Thick-AlN-barrier AlN/GaN-based HEMTs with superior power and noise performance for low-voltage RF front-end applications

Herein, we report a thick-AlN-barrier (TAB) based AlN/GaN RF HEMT with remarkable power performance at low voltage for sub-6G applications. Featuring a 7 nm AlN barrier layer and the regrown n+-GaN Ohmic contacts, the device shows low sheet and contact resistances, leading to 1.6-A/mm output current, 3-V knee voltage, and consequent 75% power-added efficiency (PAE) and 1.3-W/mm output power density (Pout) at 2.6 GHz and 6-V drain voltage (VDS). This PAE-Pout result represents the state-of-the-art levels of low-voltage power amplifiers (LV PAs) for sub-6G applications. Meanwhile, the TAB-HEMT is found to exhibit satisfactory linearity and noise performance as well. The OIP3 (output third-order intercept point) value of 35.3 dBm is obtained at 6-V VDS, thanks to the elaborately designed thick AlN barrier. A minimum noise figure (NFmin) as low as 0.32 dB at 2.6 GHz and VDS = 6 V is achieved thanks to the suppressed thermal noise enabled by low channel resistance. These results highlight the potential of the TAB-HEMT as an all-around and compact device platform for LV RF front-end-module applications.