Article
Energy & Fuels
Florian Rigaud-Minet, Christophe Raynaud, Julien Buckley, Matthew Charles, Patricia Pimenta-Barros, Romain Gwoziecki, Charlotte Gillot, Veronique Sousa, Herve Morel, Dominique Planson
Summary: Many kinds of defects are present in AlGaN/GaN-on-Si based power electronics devices. Electron traps in AlGaN/GaN-on-Si power diodes were investigated using DLTFS, and seven different traps corresponding to point defects were identified. Two new traps related to etching were reported, while others were proposed to be related to carbon and nitrogen vacancies or carbon. Crystal surface recombination, native defects, and nitrogen antisite were also likely origins of the identified traps.
Article
Physics, Condensed Matter
Ashish Kumar, Jayjit Mukherjee, D. S. Rawal, K. Asokan, D. Kanjilal
Summary: Trap characterization on GaN Schottky barrier diodes (SBDs) was conducted using deep-level transient spectroscopy (DLTS). By varying the ratio of rate window values (r), selective probing revealed different trap signatures at similar temperature ranges. Electron traps were found within 0.05-1.2 eV from the conduction band edge, while hole traps were located at 1.37-2.66 eV from the valence band edge on the SBDs. Deeper electron traps contributed to capacitance transients at lower temperatures with increasing r values, while a slow variation of trap levels (both electrons and holes) was observed at higher temperatures (>300 K) when r was varied. These traps were mainly attributed to dislocations, interfaces, and vacancies within the structure.
JOURNAL OF SEMICONDUCTORS
(2023)
Article
Engineering, Electrical & Electronic
Xiaoyan Tang, Simon Hammersley, Vladimir Markevich, Ian Hawkins, Iain Crowe, Trevor Martin, Tony Peaker, Matthew Halsall
Summary: Comparing GaN Schottky diodes prepared by resistive thermal evaporation and plasma sputter deposition, it was found that diodes prepared by sputter deposition have significantly higher reverse leakage current and contain two defects which may affect device performance.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Min Li, Sen Huang, Xinhua Wang, Fuqiang Guo, Yixu Yao, Jingyuan Shi, Ke Wei, Xinyu Liu
Summary: An irreversible degradation of gate leakage is observed in AlGaN/GaN HEMTs under high OFF-state drain bias stress, with the evolution of traps in HEMTs before and after stress being observed through current-mode deep-level transient spectroscopy. The study reveals that the construction and changes in deep traps have a significant impact on the performance of HEMTs.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Norikazu Ito, Taketoshi Tanaka, Ken Nakahara
Summary: A mesa gate structure with Zn-doped GaN enables the normally off operation of AlGaN/GaN heterostructure field-effect transistors (HFETs) and estimates the energy level of Zn within the energy band of GaN.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Physics, Applied
Hongyue Wang, Po-Chun (Brent) Hsu, Ming Zhao, Eddy Simoen, Stefan De Gendt, Arturo Sibaja-Hernandez, Jinyan Wang
Summary: The study investigates electrically active defects in carbon-doped GaN layers using a metal/carbon-doped GaN/Si-doped GaN MIS structure, revealing trap states associated with different carbon doping concentrations. This provides further insights into the impact of these defects on the electrical characteristics of GaN power devices.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Abdulraoof I. A. Ali, Helga T. Danga, Jacqueline M. Nel, Walter E. Meyer
Summary: This study investigated the growth of GaN using electrochemical deposition on different substrates and found that the properties of the film were influenced by both the substrate type and deposition conditions. X-ray diffraction analysis revealed a mixture of hexagonal and cubic structures in the film, with crystallite sizes ranging from 11 nm to 18 nm. Schottky diodes fabricated on the thin films demonstrated specific electrical characteristics, including barrier height and carrier density, which changed after irradiation with alpha particles.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Physics, Condensed Matter
Yan Liu, Simin Chen, Zhiqun Cheng, Tao Wang, Changyang Huang, Guangyuan Jiang, Haipeng Zhang, Yingqi Cai
Summary: This study investigates the strain of the AlGaN barrier layer underneath the gate in two AlGaN/AlN/GaN HFETs with different dimensions but the same ratio of gate length to source-drain distance at temperatures ranging from 300 K to 450 K. The results show that temperature has a significant influence on the strain, and the temperature dependence of the strain is related to the device dimensions, possibly due to the diffusion of metal atoms and lattice mismatch. This study is important for understanding the impact of temperature on the performance of AlGaN/AlN/GaN HFETs.
