Short-term reliability of high performance Q-band AlN/GaN HEMTs

We report on an on-wafer short-term 40 GHz RF reliability stress test comparison up to 140°C base plate temperature between a 3 nm and 4 nm barrier thickness AlN/GaN HEMT technology showing high power performances in the millimeter wave range. It is found that the barrier thickness in this highly strain heterostructure has a major impact on the device reliability. The superior robustness when using thinner barrier (closer to the critical thickness) is attributed to the reduced strain.