Reliable GaN HEMTS for high frequency applications

This paper describes our team's efforts to develop a manufacturable 0.2 um T-gate process for GaN HEMTs that enables high performance and enhanced reliability at high frequencies. Our team has demonstrated highly repeatable and uniform HEMT performance measured at 40 GHz with 3.6 W/mm median output power densities, 36.6% median PAE, and 8.4 dB associated gain. RF-driven, temperature-accelerated life tests show a mean-time-to-failure (MTTF) > 6 × 10
⁷
hours at 150°C junction temperature. Using this GaN HEMT process our team has demonstrated V-band circuits with output power of 1.13 W (2.83 W/mm) with 23.3 % power-added-efficiency measured under CW operation. Furthermore, by increasing the drain bias to 38 V, the circuit demonstrated state-of-the-art power density of 3.96 W/mm (1.58 W total power).