Design of 30 nm multi-finger gate GaN HEMT for high frequency device

In this study, the DC and RF performances of multi fingered AlGaN/GaN are studied in simulation, and the DC and RF performance of the traditional T-gate HEMT and the multi-finger HEMT are compared.The reason for the performance difference is that the use of multi finger gate technology reduces the total parasitic capacitance and the total transit time of the carrier through the device compared to conventional T-gate devices, resulting in an increase in FT and Fmax. Based on the study of conventional AlGaN/GaN HEMT devices, an InAlN/GaN HEMT device with two-finger gate is designed. Due to the matching of InAlN and GaN lattice, the polarisation effect and carrier density of the heterojunction formed by InAlN and GaN are larger than those of conventional AlGaN/GaN heterojunction, which can ensure the device to have a larger output current while operating at high frequency. The results show that the peak FT and Fmax of the proposed InAlN/GaN HEMT are 239.5 GHz and 331.5 GHz, respectively.