scholarly journals Simulation of AlGaN/GaN HEMTs’ Breakdown Voltage Enhancement Using Gate Field-Plate, Source Field-Plate and Drain Field Plate

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 406 ◽  
Author(s):  
Biyan Liao ◽  
Quanbin Zhou ◽  
Jian Qin ◽  
Hong Wang

A 2-D simulation of off-state breakdown voltage (VBD) for AlGaN/GaN high electron mobility transistors (HEMTs) with multi field-plates (FPs) is presented in this paper. The effect of geometrical variables of FP and insulator layer on electric field distribution and VBD are investigated systematically. The FPs can modulate the potential lines and distribution of an electric field, and the insulator layer would influence the modulation effect of FPs. In addition, we designed a structure of HEMT which simultaneously contains gate FP, source FP and drain FP. It is found that the VBD of AlGaN/GaN HEMTs can be improved greatly with the corporation of gate FP, source FP and drain FP. We achieved the highest VBD in the HEMT contained with three FPs by optimizing the structural parameters including length of FPs, thickness of FPs, and insulator layer. For HEMT with three FPs, FP-S alleviates the concentration of the electric field more effectively. When the length of the source FP is 24 μm and the insulator thickness between the FP-S and the AlGaN surface is 1950 nm, corresponding to the average electric field of about 3 MV/cm at the channel, VBD reaches 2200 V. More importantly, the 2D simulation model is based on a real HMET device and will provide guidance for the design of a practical device.

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1318
Author(s):  
Xiaoyu Xia ◽  
Zhiyou Guo ◽  
Huiqing Sun

In this article, we introduce a new type of AlGaN/GaN high electron mobility transistor (HEMT) with microfield plate (FP). We use Silvaco-ATLAS two-dimensional numerical simulation to calculate the performance of conventional HEMT and HEMT with micro-FP and analyze its principle. By studying a new charge balance method provided by HEMTs and micro-FPs, the physical mechanism of FP adjusting the HEMT potential distribution and channel electric field distribution is analyzed. The new FP structure consists of a drain field plate (D-FP), a source field plate (S-FP) and several micro-gate field plates (G-FP) to improve the output characteristics of HEMTs. By adjusting the distribution of potential and channel electric field, a wider and more uniform channel electric field can be obtained, and the breakdown voltage can be increased to 1278 V. Although the on-resistance of the HEMT is slightly increased to 5.24 Ωmm, it is still lower than other reference values. These results may open up a new and effective method for manufacturing high-power devices for power electronics applications.


2011 ◽  
Vol 1324 ◽  
Author(s):  
Takuma Nanjo ◽  
Misaichi Takeuchi ◽  
Akifumi Imai ◽  
Yousuke Suzuki ◽  
Muneyoshi Suita ◽  
...  

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.


2012 ◽  
Vol 711 ◽  
pp. 218-222
Author(s):  
Cristina Miccoli ◽  
Valeria Cinnera Martino ◽  
Salvatore Rinaudo

AlGaN/GaN high electron mobility transistors (HEMTs) have shown outstanding improvements in performance and reliability, becoming the leading option for power applications in the 1-40 GHz range. However, the presence of traps and defects in the hetero-structure are strongly correlated to the tolerance of the fabrication process. New powerful models designed to overcome limitations associated with the Process Variability (PV) may be part of the exploitation outcome. This work describes a methodology useful to characterize the effects of PV on AlGaN/GaN HEMTs performance, by deriving Process Compact Model (PCM) from systematic TCAD simulations. The device under examination is an Al0.26Ga0.74N/GaN HEMT and the selected critical process parameters are: molar fraction of the first AlGaN layer, AlGaN layer thickness, source-gate and drain-gate distance, field plate extension, gate height and width, recessed effect under the gate contact.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 400
Author(s):  
Van Cuong Nguyen ◽  
Kwangeun Kim ◽  
Hyungtak Kim

We investigated the sensing characteristics of NO2 gas sensors based on Pd-AlGaN/GaN high electron mobility transistors (HEMTs) at high temperatures. In this paper, we demonstrated the optimization of the sensing performance by the gate bias, which exhibited the advantage of the FET-type sensors compared to the diode-type ones. When the sensor was biased near the threshold voltage, the electron density in the channel showed a relatively larger change with a response to the gas exposure and demonstrated a significant improvement in the sensitivity. At 300 °C under 100 ppm concentration, the sensor’s sensitivities were 26.7% and 91.6%, while the response times were 32 and 9 s at VG = 0 V and VG = −1 V, respectively. The sensor demonstrated the stable repeatability regardless of the gate voltage at a high temperature.


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