NPDC structure double-channel N-polar E-mode GaN HEMTs: Innovations in enhancing RF and DC performance and mitigating trap effects

-High-electron-mobility transistors (HEMTs) based on gallium nitride (GaN) are favored for their exceptional performance in high-power and high-frequency applications. However, developing dual-channel HEMTs presents challenges due to spontaneous polarization effects and design complexities. This study introduces a novel N-polar E-mode GaN HEMT with a dual-channel structure, featuring recessed drain-source regions and non-alloyed ohmic contacts. TCAD simulations provide theoretical insights and optimization strategies for these structures, focusing on the combination of N-polar GaN and ultra-wide bandgap AlN barrier layers. The optimized device demonstrates a threshold voltage of +1.08 V and a 45.9 % increase in current density. The N-polar doublechannel HEMT (NPDC-HEMT) exhibited a 55.75 % improvement in peak transconductance, with Ftincreasing from 13.3 GHz to 30.1 GHz and Fmax from 63.7 GHz to 65.9 GHz. Further enhancement was achieved in the Tgate variant (NPDC-T-HEMT), with Ftreaching 52.6 GHz and Fmax 94.4 GHz. The dual-channel design effectively mitigated short-channel effects and current collapse, demonstrating the potential for high-power RF applications.