Mechanisms of RF Current Collapse in AlGaN–GaN High Electron Mobility Transistors

Faqir, Mustapha; Verzellesi, Giovanni; Chini, Alessandro; Fantini, Fausto; Danesin, F.; Meneghesso, G.; Zanoni, Enrico; Dua, C.

doi:10.1109/tdmr.2008.922017

Cited by 91 publications

(52 citation statements)

References 32 publications

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“…In RF applications, where low off-state voltages and high frequencies are employed, the current collapse is dominated by charge injection and trapping on the surface [18], while charge injection and trapping in the bulk is minimal. In power switching applications, however, the off-state operation voltage is much higher than in RF applications, while the operation frequencies are much lower (MHz compared to several GHz).…”

Section: Role Of Threading Dislocations In Gan Hemtsmentioning

confidence: 99%

Low-Dispersion, High-Voltage, Low-Leakage GaN HEMTs on Native GaN Substrates

Alshahed

Heuken

Alomari

et al. 2018

IEEE Trans. Electron Devices

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Abstract-In this work the advantages of GaN HEMTs grown on native GaN substrates over GaN/Si or GaN/Sapphire substrates are investigated, and correlated with epitaxial quality. TEM plane view and cross section analysis of GaN/GaN revealed dislocation density lower than 1 × 10 6 cm −2 , which is at least 3 orders of magnitude lower than the case of GaN/Si or GaN/Sapphire. In the case of GaN/Si, the dislocations did not necessarily originate from the substrate/nucleation layer interface, but the strain relief and isolation buffer stacks were main contributors to the dislocation density. GaN/GaN HEMTs demonstrated superior electrical and thermal performance. GaN/GaN demonstrated 3 orders of magnitude lower off-state leakage, current collapse (Ron increase) after stress bias less than 15% compared to 50% in the case of GaN/Si, and 2% drop of the onstate current due to self-heating in DC operation as compared to 13% and 16% for GaN/Si and GaN/Sapphire respectively. The GaN/Si thermal performance approached GaN/GaN only by substrate removal. Therefore GaN/GaN can allow high on-state current, low off-state leakage current, minimal current collapse, and enhanced thermal dissipation capability at the same time, which can be directly correlated to the absence of high dislocation densities.

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Section: Role Of Threading Dislocations In Gan Hemtsmentioning

confidence: 99%

Low-Dispersion, High-Voltage, Low-Leakage GaN HEMTs on Native GaN Substrates

Alshahed

Heuken

Alomari

et al. 2018

IEEE Trans. Electron Devices

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“…Defects can affect the device properties such as the background current levels, the turn-on and turn-off voltage levels, increase intrinsic noise, and lead to current collapse. Current collapse [9][10][11][12][13][14] reduces the transistor RF output power. Basically, under high voltage conditions in small devices (with reduced size intended to decrease transit time and improve frequency response), the high electric fields introduce strong tensile stress in the AlGaN barrier layer that peaks in regions which are typically below the gate edge on the drain side.…”

Section: Introductionmentioning

confidence: 99%

Simulation study of HEMT structures with HfO2 cap layer for mitigating inverse piezoelectric effect related device failures

2015

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The Inverse Piezoelectric Effect (IPE) is thought to contribute to possible device failure of GaN High Electron Mobility Transistors (HEMTs). Here we focus on a simulation study to probe the possible mitigation of the IPE by reducing the internal electric fields and related elastic energy through the use of high-k materials. Inclusion of a HfO2 “cap layer” above the AlGaN barrier particularly with a partial mesa structure is shown to have potential advantages. Simulations reveal even greater reductions in the internal electric fields by using “field plates” in concert with high-k oxides.

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“…The latter leads to current collapse due to the gate-and drain-lag phenomena [15][16][17][18][19]. For such devices the need for a more accurate simulation model which accounts for such effects in a relatively simple manner is imperative.…”

Section: Introductionmentioning

confidence: 99%

NONLINEAR MODELING OF TRAPPING AND THERMAL EFFECTS ON GaAs AND GaN MESFET/HEMT DEVICES

Chaibi¹,

Fernández

Mimouni³

et al. 2012

PIER

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Abstract-A novel nonlinear model for MESFET/HEMT devices is presented. The model can be applied to low power (GaAs) and high power (GaN) devices with equal success. The model provides accurate simulation of the static (DC) and dynamic (Pulsed) I-V characteristics of the device over a wide bias and ambient temperature range (from −70 • C to +70 • C) without the need of an additional electro-thermal sub-circuit. This is an important issue in high power GaN HEMT devices where self-heating and current collapse due to traps is a more serious problem. The parameter extraction strategy of the new model is simple to implement. The robustness of the model when performing harmonic balance simulation makes it suitable for RF and microwave designers. Experimental results presented demonstrate the accuracy of the model when simulating both the small-signal and largesignal behavior of the device over a wide range of frequency, bias and ambient temperature operating points. The model described has been implemented in the Advanced Design System (ADS) simulator to validate the proposed approach without convergence problems.

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Mechanisms of RF Current Collapse in AlGaN–GaN High Electron Mobility Transistors

Cited by 91 publications

References 32 publications

Low-Dispersion, High-Voltage, Low-Leakage GaN HEMTs on Native GaN Substrates

Low-Dispersion, High-Voltage, Low-Leakage GaN HEMTs on Native GaN Substrates

Simulation study of HEMT structures with HfO2 cap layer for mitigating inverse piezoelectric effect related device failures

NONLINEAR MODELING OF TRAPPING AND THERMAL EFFECTS ON GaAs AND GaN MESFET/HEMT DEVICES

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