especially in regions of interest requiring nanometer resolution.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
M. Millesimo, N. Posthuma, Benoit Bakeroot, M. Borga, S. Decoutere, A. N. Tallarico
Summary: This article presents an extensive investigation of time-dependent drain breakdown in GaN-on-Si power HEMTs with p-GaN gate under long-term OFF-state stress, showing that the physical location of failure changes with variations in the gate-to-drain distance and field plates configuration. The role of process and structural variations in influencing the time-dependent breakdown is analyzed, with emphasis on the impact of gate-to-drain distances and field plate lengths on device robustness.
IEEE TRANSACTIONS ON DEVICE AND MATERIALS RELIABILITY
(2021)
Article
Engineering, Electrical & Electronic
M. Millesimo, C. Fiegna, N. Posthuma, M. Borga, B. Bakeroot, S. Decoutere, A. N. Tallarico
Summary: This article conducts an in-depth high-temperature analysis of the long-term gate reliability in GaN-based power HEMTs with p-type gates. Three different isolation process options are proposed to improve time-dependent gate breakdown, compared through constant voltage stress tests. Results show different voltage dependencies for failure locations, requiring two field-acceleration fitting models for lifetime estimation. Additionally, gate time-to-failure exhibits a non-monotonous temperature dependency at given gate bias, showing positive/negative T-derivatives related to active gate area and isolation region failures.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
A. N. Tallarico, M. Millesimo, B. Bakeroot, M. Borga, N. Posthuma, S. Decoutere, E. Sangiorgi, C. Fiegna
Summary: This study reports for the first time the TCAD modeling of dynamic threshold voltage shift in Schottky-type p-GaN gate HEMTs under fast sweeping characterization. The experimental characterization and TCAD simulations demonstrate that the dynamic V_TH hysteresis is mainly influenced by time-dependent hole charging/discharging processes in the floating p-GaN layer.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Physics, Applied
K. Mukherjee, C. De Santi, S. You, K. Geens, M. Borga, S. Decoutere, B. Bakeroot, P. Diehle, F. Altmann, G. Meneghesso, E. Zanoni, M. Meneghini
Summary: This paper investigates the effect of planar etching treatment and trench formation on the performance of GaN-based MOS stacks. It is found that blanket etching the GaN surface does not degrade the robustness of the deposited dielectric layer. However, the addition of the trench etch improves reproducibility but results in a decrease in breakdown performance. Capacitance-voltage measurements reveal that as-grown planar capacitors have the lowest trapping, while trench capacitors have higher interface and bulk trapping. High resolution scanning transmission electron microscopy confirms an increased roughness at the GaN surface after blanket etching, correlated with higher density of interface traps.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Anurag Vohra, Karen Geens, Ming Zhao, Olga Syshchyk, Herwig Hahn, Dirk Fahle, Benoit Bakeroot, Dirk Wellekens, Benjamin Vanhove, Robert Langer, Stefaan Decoutere
Summary: In this study, the epitaxial growth of a GaN buffer structure with a hard breakdown voltage of >1200V on 200mm engineered poly-AlN substrates was successfully demonstrated. This achievement is significant for high voltage GaN-based power applications, such as electric cars.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
N. Modolo, C. De Santi, G. Baratella, A. Bettini, M. Borga, N. Posthuma, B. Bakeroot, S. You, S. Decoutere, A. Bevilacqua, A. Neviani, G. Meneghesso, E. Zanoni, M. Meneghini
Summary: This article proposes a methodology for modeling the dynamic characteristics of GaN power HEMTs, considering the realistic trapping/detrapping kinetics described by stretched exponentials. The analysis accurately describes stretched-exponential transients and extracts the related parameters, and reproduces the stretched exponential behavior using multiple RC networks.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Shun-Wei Tang, Zhen-Hong Huang, Szu-Chia Chen, Wei-Syuan Lin, Brice de Jaeger, Dirk Wellekens, Matteo Borga, Benoit Bakeroot, Stefaan Decoutere, Tian-Li Wu
Summary: In this work, we demonstrate enhancement-mode regrown p-GaN gate devices with high threshold voltage and robust forward time-dependent gate breakdown stability. The devices are fabricated with two different AlGaN barriers, and it is found that 7nm AlGaN barrier exhibits higher threshold voltage and gate breakdown voltage. Furthermore, the regrown p-GaN gate HEMTs show high operating voltage under high temperature and room temperature conditions.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
N. Modolo, M. Fregolent, F. Masin, A. Benato, A. Bettini, M. Buffolo, C. De Santi, M. Borga, N. Posthuma, B. Bakeroot, S. Decoutere, D. Vogrig, A. Neviani, G. Meneghesso, E. Zanoni, M. Meneghini
Summary: This paper investigates the threshold voltage instability of 100 V rated p-GaN power HEMTs for the first time. The study combines pulsed-IV measurements and capture and emission time (CET) MAPS, and explores a wide time window from 1 µs to 1000 s. The results show a non-monotonic Delta VTH shift, and provide insights into the physical properties of the traps responsible for the threshold shift at the AlGaN/GaN interface.
