scholarly journals Mechanism Analysis of Dynamic On-State Resistance Degradation for a Commercial GaN HEMT Using Double Pulse Test

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1202
Author(s):  
Wei Wang ◽  
Yan Liang ◽  
Minghui Zhang ◽  
Fang Lin ◽  
Feng Wen ◽  
...  
Keyword(s):  
Gradual Increase ◽  
Dynamic Resistance ◽  
Mechanism Analysis ◽  
Pulse Test ◽  
Gan Hemt ◽  
Resistance Degradation ◽  
Dielectric Model ◽  
Leaky Dielectric Model ◽  
State Resistance ◽  
Stress Voltage

The dynamic on-resistance (RON) behavior of one commercial GaN HEMT device with p-GaN gate is investigated under hard-switching conditions. The non-monotonic performance of dynamic RON with off-state voltage ranging from 50 to 400 V is ascribed to the “leaky dielectric” model. The highest normalized RON value of 1.22 appears at 150 and 200 V. The gradual increase and following maximum of dynamic RON are found when the device is exposed to a stress voltage for an extended stress time under 100 and 200 V, which is due to a much longer trapping time compared to detrapping time related to deep acceptors and donors. No obvious RON degradation, thanks to the suppressed trapping effect, is observed at higher VDS. From the multi-pulse test, the dynamic RON is seen to be insensitive to the frequency. It is demonstrated that the leakage, especially under source and drain contact, is a key issue in the dynamic resistance degradation.

scholarly journals Impact of Gamma Radiation on Dynamic RDSON Characteristics in AlGaN/GaN Power HEMTs

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2760 ◽  
Author(s):  
Pedro J. Martínez ◽  
Enrique Maset ◽  
Pedro Martín-Holgado ◽  
Yolanda Morilla ◽  
David Gilabert ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Wide Band ◽  
High Electron Mobility Transistors ◽  
Dynamic Resistance ◽  
High Electron ◽  
Power Switching ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Free Current ◽  
60Co Gamma Radiation

GaN high-electron-mobility transistors (HEMTs) are promising next-generation devices in the power electronics field which can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters, where high frequencies and voltages are also needed. Its wide band gap (WBG), large breakdown electric field, and thermal stability improve actual silicon performances. However, at the moment, GaN HEMT technology suffers from some reliability issues, one of the more relevant of which is the dynamic on-state resistance (RON_dyn) regarding power switching converter applications. In this study, we focused on the drain-to-source on-resistance (RDSON) characteristics under 60Co gamma radiation of two different commercial power GaN HEMT structures. Different bias conditions were applied to both structures during irradiation and some static measurements, such as threshold voltage and leakage currents, were performed. Additionally, dynamic resistance was measured to obtain practical information about device trapping under radiation during switching mode, and how trapping in the device is affected by gamma radiation. The experimental results showed a high dependence on the HEMT structure and the bias condition applied during irradiation. Specifically, a free current collapse structure showed great stability until 3.7 Mrad(Si), unlike the other structure tested, which showed high degradation of the parameters measured. The changes were demonstrated to be due to trapping effects generated or enhanced by gamma radiation. These new results obtained about RON_dyn will help elucidate trap behaviors in switching transistors.

scholarly journals Electrohydrodynamics of viscous drops in strong electric fields: numerical simulations

2017 ◽  
Vol 829 ◽  
pp. 127-152 ◽  
Author(s):  
Debasish Das ◽  
David Saintillan
Keyword(s):  
Numerical Simulations ◽  
Electric Fields ◽  
Small Deformation ◽  
Dielectric Liquid ◽  
Uniform Electric Field ◽  
Liquid Drops ◽  
Wide Range ◽  
Dielectric Model ◽  
Leaky Dielectric Model ◽  
Leaky Dielectric

Weakly conducting dielectric liquid drops suspended in another dielectric liquid and subject to an applied uniform electric field exhibit a wide range of dynamical behaviours contingent on field strength and material properties. These phenomena are best described by the Melcher–Taylor leaky dielectric model, which hypothesizes charge accumulation on the drop–fluid interface and prescribes a balance between charge relaxation, the jump in ohmic currents from the bulk and charge convection by the interfacial fluid flow. Most previous numerical simulations based on this model have either neglected interfacial charge convection or restricted themselves to axisymmetric drops. In this work, we develop a three-dimensional boundary element method for the complete leaky dielectric model to systematically study the deformation and dynamics of liquid drops in electric fields. The inclusion of charge convection in our simulations permits us to investigate drops in the Quincke regime, in which experiments have demonstrated a symmetry-breaking bifurcation leading to steady electrorotation. Our simulation results show excellent agreement with existing experimental data and small-deformation theories.

