Gan-On-Diamond Hemt Technology With T-Avg=176 Degrees C At P-Dc,P- Max=56 W/Mm Measured By Transient Thermoreflectance Imaging

Record DC power has been demonstrated in AlGaN/GaN high electron mobility transistors fabricated using a substrate replacement process in which a thick diamond substrate is grown by chemical vapor deposition following removal of the original Si substrate. Crucial to the process is a similar to 30 nm thick SiN interlayer that has been optimized for thermal resistance. The reductions obtained in self-heating have been quantified by transient thermoreflectance imaging and interpreted using 3D numerical simulation. With a DC power dissipation level of 56 W/mm, the measured average and maximum temperatures in the gate-drain access region were 176 degrees C and 205 degrees C, respectively.