MICRO AND NANOSTRUCTURES
(2022)
Article
Physics, Condensed Matter
Salah Saadaoui, Olfa Fathallah, Hassen Maaref
Summary: This paper presents a detailed investigation of the degradation of two (Pt/Au)-Al0.2Ga0.8N/GaN/Al2O3 high-electron-mobility transistor(HEMT) structures, identifying Fermi level pinning and abnormal behaviors in capacitance-voltage measurements, and confirming the preponderant tunnel effect assisted by defects in current transport mechanisms. The existence of two hole traps extending from the GaN layer to the (Pt/Au)-AlGaN interface was verified using capacitance deep-level transient spectroscopy (DLTS) measurements.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Physics, Applied
Hui Guo, Hehe Gong, Xinxin Yu, Rui Wang, Qing Cai, Junjun Xue, Jin Wang, Danfeng Pan, Jiandong Ye, Bin Liu, Dunjun Chen, Hai Lu, Rong Zhang, Youdou Zheng
Summary: In this study, p-NiO was used as a gate stack to manipulate channel transport of AlGaN/GaN high electron mobility transistors by post-annealing, resulting in significant improvements in gate leakage and On/Off drain current ratio. However, high annealing temperature led to increased ON resistance and knee voltage (VK) due to the formation of an ultra-thin gamma-Al2O3 layer at the p-NiO/AlGaN interface. Theoretical calculations showed that the interface reconstruction created an additional potential well, leading to the increased VK under high forward gate voltage. An optimized annealing condition was identified to eliminate the increased VK phenomenon while maintaining improved device performances.
APPLIED PHYSICS REVIEWS
(2021)
Article
Physics, Applied
Heng Zhou, Yuanjie Lv, Yang Liu, Mingyan Wang, Peng Cui, Zhaojun Lin
Summary: This study reports on the DC and frequency characteristics of split-gate heterostructure field-effect transistors (HFETs) with different split-gate lengths. The split-gate HFET exhibits high unilateral power gain and low DC power consumption, making it suitable for various amplifier applications.
MODERN PHYSICS LETTERS B
(2023)
Article
Engineering, Electrical & Electronic
Yixu Yao, Sen Huang, Qimeng Jiang, Xinhua Wang, Lan Bi, Wen Shi, Fuqiang Guo, Tiantian Luan, Jie Fan, Haibo Yin, Ke Wei, Yingkui Zheng, Jingyuan Shi, Yankui Li, Qian Sun, Xinyu Liu
Summary: A drain-controlled current-mode deep level transient spectroscopy (I-DLTS) was developed to investigate the Semi-ON-state current collapse in AlGaN/GaN high electron mobility transistors (HEMTs). By inserting a graded AlGaN back-barrier, the charging of buffer traps induced by hot-electron effect was effectively blocked, resulting in a suppressed current collapse in AlGaN/GaN HEMTs under Semi-ON-state stress.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Shijie Pan, Shiwei Feng, Xuan Li, Kun Bai, Xiaozhuang Lu, Yamin Zhang, Lixing Zhou, Erming Rui, Qiang Jiao, Yu Tian
Summary: This paper investigates trapping effect in AlGaN/GaN high-electron-mobility transistors using pulsed current-voltage characterization, drain voltage transient (DVT) measurement, and capacitance deep-level transient spectroscopy (C-DLTS). Three electron traps with different energy levels were identified, and the correlation of different techniques was demonstrated to investigate the physical origin of traps.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Physics, Applied
S. DasGupta, O. Slobodyan, T. Smith, A. Binder, J. Flicker, R. Kaplar, J. Mueller, L. Garcia Rodriguez, S. Atcitty
Summary: Deep level defects in wide bandgap semiconductors can significantly affect the efficiency of power converters. This study uses deep level transient spectroscopy (DLTS) to evaluate such defects in the n-drift layer of vertical gallium nitride (v-GaN) power diodes. The results reveal three energy levels, with the 0.6 eV level having a similar density to the defect that causes current collapse in GaN-based surface conducting devices.
APPLIED PHYSICS LETTERS
(2022)
Article
Energy & Fuels
Yun Jia, Xiaolei Ding, Rui Wang, Youyang Wang, Shiqi Zheng, Xiaobo Hu, Guoen Weng, Shaoqiang Chen, Takeaki Sakurai, Hidefumi Akiyama
Summary: This article presents a new, widely-used DLTS test and measurement system based on a lock-in amplifier, which efficiently digitizes and analyzes data. The experimental results demonstrate that the performance of this system is consistent with mainstream systems in various test scenarios.