High Breakdown Voltage GaN Power HEMT on Si Substrate

2013 ◽  
Vol 805-806 ◽  
pp. 948-953
Author(s):  
Cen Kong ◽  
Jian Jun Zhou ◽  
Jin Yu Ni ◽  
Yue Chan Kong ◽  
Tang Sheng Chen
Keyword(s):  
Breakdown Voltage ◽  
Low Cost ◽  
Electronic Devices ◽  
Power Electronic ◽  
Si Substrate ◽  
Field Plate ◽  
Maximum Current Density ◽  
Gan Hemt ◽  
Maximum Current ◽  
State Resistance

GaN high electronic mobility transistor (HEMT) was fabricated on silicon substrate. A breakdown voltage of 800V was obtained without using field plate technology. The fabrication processes were compatible with the conventional GaN HEMTs fabrication processes. The length between drain and gate (Lgd) has a greater impact on breakdown voltage of the device. A breakdown voltage of 800V with maximum current density of 536 mA/mm was obtained while Lgd was 15μm and the Wg was 100μm. The specific on-state resistance of this devices was 1.75 mΩ·cm2, which was 85 times lower than that of silicon MOSFET with same breakdown voltage. The results establish the foundation of low cost GaN HEMT power electronic devices.

Transient Electrohydrodynamic Manipulation of Particles on the Surface of a Drop

2016 ◽  
Author(s):  
Edison C. Amah ◽  
Ian S. Fischer ◽  
Pushpendra Singh
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Control Parameter ◽  
Transient Behavior ◽  
Uniform Electric Field ◽  
Electrohydrodynamic Flow ◽  
Dielectric Model ◽  
Leaky Dielectric Model ◽  
Leaky Dielectric

In our previous studies we have shown that particles adsorbed on the surface of a drop can be concentrated at its poles or equator by applying a uniform electric field. This happens even when the applied electric field is uniform; the electric field on the surface of the drop is nonuniform, and so particles adsorbed on the surface are subjected to dielectrophoretic (DEP) forces. In this study, we use leaky dielectric model to model the transient behavior of particles at low electric field frequencies. We show that the frequency of the electric field is an important control parameter that under certain conditions can be used to collect particles at the poles or the equator, and to move them from the poles to the equator. The speed with which particles move on the surface depends on the strength of the electrohydrodynamic flow which diminishes with increasing frequency.

scholarly journals “Leaky Dielectric” Model for the Suppression of Dynamic $R_{\mathrm{ON}}$ in Carbon-Doped AlGaN/GaN HEMTs

2017 ◽  
Vol 64 (7) ◽  
pp. 2826-2834 ◽  
Author(s):  
Michael J. Uren ◽  
Serge Karboyan ◽  
Indranil Chatterjee ◽  
Alexander Pooth ◽  
Peter Moens ◽  
...  
Keyword(s):  
Carbon Doped ◽  
Dielectric Model ◽  
Leaky Dielectric Model ◽  
Gan Hemts ◽  
Leaky Dielectric

The electrostatically forced Faraday instability: theory and experiments

2019 ◽  
Vol 862 ◽  
pp. 696-731 ◽  
Author(s):  
Kevin Ward ◽  
Satoshi Matsumoto ◽  
Ranga Narayanan
Keyword(s):  
Interfacial Instability ◽  
Perfect Conductor ◽  
Dc Voltage ◽  
Fluid Systems ◽  
Instability Theory ◽  
Dielectric Model ◽  
Leaky Dielectric Model ◽  
Leaky Dielectric ◽  
Rigorous Model ◽  
Parametric Frequency

The onset of interfacial instability in two-fluid systems using a viscous, leaky dielectric model is studied. The instability arises as a result of resonance between the parametric frequency of an imposed electric field and the system’s natural frequency. In addition to a rigorous model that uses Floquet instability analysis, where both viscous and charge effects are considered, this study also provides convincing validating experiments. In other results, it is shown that (a) the imposition of a periodic electrostatic potential acts to counter gravity and this countering effect becomes more effective if a DC voltage is also added, (b) a critical DC voltage exists at which the interface becomes unstable such that no parametric frequency is required to completely destabilize the interface and (c) the leaky dielectric model approaches a model for a perfect dielectric/perfect conductor pair as the conductivity ratio becomes large. It is also shown via experiments that parametric resonant instability using electrostatic forcing may be reliably used to estimate interfacial tension to sufficient accuracy.

