Influence of the Passivation Layers on the Self-Heating Effect in the Double Channel AlGaN/GaN MOS-HEMT Device

Abstract: In this paper, a Two-Channel AlGaN/GaN structure of Metal-Oxide Semiconductor High-Electron Mobility Transistors (MOS-HEMTs) with TiO2 gate dielectric is presented. Also, we have examined its electrical characteristics, such as band structure, the electric field, and electric potential. The proposed device’s performance is always affected by the effects of self-heating. The performance of the proposed transistor has been evaluated by considering thermal models in Silvaco TCAD software. The simulation results show that the self-heating has significant effects on the response of the proposed device. We conclude that the drain current at V DS = 2 V is reduced by about 16%. Also, the mobility of electrons in both created channels of the structure can significantly reduce (nearly 34%). Therefore, it can be found that the self-heating effect leads to the degradation of the proposed transistor performance. In this paper, the self-heating effects of the MOS-HEMT transistor are reduced by using 6H-SiC material as a passive layer and placing a field plate near the gate. The results confirm that the breakdown voltage and drain current have increased by more than 78 and 20%, respectively. © 2023, Pleiades Publishing, Ltd.