Electrical and Structural Properties of AlGaN/GaN Heterostructures Grown onto 8°-Off-Axis 4H-SiC Epilayers

2011 ◽  
Vol 679-680 ◽  
pp. 808-811
Author(s):  
Fabrizio Roccaforte ◽  
Giuseppe Greco ◽  
Ming Hung Weng ◽  
Filippo Giannazzo ◽  
Vito Raineri
Keyword(s):  
Structural Properties ◽  
Surface Defects ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Near Surface ◽  
Channel Mobility ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Current Voltage ◽  
Current Voltage Characteristics

In this work the electrical and structural properties of AlGaN/GaN heterostructures grown onto 8°-off-axis 4H-SiC epilayers were investigated. A morphological and structural analysis of the samples showed the presence of “V-shaped” near-surface defects in the AlGaN layer, with a preferential orientation along the miscut direction [11-20]. In the presence of these defects an anisotropy of the current-voltage characteristics of high electron mobility transistors (HEMTs), fabricated with two different orientations, was observed. The sheet carrier density ns and the channel mobility n were determined from the device characteristics. The results were discussed considering the possible implications for AlGaN/GaN HEMT technology.

IR Thermography for Temperature Measurements and Fault Location on AlGaN/GaN HEMTs and MMICs

2015 ◽  
Author(s):  
Lény Baczkowski ◽  
Franck Vouzelaud ◽  
Dominique Carisetti ◽  
Nicolas Sarazin ◽  
Jean-Claude Clément ◽  
...  
Keyword(s):  
Fault Location ◽  
Hot Spot ◽  
Life Time ◽  
High Electron Mobility Transistors ◽  
Junction Temperature ◽  
High Electron ◽  
Ir Thermography ◽  
Operating Life ◽  
Gan Hemt ◽  
Electron Mobility Transistors

Abstract This paper shows a specific approach based on infrared (IR) thermography to face the challenging aspects of thermal measurement, mapping, and failure analysis on AlGaN/GaN high electron-mobility transistors (HEMTs) and MMICs. In the first part of this paper, IR thermography is used for the temperature measurement. Results are compared with 3D thermal simulations (ANSYS) to validate the thermal model of an 8x125pm AIGaN/GaN HEMT on SiC substrate. Measurements at different baseplate temperature are also performed to highlight the non-linearity of the thermal properties of materials. Then, correlations between the junction temperature and the life time are also discussed. In the second part, IR thermography is used for hot spot detection. The interest of the system for defect localization on AIGaN/GaN HEMT technology is presented through two case studies: a high temperature operating life test and a temperature humidity bias test.

scholarly journals Development of AlGaN/GaN/SiC high-electron-mobility transistors for THz detection

2018 ◽  
Vol 58 (2) ◽  
Author(s):  
Vytautas Jakštas ◽  
Justinas Jorudas ◽  
Vytautas Janonis ◽  
Linas Minkevičius ◽  
Irmantas Kašalynas ◽  
...  
Keyword(s):  
Electron Mobility ◽  
Schottky Diodes ◽  
Electronic Devices ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
High Electron Mobility ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Steady Current ◽  
Improved Performance

This paper reports on the AlGaN/GaN Schottky diodes (SDs) and high-electron-mobility transistors (HEMTs) grown on a semi-insulating SiC substrate. The electronic devices demonstrate an improved performance in comparison with the ones processed on a sapphire substrate. Both the SDs and HEMTs show much smaller leakage current density and a higher ION/IOFF ratio, reaching values down to 3.0±1.2 mA/cm2 and up to 70 dB under the reverse electric field of 340 kV/cm, respectively. The higher thermal conductivity of the SiC substrate leads to the increase of steady current and transconductance, and better thermal management of the HEMT devices. In addition, a successful detection of terahertz (THz) waves with the AlGaN/GaN HEMT is demonstrated at room temperature. These results open further routes for the optimization of THz designs which may result in development of novel plasmonic THz devices.

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 Comparisons on Different Innovative Cascode GaN HEMT E-Mode Power Modules and Their Efficiencies on the Flyback Converter

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5966
Author(s):  
Chih-Chiang Wu ◽  
Ching-Yao Liu ◽  
Sandeep Anand ◽  
Wei-Hua Chieng ◽  
Edward-Yi Chang ◽  
...  
Keyword(s):  
High Electron Mobility Transistors ◽  
Switching Frequency ◽  
High Electron ◽  
Flyback Converter ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
High Switching Frequency ◽  
In Series ◽  
Source Voltage ◽  
A Charge

The conventional cascode structure for driving depletion-mode (D-mode) gallium nitride (GaN) high electron mobility transistors (HEMTs) raises reliability concerns. This is because of the possibility of the gate to source voltage of the GaN HEMT surging to a negative voltage during the turn off transition. The existing solutions for this problem in the literature produce additional drawbacks such as reducing the switching frequency or introducing many additional components. These drawbacks may outweigh the advantages of using a GaN HEMT over its silicon (Si) alternative. This paper proposes two innovative gate drive circuits for D-mode GaN HEMTs—namely the GaN-switching based cascode GaN HEMT and the modified GaN-switching based cascode GaN HEMT. In these schemes, the Si MOSFET in series with the D-mode GaN HEMT is always turned on during regular operation. The GaN HEMT is then switched on and off by using a charge pump based circuit and a conventional gate driver. Since the GaN HEMT is driven independently, the highly negative gate-to-source voltage surge during turn off is avoided, and in addition, high switching frequency operation is made possible. Only two diodes and one capacitor are used in each of the schemes. The application of the proposed circuits is experimentally demonstrated in a high voltage flyback converter, where more than 96% efficiency is obtained for 60 W output load.

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.

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