The Effect of Film Thickness on EHD-Driven Instability of Interface Separating Two Liquids

2009 ◽  
Author(s):  
Payam Sharifi ◽  
Asghar Esmaeeli
Keyword(s):  
Stokes Equations ◽  
Thin Liquid Film ◽  
Front Tracking ◽  
Thin Layers ◽  
Navier Stokes ◽  
Physical Parameters ◽  
Interface Instability ◽  
Navier Stokes Equations ◽  
Dielectric Model ◽  
Leaky Dielectric Model

Most of the studies conducted so far on EHD-driven instability of superimposed fluids have been concerned with liquid layers of modest depths. In many applications, however, the liquid layers can be very thin. Since the dynamics in thin films is generally governed by lubrication equations rather than full Navier-Stokes equations, it is expected that the interface dynamics will be quite different from that of the liquids with modest depths. The objective of this study is to explore the effect of initial liquid thickness on the dynamics of the phase boundary. To do this end, we perform Direct Numerical Simulations (DNS) using a front tracking/finite difference scheme, in conjunction with Taylor’s leaky dielectric model. For the physical parameters used here, it is shown that for sufficiently thick liquid layers, the interface instability leads to formation of liquid columns that merge together to form a big column. However, for thin layers, the interactions between the columns are weaker and lead to a short and a longer column that are connected by a thin liquid film.

Linear Instability of Liquid Sheets Subjected to a Transverse Electric Field

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Xiao Cui ◽  
Qing-Fei Fu ◽  
Lijun Yang ◽  
Luo Xie ◽  
Bo-Qi Jia
Keyword(s):  
Growth Rate ◽  
Liquid Sheet ◽  
Linear Instability ◽  
Wave Number ◽  
Perfect Conductor ◽  
Liquid Density ◽  
Dielectric Model ◽  
Leaky Dielectric Model ◽  
Leaky Dielectric ◽  
Gas To Liquid

Abstract A temporal linear instability analysis was performed for a liquid sheet moving around the inviscid gas in transverse electrical field. The fluid was described by the leaky-dielectric model, which is more complex and more comparable to the liquid electrical properties than existing models. As a result, the sinuous and the varicose modes exist, in which the dimensionless dispersion relation between wave number and temporal growth rate can be derived as a 3 × 3 matrix. According to this relationship, the effects of liquid properties on sheet instability were performed. It was concluded that, as the electrical Euler number (Eu), the ratio of gas-to-liquid density (ρ), Weber number (We), Reynolds number (Re), and the relative relaxation time (τ) increased, the instability of the sheet was enhanced. This work also compared the leaky-dielectric model with the perfect conductor model and found that the unstable growth rate in the leaky-dielectric model was higher than the one in the perfect conductor model. Moreover, as the ratio of gas-to-liquid improved, this difference decreased. Finally, an energy approach was adopted to investigate the instability mechanism for the two models.

scholarly journals An RF Approach to Modelling Gallium Nitride Power Devices Using Parasitic Extraction

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2007
Author(s):  
Nikita Hari ◽  
Sridhar Ramasamy ◽  
Mominul Ahsan ◽  
Julfikar Haider ◽  
Eduardo M. G. Rodrigues
Keyword(s):  
High Speed ◽  
Power Devices ◽  
Parasitic Extraction ◽  
Switching Model ◽  
Pulse Test ◽  
Gan Hemt ◽  
Proposed Model ◽  
Original Contribution ◽  
Network Analyser ◽  
High Speed Switching

This paper begins with a comprehensive review into the existing GaN device models. Secondly, it identifies the need for a more accurate GaN switching model. A simple practical process based on radio frequency techniques using Vector Network Analyser is introduced in this paper as an original contribution. It was applied to extract the impedances of the GaN device to develop an efficient behavioural model. The switching behaviour of the model was validated using both simulation and real time double pulse test experiments at 500 V, 15 A conditions. The proposed model is much easier for power designers to handle, without the need for knowledge about the physics or geometry of the device. The proposed model for Transphorm GaN HEMT was found to be 95.2% more accurate when compared to the existing LT-Spice manufacturer model. This work additionally highlights the need to adopt established RF techniques into power electronics to reduce the learning curve while dealing with these novel high-speed switching devices.

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