Analysis of current collapse effect in AlGaN/GaN HEMT: Experiments and numerical simulations

Faqir, Mustapha; Bouya, Mohsine; Malbert, Nathalie; Labat, Nathalie; Carisetti, Dominique; Lambert, Benoît; Verzellesi, Giovanni; Fantini, Fausto

doi:10.1016/j.microrel.2010.07.020

Cited by 23 publications

(8 citation statements)

References 14 publications

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“…During drain voltage sweeps, donor-like barrier traps can be ionized by field-enhanced electron emission [403], [404] [mechanism Ba3 in Table 8], in this case inducing an increase in the output conductance sometimes termed "kink effect" (see Section 8.7.4).…”

Section: Barrier Trapsmentioning

confidence: 99%

GaN-based power devices: Physics, reliability, and perspectives

Meneghini

Santi

Abid

et al. 2021

Journal of Applied Physics

250

126

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Over the last decade, gallium nitride has emerged as an excellent material for the fabrication of power devices. Among the semiconductors for which power devices are already available on the market, GaN has the widest energy gap, the largest critical field, the highest saturation velocity, thus representing an excellent material for the fabrication of high speed/high voltage components.The presence of spontaneous and piezoelectric polarization allows to create a 2-dimensional electron gas, with high mobility and large channel density, in absence of any doping, thanks to the use of AlGaN/GaN heterostructures. This contributes to minimize resistive losses; at the same time, for GaN transistors switching losses are very low, thanks to the small parasitic capacitances and switching charges. Device scaling and monolithic integration enable high frequency operation, with consequent advantages in terms of miniaturization.For high power/high voltage operation, vertical device architectures are being proposed and investigated, and 3-dimensional structuresfin-shaped, trench-structured, nanowire-basedare demonstrating a great potential. Contrary to silicon, GaN is a relatively young material: trapping and degradation processes must be understood and described in detail, with the aim of optimizing device stability and reliability. This tutorial paper describes the physics, technology and reliability of GaN-based power devices: in the first part of the article, starting from a discussion of the main properties of the material, the characteristics of lateral and vertical GaN transistors are discussed in detail, to provide guidance in this complex and interesting field. The second part of the paper focuses on trapping and reliability aspects: the physical origin of traps in GaN, and the main degradation mechanisms are discussed in detail. The wide set of referenced papers and the insight on the most relevant aspects gives the reader a comprehensive overview on present and next-generation GaN electronics. IntroductionOver the past decade, gallium nitride has emerged as an excellent material for the fabrication of power semiconductor devices. Thanks to the unique properties of GaN, diodes and transistors based on this material have excellent performance, compared to their silicon counterparts, and are expected to find wide application in the next-generation power converters. Owing to the flexibility and the energy efficiency of GaN-based power converters, the interest towards this technology is rapidly growing: the aim of this tutorial is to review the most relevant physical properties, the operating principles, the fabrication parameters, and the stability/reliability issues of GaN-based power transistors. For introductory purposes, we start summarizing the physical reasons why GaN transistors achieve a much better performance than the corresponding silicon devices, to help the reader understanding the unique advantages of this technology.The properties of GaN devices allow the fabrication of high-efficiency (near or above 99 %)...

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Section: Barrier Trapsmentioning

confidence: 99%

GaN-based power devices: Physics, reliability, and perspectives

Meneghini

Santi

Abid

et al. 2021

Journal of Applied Physics

250

126

View full text Add to dashboard Cite

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“…With the increase of VDD, electrons are injected from the gate edge and trapped by the surface defects because of the strong reverse electric field between the gate and drain during the stress state. There are also electrons in the channel (2DEG carriers) that move across the GaN barrier along the fringing field and are trapped in the buffer region [6,21,22]. The above two phenomena result in decreased drain current in the measurement state and increased normalized dynamic RON [7].…”

Section: Measurement and Experimental Setupmentioning

confidence: 99%

Deep Source Metal Trenches in GaN-On-Si HEMTs for Relieving Current Collapse

Yang

Lin

et al. 2021

IEEE J. Electron Devices Soc.

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The dynamic on-resistance increase during power switching is one of the challenges of GaN-based HEMTs (high-electron-mobility transistors) for power electronic applications. Both the surface traps and buffer traps reduce channel carriers, resulting in decreased operating current during power switching. In this work, we propose a source metal trench toward the buffer region to alleviate channel carriers' trapping in the buffer region. We compare the dynamic behaviors of the HEMTs with the source trench fabricated within and out of the mesa region. The results indicate less dynamic on-resistance increase at higher drain and gate stress voltages of the device with source trench in the mesa, as compared with the device with source trench fabricated away from mesa, or the one without a trench. We further develop physical models, including multiple current-conducting paths, reduction of buffer traps through source trench, and the re-distribution of the electric field profile, to explain the phenomenon.

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“…Some studies revealed that the drain current collapse and Kink effect in HEMT devices were correlated to the presence of traps. 7,8 Therefore, it is necessary to perform basic investigations of deep level defects in AlGaN/GaN heterostructures. To date, a number of researchers have investigated the deep level defects in AlGaN/GaN heterostructures using various characterization techniques, such as photo-ionization spectroscopy, 9 chargebased deep level transient spectroscopy (QDLTS), 10 deep level optical spectroscopy (DLOS), 11 current deep level tran-sient spectroscopy (CDLTS), 12,13 and deep level transient spectroscopy (DLTS).…”

Section: Introductionmentioning

confidence: 99%

Anomaly and defects characterization by I-V and current deep level transient spectroscopy of Al0.25Ga0.75N/GaN/SiC high electron-mobility transistors

Saadaoui

Salem

Gassoumi

et al. 2012

Journal of Applied Physics

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In this paper, we report static electric drain-source current-voltage measurements for different gate voltages and at different temperatures, performed on Al0.25Ga0.75N/GaN/SiC high electron-mobility transistors (HEMT). The results show the presence of kink and collapse effects. We have demonstrated that these effects are significant in the temperature range varying from 150 to 400 K with a maximum around 300 K. This parasitic effect was correlated with the presence of deep levels in our transistor. Indeed, we have noticed the presence of two electron traps named A1 and A2, and one hole trap named H1; their respective activation energies, which are determined using current deep level transient spectroscopy (CDLTS), are, respectively, 0.56, 0.82, and 0.75 eV. Traps H1 and A1 are shown to be extended defects in the Al0.25Ga0.75N/GaN heterostructure; they are supposed to be the origin of the kink and collapse effects. However, the punctual defect A2 seems to be located either in the free gate-drain surface, in the metal/AlGaN interface, or in the AlGaN/GaN interface.

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Analysis of current collapse effect in AlGaN/GaN HEMT: Experiments and numerical simulations

Cited by 23 publications

References 14 publications

GaN-based power devices: Physics, reliability, and perspectives

GaN-based power devices: Physics, reliability, and perspectives

Deep Source Metal Trenches in GaN-On-Si HEMTs for Relieving Current Collapse

Anomaly and defects characterization by I-V and current deep level transient spectroscopy of Al0.25Ga0.75N/GaN/SiC high electron-mobility transistors

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