MICROELECTRONICS RELIABILITY
(2022)
Article
Engineering, Electrical & Electronic
D. Favero, C. De Santi, K. Mukherjee, M. Borga, K. Geens, U. Chatterjee, B. Bakeroot, S. Decoutere, F. Rampazzo, G. Meneghesso, E. Zanoni, M. Meneghini
Summary: In order to develop reliable vertical GaN transistors, it is important to analyze the robustness of the gate stack as a function of process parameters and material properties. This study presents a detailed analysis of the breakdown performance of planar GaN-on-Si MOS capacitors. The results show that capacitors on p-GaN have better breakdown performance, while the presence of a trench structure significantly reduces the breakdown capabilities. Furthermore, the breakdown voltage is dependent on the area, with decreasing robustness for increasing dimensions, but independent of shape.
MICROELECTRONICS RELIABILITY
(2022)
Article
Engineering, Electrical & Electronic
Pavan Vudumula, Thibault Cosnier, Olga Syshchyk, Benoit Bakeroot, Stefaan Decoutere
Summary: This paper presents the TCAD-based design and verification of a 200 V GaN-on-SOI integrated circuits platform, which includes depletion-mode MIS-HEMTs and Gated-Edge-Termination Schottky barrier diodes (GET-SBDs). The platform also consists of low-voltage analog/logic devices and passive components to support the GaN ICs. Device simulations were validated through measurements of low voltage test structures, resulting in calibration of various parameters for HEMT and GET-SBD structures.
SOLID-STATE ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
M. Millesimo, M. Borga, B. Bakeroot, N. Posthuma, S. Decoutere, E. Sangiorgi, C. Fiegna, A. N. Tallarico
Summary: In this research, the impact of switching frequency and duty cycle on the performance of HEMTs was analyzed. It was found that reducing the frequency and duty cycle can increase the gate lifetime of HEMTs, which is beneficial for technology improvement and power circuit design.
IEEE ELECTRON DEVICE LETTERS
(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)
Proceedings Paper
Engineering, Multidisciplinary
M. Millesimo, B. Bakeroot, M. Borga, N. Posthuma, S. Decoutere, E. Sangiorgi, C. Fiegna, A. N. Tallarico
Summary: A combined experimental and simulation analysis was conducted to study the gate reliability of GaN-HEMTs with p-type gate under pulse stress conditions. The study found that the time-dependent gate breakdown (TDGB) can be determined by the total ON-time and the number of pulses. The severity of degradation during transition phases depends on the OFF-time and transition time.
2022 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM (IRPS)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Olga Syshchyk, Thibault Cosnier, Zheng-Hong Huang, Deepthi Cingu, Dirk Wellekens, Anurag Vohra, Karen Geens, Pavan Vudumula, Urmimala Chatterjee, Stefaan Decoutere, Tian-Li Wu, Benoit Bakeroot
Summary: The device performance of monolithically integrated power Schottky barrier diodes (SBDs) and depletion-mode (D-mode) MIS HEMTs is studied in relation to the thickness of the gate dielectric, the gate-edge termination (GET) layer and AlGaN barrier. The results show that SBDs with 7.5-9.5 nm AlGaN barrier thickness and 25-35 nm GET thicknesses exhibit the lowest dynamic ON-resistance (RON). On the other hand, D-mode MIS-HEMTs with 5.5 nm AlGaN barrier thickness and 45 nm gate dielectric thickness demonstrate the best performance.
ESSDERC 2022 - IEEE 52ND EUROPEAN SOLID-STATE DEVICE RESEARCH CONFERENCE (ESSDERC)
(2022)
