Dual trench AlGaN/GaN HEMT on SiC substrate: A novel device to improve the breakdown voltage and high power performance

In this paper, an excellent performance AlGaN/AlN/GaN/SiC High Electron Mobility Transistor (HEMT) with a dual trench technique (DT-HEMT) is proposed. In the proposed technique, the dual trench between the buffer layer and the nucleation layer is created. Both the trenches are made of Gallium Nitride. A trench is created under the source region to increase the breakdown voltage. In addition, the drain current will improve due to a created trench in below the gate region. The DC and RF characteristics of the DT-HEMT are investigated. Also, the characteristics of the proposed structure compared with the characteristics of a conventional structure (C-HEMT). Our results indicate that the dual trench technique has excellent impacts on the device characteristics, especially on the drain current, breakdown voltage, and maximum output power density. The breakdown voltage, drain current, and maximum power density of DT-HEMT structure improve 56%, 52%, and 310% in comparison with the C-HEMT, respectively. Also, using the dual trench technique, the maximum oscillation frequency, maximum available gain, short channel effect, maximum DC transconductance, and output resistance of the DT-HEMT structure will increase. Therefore, the proposed HEMT structure shows outstanding electrical properties compared to similar devices are based on conventional structures. (C) 2016 Elsevier B.V. All rights reserved.