High-performance AlN/GaN/AlGaN-MOSHEMTs on SiC wafer: scaling and gate material innovations for upcoming radar and communication systems

The DC/RF performance of a T-gate AlN/GaN heterojunction MOS-HEMT (AGMH) device on SiC substrate with a Hafnium-based high-k gate dielectric material is thoroughly and meticulously investigated in this article. The research investigation looks at how different gate lengths affect important device metrics, such as cut-off frequency (f_T), intrinsic capacitances (C_GD & C_GS), G_M (transconductance), and I_D (drain current). The proposed AGMH device with L_G of 40 nm, t_b of 3 nm, t_ox of 3 nm, L_GS of 250 nm, & L_GD of 400 nm exhibited I_D-max (maximum I_D) of 2.221 A/mm, G_M-peak (peak transconductance) of 505.5 mS/mm, & f_T-max (maximum f_T) of 256 GHz. The remarkable DC/RF performance results from strong carrier confinement & minimized leakage current (I_DL) enabled by scaling down the device parameters. This makes them a desirable option for RF power electronics and microwave (µw) applications in future generations, with a great deal of room for performance and efficiency gains.