Effect of Deep Trap on Breakdown Voltage in AlGaN/GaN HEMTs

2008 ◽  
Vol 600-603 ◽  
pp. 1345-1348 ◽  
Author(s):  
Akira Nakajima ◽  
Shuichi Yagi ◽  
Mitsuaki Shimizu ◽  
Hajime Okumura
Keyword(s):  
Breakdown Voltage ◽  
Device Simulation ◽  
Drain Current ◽  
High Electron Mobility Transistors ◽  
Deep Trap ◽  
High Electron ◽  
Surface Trap ◽  
Electron Mobility Transistors ◽  
Current Collapse ◽  
Good Agreement

The effect of AlGaN surface traps on breakdown voltage VB and drain current collapse in AlGaN/GaN high electron mobility transistors (HEMTs) were investigated using experimental measurement and numerical simulation. The drain current transient due to surface traps was systematically measured and analyzed, and the activation energy of a surface trap was evaluated as approximately 0.7 eV. Results from the device simulation of VB in HEMTs were in good agreement with the experimental results when assuming surface traps. The results indicate that surface traps increase VB, and induce a crucial current collapse.

AlGaN Channel HEMT with Extremely High Breakdown Voltage

2011 ◽  
Vol 1324 ◽  
Author(s):  
Takuma Nanjo ◽  
Misaichi Takeuchi ◽  
Akifumi Imai ◽  
Yousuke Suzuki ◽  
Muneyoshi Suita ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Drain Current ◽  
High Electron Mobility Transistors ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
High Electron ◽  
Field Plate ◽  
Electron Mobility Transistors ◽  
Doping Technique ◽  
Resistive Source

ABSTRACTA channel layer substitution of a wider bandgap AlGaN for a conventional GaN in high electron mobility transistors (HEMTs) is an effective method of enhancing the breakdown voltage. Wider bandgap AlGaN, however, should also increase the ohmic contact resistance. Si ion implantation doping technique was utilized to achieve sufficiently low resistive source/drain contacts. The fabricated AlGaN channel HEMTs with the field plate structure demonstrated good pinch-off operation with sufficiently high drain current density of 0.5 A/mm without noticeable current collapse. The obtained maximum breakdown voltages was 1700 V in the AlGaN channel HEMT with the gate-drain distance of 10 μm. These remarkable results indicate that AlGaN channel HEMTs could become future strong candidates for not only high-frequency devices such as low noise amplifiers but also high-power devices such as switching applications.

scholarly journals Development of Catalytic-CVD SiNx Passivation Process for AlGaN/GaN-on-Si HEMTs

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 842 ◽  
Author(s):  
Myoung-Jin Kang ◽  
Hyun-Seop Kim ◽  
Ho-Young Cha ◽  
Kwang-Seok Seo
Keyword(s):  
Chemical Vapor ◽  
Drain Current ◽  
High Electron Mobility Transistors ◽  
Breakdown Field ◽  
High Electron ◽  
Electron Mobility Transistors ◽  
Current Collapse ◽  
Passivation Process ◽  
Gan On Si ◽  
Sinx Film

We optimized a silicon nitride (SiNx) passivation process using a catalytic-chemical vapor deposition (Cat-CVD) system to suppress the current collapse phenomenon of AlGaN/GaN-on-Si high electron mobility transistors (HEMTs). The optimized Cat-CVD SiNx film exhibited a high film density of 2.7 g/cm3 with a low wet etch rate (buffered oxide etchant (BOE) 10:1) of 2 nm/min and a breakdown field of 8.2 MV/cm. The AlGaN/GaN-on-Si HEMT fabricated by the optimized Cat-CVD SiNx passivation process, which had a gate length of 1.5 μm and a source-to-drain distance of 6 μm, exhibited the maximum drain current density of 670 mA/mm and the maximum transconductance of 162 mS/mm with negligible hysteresis. We found that the optimized SiNx film had positive charges, which were responsible for suppressing the current collapse phenomenon.

scholarly journals Влияние технологии двойного травления под затвор на параметры HEMT транзисторов на подложках GaAs и InP

2021 ◽  
Vol 55 (10) ◽  
pp. 890
Author(s):  
В.А. Беляков ◽  
И.В. Макарцев ◽  
А.Г. Фефелов ◽  
С.В. Оболенский ◽  
А.П. Васильев ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Breakdown Voltage ◽  
Cutoff Frequency ◽  
Drain Current ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Electron Mobility Transistors ◽  
Inp Substrate ◽  
Current Voltage ◽  
Unity Gain

