Modelling and Simulation of a New π-Gate AlGaN/GaN HEMT with High Voltage Withstand and High RF Performance

Aiming at the problems of low withstand voltage and poor RF performance of traditional HEMT devices, a new AlGaN/GaN high electron mobility transistor device with a π-gate (NπGS HEMT) is designed in this paper. The new structure incorporates a π-gate design along with a PN-junction field plate and an AlGaN back-barrier layer. The device is modeled and simulated in Silvaco TCAD 2015 software and compared with traditional t-gate HEMT devices. The results show that the NπGS HEMT has a significant improvement in various characteristics. The new structure has a higher peak transconductance of 336 mS·mm−1, which is 13% higher than that of the traditional HEMT structure. In terms of output characteristics, the new structure has a higher saturation drain current of 0.188 A/mm. The new structure improves the RF performance of the device with a higher maximum cutoff frequency of about 839 GHz. The device also has a better performance in terms of voltage withstand, exhibiting a higher breakdown voltage of 1817 V. These results show that the proposed new structure could be useful for future research on high voltage withstand and high RF HEMT devices.