Impact of Channel Hot Electrons on Current Collapse in AlGaN/GaN HEMTs

Hwang, In-Sun; Kim, Jongseob; Chong, Soogine; Choi, Hyun‐Sik; Hwang, Sun-Kyu; Oh, Jaejoon; Shin, Jai Kwang; Chung, U‐In

doi:10.1109/led.2013.2286173

Cited by 91 publications

(31 citation statements)

References 9 publications

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“…Despite the good materials property and recent advances, one of the key remaining issue is that of current collapse [4], [5] surface of AlGaN/GaN heterostructure due to gate leakage current [4] or hot electron injection [5] is supposed to be primary reason for the current collapse (CC) in GaN HEMT. The trap density in the buffer layer of power switch devices on Si substrate for low cost is supposed to be increased due to the larger lattice mismatch between GaN and Si [6], [7], comparing with SiC and sapphire.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Surface- and Buffer-Induced Current Collapse in GaN High-Electron Mobility Transistors Using a Soft Switched Pulsed \(I-V\) Measurement

Wang

Yan

Zhang

et al. 2014

IEEE Electron Device Lett.

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In this letter, we investigated the behaviors of surface-and buffer-induced current collapse in AlGaN/GaN high-electron mobility transistors (HEMTs) using a soft-switched pulsed I-V measurement with different quiescent bias points. It is found that the surface-and buffer-related current collapse have different relationship with the gate and drain biases (V GS0, V DS0 ) during quiescent bias stress. The surface-induced current collapse in devices without passivation monotonically increases with the negative V GS0 , suggesting that an electron injection to the surface from gate leakage is the dominant mechanism and the Si 3 N 4 passivation could effectively eliminate such current collapse. The buffer-induced current collapse in devices with intentionally carbon-doped buffer layer exhibits a different relationship with V GS0 after surface passivation. The buffer-related current collapse shows a bell-shaped behavior with V GS0 , suggesting that a hot electron trapping in the buffer is the dominant mechanism. The soft-switched pulsed I-V measurement provides an effective method to distinguish between the surface-and buffer-related current collapse in group III-nitride HEMTs.

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Section: Introductionmentioning

confidence: 99%

Investigation of Surface- and Buffer-Induced Current Collapse in GaN High-Electron Mobility Transistors Using a Soft Switched Pulsed \(I-V\) Measurement

Wang

Yan

Zhang

et al. 2014

IEEE Electron Device Lett.

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“…Therefore, the current collapse is ascribed to electron injection to the surface states by gate leakage current at OFF-state and hot electron injection from channel during the high-power hard switching transients. Despite the effectiveness of AlN passivation in suppressing gate injection induced current collapse, as has been well proved by the double pulse [12], it has been widely reported that highpower stress could significantly enhance current collapse by injection of hot electrons into trap states at the surface or in the barrier [9]- [11]. However, our measurement results under hard switching operation show no further degradation in R ON_Dyn compared with that under soft switching condition [12], suggesting that current collapse induced by hot electron trapping is also suppressed by AlN passivation.…”

Section: Resultsmentioning

confidence: 99%

“…In contrast to the results in [11], where a clear suppression of current collapse was observed at higher temperatures, our device shows good suppression of current collapse from room temperature to 200°C (Table I). This is attributed to suppressed influence of trap states with emission time constants in sub-ms and sub-s range observed in [9]- [11], by the high-density positive polarization charges originated from monocrystal-like AlN at the AlN/III-nitride interface [14]. Without AlN passivation, these traps were filled with electrons injected from the gate or the channel (i.e.…”

Section: Resultsmentioning

confidence: 99%

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Dynamic Performance of AlN-Passivated AlGaN/GaN MIS-High Electron Mobility Transistors Under Hard Switching Operation

Wang

Liu

Jiang

et al. 2015

IEEE Electron Device Lett.

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High-frequency and high-temperature dynamic performance of plasma-enhanced atomic layer deposition AlN-passivated enhancement-mode GaN metal-insulatorsemiconductor high electron mobility transistors (MIS-HEMTs) has been investigated under hard switching conditions. Low dynamic ON-resistance (R ON ) degradation with small frequency dispersion and weak temperature dependence is obtained. The effectiveness of AlN passivation in suppressing current collapse is proved even under hard switching operations, which, according to other reports of SiN x -passivated devices, could worsen the dynamic R ON degradation due to the trapping of additional hot electrons.

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“…In contrary to inductive loads, the switching losses are lower with a resistive load. This could potentially change the trapping behaviour, as hot electrons during this high power state have been shown to contribute to the increased on-state resistance [12]. Also, inductive load is closer to application for most hard switched applications.…”

Section: Methodsmentioning

confidence: 99%

Modelling and quantification of power losses due to dynamic on-state resistance of GaN E-mode HEMT

Spro

Peftitsis

Midtgård

et al. 2017

2017 IEEE 18th Workshop on Control and Modeling for Power Electronics (COMPEL)

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Abstract-This paper investigates a method for quantifying the additional losses in high-voltage GaN enhancement mode HEMTs (eHEMT) employed in converter applications. The additional losses stem from the phenomenon known as current collapse or dynamic on-state resistance. The goal of this work is to investigate how these losses contribute to the total power loss in converter application. Measurement and modelling methods in the literature are reviewed. Changes to the measurement circuit are made to improve measurement accuracy. Measurements of dynamic on-state resistance are made on a commercial GaN eHEMT. The experimental results shows that the resistance depends on both dc-link voltage and blocking time. The resistance waveform and initial attempts at modelling the dynamic onstate resistance indicate that the suggested model is suitable for modelling the losses in LTSPICE software.

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Impact of Channel Hot Electrons on Current Collapse in AlGaN/GaN HEMTs

Cited by 91 publications

References 9 publications

Investigation of Surface- and Buffer-Induced Current Collapse in GaN High-Electron Mobility Transistors Using a Soft Switched Pulsed \(I-V\) Measurement

Investigation of Surface- and Buffer-Induced Current Collapse in GaN High-Electron Mobility Transistors Using a Soft Switched Pulsed \(I-V\) Measurement

Dynamic Performance of AlN-Passivated AlGaN/GaN MIS-High Electron Mobility Transistors Under Hard Switching Operation

Modelling and quantification of power losses due to dynamic on-state resistance of GaN E-mode HEMT

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