High electron mobility transistors (HEMTs) have been developed based on InAlAs/InGaAs heterostructures on an InP substrate, with a transconductance of about 1000 mS/mm, a reverse breakdown voltage of more than 10 V and a unity-gain cutoff frequency is 140 GHz. In addition, HEMT transistors based on AlGaAs/InGaAs/GaAs heterostructures on a GaAs substrate with double gate recessing technology have been developed. This transistors demonstrate a maximum measured transconductance of the current-voltage characteristic of 520 mS/mm, a maximum drain current of 670 mA/mm, and a gate-drain breakdown voltage of 14 V and a unity-gain cut-off frequency is 120 GHz. Due to the increased breakdown voltage, the developed transistors have been used in monolithic integrated circuits of millimeter-wave power amplifiers with an output power of more than 110 mW.

scholarly journals On the Modeling of the Donor/Acceptor Compensation Ratio in Carbon-Doped GaN to Univocally Reproduce Breakdown Voltage and Current Collapse in Lateral GaN Power HEMTs

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 709
Author(s):  
Nicolò Zagni ◽  
Alessandro Chini ◽  
Francesco Maria Puglisi ◽  
Paolo Pavan ◽  
Giovanni Verzellesi
Keyword(s):  
Breakdown Voltage ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Trap Concentration ◽  
Electron Mobility Transistors ◽  
Compensation Ratio ◽  
Current Collapse ◽  
Donor Acceptor ◽  
The Difference ◽  
Trap Levels

The intentional doping of lateral GaN power high electron mobility transistors (HEMTs) with carbon (C) impurities is a common technique to reduce buffer conductivity and increase breakdown voltage. Due to the introduction of trap levels in the GaN bandgap, it is well known that these impurities give rise to dispersion, leading to the so-called “current collapse” as a collateral effect. Moreover, first-principles calculations and experimental evidence point out that C introduces trap levels of both acceptor and donor types. Here, we report on the modeling of the donor/acceptor compensation ratio (CR), that is, the ratio between the density of donors and acceptors associated with C doping, to consistently and univocally reproduce experimental breakdown voltage (VBD) and current-collapse magnitude (ΔICC). By means of calibrated numerical device simulations, we confirm that ΔICC is controlled by the effective trap concentration (i.e., the difference between the acceptor and donor densities), but we show that it is the total trap concentration (i.e., the sum of acceptor and donor densities) that determines VBD, such that a significant CR of at least 50% (depending on the technology) must be assumed to explain both phenomena quantitatively. The results presented in this work contribute to clarifying several previous reports, and are helpful to device engineers interested in modeling C-doped lateral GaN power HEMTs.

Hot Electron Induced Current Collapse in AlGaN/GaN HEMTs

2007 ◽  
Vol 556-557 ◽  
pp. 1035-1038 ◽  
Author(s):  
Akira Nakajima ◽  
Shuichi Yagi ◽  
Mitsuaki Shimizu ◽  
Kazuhiro Adachi ◽  
Hajime Okumura
Keyword(s):  
Drain Current ◽  
High Electron Mobility Transistors ◽  
Experimental Results ◽  
High Electron ◽  
Hot Electron ◽  
Electron Generation ◽  
Electron Mobility Transistors ◽  
Current Collapse ◽  
Numerical Device ◽  
Current Transients

The mechanism of drain current collapse in AlGaN/GaN high electron mobility transistors (HEMTs) was investigated. Current collapse was clearly observed for TiO2 passivated HEMTs. However, no evidence of current collapse was apparent for SiNx passivated HEMTs. This suggests that AlGaN surface traps play a major role in current collapse. The experimental results were compared with numerical device simulation results. The device simulations were performed taking into account hot electron generation and deep traps at the AlGaN surface. The simulated drain current transients were consistent with the degradation and recovery behavior of the experimental results. These results indicate that current collapse is caused by the trapping of hot electrons in deep levels at the AlGaN surface.

HVPE-GROWN AlGaN/GaN HEMTs

2003 ◽  
Vol 764 ◽  
Author(s):  
B. Luo ◽  
F. Ren ◽  
M. A. Mastro ◽  
D. Tsvetkov ◽  
A. Pechnikov ◽  
...  
Keyword(s):  
High Electron Mobility Transistors ◽  
Hydride Vapor Phase Epitaxy ◽  
Root Mean Square Roughness ◽  
High Electron ◽  
Electron Mobility Transistors ◽  
Current Collapse ◽  
Collapse Characteristics ◽  
Capacitance Voltage ◽  
Source Current ◽  
Measurement Area

AbstractHigh quality undoped AlGaN/GaN high electron mobility transistors(HEMTs) structures have been gorwn by Hydride Vapor Phase Epitaxy (HVPE). The morphology of the films grown on Al2O3 substrates is excellent with root-mean-square roughness of ∼0.2nm over 10×10μm2 measurement area. Capacitance-voltage measurements show formation of dense sheet of charge at the AlGaN/GaN interface. HEMTs with 1μm gate length fabricated on these structures show transconductances in excess of 110 mS/mm and drain-source current above 0.6A/mm. Gate lag measurements show similar current collapse characteristics to HEMTs fabricated in MBE- or MOCVD grown material.

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