Study of Normally-Off AlGaN/GaN HEMT with Microfield Plate for Improvement of Breakdown Voltage.

Xiaoyu Xia,Zhiyou Guo,Huiqing Sun

doi:10.3390/mi12111318

Xiaoyu Xia, Zhiyou Guo + Show 1 more

Open Access

https://doi.org/10.3390/mi12111318

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Abstract

In this paper, 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 mm, 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.

Highlights

Improvement of Breakdown Voltage.GaN-based high electron mobility transistors (HEMTs) have shown great potential for applications in microwave power amplifier and power conversion applications due to their fast switching speed, low switching loss, high saturation electron velocity, and high breakdown voltage (Vbr ) [1,2,3,4,5]
With the micro-Field plate (FP), the current value is increased to 744.9 mA/mm, and the on-resistance is
In order to study the influence of the distance between the field plates on the breakdown voltage, we study the impact of the distance between the source field plate (S-FP) and the device surface (LSD ) on the breakdown voltage and the influence of the length of drain field plate (D-FP)(LD ) on the breakdown voltage [7]

Summary

Introduction

Most of the GaN HEMTs reported are usually in the on state, taking advantage of the inherent high sheet carrier density inherent in the built-in polarized electric field. This type of normally open HEMT is not suitable for practical power switching applications where safe operation is the main concern. The field technology provides a new way of charge balance, and second, the field plate technology has obvious optimization effects on the electric field This field plate technology can solve the existing problems and realize the electric field optimization of GaN-HEMT. This technology increases the breakdown voltage and reduces on-resistance of the device

Device Structure and Simulation Model

Simulation Results and Discussion

Conclusions