- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Gate Conduction Mechanisms and Lifetime Modeling of p-Gate AlGaN/GaN High-Electron-Mobility Transistors
摘要： The gate conduction mechanisms in p-gallium nitride (GaN)/AlGaN/GaN enhancement mode transistors are investigated using temperature-dependent dc gate current measurements. In each of the different gate voltage regions, a physical model is proposed and compared to experiment. At negative gate bias, Poole–Frenkel emission (PFE) occurs within the passivation dielectric from gate to source. At positive gate bias, the p-GaN/AlGaN/GaN “p-i-n” diode is in forward operation mode, and the gate current is limited by hole supply at the Schottky contact. At low gate voltages, the current is governed by thermionic emission with Schottky barrier lowering in dislocation lines. Increasing the gate voltage and temperature results in thermally assisted tunneling (TAT) across the same barrier. An improved gate process reduces the gate current in the positive gate bias region and eliminates the onset of TAT. However, at high positive gate bias, a sharp increase in current is observed originating from PFE at the metal/p-GaN interface. Using the extracted conduction mechanisms for both devices, accurate lifetime models are constructed. The device fabricated with the novel gate process exhibits a maximum gate voltage of 7.2 V at t1% = 10 years.
关键词： time-dependent breakdown (TDB),p-GaN gate,high-electron-mobility transistor (HEMT),enhancement mode,gallium nitride (GaN),Conduction mechanism
更新于2025-09-23 15:21:21
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[Lecture Notes in Electrical Engineering] Microelectronics, Electromagnetics and Telecommunications Volume 521 (Proceedings of the Fourth ICMEET 2018) || Impact of p-GaN Gate Length on Performance of AlGaN/GaN Normally-off HEMT Devices
摘要： In this work, we have studied the effect of variation in length of GaN gate with p-type doping concentration on the DC performances of AlGaN/GaN normally-off HEMT using 2D Atlas TCAD simulator. A comprehensive simulation is undertaken on the proposed device to examine different performance parameters such as drain current, transconductance factor, energy band diagram, and surface potential with respect to change in p-type GaN gate lengths. The gate lengths are varied from 60 to 90 nm, and it is noticed from the simulation results that with a decrease in gate length the drain current increases and transconductance increases. A proper optimization of gate length is indispensable to preserve the normally-off mode operation and at the same time enhancing certain performance parameters.
关键词： 2DEG,AlGaN/GaN,p-GaN gate,ATLAS
更新于2025-09-23 15:21:21
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Mechanism of leakage current increase in p-GaN gate AlGaN/GaN power devices induced by ON-state gate bias
摘要： An increase in OFF-state leakage current in p-GaN gate AlGaN/GaN high-electron-mobility transistors (HEMTs), induced by ON-state gate bias, was observed and reported in this paper. Higher OFF-state leakage current was observed with higher gate bias voltage and longer bias duration. We propose that the initial increase in OFF-state leakage current and its subsequent decay with time are due to persistent photoconductivity effects in GaN induced by hole injection and electroluminescence during the ON-state gate bias. At room temperature, it took more than 20 s for the increased leakage current to reduce to its equilibrium level in the dark. The related physical mechanisms underlying this phenomenon in the p-GaN gate HEMT structure are also proposed.
关键词： p-GaN gate,AlGaN/GaN HEMTs,persistent photoconductivity,leakage current,electroluminescence
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Stretching in Time of GaN Active Gate Driving Profiles to Adapt to Changing Load Current
摘要： Active gate driving, where the gate signal is actively profiled, has been shown to reduce EMI, overshoot, and switching loss, in silicon power converters. Recently, much faster gate drivers with the ability to profile at a 100 ps resolution have been reported, which has opened up the possibility of actively driving emerging wide-bandgap devices. This could allow Gallium Nitride (GaN) and Silicon Carbide (SiC) FETs to be switched faster than is currently possible, as unwanted switching features such as current ringing at turn-on could be eliminated. However, these drivers have previously only been demonstrated with pre-programmed gate profiles that have been optimized at certain operating conditions, whereas converters typically operate in a range of conditions. In this paper, some limitations of using fixed gate profiles on GaN FETs are reported for the first time, and a new method of profile adaptation is demonstrated. First, the gate profiles in a 400 V GaN bridge-leg are optimized to minimize current ringing at turn-on for a given load current. Then, the load current is varied, showing that the gate signal profile remains close to optimal for ±20% changes in current. Also, over a larger range of at least ±35%, the profiled waveform performs better than a non-profiled gate waveform. It is then demonstrated that by slightly reducing the driver’s internal clock frequency with increasing load current, the profile is re-optimized for new load currents. It is concluded that driver clock frequency adaptation may be a means of adapting gate profiles to load current variation and possibly also to temperature variation.
关键词： Active Gate Driving,Arbitrary Waveform Gate Driver,GaN Gate Driver,Dynamic Output Resistance Gate Driver,GaN FET
更新于2025-09-04 15:30:14